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<div class="frontmatter" align="center">	<div class="frontmatter" align="center">

<h1>The Languages of Thot</h1>	<h1>The Languages of Thot</h1>

<h3>Vincent Quint</h3>	<h3>Vincent Quint</h3>

<h4>Translated from French by Ethan Munson</h4>	<h4>Translated from French by Ethan Munson</h4>

<h4>Version of September 15, 2000</h4>	<h4>Version of November 21, 2000</h4>
<p>
© 1996-2000 INRIA</p>
<hr>

	<p>© 1996-2000 INRIA</p>
	<hr>
</div>	</div>

<div class="tableofcontents">	<div class="tableofcontents">

<h2><a href="languages.toc.html">Contents</a></h2>	<h2><a href="languages.toc.html">Contents</a></h2>
<ul>	<ul>
<li>	<li><big><a href="#sect2">The document model of Thot</a></big>
<big><a href="#sect2">The document model of Thot</a></big>	<ul>
<ul>	<li><strong><a href="#sectb21">The logical structure of
<li>	documents</a></strong></li>
<strong><a href="#sectb21">The logical structure of documents</a></strong>	<li><strong><a href="#sectb22">Generic and specific
</li>	structures</a></strong></li>
<li>	<li><strong><a href="#sectb23">Logical structure and physical
<strong><a href="#sectb22">Generic and specific structures</a></strong>	structure</a></strong></li>
</li>	<li><strong><a href="#sectb24">Document structures and object
<li>	structures</a></strong></li>
<strong><a href="#sectb23">Logical structure and physical	</ul>
structure</a></strong>	</li>
</li>	<li><big><a href="#sect3">The S language</a></big>
<li>	<ul>
<strong><a href="#sectb24">Document structures and object	<li><strong><a href="#sectb31">Document meta-structure</a></strong>
structures</a></strong>	<ul>
</li>	<li><a href="#sectc311">The basic types</a></li>
</ul>	<li><a href="#sectc312">Constructed elements</a></li>
</li>	<li><a href="#sectc313">Logical structure constructors</a>
<li>	<ul>
<big><a href="#sect3">The S language</a></big>	<li><small><a href="#sectd3131">Aggregate and
<ul>	List</a></small></li>
<li>	<li><small><a href="#sectd3132">Choice, Schema, and
<strong><a href="#sectb31">Document meta-structure</a></strong>	Unit</a></small></li>
<ul>	<li><small><a href="#sectd3133">Reference and
<li>	Inclusion</a></small></li>
<a href="#sectc311">The basic types</a>	<li><small><a href="#sectd3134">Mark pairs</a></small></li>
</li>	<li><small><a href="#sectd3135">Restrictions and
<li>	Extensions</a></small></li>
<a href="#sectc312">Constructed elements</a>	<li><small><a href="#sectd3136">Summary</a></small></li>
</li>	</ul>
<li>	</li>
<a href="#sectc313">Logical structure constructors</a>	<li><a href="#sectc314">Associated Elements</a></li>
<ul>	<li><a href="#sectc315">Attributes</a></li>
<li>	<li><a href="#sectc316">Discussion of the model</a></li>
<small><a href="#sectd3131">Aggregate and List</a></small>	</ul>
</li>	</li>
<li>	<li><strong><a href="#sectb32">The definition language for generic
<small><a href="#sectd3132">Choice, Schema, and Unit</a></small>	structures</a></strong>
</li>	<ul>
<li>	<li><a href="#sectc321">Writing Conventions</a></li>
<small><a href="#sectd3133">Reference and Inclusion</a></small>	<li><a href="#sectc322">Extension schemas</a></li>
</li>	<li><a href="#sectc323">The general organization of structure
<li>	schemas</a></li>
<small><a href="#sectd3134">Mark pairs</a></small>	<li><a href="#sectc324">The default presentation</a></li>
</li>	<li><a href="#sectc325">Global Attributes</a></li>
<li>	<li><a href="#sectc326">Parameters</a></li>
<small><a href="#sectd3135">Restrictions and Extensions</a></small>	<li><a href="#sectc327">Structured elements</a></li>
</li>	<li><a href="#sectc328">Structure definitions</a>
<li>	<ul>
<small><a href="#sectd3136">Summary</a></small>	<li><small><a href="#sectd3281">List</a></small></li>
</li>	<li><small><a href="#sectd3282">Aggregate</a></small></li>
</ul>	<li><small><a href="#sectd3283">Choice</a></small></li>
</li>	<li><small><a href="#sectd3284">Reference</a></small></li>
<li>	<li><small><a href="#sectd3285">Mark pairs</a></small></li>
<a href="#sectc314">Associated Elements</a>	</ul>
</li>	</li>
<li>	<li><a href="#sectc329">Imports</a></li>
<a href="#sectc315">Attributes</a>	<li><a href="#sectc3210">Extension rules</a></li>
</li>	<li><a href="#sectc3211">Associated elements</a></li>
<li>	<li><a href="#sectc3212">Units</a></li>
<a href="#sectc316">Discussion of the model</a>	<li><a href="#sectc3213">Skeleton elements</a></li>
</li>	<li><a href="#sectc3214">Exceptions</a></li>
</ul>	</ul>
</li>	</li>
<li>	<li><strong><a href="#sectb33">Some examples</a></strong>
<strong><a href="#sectb32">The definition language for generic	<ul>
structures</a></strong>	<li><a href="#sectc331">A class of documents: articles</a></li>
<ul>	<li><a href="#sectc332">A class of objects: mathematical
<li>	formulas</a></li>
<a href="#sectc321">Writing Conventions</a>	</ul>
</li>	</li>
<li>	</ul>
<a href="#sectc322">Extension schemas</a>	</li>
</li>	<li><big><a href="#sect4">The P language</a></big>
<li>	<ul>
<a href="#sectc323">The general organization of structure schemas</a>	<li><strong><a href="#sectb41">Document presentation</a></strong>
</li>	<ul>
<li>	<li><a href="#sectc411">Two levels of presentation</a></li>
<a href="#sectc324">The default presentation</a>	<li><a href="#sectc412">Boxes</a></li>
</li>	<li><a href="#sectc413">Views and visibility</a></li>
<li>	<li><a href="#sectc414">Pages</a></li>
<a href="#sectc325">Global Attributes</a>	<li><a href="#sectc415">Numbering</a></li>
</li>	<li><a href="#sectc416">Presentation parameters</a></li>
<li>	</ul>
<a href="#sectc326">Parameters</a>	</li>
</li>	<li><strong><a href="#sectb42">Presentation description
<li>	language</a></strong>
<a href="#sectc327">Structured elements</a>	<ul>
</li>	<li><a href="#sectc421">The organization of a presentation
<li>	schema</a></li>
<a href="#sectc328">Structure definitions</a>	<li><a href="#sectc422">Views</a></li>
<ul>	<li><a href="#sectc423">Print Views</a></li>
<li>	<li><a href="#sectc424">Counters</a></li>
<small><a href="#sectd3281">List</a></small>	<li><a href="#sectc425">Presentation constants</a></li>
</li>	<li><a href="#sectc426">Variables</a></li>
<li>	<li><a href="#sectc427">Default presentation rules</a></li>
<small><a href="#sectd3282">Aggregate</a></small>	<li><a href="#sectc428">Presentation and page layout boxes</a></li>
</li>	<li><a href="#sectc429">Presentation of structured elements</a></li>
<li>	<li><a href="#sectc4210">Logical attribute presentation</a></li>
<small><a href="#sectd3283">Choice</a></small>	<li><a href="#sectc4212">Value transmission rules</a></li>
</li>	<li><a href="#sectc4213">Presentation rules</a></li>
<li>	<li><a href="#sectc4214">Conditions applying to presentation
<small><a href="#sectd3284">Reference</a></small>	rules</a>
</li>	<ul>
<li>	<li><small><a href="#sectd42141">Conditions based on the logical
<small><a href="#sectd3285">Mark pairs</a></small>	position of the element</a></small></li>
</li>	<li><small><a href="#sectd42142">Conditions on
</ul>	references</a></small></li>
</li>	<li><small><a href="#sectd42143">Conditions on logical
<li>	attributes</a></small></li>
<a href="#sectc329">Imports</a>	<li><small><a href="#sectd42144">Conditions on page
</li>	breaks</a></small></li>
<li>	<li><small><a href="#sectd42145">Conditions on the element's
<a href="#sectc3210">Extension rules</a>	content</a></small></li>
</li>	<li><small><a href="#sectd42146">Conditions on
<li>	counters</a></small></li>
<a href="#sectc3211">Associated elements</a>	</ul>
</li>	</li>
<li>	<li><a href="#sectc4215">A presentation rule</a></li>
<a href="#sectc3212">Units</a>	<li><a href="#sectc4216">Box axes</a></li>
</li>	<li><a href="#sectc4217">Distance units</a></li>
<li>	<li><a href="#sectc4218">Relative positions</a></li>
<a href="#sectc3213">Skeleton elements</a>	<li><a href="#sectc4219">Box extents</a>
</li>	<ul>
<li>	<li><small><a href="#sectd42191">Fixed extents</a></small></li>
<a href="#sectc3214">Exceptions</a>	<li><small><a href="#sectd42192">Relative
</li>	extents</a></small></li>
</ul>	<li><small><a href="#sectd42193">Elastic
</li>	extents</a></small></li>
<li>	</ul>
<strong><a href="#sectb33">Some examples</a></strong>	</li>
<ul>	<li><a href="#sectc4220">Overflow</a></li>
<li>	<li><a href="#sectc4221">Inheritance</a></li>
<a href="#sectc331">A class of documents: articles</a>	<li><a href="#sectc4222">Line breaking</a>
</li>	<ul>
<li>	<li><small><a href="#sectd42221">Line spacing</a></small></li>
<a href="#sectc332">A class of objects: mathematical formulas</a>	<li><small><a href="#sectd42222">First line
</li>	indentation</a></small></li>
</ul>	<li><small><a href="#sectd42223">Alignment</a></small></li>
</li>	<li><small><a href="#sectd42224">Justification</a></small></li>
</ul>	<li><small><a href="#sectd42225">Hyphenation</a></small></li>
</li>	<li><small><a href="#sectd42226">Avoiding line
<li>	breaking</a></small></li>
<big><a href="#sect4">The P language</a></big>	</ul>
<ul>	</li>
<li>	<li><a href="#sectc4223">Page breaking and line breaking
<strong><a href="#sectb41">Document presentation</a></strong>	conditions</a></li>
<ul>	<li><a href="#sectc4224">Visibility</a></li>
<li>	<li><a href="#sectc4225">Character style parameters</a>
<a href="#sectc411">Two levels of presentation</a>	<ul>
</li>	<li><small><a href="#sectd42251">Character size</a></small></li>
<li>	<li><small><a href="#sectd42252">Font and character
<a href="#sectc412">Boxes</a>	style</a></small></li>
</li>	<li><small><a href="#sectd42253">Underlining</a></small></li>
<li>	</ul>
<a href="#sectc413">Views and visibility</a>	</li>
</li>	<li><a href="#sectc4226">Stacking order</a></li>
<li>	<li><a href="#sectc4227">Line style</a></li>
<a href="#sectc414">Pages</a>	<li><a href="#sectc4228">Line thickness</a></li>
</li>	<li><a href="#sectc4229">Fill pattern</a></li>
<li>	<li><a href="#sectc4230">Colors</a></li>
<a href="#sectc415">Numbering</a>	<li><a href="#sectc4230a">Background color and border</a></li>
</li>	<li><a href="#sectc4230b">Background pictures</a></li>
<li>	<li><a href="#sectc4231">Presentation box content</a></li>
<a href="#sectc416">Presentation parameters</a>	<li><a href="#sectc4232">Presentation box creation</a></li>
</li>	<li><a href="#sectc4233">Page layout</a></li>
</ul>	<li><a href="#sectc4234">Box copies</a></li>
</li>	</ul>
<li>	</li>
<strong><a href="#sectb42">Presentation description language</a></strong>	</ul>
<ul>	</li>
<li>	<li><big><a href="#sect5">The T language</a></big>
<a href="#sectc421">The organization of a presentation schema</a>	<ul>
</li>	<li><strong><a href="#sectb51">Document translation</a></strong>
<li>	<ul>
<a href="#sectc422">Views</a>	<li><a href="#sectc511">Translation principles</a></li>
</li>	<li><a href="#sectc512">Translation procedure</a></li>
<li>	</ul>
<a href="#sectc423">Print Views</a>	</li>
</li>	<li><strong><a href="#sectb52">Translation definition
<li>	language</a></strong>
<a href="#sectc424">Counters</a>	<ul>
</li>	<li><a href="#sectc521">Organization of a translation
<li>	schema</a></li>
<a href="#sectc425">Presentation constants</a>	<li><a href="#sectc522">Line length</a></li>
</li>	<li><a href="#sectc523">Buffers</a></li>
<li>	<li><a href="#sectc524">Counters</a></li>
<a href="#sectc426">Variables</a>	<li><a href="#sectc525">Constants</a></li>
</li>	<li><a href="#sectc526">Variables</a></li>
<li>	<li><a href="#sectc527">Translating structure elements</a></li>
<a href="#sectc427">Default presentation rules</a>	<li><a href="#sectc528">Conditional rules</a>
</li>	<ul>
<li>	<li><small><a href="#sectd5281">Conditions based on the logical
<a href="#sectc428">Presentation and page layout boxes</a>	position of the element</a></small></li>
</li>	<li><small><a href="#sectd5282">Conditions on
<li>	references</a></small></li>
<a href="#sectc429">Presentation of structured elements</a>	<li><small><a href="#sectd5283">Conditions on the
</li>	parameters</a></small></li>
<li>	<li><small><a href="#sectd5284">Conditions on the
<a href="#sectc4210">Logical attribute presentation</a>	alphabets</a></small></li>
</li>	<li><small><a href="#sectd5285">Conditions on page
<li>	breaks</a></small></li>
<a href="#sectc4212">Value transmission rules</a>	<li><small><a href="#sectd5286">Conditions on the element's
</li>	content</a></small></li>
<li>	<li><small><a href="#sectd5287">Conditions on the presence of
<a href="#sectc4213">Presentation rules</a>	comments</a></small></li>
</li>	<li><small><a href="#sectd5288">Conditions on the presence of
<li>	specific presentation rules</a></small></li>
<a href="#sectc4214">Conditions applying to presentation rules</a>	<li><small><a href="#sectd5289">Conditions on the presence of
<ul>	logical attributes</a></small></li>
<li>	<li><small><a href="#sectd52810">Conditions on logical
<small><a href="#sectd42141">Conditions based on the logical position of the	attributes</a></small></li>
element</a></small>	<li><small><a href="#sectd52811">Conditions on specific
</li>	presentation rules</a></small></li>
<li>	</ul>
<small><a href="#sectd42142">Conditions on references</a></small>	</li>
</li>	<li><a href="#sectc529">Translation rules</a></li>
<li>	<li><a href="#sectc5210">The <tt>Create</tt> rule</a></li>
<small><a href="#sectd42143">Conditions on logical attributes</a></small>	<li><a href="#sectc5211">The <tt>Write</tt> rule</a></li>
</li>	<li><a href="#sectc5212">The <tt>Read</tt> rule</a></li>
<li>	<li><a href="#sectc5213">The <tt>Include</tt> rule</a></li>
<small><a href="#sectd42144">Conditions on page breaks</a></small>	<li><a href="#sectc5214">The <tt>Get</tt> rule</a></li>
</li>	<li><a href="#sectc5215">The <tt>Copy</tt> rule</a></li>
<li>	<li><a href="#sectc5216">The <tt>Use</tt> rule</a></li>
<small><a href="#sectd42145">Conditions on the element's content</a></small>	<li><a href="#sectc5217">The <tt>Remove</tt> rule</a></li>
</li>	<li><a href="#sectc5218">The <tt>NoTranslation</tt> rule</a></li>
<li>	<li><a href="#sectc5219">The <tt>NoLineBreak</tt> rule</a></li>
<small><a href="#sectd42146">Conditions on counters</a></small>	<li><a href="#sectc5220">The <tt>ChangeMainFile</tt> rule</a></li>
</li>	<li><a href="#sectc5220a">The <tt>RemoveFile</tt> rule</a></li>
</ul>	<li><a href="#sectc5221">The <tt>Set</tt> and <tt>Add</tt>
</li>	rules</a></li>
<li>	<li><a href="#sectc5221a">The <tt>Indent</tt> rule</a></li>
<a href="#sectc4215">A presentation rule</a>	<li><a href="#sectc5222">Rule application order</a></li>
</li>	<li><a href="#sectc5223">Translation of logical attributes</a></li>
<li>	<li><a href="#sectc5224">Translation of specific
<a href="#sectc4216">Box axes</a>	presentations</a></li>
</li>	<li><a href="#sectc5225">Recoding of characters, symbols and
<li>	graphics</a></li>
<a href="#sectc4217">Distance units</a>	</ul>
</li>	</li>
<li>	</ul>
<a href="#sectc4218">Relative positions</a>	</li>
</li>	<li><big><a href="#sect6">Language grammars</a></big>
<li>	<ul>
<a href="#sectc4219">Box extents</a>	<li><strong><a href="#sectb61">The M meta-language</a></strong></li>
<ul>	<li><strong><a href="#sectb62">The S language</a></strong></li>
<li>	<li><strong><a href="#sectb63">The P language</a></strong></li>
<small><a href="#sectd42191">Fixed extents</a></small>	<li><strong><a href="#sectb64">The T language</a></strong></li>
</li>	</ul>
<li>	</li>
<small><a href="#sectd42192">Relative extents</a></small>	<li><big><a href="#sect7">Character coding</a></big>
</li>	<ul>
<li>	<li><strong><a href="#sectb71">Characters</a></strong></li>
<small><a href="#sectd42193">Elastic extents</a></small>	<li><strong><a href="#sectb72">Symbols</a></strong></li>
</li>	<li><strong><a href="#sectb73">Graphical elements</a></strong></li>
</ul>	</ul>
</li>	</li>
<li>
<a href="#sectc4220">Overflow</a>
</li>
<li>
<a href="#sectc4221">Inheritance</a>
</li>
<li>
<a href="#sectc4222">Line breaking</a>
<ul>
<li>
<small><a href="#sectd42221">Line spacing</a></small>
</li>
<li>
<small><a href="#sectd42222">First line indentation</a></small>
</li>
<li>
<small><a href="#sectd42223">Alignment</a></small>
</li>
<li>
<small><a href="#sectd42224">Justification</a></small>
</li>
<li>
<small><a href="#sectd42225">Hyphenation</a></small>
</li>
<li>
<small><a href="#sectd42226">Avoiding line breaking</a></small>
</li>
</ul>
</li>
<li>
<a href="#sectc4223">Page breaking and line breaking conditions</a>
</li>
<li>
<a href="#sectc4224">Visibility</a>
</li>
<li>
<a href="#sectc4225">Character style parameters</a>
<ul>
<li>
<small><a href="#sectd42251">Character size</a></small>
</li>
<li>
<small><a href="#sectd42252">Font and character style</a></small>
</li>
<li>
<small><a href="#sectd42253">Underlining</a></small>
</li>
</ul>
</li>
<li>
<a href="#sectc4226">Stacking order</a>
</li>
<li>
<a href="#sectc4227">Line style</a>
</li>
<li>
<a href="#sectc4228">Line thickness</a>
</li>
<li>
<a href="#sectc4229">Fill pattern</a>
</li>
<li>
<a href="#sectc4230">Colors</a>
</li>
<li>
<a href="#sectc4230a">Background color and border</a>
</li>
<li>
<a href="#sectc4230b">Background pictures</a>
</li>
<li>
<a href="#sectc4231">Presentation box content</a>
</li>
<li>
<a href="#sectc4232">Presentation box creation</a>
</li>
<li>
<a href="#sectc4233">Page layout</a>
</li>
<li>
<a href="#sectc4234">Box copies</a>
</li>
</ul>
</li>
</ul>
</li>
<li>
<big><a href="#sect5">The T language</a></big>
<ul>
<li>
<strong><a href="#sectb51">Document translation</a></strong>
<ul>
<li>
<a href="#sectc511">Translation principles</a>
</li>
<li>
<a href="#sectc512">Translation procedure</a>
</li>
</ul>
</li>
<li>
<strong><a href="#sectb52">Translation definition language</a></strong>
<ul>
<li>
<a href="#sectc521">Organization of a translation schema</a>
</li>
<li>
<a href="#sectc522">Line length</a>
</li>
<li>
<a href="#sectc523">Buffers</a>
</li>
<li>
<a href="#sectc524">Counters</a>
</li>
<li>
<a href="#sectc525">Constants</a>
</li>
<li>
<a href="#sectc526">Variables</a>
</li>
<li>
<a href="#sectc527">Translating structure elements</a>
</li>
<li>
<a href="#sectc528">Conditional rules</a>
<ul>
<li>
<small><a href="#sectd5281">Conditions based on the logical position of the
element</a></small>
</li>
<li>
<small><a href="#sectd5282">Conditions on references</a></small>
</li>
<li>
<small><a href="#sectd5283">Conditions on the parameters</a></small>
</li>
<li>
<small><a href="#sectd5284">Conditions on the alphabets</a></small>
</li>
<li>
<small><a href="#sectd5285">Conditions on page breaks</a></small>
</li>
<li>
<small><a href="#sectd5286">Conditions on the element's content</a></small>
</li>
<li>
<small><a href="#sectd5287">Conditions on the presence of comments</a></small>
</li>
<li>
<small><a href="#sectd5288">Conditions on the presence of specific
presentation rules</a></small>
</li>
<li>
<small><a href="#sectd5289">Conditions on the presence of logical
attributes</a></small>
</li>
<li>
<small><a href="#sectd52810">Conditions on logical attributes</a></small>
</li>
<li>
<small><a href="#sectd52811">Conditions on specific presentation
rules</a></small>
</li>
</ul>
</li>
<li>
<a href="#sectc529">Translation rules</a>
</li>
<li>
<a href="#sectc5210">The <tt>Create</tt> rule</a>
</li>
<li>
<a href="#sectc5211">The <tt>Write</tt> rule</a>
</li>
<li>
<a href="#sectc5212">The <tt>Read</tt> rule</a>
</li>
<li>
<a href="#sectc5213">The <tt>Include</tt> rule</a>
</li>
<li>
<a href="#sectc5214">The <tt>Get</tt> rule</a>
</li>
<li>
<a href="#sectc5215">The <tt>Copy</tt> rule</a>
</li>
<li>
<a href="#sectc5216">The <tt>Use</tt> rule</a>
</li>
<li>
<a href="#sectc5217">The <tt>Remove</tt> rule</a>
</li>
<li>
<a href="#sectc5218">The <tt>NoTranslation</tt> rule</a>
</li>
<li>
<a href="#sectc5219">The <tt>NoLineBreak</tt> rule</a>
</li>
<li>
<a href="#sectc5220">The <tt>ChangeMainFile</tt> rule</a>
</li>
<li>
<a href="#sectc5220a">The <tt>RemoveFile</tt> rule</a>
</li>
<li>
<a href="#sectc5221">The <tt>Set</tt> and <tt>Add</tt> rules</a>
</li>
<li>
<a href="#sectc5221a">The <tt>Indent</tt> rule</a>
</li>
<li>
<a href="#sectc5222">Rule application order</a>
</li>
<li>
<a href="#sectc5223">Translation of logical attributes</a>
</li>
<li>
<a href="#sectc5224">Translation of specific presentations</a>
</li>
<li>
<a href="#sectc5225">Recoding of characters, symbols and graphics</a>
</li>
</ul>
</li>
</ul>
</li>
<li>
<big><a href="#sect6">Language grammars</a></big>
<ul>
<li>
<strong><a href="#sectb61">The M meta-language</a></strong>
</li>
<li>
<strong><a href="#sectb62">The S language</a></strong>
</li>
<li>
<strong><a href="#sectb63">The P language</a></strong>
</li>
<li>
<strong><a href="#sectb64">The T language</a></strong>
</li>
</ul>
</li>
<li>
<big><a href="#sect7">Character coding</a></big>
<ul>
<li>
<strong><a href="#sectb71">Characters</a></strong>
</li>
<li>
<strong><a href="#sectb72">Symbols</a></strong>
</li>
<li>
<strong><a href="#sectb73">Graphical elements</a></strong>
</li>
</ul>
</li>
</ul>	</ul>
<hr>	<hr>

</div>	</div>

<div class="chapter">	<div class="chapter">

<h1><a name="sect2">The document model of Thot</a></h1>	<h1><a name="sect2">The document model of Thot</a></h1>
<p>
All of the services which Thot provides to the user are based on the system's
internal document representation. This representation is itself derived from
the document model which underlies Thot. The model is presented here, prior
to the description of the languages which permit the generic specification of
documents.</p>

<div class="section">	<p>All of the services which Thot provides to the user are based on the
	system's internal document representation. This representation is itself
	derived from the document model which underlies Thot. The model is presented
	here, prior to the description of the languages which permit the generic
	specification of documents.</p>

	<div class="section">
<h2><a name="sectb21">The logical structure of documents</a></h2>	<h2><a name="sectb21">The logical structure of documents</a></h2>
<p>
The document model of Thot is primarily designed to allow the user to operate	<p>The document model of Thot is primarily designed to allow the user to
on those entities which s/he has in mind when s/he works on a document. The	operate on those entities which s/he has in mind when s/he works on a
model makes no assumptions about the nature of these entities. It is	document. The model makes no assumptions about the nature of these entities.
essentially these logical entities, such as paragraphs, sections, chapters,	It is essentially these logical entities, such as paragraphs, sections,
notes, titles, and cross-references which give a document its logical	chapters, notes, titles, and cross-references which give a document its
structure.</p>	logical structure.</p>
<p>
Because of this model, the author can divide the document into chapters,	<p>Because of this model, the author can divide the document into chapters,
giving each one a title. The content of these chapters can be further divided	giving each one a title. The content of these chapters can be further divided
into sections, subsections, etc. The text is organized into successive	into sections, subsections, etc. The text is organized into successive
paragraphs, according to the content. In the writing phase, the lines, pages,	paragraphs, according to the content. In the writing phase, the lines, pages,
Line 576 if the system requires documents to be w	Line 314 if the system requires documents to be w
way. So, Thot's model is primarily based on the logical aspect of documents.	way. So, Thot's model is primarily based on the logical aspect of documents.
The creation of a model of this type essentially requires the definition :</p>	The creation of a model of this type essentially requires the definition :</p>
<ul>	<ul>
<li>	<li>of the entities which can appear in the documents,</li>
of the entities which can appear in the documents,	<li>and the relations between these entities.</li>
</li>
<li>
and the relations between these entities.
</li>
</ul>	</ul>
<p>
The choice of entities to include in the model can be subtle. Some documents	<p>The choice of entities to include in the model can be subtle. Some
require chapters, while others only need various levels of sections. Certain	documents require chapters, while others only need various levels of sections.
documents contain appendices, others don't. In different documents the same	Certain documents contain appendices, others don't. In different documents
logical entity may go by different names (e.g. ``Conclusion'' and	the same logical entity may go by different names (e.g. ``Conclusion'' and
``Summary''). Certain entities which are absolutely necessary in some	``Summary''). Certain entities which are absolutely necessary in some
documents, such as clauses in a contract or the address of the recipient in a	documents, such as clauses in a contract or the address of the recipient in a
letter, are useless in most other cases.</p>	letter, are useless in most other cases.</p>
<p>
The differences between documents result from more than just the entities that	<p>The differences between documents result from more than just the entities
appear in them, but also from the relationships between these entities and the	that appear in them, but also from the relationships between these entities
ways that they are linked. In certain documents, notes are spread throughout	and the ways that they are linked. In certain documents, notes are spread
the document, for example at the bottom of the page containing the	throughout the document, for example at the bottom of the page containing the
cross-reference to them, while in other documents they are collected at the	cross-reference to them, while in other documents they are collected at the
end of each chapter or even at the end of the work. As another example, the	end of each chapter or even at the end of the work. As another example, the
introduction of some documents can contain many sections, while in other	introduction of some documents can contain many sections, while in other
documents, the introduction is restricted to be a short sequence of	documents, the introduction is restricted to be a short sequence of
paragraphs.</p>	paragraphs.</p>
<p>
All of this makes it unlikely that a single model can describe any document at	<p>All of this makes it unlikely that a single model can describe any document
a relatively high level. It is obviously tempting to make up a list of widely	at a relatively high level. It is obviously tempting to make up a list of
used entities, such as chapters, sections, paragraphs, and titles, and then	widely used entities, such as chapters, sections, paragraphs, and titles, and
map all other entities onto the available choices. In this way, an	then map all other entities onto the available choices. In this way, an
introduction can be supported as a chapter and a contract clause supported as	introduction can be supported as a chapter and a contract clause supported as
a paragraph or section. However, in trying to widen the range of usage of	a paragraph or section. However, in trying to widen the range of usage of
certain entities, their meaning can be lost and the power of the model	certain entities, their meaning can be lost and the power of the model
Line 621 of widely used entities.</p>	Line 355 of widely used entities.</p>
</div>	</div>

<div class="section">	<div class="section">

<h2><a name="sectb22">Generic and specific structures</a></h2>	<h2><a name="sectb22">Generic and specific structures</a></h2>
<p>
Thus, it is apparently impossible to construct an exhaustive inventory of all	<p>Thus, it is apparently impossible to construct an exhaustive inventory of
those entities which are necessary and sufficient to precisely describe any	all those entities which are necessary and sufficient to precisely describe
document. It also seems impossible to specify all possible arrangements of	any document. It also seems impossible to specify all possible arrangements of
these entities in a document. This is why Thot uses a <em>meta-model</em>	these entities in a document. This is why Thot uses a <em>meta-model</em>
instead, which permits the description of numerous <em>models</em>, each one	instead, which permits the description of numerous <em>models</em>, each one
describing a <em>class</em> of documents.</p>	describing a <em>class</em> of documents.</p>
<p>
A <em>class</em> is a set of documents having very similar structure. Thus,	<p>A <em>class</em> is a set of documents having very similar structure. Thus,
the collection of research reports published by a laboratory constitutes a	the collection of research reports published by a laboratory constitutes a
class; the set of commercial proposals by the sales department of a company	class; the set of commercial proposals by the sales department of a company
constitutes another class; the set of articles published by a journal	constitutes another class; the set of articles published by a journal
constitutes a third class. Clearly, it is not possible to enumerate every	constitutes a third class. Clearly, it is not possible to enumerate every
possible document class. It is also clear that new document classes must be	possible document class. It is also clear that new document classes must be
created to satisfy new needs and applications.</p>	created to satisfy new needs and applications.</p>
<p>
To give a more rigorous definition of classes, we must introduce the ideas of	<p>To give a more rigorous definition of classes, we must introduce the ideas
<em>generic structure</em> and <em>specific structure</em>. Each document has	of <em>generic structure</em> and <em>specific structure</em>. Each document
a <em>specific structure</em> which organizes the various parts which comprise	has a <em>specific structure</em> which organizes the various parts which
it. We illustrate this with the help of a simple example comparing two	comprise it. We illustrate this with the help of a simple example comparing
reports, A and B (<a href="#specstruct">see Figure</a>). The report A contains	two reports, A and B (<a href="#specstruct">see Figure</a>). The report A
an introduction followed by three chapters and a conclusion. The first	contains an introduction followed by three chapters and a conclusion. The
chapter contains two sections, the second, three sections. That is the	first chapter contains two sections, the second, three sections. That is the
<em>specific</em> structure of document A. Similarly, the structure of	<em>specific</em> structure of document A. Similarly, the structure of
document B is: an introduction, two chapters, a conclusion; Chapter 1 has	document B is: an introduction, two chapters, a conclusion; Chapter 1 has
three sections while Chapter 2 has four. The specific structures of these two	three sections while Chapter 2 has four. The specific structures of these two
Line 653 documents are thus different.</p>	Line 386 documents are thus different.</p>

<div class="figure">	<div class="figure">
<hr>	<hr>

<pre> Report A Report B	<pre> Report A Report B
Introduction Introduction	Introduction Introduction
Chapter 1 Chapter 1	Chapter 1 Chapter 1
Line 666 documents are thus different.</p>	Line 398 documents are thus different.</p>
Chapter 3 Section 2.3	Chapter 3 Section 2.3
Conclusion Section 2.4	Conclusion Section 2.4
Conclusion</pre>	Conclusion</pre>
<p align="center">
<em><a name="specstruct">Two specific structures</a></em></p>
<hr>

	<p align="center"><em><a name="specstruct">Two specific
	structures</a></em></p>
	<hr>
</div>	</div>
<p>
The <em>generic structure</em> defines the ways in which specific structures	<p>The <em>generic structure</em> defines the ways in which specific
can be constructed. It specifies how to generate specific structures. The	structures can be constructed. It specifies how to generate specific
reports A and B, though different, are constructed in accordance with the same	structures. The reports A and B, though different, are constructed in
generic structure, which specifies that a report contains an introduction	accordance with the same generic structure, which specifies that a report
followed by a variable number of chapters and a conclusion, with each chapter	contains an introduction followed by a variable number of chapters and a
containing a variable number of sections.</p>	conclusion, with each chapter containing a variable number of sections.</p>
<p>
There is a one-to-one correspondence between a class and a generic structure:	<p>There is a one-to-one correspondence between a class and a generic
all the documents of a class are constructed in accordance with the same	structure: all the documents of a class are constructed in accordance with the
generic structure. Hence the definition of the class: a class is a set of	same generic structure. Hence the definition of the class: a class is a set
documents whose specific structure is constructed in accordance with the same	of documents whose specific structure is constructed in accordance with the
generic structure. A class is characterized by its generic structure.</p>	same generic structure. A class is characterized by its generic
<p>	structure.</p>
Thus, a generic structure can be considered to be a model at the level which
interests us, but only for one class of documents. When the definition is	<p>Thus, a generic structure can be considered to be a model at the level
limited to a single class of documents, it is possible to define a model which	which interests us, but only for one class of documents. When the definition
does a good job of representing the documents of the class, including the	is limited to a single class of documents, it is possible to define a model
necessary entities and unencumbered by useless entities. The description of	which does a good job of representing the documents of the class, including
the organization of the documents in the class can then be sufficiently	the necessary entities and unencumbered by useless entities. The description
	of the organization of the documents in the class can then be sufficiently
precise.</p>	precise.</p>
</div>	</div>

<div class="section">	<div class="section">

<h2><a name="sectb23">Logical structure and physical structure</a></h2>	<h2><a name="sectb23">Logical structure and physical structure</a></h2>
<p>
Generic structures only describe the <em>logical</em> organization of	<p>Generic structures only describe the <em>logical</em> organization of
documents, not their <em>physical</em> presentation on a screen or on sheets	documents, not their <em>physical</em> presentation on a screen or on sheets
of paper. However, for a document to be displayed or printed, its graphic	of paper. However, for a document to be displayed or printed, its graphic
presentation must be taken into account.</p>	presentation must be taken into account.</p>
<p>
An examination of current printed documents shows that the details of	<p>An examination of current printed documents shows that the details of
presentation essentially serve to bring out their logical structure. Outside	presentation essentially serve to bring out their logical structure. Outside
of some particular domains, notably advertising, the presentation is rarely	of some particular domains, notably advertising, the presentation is rarely
independent of the logical organization of the text. Moreover, the art of	independent of the logical organization of the text. Moreover, the art of
Line 717 combined with the changes in the shapes	Line 449 combined with the changes in the shapes
effects serve to indicate the transitions between paragraphs, sections, or	effects serve to indicate the transitions between paragraphs, sections, or
chapters: an object's level in the logical structure of the document is shown	chapters: an object's level in the logical structure of the document is shown
by the markedness of the effects.</p>	by the markedness of the effects.</p>
<p>
Since the model permits the description of all of the logical structure of the	<p>Since the model permits the description of all of the logical structure of
document, the presentation can be derived from the model without being	the document, the presentation can be derived from the model without being
submerged in the document itself. It suffices to use the logical structure of	submerged in the document itself. It suffices to use the logical structure of
the document to make the desired changes in its presentation: changes in type	the document to make the desired changes in its presentation: changes in type
size, type style, spacing, margin, centering, etc.</p>	size, type style, spacing, margin, centering, etc.</p>
<p>
Just as one cannot define a unique generic logical structure for all document	<p>Just as one cannot define a unique generic logical structure for all
classes, one cannot define universal presentation rules which can be applied	document classes, one cannot define universal presentation rules which can be
to all document classes. For certain types of documents the chapter titles	applied to all document classes. For certain types of documents the chapter
will be centered on the page and printed in large, bold type. For other	titles will be centered on the page and printed in large, bold type. For
documents, the same chapter titles will be printed in small, italic type and	other documents, the same chapter titles will be printed in small, italic type
aligned on the left margin.</p>	and aligned on the left margin.</p>
<p>
Therefore, it is necessary to base the presentation specifications for	<p>Therefore, it is necessary to base the presentation specifications for
documents on their class. Such a specification can be very fine-grained,	documents on their class. Such a specification can be very fine-grained,
because the presentation is expressed in terms of the entities defined in the	because the presentation is expressed in terms of the entities defined in the
generic logical structure of the class. Thus, it is possible to specify a	generic logical structure of the class. Thus, it is possible to specify a
Line 740 similarly to specify titles for the sect	Line 472 similarly to specify titles for the sect
section hierarchy. The set of rules which specify the presentation of all the	section hierarchy. The set of rules which specify the presentation of all the
elements defined in a generic logical structure is called a <em>generic	elements defined in a generic logical structure is called a <em>generic
presentation</em>.</p>	presentation</em>.</p>
<p>
There are several advantages derived from having a presentation linked to the	<p>There are several advantages derived from having a presentation linked to
generic structure and described by a generic presentation. Homogeneity is the	the generic structure and described by a generic presentation. Homogeneity is
first. Since every document in a class corresponds to the same generic	the first. Since every document in a class corresponds to the same generic
logical structure, a homogenous presentation for different documents of the	logical structure, a homogenous presentation for different documents of the
same class can be assured by applying the same generic presentation to all	same class can be assured by applying the same generic presentation to all
documents of the class. Homogeneity of presentation can also be found among	documents of the class. Homogeneity of presentation can also be found among
the entities of a single document: every section heading will be presented in	the entities of a single document: every section heading will be presented in
the same way, the first line of every paragraph of the same type will have the	the same way, the first line of every paragraph of the same type will have the
same indentation, etc.</p>	same indentation, etc.</p>
<p>
Another advantage of this approach to presentation is that it facilitates	<p>Another advantage of this approach to presentation is that it facilitates
changes to the graphical aspect of documents. A change to the generic	changes to the graphical aspect of documents. A change to the generic
presentation rules attached to each type of entity will alter the presentation	presentation rules attached to each type of entity will alter the presentation
of the entire document, and will do so homogenously. In this case, the	of the entire document, and will do so homogenously. In this case, the
internal homogeneity of the class is no longer assured, but the way to control	internal homogeneity of the class is no longer assured, but the way to control
it is simple. It suffices to adopt a single generic presentation for the	it is simple. It suffices to adopt a single generic presentation for the
entire class.</p>	entire class.</p>
<p>
If the presentation of the class does not have to be homogenous, then the	<p>If the presentation of the class does not have to be homogenous, then the
appearance of the document can be adapted to the way it will be used or to the	appearance of the document can be adapted to the way it will be used or to the
device used to render it. This quality is sufficient to allow the existence	device used to render it. This quality is sufficient to allow the existence
of <a name="mulpres">many generic presentations</a> for the same document	of <a name="mulpres">many generic presentations</a> for the same document
Line 771 appearance at the time of editing or pri	Line 503 appearance at the time of editing or pri
</div>	</div>

<div class="section">	<div class="section">

<h2><a name="sectb24">Document structures and object structures</a></h2>	<h2><a name="sectb24">Document structures and object structures</a></h2>
<p>
So far, we have only discussed the global structure of documents and have not	<p>So far, we have only discussed the global structure of documents and have
considered the contents found in that structure. We could limit ourselves to	not considered the contents found in that structure. We could limit ourselves
purely textual contents by assuming that a title or a paragraph contains a	to purely textual contents by assuming that a title or a paragraph contains a
simple linear text. But this model would be too restrictive. In fact,	simple linear text. But this model would be too restrictive. In fact,
certain documents contain not only text, but also contain tables, diagrams,	certain documents contain not only text, but also contain tables, diagrams,
photographs, mathematical formulas, and program fragments. The model must	photographs, mathematical formulas, and program fragments. The model must
permit the representation of such <em>objects</em>.</p>	permit the representation of such <em>objects</em>.</p>
<p>
Just as with the whole of the document, the model takes into account the	<p>Just as with the whole of the document, the model takes into account the
logical structure of objects of this type. Some are clearly structured,	logical structure of objects of this type. Some are clearly structured,
others are less so. Logical structure can be recognized in mathematical	others are less so. Logical structure can be recognized in mathematical
formulas, in tables, and in certain types of diagrams. On the other hand, it	formulas, in tables, and in certain types of diagrams. On the other hand, it
Line 792 can represent every one of these types o	Line 523 can represent every one of these types o
definition of meta-structure and document classes also applies to objects.	definition of meta-structure and document classes also applies to objects.
Object classes can be defined which put together objects of similar type,	Object classes can be defined which put together objects of similar type,
constructed from the same generic logical structure.</p>	constructed from the same generic logical structure.</p>
<p>
Thus, a mathematical class can be defined and have a generic logical structure	<p>Thus, a mathematical class can be defined and have a generic logical
associated with it. But even if a single generic structure can represent a	structure associated with it. But even if a single generic structure can
sufficient variety of mathematical formulas, for other objects with less	represent a sufficient variety of mathematical formulas, for other objects
rigorous structure, multiple classes must be defined. As for documents, using	with less rigorous structure, multiple classes must be defined. As for
multiple classes assures that the model can describe the full range of objects	documents, using multiple classes assures that the model can describe the full
to be presented. It also permits the system to support objects which were not	range of objects to be presented. It also permits the system to support
initially anticipated. Moreover, this comment applies equally to mathematics:	objects which were not initially anticipated. Moreover, this comment applies
different classes of formulas can be described depending on the domain of	equally to mathematics: different classes of formulas can be described
mathematics being described.</p>	depending on the domain of mathematics being described.</p>
<p>
Since objects have the same level of logical representation as documents, they	<p>Since objects have the same level of logical representation as documents,
gain the same advantages. In particular, it is possible to define the	they gain the same advantages. In particular, it is possible to define the
presentation separately from the objects themselves and attach it to the	presentation separately from the objects themselves and attach it to the
class. Thus, as for documents, objects of the same type have a uniform	class. Thus, as for documents, objects of the same type have a uniform
presentation and the presentation of every object in a given class can be	presentation and the presentation of every object in a given class can be
Line 812 changed simply by changing the generic p	Line 543 changed simply by changing the generic p
advantage of using this document model is that the system does not bother the	advantage of using this document model is that the system does not bother the
user with the details of presentation, but rather allows the user to	user with the details of presentation, but rather allows the user to
concentrate on the logical aspect of the document and the objects.</p>	concentrate on the logical aspect of the document and the objects.</p>
<p>
It is clear that the documents in a class do not necessarily use the same	<p>It is clear that the documents in a class do not necessarily use the same
classes of objects: one technical report will contain tables while another	classes of objects: one technical report will contain tables while another
report will have no tables but will use mathematical formulas. The usable	report will have no tables but will use mathematical formulas. The usable
object classes are not always mentioned in a limiting way in the generic	object classes are not always mentioned in a limiting way in the generic
logical structure of documents. Rather, they can be chosen freely from a	logical structure of documents. Rather, they can be chosen freely from a
large set, independent of the document class.</p>	large set, independent of the document class.</p>
<p>
Thus, the object classes will be made commonplace and usable in every	<p>Thus, the object classes will be made commonplace and usable in every
document. The notion of ``object'' can be enlarged to include not only	document. The notion of ``object'' can be enlarged to include not only
non-textual elements, but also certain types of textual elements which can	non-textual elements, but also certain types of textual elements which can
appear in practically every document, whatever their class. Among these	appear in practically every document, whatever their class. Among these
textual elements, one can mention enumerations, descriptions, examples,	textual elements, one can mention enumerations, descriptions, examples,
quotations, even paragraphs.</p>	quotations, even paragraphs.</p>
<p>
Thus, the document model is not a single, general model describing every type	<p>Thus, the document model is not a single, general model describing every
of document in one place. Rather, it is a meta-model which can be used to	type of document in one place. Rather, it is a meta-model which can be used
describe many different models each of which represents either a class of	to describe many different models each of which represents either a class of
similar documents or a class of similar objects which every document can	similar documents or a class of similar objects which every document can
include.</p>	include.</p>
</div>	</div>
<hr>	<hr>

</div>	</div>

<div class="chapter">	<div class="chapter">

<h1><a name="sect3">The S language</a></h1>	<h1><a name="sect3">The S language</a></h1>

<div class="section">	<div class="section">

<h2><a name="sectb31">Document meta-structure</a></h2>	<h2><a name="sectb31">Document meta-structure</a></h2>
<p>
Since the concept of meta-structure is well suited to the task of describing	<p>Since the concept of meta-structure is well suited to the task of
documents at a high level of abstraction, this meta-structure must be	describing documents at a high level of abstraction, this meta-structure must
precisely defined. Toward that end this section first presents the basic	be precisely defined. Toward that end this section first presents the basic
elements from which documents and structured objects are composed and then	elements from which documents and structured objects are composed and then
specifies the ways in which these basic elements are assembled into structures	specifies the ways in which these basic elements are assembled into structures
representing complete documents and objects.</p>	representing complete documents and objects.</p>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc311">The basic types</a></h3>	<h3><a name="sectc311">The basic types</a></h3>
<p>
At the lowest level of a document's structure, the first atom considered is	<p>At the lowest level of a document's structure, the first atom considered is
the character. However, since characters are seldom isolated, usually	the character. However, since characters are seldom isolated, usually
appearing as part of a linear sequence, and in order to reduce the complexity	appearing as part of a linear sequence, and in order to reduce the complexity
of the document structure, <em>character strings</em> are used as atoms and	of the document structure, <em>character strings</em> are used as atoms and
consecutive characters belonging to the same structural element are grouped in	consecutive characters belonging to the same structural element are grouped in
the same character string.</p>	the same character string.</p>
<p>
If the structure of a document is not refined to go down to the level of	<p>If the structure of a document is not refined to go down to the level of
words or phrases, the contents of a simple paragraph can be considered to be a	words or phrases, the contents of a simple paragraph can be considered to be a
single character string. On the other hand, the title of a chapter, the title	single character string. On the other hand, the title of a chapter, the title
of the first section of that chapter, and the text of the first paragraph of	of the first section of that chapter, and the text of the first paragraph of
that section constitute three different character strings, because they belong	that section constitute three different character strings, because they belong
to distinct structural elements.</p>	to distinct structural elements.</p>
<p>
If, instead, a very fine-grained representation for the structure of a	<p>If, instead, a very fine-grained representation for the structure of a
document is sought, character strings could be defined to contain only a	document is sought, character strings could be defined to contain only a
single word, or even just a single character. This is the case, for example,	single word, or even just a single character. This is the case, for example,
in programs, for which one wants to retain a structure very close to the	in programs, for which one wants to retain a structure very close to the
Line 878 syntax of the programming language. In	Line 605 syntax of the programming language. In
initializing a simple variable to zero would be composed of two structural	initializing a simple variable to zero would be composed of two structural
elements, the identifier of the variable (a short character string) and the	elements, the identifier of the variable (a short character string) and the
assigned value (a string of a single character, `0').</p>	assigned value (a string of a single character, `0').</p>
<p>
The character string is not the only atom necessary for representing those	<p>The character string is not the only atom necessary for representing those
documents that interest us. It suffices for purely textual documents, but as	documents that interest us. It suffices for purely textual documents, but as
soon as the non-textual objects which we have considered arise, there must be	soon as the non-textual objects which we have considered arise, there must be
other atoms; the number of objects which are to be represented determines the	other atoms; the number of objects which are to be represented determines the
number of types of atoms that are necessary.</p>	number of types of atoms that are necessary.</p>
<p>
Primitive <em>graphical elements</em> are used for tables and figures of	<p>Primitive <em>graphical elements</em> are used for tables and figures of
different types. These elements are simple geometric shapes like horizontal	different types. These elements are simple geometric shapes like horizontal
or vertical lines, which are sufficient for tables, or even oblique lines,	or vertical lines, which are sufficient for tables, or even oblique lines,
arrows, rectangles, circles, polygons, and curves for use in figures. From	arrows, rectangles, circles, polygons, and curves for use in figures. From
these elements and character strings, graphical objects and tables can be	these elements and character strings, graphical objects and tables can be
constructed.</p>	constructed.</p>
<p>
Photographs, though having very little structure, must still appear in	<p>Photographs, though having very little structure, must still appear in
documents. They are supported by <em>picture</em> elements, which are	documents. They are supported by <em>picture</em> elements, which are
represented as matrices of pixels.</p>	represented as matrices of pixels.</p>
<p>
Finally, mathematical notations require certain elements which are	<p>Finally, mathematical notations require certain elements which are
simultaneously characters and graphical elements, the <em>symbols</em>. By way	simultaneously characters and graphical elements, the <em>symbols</em>. By way
of example, radicals, integration signs, or even large parentheses are	of example, radicals, integration signs, or even large parentheses are
examples of this type of atom. The size of each of these symbols is	examples of this type of atom. The size of each of these symbols is
determined by its environment, that is to say, by the expression to which it	determined by its environment, that is to say, by the expression to which it
is attached.</p>	is attached.</p>
<p>
To summarize, the primitive elements which are used in the construction of	<p>To summarize, the primitive elements which are used in the construction of
documents and structured objects are:</p>	documents and structured objects are:</p>
<ul>	<ul>
<li>	<li>character strings,</li>
character strings,	<li>graphical elements,</li>
</li>	<li>pictures,</li>
<li>	<li>and mathematical symbols.</li>
graphical elements,
</li>
<li>
pictures,
</li>
<li>
and mathematical symbols.
</li>
</ul>	</ul>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc312">Constructed elements</a></h3>	<h3><a name="sectc312">Constructed elements</a></h3>
<p>
A document is evidently formed from primitive elements. But the model of Thot	<p>A document is evidently formed from primitive elements. But the model of
also proposes higher level elements. Thus, in a document composed of several	Thot also proposes higher level elements. Thus, in a document composed of
chapters, each chapter is an element, and in the chapters each section is also	several chapters, each chapter is an element, and in the chapters each section
an element, and so on. A document is thus an organized set of elements.</p>	is also an element, and so on. A document is thus an organized set of
<p>	elements.</p>
In a document there are different sorts of elements. Each element has a
	<p>In a document there are different sorts of elements. Each element has a
<em>type</em> which indicates the role of the element within the document as a	<em>type</em> which indicates the role of the element within the document as a
whole. Thus, we have, for example, the chapter and section types. The	whole. Thus, we have, for example, the chapter and section types. The
document is made up of typed elements: elements of the type chapter and	document is made up of typed elements: elements of the type chapter and
Line 938 elements of the type section, among othe	Line 657 elements of the type section, among othe
and graphical elements: the primitive elements are typed elements just as	and graphical elements: the primitive elements are typed elements just as
well. At the other extreme, the document itself is also considered to be a	well. At the other extreme, the document itself is also considered to be a
typed element.</p>	typed element.</p>
<p>
The important difference between the primitive elements and the other elements	<p>The important difference between the primitive elements and the other
of the document is that the primitive elements are atoms (they cannot be	elements of the document is that the primitive elements are atoms (they cannot
decomposed), whereas the others, called <em>constructed elements</em>, are	be decomposed), whereas the others, called <em>constructed elements</em>, are
composed of other elements, which can either be primitive elements or	composed of other elements, which can either be primitive elements or
constructed elements. A constructed element of type chapter (or more simply,	constructed elements. A constructed element of type chapter (or more simply,
``a chapter'') is composed of sections, which are also constructed elements. A	``a chapter'') is composed of sections, which are also constructed elements. A
paragraph, a constructed element, can be made up of character strings, which	paragraph, a constructed element, can be made up of character strings, which
are primitive elements, and of equations, which are constructed elements.</p>	are primitive elements, and of equations, which are constructed elements.</p>
<p>
A document is also a constructed element. This is an important point. In	<p>A document is also a constructed element. This is an important point. In
particular, it allows a document to be treated as part of another document,	particular, it allows a document to be treated as part of another document,
and conversely, permits a part of a document to be treated as a complete	and conversely, permits a part of a document to be treated as a complete
document. Thus, an article presented in a journal is treated by its author as	document. Thus, an article presented in a journal is treated by its author as
Line 956 a document in itself, while the editor o	Line 675 a document in itself, while the editor o
of an issue. A table or a figure appearing in a document can be extracted and	of an issue. A table or a figure appearing in a document can be extracted and
treated as a complete document, for example to prepare transparencies for a	treated as a complete document, for example to prepare transparencies for a
conference.</p>	conference.</p>
<p>
These thoughts about types and constructed elements apply just as well to	<p>These thoughts about types and constructed elements apply just as well to
objects as they do to documents. A table is a constructed element made up of	objects as they do to documents. A table is a constructed element made up of
other constructed elements, rows and columns. A row is formed of cells, which	other constructed elements, rows and columns. A row is formed of cells, which
are also constructed elements which contain primitive elements (character	are also constructed elements which contain primitive elements (character
Line 965 strings) and/or constructed elements lik	Line 684 strings) and/or constructed elements lik
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc313">Logical structure constructors</a></h3>	<h3><a name="sectc313">Logical structure constructors</a></h3>
<p>
Having defined the primitive elements and the constructed elements, it is now	<p>Having defined the primitive elements and the constructed elements, it is
time to define the types of organization which allow the building of	now time to define the types of organization which allow the building of
structures. For this, we rely on the notion of the <em>constructor</em>. A	structures. For this, we rely on the notion of the <em>constructor</em>. A
constructor defines a way of assembling certain elements in a structure. It	constructor defines a way of assembling certain elements in a structure. It
resides at the level of the meta-structure: it does not describe the existing	resides at the level of the meta-structure: it does not describe the existing
relations in a given structure, but rather defines how elements are assembled	relations in a given structure, but rather defines how elements are assembled
to build a structure that conforms to a model.</p>	to build a structure that conforms to a model.</p>
<p>
In defining the overall organization of documents, the first two constructors
considered are the aggregate and the list.</p>

<div class="subsubsection">	<p>In defining the overall organization of documents, the first two
	constructors considered are the aggregate and the list.</p>

	<div class="subsubsection">
<h4><a name="sectd3131">Aggregate and List</a></h4>	<h4><a name="sectd3131">Aggregate and List</a></h4>
<p>
The <em>aggregate</em> constructor is used to define constructed element types	<p>The <em>aggregate</em> constructor is used to define constructed element
which are collections of a given number of other elements. These collections	types which are collections of a given number of other elements. These
may or may not be ordered. The elements may be either constructed or	collections may or may not be ordered. The elements may be either constructed
primitive and are specified by their type. A report (that is, a constructed	or primitive and are specified by their type. A report (that is, a
element of the report type) has an aggregate structure. It is formed from a	constructed element of the report type) has an aggregate structure. It is
title, an author's name, an introduction, a body, and a conclusion, making it	formed from a title, an author's name, an introduction, a body, and a
a collection of five element types. This type of constructor is found in	conclusion, making it a collection of five element types. This type of
practically every document, and generally at several levels in a document.</p>	constructor is found in practically every document, and generally at several
<p>	levels in a document.</p>
The <em>list</em> constructor is used to define constructed elements which are
ordered sequences of elements (constructed or primitive) having the same type.	<p>The <em>list</em> constructor is used to define constructed elements which
The minimum and maximum numbers of elements for the sequence can be specified	are ordered sequences of elements (constructed or primitive) having the same
in the list constructor or the number of elements can be left unconstrained.	type. The minimum and maximum numbers of elements for the sequence can be
The body of a report is a list of chapters and is typically required to	specified in the list constructor or the number of elements can be left
contain a minimum of two chapters (is a chapter useful if it is the only one	unconstrained. The body of a report is a list of chapters and is typically
in the report?) The chapter itself can contain a list of sections, each	required to contain a minimum of two chapters (is a chapter useful if it is
section containing a list of paragraphs. In the same way as the aggregate,	the only one in the report?) The chapter itself can contain a list of
the list is a very frequently used constructor in every type of document.	sections, each section containing a list of paragraphs. In the same way as
However, these two constructors are not sufficient to describe every document	the aggregate, the list is a very frequently used constructor in every type of
structure; thus other constructors supplement them.</p>	document. However, these two constructors are not sufficient to describe every
	document structure; thus other constructors supplement them.</p>
</div>	</div>

<div class="subsubsection">	<div class="subsubsection">

<h4><a name="sectd3132">Choice, Schema, and Unit</a></h4>	<h4><a name="sectd3132">Choice, Schema, and Unit</a></h4>
<p>
The <em>choice</em> constructor is used to define the structure of an element	<p>The <em>choice</em> constructor is used to define the structure of an
type for which one alternative is chosen from several possibilities. Thus, a	element type for which one alternative is chosen from several possibilities.
paragraph can be either a simple text paragraph, or an enumeration, or a	Thus, a paragraph can be either a simple text paragraph, or an enumeration, or
citation.</p>	a citation.</p>
<p>
The choice constructor indicates the complete list of possible options, which	<p>The choice constructor indicates the complete list of possible options,
can be too restrictive in certain cases, the paragraph being one such case.	which can be too restrictive in certain cases, the paragraph being one such
Two constructors, <em>unit</em> and <em>schema</em>, address this	case. Two constructors, <em>unit</em> and <em>schema</em>, address this
inconvenience. They allow more freedom in the choice of an element type. If	inconvenience. They allow more freedom in the choice of an element type. If
a paragraph is defined by a schema constructor, it is possible to put in the	a paragraph is defined by a schema constructor, it is possible to put in the
place of a paragraph a table, an equation, a drawing or any other object	place of a paragraph a table, an equation, a drawing or any other object
Line 1025 paragraph as a sequence of units, which	Line 742 paragraph as a sequence of units, which
or pictures. The choice constructor alone defines a generic logical structure	or pictures. The choice constructor alone defines a generic logical structure
that is relatively constrained; in contrast, using units and schemas, a very	that is relatively constrained; in contrast, using units and schemas, a very
open structure can be defined.</p>	open structure can be defined.</p>
<p>
The <em>schema</em> constructor represents an object defined by a generic	<p>The <em>schema</em> constructor represents an object defined by a generic
logical structure chosen freely from among those available.</p>	logical structure chosen freely from among those available.</p>
<p>
The <em>unit</em> constructor represents an element whose type can be either a	<p>The <em>unit</em> constructor represents an element whose type can be
primitive type or an element type defined as a unit in the generic logical	either a primitive type or an element type defined as a unit in the generic
structure of the document, or in another generic logical structure used in the	logical structure of the document, or in another generic logical structure
document. Such an element may be used in document objects constructed	used in the document. Such an element may be used in document objects
according to other generic structures.</p>	constructed according to other generic structures.</p>
<p>
Thus, for example, if a cross-reference to a footnote is defined in the	<p>Thus, for example, if a cross-reference to a footnote is defined in the
generic logical structure ``Article'' as a unit, a table (an object defined by	generic logical structure ``Article'' as a unit, a table (an object defined by
another generic structure) can contain cross-references to footnotes, when	another generic structure) can contain cross-references to footnotes, when
they appear in an article. In another type of document, a table defined by	they appear in an article. In another type of document, a table defined by
Line 1048 environment into which they are inserted	Line 765 environment into which they are inserted
</div>	</div>

<div class="subsubsection">	<div class="subsubsection">

<h4><a name="sectd3133">Reference and Inclusion</a></h4>	<h4><a name="sectd3133">Reference and Inclusion</a></h4>
<p>
The <em>reference</em> is used to define document elements that are	<p>The <em>reference</em> is used to define document elements that are
cross-references to other elements, such as a section, a chapter, a	cross-references to other elements, such as a section, a chapter, a
bibliographic citation, or a figure. The reference is bi-directional. It can	bibliographic citation, or a figure. The reference is bi-directional. It can
be used to access both the element being cross-referenced and each of the	be used to access both the element being cross-referenced and each of the
elements which make use of the cross-reference.</p>	elements which make use of the cross-reference.</p>
<p>
References can be either <em>internal</em> or <em>external</em>. That is,	<p>References can be either <em>internal</em> or <em>external</em>. That is,
they can designate elements which appear in the same document or in another	they can designate elements which appear in the same document or in another
document.</p>	document.</p>
<p>
The <em><a name="inclusion">inclusion</a></em> constructor is a special type	<p>The <em><a name="inclusion">inclusion</a></em> constructor is a special
of reference. Like the reference, it is an internal or external bidirectional	type of reference. Like the reference, it is an internal or external
link, but it is not a cross-reference. This link represents the ``live''	bidirectional link, but it is not a cross-reference. This link represents the
inclusion of the designated element; it accesses the most recent version of	``live'' inclusion of the designated element; it accesses the most recent
that element and not a ``dead'' copy, fixed in the state in which it was found	version of that element and not a ``dead'' copy, fixed in the state in which
at the moment the copy was made. As soon as an element is modified, all of	it was found at the moment the copy was made. As soon as an element is
its inclusions are automatically brought up to date. It must be noted that,	modified, all of its inclusions are automatically brought up to date. It must
in addition to inclusion, Thot permits the creation of ``dead'' copies.</p>	be noted that, in addition to inclusion, Thot permits the creation of ``dead''
<p>	copies.</p>
There are three types of inclusions: inclusions with full expansion,
	<p>There are three types of inclusions: inclusions with full expansion,
inclusions with partial expansion, and inclusions without expansion. During	inclusions with partial expansion, and inclusions without expansion. During
editing, inclusions without expansion are represented on the screen by the	editing, inclusions without expansion are represented on the screen by the
name of the included document, in a special color, while inclusions with	name of the included document, in a special color, while inclusions with
Line 1078 expansion (full or partial) are represen	Line 795 expansion (full or partial) are represen
included element (also in a special color). The on-screen representation of a	included element (also in a special color). The on-screen representation of a
partial inclusion is a <a href="#sectc3213">``skeleton''</a> image of the	partial inclusion is a <a href="#sectc3213">``skeleton''</a> image of the
included document.</p>	included document.</p>
<p>
Inclusion with complete expansion can be used to include parts of the same	<p>Inclusion with complete expansion can be used to include parts of the same
document or of other documents. Thus, it can be either an internal or an	document or of other documents. Thus, it can be either an internal or an
external link. It can be used to include certain bibliographic entries of a	external link. It can be used to include certain bibliographic entries of a
scientific article in another article, or to copy part of a mathematical	scientific article in another article, or to copy part of a mathematical
formula into another formula of the same document, thus assuring that both	formula into another formula of the same document, thus assuring that both
copies will remain synchronized.</p>	copies will remain synchronized.</p>
<p>
Inclusion without expansion or with partial expansion is used to include	<p>Inclusion without expansion or with partial expansion is used to include
complete documents. It is always an external link. It is used primarily to	complete documents. It is always an external link. It is used primarily to
divide very large documents into sub-documents that are easier to manipulate,	divide very large documents into sub-documents that are easier to manipulate,
especially when there are many authors. So, a book can include some chapters,	especially when there are many authors. So, a book can include some chapters,
Line 1094 where each chapter is a different docume	Line 811 where each chapter is a different docume
When viewing the book on the screen, it might be desirable to see only the	When viewing the book on the screen, it might be desirable to see only the
titles of the chapters and sections. This can be achieved using inclusion	titles of the chapters and sections. This can be achieved using inclusion
with partial expansion.</p>	with partial expansion.</p>
<p>
During printing, inclusions without expansion or with partial expansion can be	<p>During printing, inclusions without expansion or with partial expansion can
represented either as they were shown on the screen or by a complete (and	be represented either as they were shown on the screen or by a complete (and
up-to-date) copy of the included element or document.</p>	up-to-date) copy of the included element or document.</p>
<p>
The inclusion constructor, whatever its type, respects the generic structure:	<p>The inclusion constructor, whatever its type, respects the generic
only those elements authorized by the generic structure can be included at a	structure: only those elements authorized by the generic structure can be
given position in a document.</p>	included at a given position in a document.</p>
</div>	</div>

<div class="subsubsection">	<div class="subsubsection">

<h4><a name="sectd3134">Mark pairs</a></h4>	<h4><a name="sectd3134">Mark pairs</a></h4>
<p>
It is often useful to delimit certain parts of a document independently from	<p>It is often useful to delimit certain parts of a document independently
the logical structure. For example, one might wish to attach some information	from the logical structure. For example, one might wish to attach some
(in the form of an <a href="#sectc315">attribute</a>) or a particular	information (in the form of an <a href="#sectc315">attribute</a>) or a
treatment to a group of words or a set of consecutive paragraphs. <em>Mark	particular treatment to a group of words or a set of consecutive paragraphs.
pairs</em> are used to do this.</p>	<em>Mark pairs</em> are used to do this.</p>
<p>
Mark pairs are elements which are always paired and are terminals in the	<p>Mark pairs are elements which are always paired and are terminals in the
logical structure of the document. Their position in the structure of the	logical structure of the document. Their position in the structure of the
document is defined in the generic structure. It is important to note that	document is defined in the generic structure. It is important to note that
when the terminals of a mark pair are <em>extensions</em> (see the next	when the terminals of a mark pair are <em>extensions</em> (see the next
Line 1122 section), they can be used quite freely.	Line 838 section), they can be used quite freely.
</div>	</div>

<div class="subsubsection">	<div class="subsubsection">

<h4><a name="sectd3135">Restrictions and Extensions</a></h4>	<h4><a name="sectd3135">Restrictions and Extensions</a></h4>
<p>
The primitive types and the constructors presented so far permit the	<p>The primitive types and the constructors presented so far permit the
definition of the logical structure of documents and objects in a rigorous	definition of the logical structure of documents and objects in a rigorous
way. But this definition can be very cumbersome in certain cases, notably	way. But this definition can be very cumbersome in certain cases, notably
when trying to constrain or extend the authorized element types in a	when trying to constrain or extend the authorized element types in a
particular context. <em>Restrictions</em> and <em>extensions</em> are used to	particular context. <em>Restrictions</em> and <em>extensions</em> are used to
cope with these cases.</p>	cope with these cases.</p>
<p>
A restriction associates with a particular element type <em>A</em>, a list of	<p>A restriction associates with a particular element type <em>A</em>, a list
those element types which elements of type <em>A</em> may not contain, even if	of those element types which elements of type <em>A</em> may not contain, even
the definition of type <em>A</em> and those of its components authorize them	if the definition of type <em>A</em> and those of its components authorize
otherwise. This simplifies the writing of generic logical structures and	them otherwise. This simplifies the writing of generic logical structures and
allows limitations to be placed, when necessary, on the choices offered by the	allows limitations to be placed, when necessary, on the choices offered by the
schema and unit constructors.</p>	schema and unit constructors.</p>
<p>
Extensions are the inverse of restrictions. They identify a list of element	<p>Extensions are the inverse of restrictions. They identify a list of
types whose presence <em>is</em> permitted, even if its definition and those	element types whose presence <em>is</em> permitted, even if its definition and
of its components do not authorize them otherwise.</p>	those of its components do not authorize them otherwise.</p>
</div>	</div>

<div class="subsubsection">	<div class="subsubsection">

<h4><a name="sectd3136">Summary</a></h4>	<h4><a name="sectd3136">Summary</a></h4>
<p>
Thus, four constructors are used to construct a document:</p>	<p>Thus, four constructors are used to construct a document:</p>
<ul>	<ul>
<li>	<li>the aggregate constructor (ordered or not),</li>
the aggregate constructor (ordered or not),	<li>the list constructor,</li>
</li>	<li>the choice constructor and its extensions, the unit and schema
<li>	constructors,</li>
the list constructor,	<li>the reference constructor and its variant, the inclusion.</li>
</li>	</ul>
<li>
the choice constructor and its extensions, the unit and schema constructors,	<p>These constructors are also sufficient for objects. Thus, these
</li>	constructors provide a homogenous meta-model which can describe both the
<li>	organization of the document as a whole and that of the various types of
the reference constructor and its variant, the inclusion.	objects which it contains. After presenting the description language for
</li>	generic structures, we will present several examples which illustrate the
</ul>	appropriateness of the model.</p>
<p>
These constructors are also sufficient for objects. Thus, these constructors	<p>The first three constructors (aggregate, list and choice) lead to tree-like
provide a homogenous meta-model which can describe both the organization of
the document as a whole and that of the various types of objects which it
contains. After presenting the description language for generic structures,
we will present several examples which illustrate the appropriateness of the
model.</p>
<p>
The first three constructors (aggregate, list and choice) lead to tree-like
structures for documents and objects, the objects being simply the subtrees of	structures for documents and objects, the objects being simply the subtrees of
the tree of a document (or even of other objects' subtrees). The reference	the tree of a document (or even of other objects' subtrees). The reference
constructor introduces other, non-hierarchical, relations which augment those	constructor introduces other, non-hierarchical, relations which augment those
Line 1183 documents, thus creating a hypertext str	Line 890 documents, thus creating a hypertext str
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc314">Associated Elements</a></h3>	<h3><a name="sectc314">Associated Elements</a></h3>
<p>
Thanks to the list, aggregate and choice constructors, the organization of the	<p>Thanks to the list, aggregate and choice constructors, the organization of
document is specified rigorously, using constructed and primitive elements.	the document is specified rigorously, using constructed and primitive
But a document is made up of more than just its elements; it clearly also	elements. But a document is made up of more than just its elements; it clearly
contains links between them. There exist elements whose position in the	also contains links between them. There exist elements whose position in the
document's structure is not determinable. This is notably the case for	document's structure is not determinable. This is notably the case for
figures and notes. A figure can be designated at many points in the same	figures and notes. A figure can be designated at many points in the same
document and its place in the physical document can vary over the life of the	document and its place in the physical document can vary over the life of the
Line 1205 documents that are broken into pages, bu	Line 911 documents that are broken into pages, bu
instability of these elements. They cannot be treated the same way as	instability of these elements. They cannot be treated the same way as
elements like paragraphs or sections, whose position in the structure is	elements like paragraphs or sections, whose position in the structure is
directly linked to the semantics of the document.</p>	directly linked to the semantics of the document.</p>
<p>
Those elements whose position in the structure of the document is not fixed,	<p>Those elements whose position in the structure of the document is not
even though they are definitely part of the document, are called	fixed, even though they are definitely part of the document, are called
<em>associated elements</em>. Associated elements are themselves structures,	<em>associated elements</em>. Associated elements are themselves structures,
which is to say that their content can be organized logically by the	which is to say that their content can be organized logically by the
constructors from primitive and constructed elements.</p>	constructors from primitive and constructed elements.</p>
<p>
It can happen that the associated elements are totally disconnected from the	<p>It can happen that the associated elements are totally disconnected from
structure of the document, as in a commentary or appraisal of the entire work.	the structure of the document, as in a commentary or appraisal of the entire
But more often, the associated elements are linked to the content of the	work. But more often, the associated elements are linked to the content of the
document by references. This is generally the case for notes and figures,	document by references. This is generally the case for notes and figures,
among others.</p>	among others.</p>
<p>
Thus, associated elements introduce a new use for the reference constructor.	<p>Thus, associated elements introduce a new use for the reference
It not only serves to create links between elements of the principal structure	constructor. It not only serves to create links between elements of the
of the document, but also serves to link the associated elements to the	principal structure of the document, but also serves to link the associated
primary structure.</p>	elements to the primary structure.</p>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc315">Attributes</a></h3>	<h3><a name="sectc315">Attributes</a></h3>
<p>
There remain logical aspects of documents that are not entirely described by	<p>There remain logical aspects of documents that are not entirely described
the structure. Certain types of semantic information, which are not stated	by the structure. Certain types of semantic information, which are not stated
explicitly in the text, must also be taken into account. In particular, such	explicitly in the text, must also be taken into account. In particular, such
information is shown by typographic effects which do not correspond to a	information is shown by typographic effects which do not correspond to a
change between structural elements. In fact, certain titles are set in bold	change between structural elements. In fact, certain titles are set in bold
Line 1239 frequently appear in the middle of conti	Line 944 frequently appear in the middle of conti
paragraph). In this case, there is no change between structural elements; the	paragraph). In this case, there is no change between structural elements; the
effect serves to highlight a word, expression, or phrase. The notion of an	effect serves to highlight a word, expression, or phrase. The notion of an
<em>attribute</em> is used to express this type of information.</p>	<em>attribute</em> is used to express this type of information.</p>
<p>
An attribute is a piece of information attached to a structural element which	<p>An attribute is a piece of information attached to a structural element
augments the type of the element and clarifies its function in the document.	which augments the type of the element and clarifies its function in the
Keywords, foreign language words, and titles of other works can all be	document. Keywords, foreign language words, and titles of other works can all
represented by character strings with attached attributes. Attributes may	be represented by character strings with attached attributes. Attributes may
also be attached to constructed elements. Thus, an attribute indicating the	also be attached to constructed elements. Thus, an attribute indicating the
language can be attached to a single word or to a large part of a	language can be attached to a single word or to a large part of a
document.</p>	document.</p>
<p>
In fact, an attribute can be any piece of information which is linked to a	<p>In fact, an attribute can be any piece of information which is linked to a
part of a document and which can be used by agents which work on the document.	part of a document and which can be used by agents which work on the document.
For example, the language in which the document is written determines the set	For example, the language in which the document is written determines the set
of characters used by an editor or formatter. It also determines the	of characters used by an editor or formatter. It also determines the
Line 1256 algorithm or hyphenation dictionary to b	Line 961 algorithm or hyphenation dictionary to b
facilitates the work of an information retrieval system. The attribute	facilitates the work of an information retrieval system. The attribute
``index word'' allows a formatter to automatically construct an index at the	``index word'' allows a formatter to automatically construct an index at the
end of the document.</p>	end of the document.</p>
<p>
As with the types of constructed elements, the attributes and the values they	<p>As with the types of constructed elements, the attributes and the values
can take are defined separately in each generic logical structure, not in the	they can take are defined separately in each generic logical structure, not in
meta-model, according to the needs of the document class or the nature of the	the meta-model, according to the needs of the document class or the nature of
object.</p>	the object.</p>
<p>
Many types of attributes are offered: numeric, textual, references, and	<p>Many types of attributes are offered: numeric, textual, references, and
enumerations:</p>	enumerations:</p>
<ul>	<ul>
<li>	<li><em>Numeric attributes</em> can take integer values (negative, positive,
<em>Numeric attributes</em> can take integer values (negative, positive, or	or null).</li>
null).	<li><em>Textual attributes</em> have as their values character strings.</li>
</li>	<li><em>Reference attributes</em> designate an element of the logical
<li>	structure.</li>
<em>Textual attributes</em> have as their values character strings.	<li><em>Enumeration attributes</em> can take one value from a limited list
</li>	of possible values, each value being a name.</li>
<li>
<em>Reference attributes</em> designate an element of the logical structure.
</li>
<li>
<em>Enumeration attributes</em> can take one value from a limited list of
possible values, each value being a name.
</li>
</ul>	</ul>
<p>
In a generic structure, there is a distinction between <em>global	<p>In a generic structure, there is a distinction between <em>global
attributes</em> and <em>local attributes</em>. A global attribute can be	attributes</em> and <em>local attributes</em>. A global attribute can be
applied to every element type defined in the generic structure where it is	applied to every element type defined in the generic structure where it is
specified. In contrast, a local attribute can only be applied to certain	specified. In contrast, a local attribute can only be applied to certain
Line 1290 presented above is an example of a globa	Line 988 presented above is an example of a globa
attribute is the rank of an author (principal author of the document or	attribute is the rank of an author (principal author of the document or
secondary author): this attribute can only be applied sensibly to an element	secondary author): this attribute can only be applied sensibly to an element
of the ``author'' type.</p>	of the ``author'' type.</p>
<p>
Attributes can be assigned to the elements which make up the document in many	<p>Attributes can be assigned to the elements which make up the document in
different ways. The author can freely and dynamically place them on any part	many different ways. The author can freely and dynamically place them on any
of the document in order to attach supplementary information of his/her	part of the document in order to attach supplementary information of his/her
choice. However, attributes may only be assigned in accordance with the rules	choice. However, attributes may only be assigned in accordance with the rules
of the generic structure; in particular, local attributes can only be assigned	of the generic structure; in particular, local attributes can only be assigned
to those element types for which they are defined.</p>	to those element types for which they are defined.</p>
<p>
In the generic structure, certain local attributes can be made mandatory for	<p>In the generic structure, certain local attributes can be made mandatory
certain element types. In this case, Thot automatically associates the	for certain element types. In this case, Thot automatically associates the
attribute with the elements of this type and it requires the user to provide a	attribute with the elements of this type and it requires the user to provide a
value for this attribute.</p>	value for this attribute.</p>
<p>
Attributes can also be automatically assigned, with a given value, by every	<p>Attributes can also be automatically assigned, with a given value, by every
application processing the document in order to systematically add a piece of	application processing the document in order to systematically add a piece of
information to certain predefined elements of the document. By way of	information to certain predefined elements of the document. By way of
example, in a report containing a French abstract and an English abstract,	example, in a report containing a French abstract and an English abstract,
each of the two abstracts is defined as a sequence of paragraphs. The first	each of the two abstracts is defined as a sequence of paragraphs. The first
abstract has a value of ``French'' for the ``language'' attribute while the	abstract has a value of ``French'' for the ``language'' attribute while the
second abstract's ``language'' attribute has a value of ``English''.</p>	second abstract's ``language'' attribute has a value of ``English''.</p>
<p>
In the case of mark pairs, attributes are logically associated with the pair	<p>In the case of mark pairs, attributes are logically associated with the
as a whole, but are actually attached to the first mark.</p>	pair as a whole, but are actually attached to the first mark.</p>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc316">Discussion of the model</a></h3>	<h3><a name="sectc316">Discussion of the model</a></h3>
<p>
The notions of attribute, constructor, structured element, and associated	<p>The notions of attribute, constructor, structured element, and associated
element are used in the definition of generic logical structures of documents	element are used in the definition of generic logical structures of documents
and objects. The problem is to assemble them to form generic structures. In	and objects. The problem is to assemble them to form generic structures. In
fact, many types of elements and attributes can be found in a variety of	fact, many types of elements and attributes can be found in a variety of
Line 1333 many document classes. This is the reas	Line 1030 many document classes. This is the reas
broad and why paragraphs and enumerations are also considered to be objects.	broad and why paragraphs and enumerations are also considered to be objects.
These object classes not only permit the sharing of the structures of	These object classes not only permit the sharing of the structures of
elements, but also of the attributes defined in the generic structures.</p>	elements, but also of the attributes defined in the generic structures.</p>
<p>
Structure, such as that presented here, can appear very rigid, and it is	<p>Structure, such as that presented here, can appear very rigid, and it is
possible to imagine that a document editing system based on this model could	possible to imagine that a document editing system based on this model could
prove very constraining to the user. This is, in fact, a common criticism of	prove very constraining to the user. This is, in fact, a common criticism of
syntax-directed editors. This defect can be avoided with Thot, primarily for	syntax-directed editors. This defect can be avoided with Thot, primarily for
three reasons:</p>	three reasons:</p>
<ul>	<ul>
<li>	<li>the generic structures are not fixed in the model itself,</li>
the generic structures are not fixed in the model itself,	<li>the model takes the dynamics of documents into account,</li>
</li>	<li>the constructors offer great flexibility.</li>
<li>
the model takes the dynamics of documents into account,
</li>
<li>
the constructors offer great flexibility.
</li>
</ul>	</ul>
<p>
When the generic structure of a document is not predefined, but rather is	<p>When the generic structure of a document is not predefined, but rather is
constructed specifically for each document class, it can be carefully adapted	constructed specifically for each document class, it can be carefully adapted
to the current needs. In cases where the generic structure is inadequate for	to the current needs. In cases where the generic structure is inadequate for
a particular document of the class, it is always possible either to create a	a particular document of the class, it is always possible either to create a
Line 1359 new class with a generic structure well	Line 1050 new class with a generic structure well
the generic structure of the existing class to take into account the specifics	the generic structure of the existing class to take into account the specifics
of the document which poses the problem. These two solutions can also be	of the document which poses the problem. These two solutions can also be
applied to objects whose structures prove to be poorly designed.</p>	applied to objects whose structures prove to be poorly designed.</p>
<p>
The model is sufficiently flexible to take into account all the phases of the	<p>The model is sufficiently flexible to take into account all the phases of
life of the document. When a generic structure specifies that a report must	the life of the document. When a generic structure specifies that a report
contain a title, an abstract, an introduction, at least two chapters, and a	must contain a title, an abstract, an introduction, at least two chapters, and
conclusion, this means only that a report, <em>upon completion</em>, will have	a conclusion, this means only that a report, <em>upon completion</em>, will
to contain all of these elements. When the author begins writing, none of	have to contain all of these elements. When the author begins writing, none
these elements is present. Thot uses this model. Therefore, it tolerates	of these elements is present. Thot uses this model. Therefore, it tolerates
documents which do not conform strictly to the generic structure of their	documents which do not conform strictly to the generic structure of their
class; it also considers the generic logical structure to be a way of helping	class; it also considers the generic logical structure to be a way of helping
the user in the construction of a complex document.</p>	the user in the construction of a complex document.</p>
<p>
In contrast, other applications may reject a document which does not conform	<p>In contrast, other applications may reject a document which does not
strictly to its generic structure. This is, for example, what is done by	conform strictly to its generic structure. This is, for example, what is done
compilers which refuse to generate code for a program which is not	by compilers which refuse to generate code for a program which is not
syntactically correct. This might also occur when using a document	syntactically correct. This might also occur when using a document
application for a report which does not have an abstract or title.</p>	application for a report which does not have an abstract or title.</p>
<p>
The constructors of the document model bring a great flexibility to the	<p>The constructors of the document model bring a great flexibility to the
generic structures. A choice constructor (and even more, a unit or schema	generic structures. A choice constructor (and even more, a unit or schema
constructor) can represent several, very different elements. The list	constructor) can represent several, very different elements. The list
constructor permits the addition of more elements of the same type. Used	constructor permits the addition of more elements of the same type. Used
Line 1384 together, these two constructors permit	Line 1075 together, these two constructors permit
types. Of course, this flexibility can be reduced wherever necessary since a	types. Of course, this flexibility can be reduced wherever necessary since a
generic structure can limit the choices or the number of elements in a	generic structure can limit the choices or the number of elements in a
list.</p>	list.</p>
<p>
Another difficulty linked to the use of structure in the document model	<p>Another difficulty linked to the use of structure in the document model
resides in the choice of the level of the structure. The structure of a	resides in the choice of the level of the structure. The structure of a
discussion could be extracted from the text itself via linguistic analysis.	discussion could be extracted from the text itself via linguistic analysis.
Some studies are exploring this approach, but the model of Thot excludes this	Some studies are exploring this approach, but the model of Thot excludes this
type of structure. It only takes into account the logical structure provided	type of structure. It only takes into account the logical structure provided
explicitly by the author.</p>	explicitly by the author.</p>
<p>
However, the level of structure of the model is not imposed. Each generic	<p>However, the level of structure of the model is not imposed. Each generic
structure defines its own level of structure, adapted to the document class or	structure defines its own level of structure, adapted to the document class or
object and to the ways in which it will be processed. If it will only be	object and to the ways in which it will be processed. If it will only be
edited and printed, a relatively simple structure suffices. If more	edited and printed, a relatively simple structure suffices. If more
Line 1405 expressions. The document model of Thot	Line 1096 expressions. The document model of Thot
</div>	</div>

<div class="section">	<div class="section">

<h2><a name="sectb32">The definition language for generic structures</a></h2>	<h2><a name="sectb32">The definition language for generic structures</a></h2>
<p>
Generic structures, which form the basis of the document model of Thot, are	<p>Generic structures, which form the basis of the document model of Thot, are
specified using a special language. This definition language, called S, is	specified using a special language. This definition language, called S, is
described in this section.</p>	described in this section.</p>
<p>
Each generic structure, which defines a class of documents or objects, is	<p>Each generic structure, which defines a class of documents or objects, is
specified by a file, written in the S language, which is called a	specified by a file, written in the S language, which is called a
<em>structure schema</em>. Structure schemas are compiled into tables, called	<em>structure schema</em>. Structure schemas are compiled into tables, called
structure tables, which are used by Thot and which determine its behavior.</p>	structure tables, which are used by Thot and which determine its behavior.</p>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc321">Writing Conventions</a></h3>	<h3><a name="sectc321">Writing Conventions</a></h3>
<p>
The grammar of S, like those of the languages P and T presented later, is	<p>The grammar of S, like those of the languages P and T presented later, is
described using the meta-language M, derived from the Backus-Naur Form	described using the meta-language M, derived from the Backus-Naur Form
(BNF).</p>	(BNF).</p>
<p>
In this meta-language each rule of the grammar is composed of a grammar symbol	<p>In this meta-language each rule of the grammar is composed of a grammar
followed by an equals sign (`=') and the right part of the rule. The equals	symbol followed by an equals sign (`=') and the right part of the rule. The
sign plays the same role as the traditional `::=' of BNF: it indicates that	equals sign plays the same role as the traditional `::=' of BNF: it indicates
the right part defines the symbol of the left part. In the right part,</p>	that the right part defines the symbol of the left part. In the right
	part,</p>
<dl>	<dl>
<dt>concatenation</dt>	<dt>concatenation</dt>
<dd>	<dd>is shown by the juxtaposition of symbols;</dd>
is shown by the juxtaposition of symbols;	<dt>character strings</dt>
</dd>	<dd>between apostrophes ' represent terminal symbols, that is, keywords in
<dt>character strings</dt>	the language defined. Keywords are written here in upper-case letters,
<dd>	but can be written in any combination of upper and lower-case letters.
between apostrophes ' represent terminal symbols, that is, keywords in the	For example, the keyword <tt>DEFPRES</tt> of S can also be written as
language defined. Keywords are written here in upper-case letters, but can be	<tt>defpres</tt> or <tt>DefPres</tt>.</dd>
written in any combination of upper and lower-case letters. For example, the	<dt>material between brackets</dt>
keyword <tt>DEFPRES</tt> of S can also be written as <tt>defpres</tt> or	<dd>(`[' and `]') is optional;</dd>
<tt>DefPres</tt>.	<dt>material between angle brackets</dt>
</dd>	<dd>(`<' and `>') can be repeated many times or omitted;</dd>
<dt>material between brackets</dt>	<dt>the slash</dt>
<dd>	<dd>(`/') indicates an alternative, a choice between the options separated
(`[' and `]') is optional;	by the slash character;</dd>
</dd>	<dt>the period</dt>
<dt>material between angle brackets</dt>	<dd>marks the end of a rule;</dd>
<dd>	<dt>text between braces</dt>
(`<' and `>') can be repeated many times or omitted;	<dd>(`{' and `}') is simply a comment.</dd>
</dd>
<dt>the slash</dt>
<dd>
(`/') indicates an alternative, a choice between the options separated by the
slash character;
</dd>
<dt>the period</dt>
<dd>
marks the end of a rule;
</dd>
<dt>text between braces</dt>
<dd>
(`{' and `}') is simply a comment.
</dd>
</dl>	</dl>
<p>
The M meta-language also uses the concepts of identifiers, strings, and	<p>The M meta-language also uses the concepts of identifiers, strings, and
integers:</p>	integers:</p>
<dl>	<dl>
<dt><tt>NAME</tt></dt>	<dt><tt>NAME</tt></dt>
<dd>	<dd>represents an identifier, a sequence of letters (upper or lower-case),
represents an identifier, a sequence of letters (upper or lower-case), digits,	digits, and underline characters (`_'), beginning with a letter. Also
and underline characters (`_'), beginning with a letter. Also considered a	considered a letter is the sequence of characters `<tt>\nnn</tt>' where
letter is the sequence of characters `<tt>\nnn</tt>' where the letter	the letter <tt>n</tt> represents the ISO Latin-1 code of the letter in
<tt>n</tt> represents the ISO Latin-1 code of the letter in octal. It is thus	octal. It is thus possible to use accented letters in identifiers. The
possible to use accented letters in identifiers. The maximum length of	maximum length of identifiers is fixed by the compiler. It is normally
identifiers is fixed by the compiler. It is normally 31 characters.	31 characters.
<p>	<p>Unlike keywords, upper and lower-case letters are distinct in
Unlike keywords, upper and lower-case letters are distinct in identifiers.	identifiers. Thus, <tt>Title</tt>, <tt>TITLE</tt>, and <tt>title</tt>
Thus, <tt>Title</tt>, <tt>TITLE</tt>, and <tt>title</tt> are considered	are considered different identifiers.</p>
different identifiers.</p>	</dd>
</dd>	<dt><tt>STRING</tt></dt>
<dt><tt>STRING</tt></dt>	<dd>represents a string. This is a string of characters delimited by
<dd>	apostrophes. If an apostrophe must appear in a string, it is doubled.
represents a string. This is a string of characters delimited by apostrophes.	As with identifiers, strings can contain characters represented by their
If an apostrophe must appear in a string, it is doubled. As with identifiers,	octal code (after a backslash). As with apostrophes, if a backslash
strings can contain characters represented by their octal code (after a	must appear in a string, it is doubled.</dd>
backslash). As with apostrophes, if a backslash must appear in a string, it	<dt><tt>NUMBER</tt></dt>
is doubled.	<dd>represents a positive integer or zero (without a sign), or said
</dd>	another way, a sequence of decimal digits.</dd>
<dt><tt>NUMBER</tt></dt>
<dd>
represents a positive integer or zero (without a sign), or said another way, a
sequence of decimal digits.
</dd>
</dl>	</dl>
<p>
The M language can be used to define itself as follows:</p>	<p>The M language can be used to define itself as follows:</p>
<pre>{ Any text between braces is a comment. }	<pre>{ Any text between braces is a comment. }
Grammar = Rule < Rule > 'END' .	Grammar = Rule < Rule > 'END' .
{ The < and > signs indicate zero }	{ The < and > signs indicate zero }
{ or more repetitions. }	{ or more repetitions. }
{ END marks the end of the grammar. }	{ END marks the end of the grammar. }
Rule = Ident '=' RightPart '.' .	Rule = Ident '=' RightPart '.' .
Line 1508 RightPart = RtTerminal / RtIntermed .	Line 1179 RightPart = RtTerminal / RtIntermed .
{ The slash indicates a choice }	{ The slash indicates a choice }
RtTerminal ='NAME' / 'STRING' / 'NUMBER' .	RtTerminal ='NAME' / 'STRING' / 'NUMBER' .
{ Right part of a terminal rule }	{ Right part of a terminal rule }
RtIntermed = Possibility < '/' Possibility > .	RtIntermed = Possibility < '/' Possibility > .
{ Right part of an intermediate rule }	{ Right part of an intermediate rule }
Possibility = ElemOpt < ElemOpt > .	Possibility = ElemOpt < ElemOpt > .
ElemOpt = Element / '[' Element < Element > ']' /	ElemOpt = Element / '[' Element < Element > ']' /
'<' Element < Element > '>' .	'<' Element < Element > '>' .
{ Brackets delimit optional parts }	{ Brackets delimit optional parts }
Element = Ident / KeyWord .	Element = Ident / KeyWord .
Ident = NAME .	Ident = NAME .
Line 1523 END</pre>	Line 1194 END</pre>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc322">Extension schemas</a></h3>	<h3><a name="sectc322">Extension schemas</a></h3>
<p>
A structure schema defines the generic logical structure of a class of	<p>A structure schema defines the generic logical structure of a class of
documents or objects, independent of the operations which can be performed on	documents or objects, independent of the operations which can be performed on
the documents. However, certain applications may require particular	the documents. However, certain applications may require particular
information to be represented by the structure for the documents that they	information to be represented by the structure for the documents that they
Line 1534 operate on. Thus a document version man	Line 1204 operate on. Thus a document version man
document the parts which belong to one version or another. An indexing system	document the parts which belong to one version or another. An indexing system
will add highly-structured index tables as well as the links between these	will add highly-structured index tables as well as the links between these
tables and the rest of the document.</p>	tables and the rest of the document.</p>
<p>
Thus, many applications need to extend the generic structure of the documents	<p>Thus, many applications need to extend the generic structure of the
on which they operate to introduce new attributes, associated elements or	documents on which they operate to introduce new attributes, associated
element types. These additions are specific to each application and must be	elements or element types. These additions are specific to each application
able to be applied to any generic structure: users will want to manage	and must be able to be applied to any generic structure: users will want to
versions or construct indices for many types of documents. Extension schemas	manage versions or construct indices for many types of documents. Extension
fulfill this role: they define attributes, elements, associated elements,	schemas fulfill this role: they define attributes, elements, associated
units, etc., but they can only be used jointly with a structure schema that	elements, units, etc., but they can only be used jointly with a structure
they complete. Otherwise, structure schemas can always be used without these	schema that they complete. Otherwise, structure schemas can always be used
extensions when the corresponding applications are not available.</p>	without these extensions when the corresponding applications are not
	available.</p>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc323">The general organization of structure schemas</a></h3>	<h3><a name="sectc323">The general organization of structure schemas</a></h3>
<p>
Every structure schema begins with the keyword <tt>STRUCTURE</tt> and ends	<p>Every structure schema begins with the keyword <tt>STRUCTURE</tt> and ends
with the keyword <tt>END</tt>. The keyword <tt>STRUCTURE</tt> is followed by	with the keyword <tt>END</tt>. The keyword <tt>STRUCTURE</tt> is followed by
the keyword <tt>EXTENSION</tt> in the case where the schema defines an	the keyword <tt>EXTENSION</tt> in the case where the schema defines an
extension, then by the name of the generic structure which the schema defines	extension, then by the name of the generic structure which the schema defines
(the name of the document or object class). The name of the structure is	(the name of the document or object class). The name of the structure is
followed by a semicolon.</p>	followed by a semicolon.</p>
<p>
In the case of a complete schema (that is, a schema which is not an	<p>In the case of a complete schema (that is, a schema which is not an
extension), the definition of the name of the structure is followed by the	extension), the definition of the name of the structure is followed by the
declarations of the default presentation schema, the global attributes, the	declarations of the default presentation schema, the global attributes, the
parameters, the structure rules, the associated elements, the units, the	parameters, the structure rules, the associated elements, the units, the
Line 1565 skeleton elements and the exceptions. O	Line 1235 skeleton elements and the exceptions. O
rules is required. Each series of declarations begins with a keyword:	rules is required. Each series of declarations begins with a keyword:
<tt>DEFPRES</tt>, <tt>ATTR</tt>, <tt>PARAM</tt>, <tt>STRUCT</tt>,	<tt>DEFPRES</tt>, <tt>ATTR</tt>, <tt>PARAM</tt>, <tt>STRUCT</tt>,
<tt>ASSOC</tt>, <tt>UNITS</tt>, <tt>EXPORT</tt>, <tt>EXCEPT</tt>.</p>	<tt>ASSOC</tt>, <tt>UNITS</tt>, <tt>EXPORT</tt>, <tt>EXCEPT</tt>.</p>
<p>
In the case of an extension schema, there are neither parameters nor skeleton	<p>In the case of an extension schema, there are neither parameters nor
elements and the <tt>STRUCT</tt> section is optional, while that section is	skeleton elements and the <tt>STRUCT</tt> section is optional, while that
required in a schema that is not an extension. On the other hand, extension	section is required in a schema that is not an extension. On the other hand,
schemas can contain an <tt>EXTENS</tt> section, which must not appear in a	extension schemas can contain an <tt>EXTENS</tt> section, which must not
schema which is not an extension; this section defines the complements to	appear in a schema which is not an extension; this section defines the
attach to the rules found in the schema to which the extension will be added.	complements to attach to the rules found in the schema to which the extension
The sections <tt>ATTR</tt>, <tt>STRUCT</tt>, <tt>ASSOC</tt>, and	will be added. The sections <tt>ATTR</tt>, <tt>STRUCT</tt>, <tt>ASSOC</tt>,
<tt>UNITS</tt> define new attributes, new elements, new associated elements,	and <tt>UNITS</tt> define new attributes, new elements, new associated
and new units which add their definitions to the principal schema.</p>	elements, and new units which add their definitions to the principal
	schema.</p>
<pre> StructSchema ='STRUCTURE' ElemID ';'	<pre> StructSchema ='STRUCTURE' ElemID ';'
'DEFPRES' PresID ';'	'DEFPRES' PresID ';'
[ 'ATTR' AttrSeq ]	[ 'ATTR' AttrSeq ]
Line 1586 and new units which add their definition	Line 1257 and new units which add their definition
[ 'EXCEPT' ExceptSeq ]	[ 'EXCEPT' ExceptSeq ]
'END' .	'END' .
ElemID = NAME .</pre>	ElemID = NAME .</pre>
<p>
or</p>	<p>or</p>
<pre> ExtensSchema ='STRUCTURE' 'EXTENSION' ElemID ';'	<pre> ExtensSchema ='STRUCTURE' 'EXTENSION' ElemID ';'
'DEFPRES' PresID ';'	'DEFPRES' PresID ';'
[ 'ATTR' AttrSeq ]	[ 'ATTR' AttrSeq ]
Line 1601 or</p>	Line 1272 or</p>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc324">The default presentation</a></h3>	<h3><a name="sectc324">The default presentation</a></h3>
<p>
It was shown <a href="#mulpres">above</a> that many different presentations	<p>It was shown <a href="#mulpres">above</a> that many different presentations
are possible for documents and objects of the same class. The structure	are possible for documents and objects of the same class. The structure
schema defines a preferred presentation for the class, called the <em>default	schema defines a preferred presentation for the class, called the <em>default
presentation</em>. Like generic structures, presentations are described by	presentation</em>. Like generic structures, presentations are described by
Line 1618 another if s/he wishes.</p>	Line 1288 another if s/he wishes.</p>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc325">Global Attributes</a></h3>	<h3><a name="sectc325">Global Attributes</a></h3>
<p>
If the generic structure includes global attributes of its own, they are	<p>If the generic structure includes global attributes of its own, they are
declared after the keyword <tt>ATTR</tt>. Each global attribute is defined by	declared after the keyword <tt>ATTR</tt>. Each global attribute is defined by
its name, followed by an equals sign and the definition of its type. The	its name, followed by an equals sign and the definition of its type. The
declaration of a global attribute is terminated by a semi-colon.</p>	declaration of a global attribute is terminated by a semi-colon.</p>
<p>
For attributes of the numeric, textual, or reference types, the type is	<p>For attributes of the numeric, textual, or reference types, the type is
indicated by a keyword, <tt>INTEGER</tt>, <tt>TEXT</tt>, or <tt>REFERENCE</tt>	indicated by a keyword, <tt>INTEGER</tt>, <tt>TEXT</tt>, or <tt>REFERENCE</tt>
respectively.</p>	respectively.</p>
<p>
In the case of a reference attribute, the keyword <tt>REFERENCE</tt> is	<p>In the case of a reference attribute, the keyword <tt>REFERENCE</tt> is
followed by the type of the referenced element in parentheses. It can refer	followed by the type of the referenced element in parentheses. It can refer
to any type at all, specified by using the keyword <tt>ANY</tt>, or to a	to any type at all, specified by using the keyword <tt>ANY</tt>, or to a
specific type. In the latter case, the element type designated by the	specific type. In the latter case, the element type designated by the
Line 1644 the case where the type is defined as <a	Line 1313 the case where the type is defined as <a
keywords indicate whether the attribute must designate the first mark of the	keywords indicate whether the attribute must designate the first mark of the
pair or the second. If the reference refers to a pair and neither of these	pair or the second. If the reference refers to a pair and neither of these
two keywords is present, then the first mark is used.</p>	two keywords is present, then the first mark is used.</p>
<p>
In the case of an enumeration attribute, the equals sign is followed by the	<p>In the case of an enumeration attribute, the equals sign is followed by the
list of names representing the possible values of the attribute, the names	list of names representing the possible values of the attribute, the names
being separated from each other by commas. An enumeration attribute has at	being separated from each other by commas. An enumeration attribute has at
least one possible value; the maximum number of values is defined by the	least one possible value; the maximum number of values is defined by the
compiler for the S language.</p>	compiler for the S language.</p>
<pre> AttrSeq = Attribute < Attribute > .	<pre> AttrSeq = Attribute < Attribute > .
Attribute = AttrID '=' AttrType ';' .	Attribute = AttrID '=' AttrType ';' .
AttrType = 'INTEGER' / 'TEXT' /	AttrType = 'INTEGER' / 'TEXT' /
'REFERENCE' '(' RefType ')' /	'REFERENCE' '(' RefType ')' /
Line 1658 compiler for the S language.</p>	Line 1327 compiler for the S language.</p>
RefType = 'ANY' / [ FirstSec ] ElemID [ ExtStruct ] .	RefType = 'ANY' / [ FirstSec ] ElemID [ ExtStruct ] .
FirstSec = 'First' / 'Second' .	FirstSec = 'First' / 'Second' .
ExtStruct = '(' ElemID ')' .	ExtStruct = '(' ElemID ')' .
ValueSeq = AttrVal < ',' AttrVal > .	ValueSeq = AttrVal < ',' AttrVal > .
AttrID = NAME .	AttrID = NAME .
AttrVal = NAME .</pre>	AttrVal = NAME .</pre>
<p>
There is a predefined global text attribute, the <em>language</em>, which is	<p>There is a predefined global text attribute, the <em>language</em>, which
automatically added to every Thot structure schema. This attribute allows	is automatically added to every Thot structure schema. This attribute allows
Thot to perform certain actions, such as hyphenation and spell-checking, which	Thot to perform certain actions, such as hyphenation and spell-checking, which
cannot be performed without knowing the language in which each part of the	cannot be performed without knowing the language in which each part of the
document is written. This attribute can be used just like any explicitly	document is written. This attribute can be used just like any explicitly
declared attribute: the system acts as if every structure schema contains</p>	declared attribute: the system acts as if every structure schema contains</p>
<pre>ATTR	<pre>ATTR
Language = TEXT;</pre>	Language = TEXT;</pre>

<blockquote class="example">	<blockquote class="example">
<p>	<p><strong>Example:</strong></p>
<strong>Example:</strong></p>
<p>	<p>The following specification defines the global enumeration attribute
The following specification defines the global enumeration attribute	WordType.</p>
WordType.</p>	<pre>ATTR
<pre>ATTR
WordType = Definition, IndexWord, DocumentTitle;</pre>	WordType = Definition, IndexWord, DocumentTitle;</pre>
</blockquote>	</blockquote>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc326">Parameters</a></h3>	<h3><a name="sectc326">Parameters</a></h3>
<p>
A parameter is a document element which can appear many times in the document,	<p>A parameter is a document element which can appear many times in the
but always has the same value. This value can only be modified in a	document, but always has the same value. This value can only be modified in a
controlled way by certain applications. For example, in an advertising	controlled way by certain applications. For example, in an advertising
circular, the name of the recipient may appear in the address part and in the	circular, the name of the recipient may appear in the address part and in the
text of the circular. If the recipient's name were a parameter, it might only	text of the circular. If the recipient's name were a parameter, it might only
be able to be changed by a ``mail-merge'' application.</p>	be able to be changed by a ``mail-merge'' application.</p>
<p>
Parameters are not needed for every document class, but if the schema includes	<p>Parameters are not needed for every document class, but if the schema
parameters they are declared after the keyword <tt>PARAM</tt>. Each parameter	includes parameters they are declared after the keyword <tt>PARAM</tt>. Each
declaration is made in the same way as a <a href="#sectc327">structure element	parameter declaration is made in the same way as a <a
declaration</a>.</p>	href="#sectc327">structure element declaration</a>.</p>
<p>
During editing, Thot permits the insertion of parameters wherever the	<p>During editing, Thot permits the insertion of parameters wherever the
structure schema allows; it also permits the removal of parameters which are	structure schema allows; it also permits the removal of parameters which are
already in the document but does not allow the modification of the parameter's	already in the document but does not allow the modification of the parameter's
content in any way. The content is generated automatically by Thot during the	content in any way. The content is generated automatically by Thot during the
Line 1706 document.</p>	Line 1374 document.</p>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc327">Structured elements</a></h3>	<h3><a name="sectc327">Structured elements</a></h3>
<p>
The rules for defining structured elements are required, except in an	<p>The rules for defining structured elements are required, except in an
extension schema: they constitute the core of a structure schema, since they	extension schema: they constitute the core of a structure schema, since they
define the structure of the different types of elements that occur in a	define the structure of the different types of elements that occur in a
document or object of the class defined by the schema.</p>	document or object of the class defined by the schema.</p>
<p>
The first structure rule after the keyword <tt>STRUCT</tt> must define the	<p>The first structure rule after the keyword <tt>STRUCT</tt> must define the
structure of the class whose name appears in the first instruction	structure of the class whose name appears in the first instruction
(<tt>STRUCTURE</tt>) of the schema. This is the root rule of the schema,	(<tt>STRUCTURE</tt>) of the schema. This is the root rule of the schema,
defining the root of the document tree or object tree.</p>	defining the root of the document tree or object tree.</p>
<p>
The remaining rules may be placed in any order, since the language permits the	<p>The remaining rules may be placed in any order, since the language permits
definition of element types before or after their use, or even in the same	the definition of element types before or after their use, or even in the same
instruction in which they are used. This last case allows the definition of	instruction in which they are used. This last case allows the definition of
recursive structures.</p>	recursive structures.</p>
<p>
Each rule is composed of a name (the name of the element type whose structure	<p>Each rule is composed of a name (the name of the element type whose
is being defined) followed by an equals sign and a structure definition.</p>	structure is being defined) followed by an equals sign and a structure
<p>	definition.</p>
If any local attributes are associated with the element type defined by the
	<p>If any local attributes are associated with the element type defined by the
rule, they appear between parentheses after the type name and before the	rule, they appear between parentheses after the type name and before the
equals sign. The parentheses contain, first, the keyword <tt>ATTR</tt>, then	equals sign. The parentheses contain, first, the keyword <tt>ATTR</tt>, then
the list of local attributes, separated by commas. Each local attribute is	the list of local attributes, separated by commas. Each local attribute is
Line 1740 can be defined as a local attribute for	Line 1408 can be defined as a local attribute for
case, the equals sign and definition of the attribute type need only appear in	case, the equals sign and definition of the attribute type need only appear in
the first occurrence of the attribute. It should be noted that global	the first occurrence of the attribute. It should be noted that global
attributes cannot also be defined as local attributes.</p>	attributes cannot also be defined as local attributes.</p>
<p>
If any <a href="#sectd3135">extensions</a> are defined for this element type,	<p>If any <a href="#sectd3135">extensions</a> are defined for this element
a plus sign follows the structure definition and the names of the extension	type, a plus sign follows the structure definition and the names of the
element types appear between parentheses after the plus. If there are	extension element types appear between parentheses after the plus. If there
multiple extensions, they are separated by commas. These types can either be	are multiple extensions, they are separated by commas. These types can either
defined in the same schema, defined in other schemas, or they may be base	be defined in the same schema, defined in other schemas, or they may be base
types identified by the keywords <tt>TEXT</tt>, <tt>GRAPHICS</tt>,	types identified by the keywords <tt>TEXT</tt>, <tt>GRAPHICS</tt>,
<tt>SYMBOL</tt>, or <tt>PICTURE</tt>.</p>	<tt>SYMBOL</tt>, or <tt>PICTURE</tt>.</p>
<p>
<a href="#sectd3135">Restrictions</a> are indicated in the same manner as	<p><a href="#sectd3135">Restrictions</a> are indicated in the same manner as
extensions, but they are introduced by a minus sign and they come after the	extensions, but they are introduced by a minus sign and they come after the
extensions, or if there are no extensions, after the structure definition.</p>	extensions, or if there are no extensions, after the structure definition.</p>
<p>
If the values of attributes must be attached systematically to this element	<p>If the values of attributes must be attached systematically to this element
type, they are introduced by the keyword <tt>WITH</tt> and declared in the	type, they are introduced by the keyword <tt>WITH</tt> and declared in the
form of a list of fixed-value attributes. When such definitions of fixed	form of a list of fixed-value attributes. When such definitions of fixed
attribute values appear, they are always the last part of the rule.</p>	attribute values appear, they are always the last part of the rule.</p>
<p>
The rule is terminated by a semicolon.</p>	<p>The rule is terminated by a semicolon.</p>
<pre> RuleSeq = Rule < Rule > .	<pre> RuleSeq = Rule < Rule > .
Rule = ElemID [ LocAttrSeq ] '=' DefWithAttr ';'.	Rule = ElemID [ LocAttrSeq ] '=' DefWithAttr ';'.
LocAttrSeq = '(' 'ATTR' LocAttr < ';' LocAttr > ')' .	LocAttrSeq = '(' 'ATTR' LocAttr < ';' LocAttr > ')' .
LocAttr = [ '!' ] AttrID [ '=' AttrType ] .	LocAttr = [ '!' ] AttrID [ '=' AttrType ] .
DefWithAttr = Definition	DefWithAttr = Definition
[ '+' '(' ExtensionSeq ')' ]	[ '+' '(' ExtensionSeq ')' ]
[ '-' '(' RestrictSeq ')' ]	[ '-' '(' RestrictSeq ')' ]
[ 'WITH' FixedAttrSeq ] .	[ 'WITH' FixedAttrSeq ] .
ExtensionSeq = ExtensionElem < ',' ExtensionElem > .	ExtensionSeq = ExtensionElem < ',' ExtensionElem > .
ExtensionElem = ElemID / 'TEXT' / 'GRAPHICS' /	ExtensionElem = ElemID / 'TEXT' / 'GRAPHICS' /
'SYMBOL' / 'PICTURE' .	'SYMBOL' / 'PICTURE' .
RestrictSeq = RestrictElem < ',' RestrictElem > .	RestrictSeq = RestrictElem < ',' RestrictElem > .
RestrictElem = ElemID / 'TEXT' / 'GRAPHICS' /	RestrictElem = ElemID / 'TEXT' / 'GRAPHICS' /
'SYMBOL' / 'PICTURE' .</pre>	'SYMBOL' / 'PICTURE' .</pre>
<p>
The list of fixed-value attributes is composed of a sequence of	<p>The list of fixed-value attributes is composed of a sequence of
attribute-value pairs separated by commas. Each pair contains the name of the	attribute-value pairs separated by commas. Each pair contains the name of the
attribute and the fixed value for this element type, the two being separated	attribute and the fixed value for this element type, the two being separated
by an equals sign. If the sign is preceded by a question mark the given value	by an equals sign. If the sign is preceded by a question mark the given value
Line 1785 appears this indicates that this element	Line 1453 appears this indicates that this element
attribute. For the other attribute types, the fixed value is indicated by a	attribute. For the other attribute types, the fixed value is indicated by a
signed integer (numeric attributes), a character string between apostrophes	signed integer (numeric attributes), a character string between apostrophes
(textual attributes) or the name of a value (enumeration attributes).</p>	(textual attributes) or the name of a value (enumeration attributes).</p>
<p>
Fixed-value attributes can either be <a href="#sectc325">global</a> or local	<p>Fixed-value attributes can either be <a href="#sectc325">global</a> or
to the element type for which they are fixed, but they must be declared before	local to the element type for which they are fixed, but they must be declared
they are used.</p>	before they are used.</p>
<pre> FixedAttrSeq = FixedAttr < ',' FixedAttr > .	<pre> FixedAttrSeq = FixedAttr < ',' FixedAttr > .
FixedAttr = AttrID [ FixedOrModifVal ] .	FixedAttr = AttrID [ FixedOrModifVal ] .
FixedOrModifVal = [ '?' ] '=' FixedValue .	FixedOrModifVal = [ '?' ] '=' FixedValue .
FixedValue = [ '-' ] NumValue / TextVal / AttrVal .	FixedValue = [ '-' ] NumValue / TextVal / AttrVal .
Line 1798 they are used.</p>	Line 1466 they are used.</p>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc328">Structure definitions</a></h3>	<h3><a name="sectc328">Structure definitions</a></h3>
<p>
The structure of an element type can be a simple base type or a constructed	<p>The structure of an element type can be a simple base type or a constructed
type.</p>	type.</p>
<p>
For constructed types, it is frequently the case that similar structures	<p>For constructed types, it is frequently the case that similar structures
appear in many places in a document. For example the contents of the	appear in many places in a document. For example the contents of the
abstract, of the introduction, and of a section can have the same structure,	abstract, of the introduction, and of a section can have the same structure,
that of a sequence of paragraphs. In this case, a single, common structure	that of a sequence of paragraphs. In this case, a single, common structure
Line 1814 follows:</p>	Line 1481 follows:</p>
<pre> Abstract = Paragraph_sequence;	<pre> Abstract = Paragraph_sequence;
Introduction = Paragraph_sequence;	Introduction = Paragraph_sequence;
Section_contents = Paragraph_sequence;</pre>	Section_contents = Paragraph_sequence;</pre>
<p>
The equals sign means ``has the same structure as''.</p>	<p>The equals sign means ``has the same structure as''.</p>
<p>
If the element type defined is a simple base type, this is indicated by one of	<p>If the element type defined is a simple base type, this is indicated by one
the keywords <tt>TEXT</tt>, <tt>GRAPHICS</tt>, <tt>SYMBOL</tt>, or	of the keywords <tt>TEXT</tt>, <tt>GRAPHICS</tt>, <tt>SYMBOL</tt>, or
<tt>PICTURE</tt>. If some local attributes must be associated with a base	<tt>PICTURE</tt>. If some local attributes must be associated with a base
type, the keyword of the base type is followed by the declaration of the local	type, the keyword of the base type is followed by the declaration of the local
attributes using the syntax <a href="#sectc327">presented above.</a></p>	attributes using the syntax <a href="#sectc327">presented above.</a></p>
<p>
In the case of an open choice, the type is indicated by the keyword	<p>In the case of an open choice, the type is indicated by the keyword
<tt>UNIT</tt> for units or the keyword <tt>NATURE</tt> for objects having a	<tt>UNIT</tt> for units or the keyword <tt>NATURE</tt> for objects having a
structure defined by any other schema.</p>	structure defined by any other schema.</p>
<p>
A unit represents one of the two following categories:</p>	<p>A unit represents one of the two following categories:</p>
<ul>	<ul>
<li>	<li>a base type: text, graphical element, symbol, picture,</li>
a base type: text, graphical element, symbol, picture,	<li>an element whose type is chosen from among the types defined as units in
</li>	the <tt>UNITS</tt> section of the document's structure schema. It can
<li>	also be chosen from among the types defined as <a
an element whose type is chosen from among the types defined as units in the	href="#sectd3132">units</a> in the <a href="#sectc3212"><tt>UNITS</tt>
<tt>UNITS</tt> section of the document's structure schema. It can also be	section</a> of the structure schemas that defines the ancestors of the
chosen from among the types defined as <a href="#sectd3132">units</a> in the	element to which the rule is applied.</li>
<a href="#sectc3212"><tt>UNITS</tt> section</a> of the structure schemas that
defines the ancestors of the element to which the rule is applied.
</li>
</ul>	</ul>
<p>
Before the creation of an element defined as a unit, Thot asks the user to	<p>Before the creation of an element defined as a unit, Thot asks the user to
choose between the categories of elements.</p>	choose between the categories of elements.</p>
<p>
Thus, the contents of a paragraph can be specified as a sequence of units,	<p>Thus, the contents of a paragraph can be specified as a sequence of units,
which will permit the inclusion in the paragraphs of character strings,	which will permit the inclusion in the paragraphs of character strings,
symbols, and various elements, such as cross-references, if these are defined	symbols, and various elements, such as cross-references, if these are defined
as units.</p>	as units.</p>
<p>
A schema object (keyword <tt>NATURE</tt>) represents an object defined by a	<p>A schema object (keyword <tt>NATURE</tt>) represents an object defined by a
structure schema freely chosen from among the available schemas; in the case	structure schema freely chosen from among the available schemas; in the case
the element type is defined by the first rule (the root rule) of the chosen	the element type is defined by the first rule (the root rule) of the chosen
schema.</p>	schema.</p>
<p>
If the element type defined is a constructed type, the list, aggregate,	<p>If the element type defined is a constructed type, the list, aggregate,
choice, and reference constructors are used. In this case the definition	choice, and reference constructors are used. In this case the definition
begins with a keyword identifying the constructor. This keyword is followed	begins with a keyword identifying the constructor. This keyword is followed
by a syntax specific to each constructor.</p>	by a syntax specific to each constructor.</p>
<p>
The local attribute definitions appear after the name of the element type	<p>The local attribute definitions appear after the name of the element type
being defined, if this element type has <a href="#sectc327">local	being defined, if this element type has <a href="#sectc327">local
attributes</a>.</p>	attributes</a>.</p>
<pre> Definition = BaseType [ LocAttrSeq ] / Constr / Element .	<pre> Definition = BaseType [ LocAttrSeq ] / Constr / Element .
Line 1877 attributes</a>.</p>	Line 1541 attributes</a>.</p>
'PAIR' .</pre>	'PAIR' .</pre>

<div class="subsubsection">	<div class="subsubsection">

<h4><a name="sectd3281">List</a></h4>	<h4><a name="sectd3281">List</a></h4>
<p>
The list constructor permits the definition of an element type composed of a	<p>The list constructor permits the definition of an element type composed of
list of elements, all of the same type. A list definition begins with the	a list of elements, all of the same type. A list definition begins with the
<tt>LIST</tt> keyword followed by an optional range, the keyword <tt>OF</tt>,	<tt>LIST</tt> keyword followed by an optional range, the keyword <tt>OF</tt>,
and the definition, between parentheses, of the element type which must	and the definition, between parentheses, of the element type which must
compose the list. The optional range is composed of the minimum and maximum	compose the list. The optional range is composed of the minimum and maximum
Line 1896 to specify any bound.</p>	Line 1559 to specify any bound.</p>
min = Integer / '*' .	min = Integer / '*' .
max = Integer / '*' .	max = Integer / '*' .
Integer = NUMBER .</pre>	Integer = NUMBER .</pre>
<p>
Before the document is edited, Thot creates the minimum number of elements for	<p>Before the document is edited, Thot creates the minimum number of elements
the list. If no minimum was given, it creates a single element. If a maximum	for the list. If no minimum was given, it creates a single element. If a
number of elements is given and that number is attained, the editor refuses to	maximum number of elements is given and that number is attained, the editor
create new elements for the list.</p>	refuses to create new elements for the list.</p>
<blockquote class="example">
<p>	<blockquote class="example">
<strong>Example:</strong></p>	<p><strong>Example:</strong></p>
<p>
The following two instructions define the body of a document as a sequence of	<p>The following two instructions define the body of a document as a
at least two chapters and the contents of a section as a sequence of	sequence of at least two chapters and the contents of a section as a
paragraphs. A single paragraph can be the entire contents of a section.</p>	sequence of paragraphs. A single paragraph can be the entire contents of a
<pre>Body = LIST [2..*] OF (Chapter);	section.</p>
	<pre>Body = LIST [2..*] OF (Chapter);
Section_contents = LIST OF (Paragraph);</pre>	Section_contents = LIST OF (Paragraph);</pre>
</blockquote>	</blockquote>
</div>	</div>

<div class="subsubsection">	<div class="subsubsection">

<h4><a name="sectd3282">Aggregate</a></h4>	<h4><a name="sectd3282">Aggregate</a></h4>
<p>
The aggregate constructor is used to define an element type as a collection of	<p>The aggregate constructor is used to define an element type as a collection
sub-elements, each having a fixed type. The collection may be ordered or	of sub-elements, each having a fixed type. The collection may be ordered or
unordered. The elements composing the collection are called	unordered. The elements composing the collection are called
<em>components</em>. In the definition of an aggregate, a keyword indicates	<em>components</em>. In the definition of an aggregate, a keyword indicates
whether or not the aggregate is ordered: <tt>BEGIN</tt> for an ordered	whether or not the aggregate is ordered: <tt>BEGIN</tt> for an ordered
Line 1926 aggregate, <tt>AGGREGATE</tt> for an uno	Line 1589 aggregate, <tt>AGGREGATE</tt> for an uno
followed by the list of component type definitions which is terminated by the	followed by the list of component type definitions which is terminated by the
<tt>END</tt> keyword. The component type definitions are separated by	<tt>END</tt> keyword. The component type definitions are separated by
commas.</p>	commas.</p>
<p>
Before creating an aggregate, the Thot editor creates all the aggregate's	<p>Before creating an aggregate, the Thot editor creates all the aggregate's
components in the order they appear in the structure schema, even for	components in the order they appear in the structure schema, even for
unordered aggregates. However, unlike ordered aggregates, the components of	unordered aggregates. However, unlike ordered aggregates, the components of
an unordered aggregate may be rearranged using operations of the Thot editor.	an unordered aggregate may be rearranged using operations of the Thot editor.
Line 1937 created by explicit request, possibly at	Line 1600 created by explicit request, possibly at
but they are not created automatically <em>prior</em> to the creation of the	but they are not created automatically <em>prior</em> to the creation of the
aggregate.</p>	aggregate.</p>
<pre> 'BEGIN' DefOptSeq 'END'	<pre> 'BEGIN' DefOptSeq 'END'
DefOptSeq = DefOpt ';' < DefOpt ';' > .	DefOptSeq = DefOpt ';' < DefOpt ';' > .
DefOpt = [ '?' ] DefWithAttr .</pre>	DefOpt = [ '?' ] DefWithAttr .</pre>

<blockquote class="example">	<blockquote class="example">
<p>	<p><strong>Example:</strong></p>
<strong>Example:</strong></p>
<p>	<p>In a bilingual document, each paragraph has an English version and a
In a bilingual document, each paragraph has an English version and a French	French version. In certain cases, the translator wants to add a marginal
version. In certain cases, the translator wants to add a marginal note, but	note, but this note is present in very few paragraphs. Thus, it must not be
this note is present in very few paragraphs. Thus, it must not be created	created systematically for every paragraph. A bilingual paragraph of this
systematically for every paragraph. A bilingual paragraph of this type is	type is declared:</p>
declared:</p>	<pre>Bilingual_paragraph = BEGIN
<pre>Bilingual_paragraph = BEGIN
French_paragraph = TEXT;	French_paragraph = TEXT;
English_paragraph = TEXT;	English_paragraph = TEXT;
? Note = TEXT;	? Note = TEXT;
Line 1957 declared:</p>	Line 1620 declared:</p>
</div>	</div>

<div class="subsubsection">	<div class="subsubsection">

<h4><a name="sectd3283">Choice</a></h4>	<h4><a name="sectd3283">Choice</a></h4>
<p>
The choice constructor permits the definition of an element type which is	<p>The choice constructor permits the definition of an element type which is
chosen from among a set of possible types. The keywords <tt>CASE</tt> and	chosen from among a set of possible types. The keywords <tt>CASE</tt> and
<tt>OF</tt> are followed by a list of definitions of possible types, which are	<tt>OF</tt> are followed by a list of definitions of possible types, which are
separated by semicolons and terminated by the <tt>END</tt> keyword.</p>	separated by semicolons and terminated by the <tt>END</tt> keyword.</p>
<pre> 'CASE' 'OF' DefSeq 'END'	<pre> 'CASE' 'OF' DefSeq 'END'
DefSeq = DefWithAttr ';' < DefWithAttr ';' > .</pre>	DefSeq = DefWithAttr ';' < DefWithAttr ';' > .</pre>
<p>
Before the creation of an element defined as a choice, the Thot editor	<p>Before the creation of an element defined as a choice, the Thot editor
presents the list of possible types for the element to the user. The user has	presents the list of possible types for the element to the user. The user has
only to select the element type that s/he wants to create from this list.</p>	only to select the element type that s/he wants to create from this list.</p>
<p>
The order of the type declarations is important. It determines the order of	<p>The order of the type declarations is important. It determines the order
the list presented to the user before the creation of the element. Also, when	of the list presented to the user before the creation of the element. Also,
a Choice element is being created automatically, the first type in the list is	when a Choice element is being created automatically, the first type in the
used. In fact, using the Thot editor, when an empty Choice element is	list is used. In fact, using the Thot editor, when an empty Choice element is
selected, it is possible to select this element and to enter its text from	selected, it is possible to select this element and to enter its text from
keyboard. In this case, the editor uses the first element type which can	keyboard. In this case, the editor uses the first element type which can
contain an atom of the character string type.</p>	contain an atom of the character string type.</p>
<p>
The two special cases of the choice constructor, the <a	<p>The two special cases of the choice constructor, the <a
href="#sectc328"><em>schema</em></a> and the <a	href="#sectc328"><em>schema</em></a> and the <a
href="#sectc3212"><em>unit</em></a> are discussed elsewhere.</p>	href="#sectc3212"><em>unit</em></a> are discussed elsewhere.</p>

<blockquote class="example">	<blockquote class="example">
<p>	<p><strong>Example:</strong></p>
<strong>Example:</strong></p>
<p>	<p>It is common in documents to treat a variety of objects as if they were
It is common in documents to treat a variety of objects as if they were	ordinary paragraphs. Thus, a ``Paragraph'' might actually be composed of a
ordinary paragraphs. Thus, a ``Paragraph'' might actually be composed of a	block of text (an ordinary paragraph), or a mathematical formula whose
block of text (an ordinary paragraph), or a mathematical formula whose	structure is defined by another structure schema named Math, or a table,
structure is defined by another structure schema named Math, or a table, also	also defined by another structure schema. Here is a definition of such a
defined by another structure schema. Here is a definition of such a	paragraph:</p>
paragraph:</p>	<pre>Paragraph = CASE OF
<pre>Paragraph = CASE OF
Simple_text = TEXT;	Simple_text = TEXT;
Formula = Math;	Formula = Math;
Table_para = Table;	Table_para = Table;
Line 2001 paragraph:</p>	Line 1663 paragraph:</p>
</div>	</div>

<div class="subsubsection">	<div class="subsubsection">

<h4><a name="sectd3284">Reference</a></h4>	<h4><a name="sectd3284">Reference</a></h4>
<p>
Like all elements in Thot, references are typed. An element type defined as a	<p>Like all elements in Thot, references are typed. An element type defined
reference is a cross-reference to an element of some other given type. The	as a reference is a cross-reference to an element of some other given type.
keyword <tt>REFERENCE</tt> is followed by the name of a type enclosed in	The keyword <tt>REFERENCE</tt> is followed by the name of a type enclosed in
parentheses. When the type which is being cross-referenced is defined in	parentheses. When the type which is being cross-referenced is defined in
another structure schema, the type name is itself followed by the name of the	another structure schema, the type name is itself followed by the name of the
external structure schema in which it is defined.</p>	external structure schema in which it is defined.</p>
<p>
When the designated element type is a <a href="#sectd3285">mark pair</a>, it	<p>When the designated element type is a <a href="#sectd3285">mark pair</a>,
can be preceded by a <tt>FIRST</tt> or <tt>SECOND</tt> keyword. These	it can be preceded by a <tt>FIRST</tt> or <tt>SECOND</tt> keyword. These
keywords indicate whether the reference points to the first or second mark of	keywords indicate whether the reference points to the first or second mark of
the pair. If the reference points to a pair and neither of these two keywords	the pair. If the reference points to a pair and neither of these two keywords
is present, the reference is considered to point to the first mark of the	is present, the reference is considered to point to the first mark of the
pair.</p>	pair.</p>
<p>
There is an exception to the principle of typed references: it is possible to	<p>There is an exception to the principle of typed references: it is possible
define a reference which designates an element of any type, which can either	to define a reference which designates an element of any type, which can
be in the same document or another document. In this case, it suffices to put	either be in the same document or another document. In this case, it suffices
the keyword <tt>ANY</tt> in the parentheses which indicate the referenced	to put the keyword <tt>ANY</tt> in the parentheses which indicate the
element type.</p>	referenced element type.</p>
<pre> 'REFERENCE' '(' RefType ')'	<pre> 'REFERENCE' '(' RefType ')'
RefType = 'ANY' / [ FirstSec ] ElemID [ ExtStruct ] .</pre>	RefType = 'ANY' / [ FirstSec ] ElemID [ ExtStruct ] .</pre>
<p>
When defining an inclusion, the <tt>REFERENCE</tt> keyword is not used.	<p>When defining an inclusion, the <tt>REFERENCE</tt> keyword is not used.
Inclusions with complete expansion are not declared as such in the structure	Inclusions with complete expansion are not declared as such in the structure
schemas, since any element defined in a structure schema can be replaced by an	schemas, since any element defined in a structure schema can be replaced by an
element of the same type. Instead, inclusions without expansion or with	element of the same type. Instead, inclusions without expansion or with
Line 2035 complete object ( and not a part of an o	Line 1696 complete object ( and not a part of an o
to be included (that is, the name of its structure schema) is followed by a	to be included (that is, the name of its structure schema) is followed by a
keyword: <tt>EXTERN</tt> for inclusion without expansion and <tt>INCLUDED</tt>	keyword: <tt>EXTERN</tt> for inclusion without expansion and <tt>INCLUDED</tt>
for partial expansion.</p>	for partial expansion.</p>
<p>
Before creating a cross-reference or an inclusion, the Thot editor asks the	<p>Before creating a cross-reference or an inclusion, the Thot editor asks the
user to choose, from the document images displayed, the referenced or included	user to choose, from the document images displayed, the referenced or included
element.</p>	element.</p>

<blockquote class="example">	<blockquote class="example">
<p>	<p><strong>Example:</strong></p>
<strong>Example:</strong></p>
<p>	<p>If the types Note and Section are defined in the Article structure
If the types Note and Section are defined in the Article structure schema, it	schema, it is possible to define, in the same structure schema, a reference
is possible to define, in the same structure schema, a reference to a note and	to a note and a reference to a section in this manner:</p>
a reference to a section in this manner:</p>	<pre>Ref_note = REFERENCE (Note);
<pre>Ref_note = REFERENCE (Note);
Ref_section = REFERENCE (Section);</pre>	Ref_section = REFERENCE (Section);</pre>
<p>
It is also possible to define the generic structure of a collection of	<p>It is also possible to define the generic structure of a collection of
articles, which include (with partial expansion) objects of the Article class	articles, which include (with partial expansion) objects of the Article
and which possess an introduction which may include cross-references to	class and which possess an introduction which may include cross-references
sections of the included articles. In the Collection structure schema, the	to sections of the included articles. In the Collection structure schema,
definitions are:</p>	the definitions are:</p>
<pre>Collection = BEGIN	<pre>Collection = BEGIN
Collection_title = TEXT;	Collection_title = TEXT;
Introduction = LIST OF (Elem = CASE OF	Introduction = LIST OF (Elem = CASE OF
TEXT;	TEXT;
Line 2063 definitions are:</p>	Line 1724 definitions are:</p>
Body = LIST OF (Article INCLUDED);	Body = LIST OF (Article INCLUDED);
END;	END;
Ref_sect = REFERENCE (Section (Article));</pre>	Ref_sect = REFERENCE (Section (Article));</pre>
<p>
Here we define a Folder document class which has a title and includes	<p>Here we define a Folder document class which has a title and includes
documents of different types, particularly Folders:</p>	documents of different types, particularly Folders:</p>
<pre>Folder = BEGIN	<pre>Folder = BEGIN
Folder_title = TEXT;	Folder_title = TEXT;
Folder_contents = LIST OF (Document);	Folder_contents = LIST OF (Document);
END;	END;
Line 2076 Document = CASE OF	Line 1737 Document = CASE OF
Collection EXTERN;	Collection EXTERN;
Folder EXTERN;	Folder EXTERN;
END;</pre>	END;</pre>
<p>
Under this definition, Folder represents either an aggregate which contains a	<p>Under this definition, Folder represents either an aggregate which
folder title and the list of included documents or an included folder. To	contains a folder title and the list of included documents or an included
resolve this ambiguity, in the P language, the placement of a star character	folder. To resolve this ambiguity, in the P language, the placement of a
in front of the type name (here, Folder) indicates an included document.</p>	star character in front of the type name (here, Folder) indicates an
	included document.</p>
</blockquote>	</blockquote>
</div>	</div>

<div class="subsubsection">	<div class="subsubsection">

<h4><a name="sectd3285">Mark pairs</a></h4>	<h4><a name="sectd3285">Mark pairs</a></h4>
<p>
Like other elements, mark pairs are typed. The two marks of the pair have the	<p>Like other elements, mark pairs are typed. The two marks of the pair have
same type, but there exist two predefined subtypes which apply to all mark	the same type, but there exist two predefined subtypes which apply to all mark
pairs: the first mark of the pair (called <tt>First</tt> in the P and T	pairs: the first mark of the pair (called <tt>First</tt> in the P and T
languages) and the second mark (called <tt>Second</tt>).</p>	languages) and the second mark (called <tt>Second</tt>).</p>
<p>
In the S language, a mark pair is noted simply by the <tt>PAIR</tt>	<p>In the S language, a mark pair is noted simply by the <tt>PAIR</tt>
keyword.</p>	keyword.</p>
<p>
In the Thot editor, marks are always moved or destroyed together. The two	<p>In the Thot editor, marks are always moved or destroyed together. The two
marks of a pair have the same identifier, unique within the document, which	marks of a pair have the same identifier, unique within the document, which
permits intertwining mark pairs without risk of ambiguity.</p>	permits intertwining mark pairs without risk of ambiguity.</p>
</div>	</div>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc329">Imports</a></h3>	<h3><a name="sectc329">Imports</a></h3>
<p>
Because of schema constructors, it is possible, before editing a document, to	<p>Because of schema constructors, it is possible, before editing a document,
use classes defined by other structure schemas whenever they are needed. It is	to use classes defined by other structure schemas whenever they are needed. It
also possible to assign specific document classes to certain element types. In	is also possible to assign specific document classes to certain element types.
this case, these classes are simply designated by their name. In fact, if a	In this case, these classes are simply designated by their name. In fact, if
type name is not defined in the structure schema, it is assumed that it	a type name is not defined in the structure schema, it is assumed that it
specifies a structure defined by another structure schema.</p>	specifies a structure defined by another structure schema.</p>

<blockquote class="example">	<blockquote class="example">
<p>	<p><strong>Example:</strong></p>
<strong>Example:</strong></p>
<p>	<p>If the types Math and Table don't appear in the left part of a structure
If the types Math and Table don't appear in the left part of a structure rule	rule in the schema, the following two rules indicate that a formula has the
in the schema, the following two rules indicate that a formula has the	structure of an object defined by the structure schema Math and that a table
structure of an object defined by the structure schema Math and that a table	element has the structure of an object defined by the Table schema.</p>
element has the structure of an object defined by the Table schema.</p>	<pre>Formula = Math;
<pre>Formula = Math;
Table_elem = Table;</pre>	Table_elem = Table;</pre>
</blockquote>	</blockquote>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc3210">Extension rules</a></h3>	<h3><a name="sectc3210">Extension rules</a></h3>
<p>
The <tt>EXTENS</tt> section, which can only appear in an extension schema,	<p>The <tt>EXTENS</tt> section, which can only appear in an extension schema,
defines complements to the rules in the primary schema (i.e. the structure	defines complements to the rules in the primary schema (i.e. the structure
schema to which the extension schema will be applied). More precisely, this	schema to which the extension schema will be applied). More precisely, this
section permits the addition to an existing type of local attributes,	section permits the addition to an existing type of local attributes,
extensions, restrictions and fixed-value attributes.</p>	extensions, restrictions and fixed-value attributes.</p>
<p>
These additions can be applied to the root rule of the primary schema,	<p>These additions can be applied to the root rule of the primary schema,
designated by the keyword <tt>Root</tt>, or to any other explicitly named	designated by the keyword <tt>Root</tt>, or to any other explicitly named
rule.</p>	rule.</p>
<p>
Extension rules are separated from each other by a semicolon and each	<p>Extension rules are separated from each other by a semicolon and each
extension rule has the same syntax as a <a href="#sectc327">structure	extension rule has the same syntax as a <a href="#sectc327">structure
rule</a>, but the part which defines the constructor is absent.</p>	rule</a>, but the part which defines the constructor is absent.</p>
<pre> ExtenRuleSeq = ExtensRule ';' < ExtensRule ';' > .	<pre> ExtenRuleSeq = ExtensRule ';' < ExtensRule ';' > .
ExtensRule = RootOrElem [ LocAttrSeq ]	ExtensRule = RootOrElem [ LocAttrSeq ]
[ '+' '(' ExtensionSeq ')' ]	[ '+' '(' ExtensionSeq ')' ]
[ '-' '(' RestrictSeq ')' ]	[ '-' '(' RestrictSeq ')' ]
Line 2151 rule</a>, but the part which defines the	Line 1810 rule</a>, but the part which defines the
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc3211">Associated elements</a></h3>	<h3><a name="sectc3211">Associated elements</a></h3>
<p>
If associated elements are necessary, they must be declared in a specific	<p>If associated elements are necessary, they must be declared in a specific
section of the structure schema, introduced by the keyword <tt>ASSOC</tt>.	section of the structure schema, introduced by the keyword <tt>ASSOC</tt>.
Each associated element type is specified like any other structured element.	Each associated element type is specified like any other structured element.
However, these types must not appear in any other element types of the schema,	However, these types must not appear in any other element types of the schema,
Line 2162 except in <tt>REFERENCE</tt> rules.</p>	Line 1820 except in <tt>REFERENCE</tt> rules.</p>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc3212">Units</a></h3>	<h3><a name="sectc3212">Units</a></h3>
<p>
The <tt>UNITS</tt> section of the structure schema contains the declarations	<p>The <tt>UNITS</tt> section of the structure schema contains the
of the element types which can be used in the external objects making up parts	declarations of the element types which can be used in the external objects
of the document or in objects of the class defined by the schema. As with	making up parts of the document or in objects of the class defined by the
associated elements, these element types are defined just like other	schema. As with associated elements, these element types are defined just
structured element types. They can be used in the other element types of the	like other structured element types. They can be used in the other element
schema, but they can also be used in any other rule of the schema.</p>	types of the schema, but they can also be used in any other rule of the
<blockquote class="example">	schema.</p>
<p>
<strong>Example:</strong></p>	<blockquote class="example">
<p>	<p><strong>Example:</strong></p>
If references to notes are declared as units:</p>
<pre>UNITS	<p>If references to notes are declared as units:</p>
	<pre>UNITS
Ref_note = REFERENCE (Note);</pre>	Ref_note = REFERENCE (Note);</pre>
<p>
then it is possible to use references to notes in a cell of a table, even when	<p>then it is possible to use references to notes in a cell of a table, even
<tt>Table</tt> is an external structure schema. The <tt>Table</tt> schema	when <tt>Table</tt> is an external structure schema. The <tt>Table</tt>
must declare a cell to be a sequence of units, which can then be base element	schema must declare a cell to be a sequence of units, which can then be base
types (text, for example) or references to notes in the document.</p>	element types (text, for example) or references to notes in the
<pre>Cell = LIST OF (UNITS);</pre>	document.</p>
	<pre>Cell = LIST OF (UNITS);</pre>
</blockquote>	</blockquote>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc3213">Skeleton elements</a></h3>	<h3><a name="sectc3213">Skeleton elements</a></h3>
<p>
When editing a document which contains or must contain external references to	<p>When editing a document which contains or must contain external references
several other documents, it may be necessary to load a large number of	to several other documents, it may be necessary to load a large number of
documents, simply to see the parts designated by the external references of	documents, simply to see the parts designated by the external references of
the document while editing, or to access the source of included elements. In	the document while editing, or to access the source of included elements. In
this case, the external documents are not modified and it is only necessary to	this case, the external documents are not modified and it is only necessary to
Line 2205 form has the advantage of being very com	Line 1863 form has the advantage of being very com
resources from the editor. This is also the skeleton form which constitutes	resources from the editor. This is also the skeleton form which constitutes
the expanded form of <a href="#inclusion">inclusions</a> with partial	the expanded form of <a href="#inclusion">inclusions</a> with partial
expansion.</p>	expansion.</p>
<p>
Skeleton elements must be declared explicitly in the <tt>EXPORT</tt> section	<p>Skeleton elements must be declared explicitly in the <tt>EXPORT</tt>
of the structure schema that defines them. This section begins with the	section of the structure schema that defines them. This section begins with
keyword <tt>EXPORT</tt> followed by a comma-separated list of the element	the keyword <tt>EXPORT</tt> followed by a comma-separated list of the element
types which must appear in the skeleton form and ending with a semicolon.	types which must appear in the skeleton form and ending with a semicolon.
These types must have been previously declared in the schema.</p>	These types must have been previously declared in the schema.</p>
<p>
For each skeleton element type, the part of the contents which is loaded by	<p>For each skeleton element type, the part of the contents which is loaded by
the editor, and therefore displayable, can be specified by putting the keyword	the editor, and therefore displayable, can be specified by putting the keyword
<tt>WITH</tt> and the name of the contained element type to be loaded after	<tt>WITH</tt> and the name of the contained element type to be loaded after
the name of the skeleton element type. In this case only that named element,	the name of the skeleton element type. In this case only that named element,
Line 2223 skeleton form not load the contents of a	Line 1881 skeleton form not load the contents of a
<tt>WITH</tt> must be followed by the word <tt>Nothing</tt>.</p>	<tt>WITH</tt> must be followed by the word <tt>Nothing</tt>.</p>
<pre> [ 'EXPORT' SkeletonSeq ]	<pre> [ 'EXPORT' SkeletonSeq ]

SkeletonSeq = SkelElem < ',' SkelElem > ';' .	SkeletonSeq = SkelElem < ',' SkelElem > ';' .
SkelElem = ElemID [ 'WITH' Contents ] .	SkelElem = ElemID [ 'WITH' Contents ] .
Contents = 'Nothing' / ElemID [ ExtStruct ] .</pre>	Contents = 'Nothing' / ElemID [ ExtStruct ] .</pre>

<blockquote class="example">	<blockquote class="example">
<p>	<p><strong>Example:</strong></p>
<strong>Example:</strong></p>
<p>	<p>Suppose that, in documents of the article class, the element types
Suppose that, in documents of the article class, the element types	Article_title, Figure, Section, Paragraph, and Biblio should appear in the
Article_title, Figure, Section, Paragraph, and Biblio should appear in the	skeleton form in order to make it easier to create external references to
skeleton form in order to make it easier to create external references to them	them from other documents. When loading an article in its skeleton form,
from other documents. When loading an article in its skeleton form, all of	all of these element types will be loaded except for paragraphs, but only
these element types will be loaded except for paragraphs, but only the article	the article title will be loaded in its entirety. For figures, the caption
title will be loaded in its entirety. For figures, the caption will be	will be loaded, while for sections, the title will be loaded, and for
loaded, while for sections, the title will be loaded, and for bibliographic	bibliographic entries, only the title that they contain will be loaded.
entries, only the title that they contain will be loaded. Note that	Note that bibliographic elements are defined in another structure schema,
bibliographic elements are defined in another structure schema, RefBib. To	RefBib. To produce this result, the following declarations should be placed
produce this result, the following declarations should be placed in the	in the Article structure schema:</p>
Article structure schema:</p>	<pre>EXPORT
<pre>EXPORT
Article_title,	Article_title,
Figure With Caption,	Figure With Caption,
Section With Section_title,	Section With Section_title,
Line 2251 Article structure schema:</p>	Line 1909 Article structure schema:</p>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc3214">Exceptions</a></h3>	<h3><a name="sectc3214">Exceptions</a></h3>
<p>
The behavior of the Thot editor and the actions that it performs are	<p>The behavior of the Thot editor and the actions that it performs are
determined by the structure schemas. These actions are applied to all	determined by the structure schemas. These actions are applied to all
document and object types in accordance with their generic structure. For	document and object types in accordance with their generic structure. For
certain object types, such as tables and graphics, these actions are not	certain object types, such as tables and graphics, these actions are not
sufficient or are poorly adapted and some special actions must be added to or	sufficient or are poorly adapted and some special actions must be added to or
substituted for certain standard actions. These special actions are called	substituted for certain standard actions. These special actions are called
<em>exceptions</em>.</p>	<em>exceptions</em>.</p>
<p>
Exceptions only inhibit or modify certain standard actions, but they can be	<p>Exceptions only inhibit or modify certain standard actions, but they can be
used freely in every structure schema.</p>	used freely in every structure schema.</p>
<p>
Each structure schema can contain a section defining exceptions. It begins	<p>Each structure schema can contain a section defining exceptions. It begins
with the keyword <tt>EXCEPT</tt> and is composed of a sequence of exception	with the keyword <tt>EXCEPT</tt> and is composed of a sequence of exception
declarations, separated by semicolons. Each declaration of an exception	declarations, separated by semicolons. Each declaration of an exception
begins with the name of an element type or attribute followed by a colon. This	begins with the name of an element type or attribute followed by a colon. This
Line 2275 pair</a>, and only in this case, the typ	Line 1932 pair</a>, and only in this case, the typ
<tt>First</tt> or <tt>Second</tt>, to indicate if the exceptions which follow	<tt>First</tt> or <tt>Second</tt>, to indicate if the exceptions which follow
are associated with the first mark of the pair or the second. In the absence	are associated with the first mark of the pair or the second. In the absence
of this keyword, the first mark is used.</p>	of this keyword, the first mark is used.</p>
<p>
When placed in an <a href="#sectc322">extension schema</a>, the keyword	<p>When placed in an <a href="#sectc322">extension schema</a>, the keyword
<tt>EXTERN</tt> indicates that the type name which follows is found in the	<tt>EXTERN</tt> indicates that the type name which follows is found in the
principal schema (the schema being extended by the extension schema). The	principal schema (the schema being extended by the extension schema). The
exceptions are indicated by a name. They are separated by semicolons.</p>	exceptions are indicated by a name. They are separated by semicolons.</p>
<pre> [ 'EXCEPT' ExceptSeq ]	<pre> [ 'EXCEPT' ExceptSeq ]

ExceptSeq = Except ';' < Except ';' > .	ExceptSeq = Except ';' < Except ';' > .
Except = [ 'EXTERN' ] [ FirstSec ] ExcTypeOrAttr	Except = [ 'EXTERN' ] [ FirstSec ] ExcTypeOrAttr
':' ExcValSeq .	':' ExcValSeq .
ExcTypeOrAttr = ElemID / AttrID .	ExcTypeOrAttr = ElemID / AttrID .
ExcValSeq = ExcValue < ',' ExcValue > .	ExcValSeq = ExcValue < ',' ExcValue > .
ExcValue ='NoCut' / 'NoCreate' / 'NoHMove' /	ExcValue ='NoCut' / 'NoCreate' / 'NoHMove' /
'NoVMove' / 'NoHResize' / 'NoVResize' /	'NoVMove' / 'NoHResize' / 'NoVResize' /
'NoMove' / 'NoResize' / 'MoveResize' /	'NoMove' / 'NoResize' / 'MoveResize' /
Line 2304 exceptions are indicated by a name. The	Line 1961 exceptions are indicated by a name. The
'IsRow' / 'IsColHead' / 'IsCell' /	'IsRow' / 'IsColHead' / 'IsCell' /
'NewPercentWidth' / 'ColRef' / 'ColSpan' /	'NewPercentWidth' / 'ColRef' / 'ColSpan' /
'RowSpan' / 'SaveDocument' / 'Shadow' .</pre>	'RowSpan' / 'SaveDocument' / 'Shadow' .</pre>
<p>
The following are the available exceptions:</p>	<p>The following are the available exceptions:</p>
<dl>	<dl>
<dt><tt>NoCut</tt></dt>	<dt><tt>NoCut</tt></dt>
<dd>	<dd>This exception can only be applied to element types. Elements of a
This exception can only be applied to element types. Elements of a type to	type to which this exception is applied cannot be deleted by the
which this exception is applied cannot be deleted by the editor.	editor.</dd>
</dd>	<dt><tt>NoCreate</tt></dt>
<dt><tt>NoCreate</tt></dt>	<dd>This exception can only be applied to element types. Elements of a
<dd>	type to which this exception is applied cannot be created by ordinary
This exception can only be applied to element types. Elements of a type to	commands for creating new elements. These elements are usually created
which this exception is applied cannot be created by ordinary commands for	by special actions associated with other exceptions.</dd>
creating new elements. These elements are usually created by special actions	<dt><tt>NoHMove</tt></dt>
associated with other exceptions.	<dd>This exception can only be applied to element types. Elements of a
</dd>	type to which this exception is applied cannot be moved horizontally
<dt><tt>NoHMove</tt></dt>	with the mouse. Their children elements cannot be moved either.</dd>
<dd>	<dt><tt>NoVMove</tt></dt>
This exception can only be applied to element types. Elements of a type to	<dd>This exception can only be applied to element types. Elements of a
which this exception is applied cannot be moved horizontally with the mouse.	type to which this exception is applied cannot be moved vertically with
Their children elements cannot be moved either.	the mouse. Their children elements cannot be moved either.</dd>
</dd>	<dt><tt>NoMove</tt></dt>
<dt><tt>NoVMove</tt></dt>	<dd>This exception can only be applied to element types. Elements of a
<dd>	type to which this exception is applied cannot be moved in any direction
This exception can only be applied to element types. Elements of a type to	with the mouse. Their children elements cannot be moved either.</dd>
which this exception is applied cannot be moved vertically with the mouse.	<dt><tt>NoHResize</tt></dt>
Their children elements cannot be moved either.	<dd>This exception can only be applied to element types. Elements of a
</dd>	type to which this exception is applied cannot be resized horizontally
<dt><tt>NoMove</tt></dt>	with the mouse. Their children elements cannot be resized either.</dd>
<dd>	<dt><tt>NoVResize</tt></dt>
This exception can only be applied to element types. Elements of a type to	<dd>This exception can only be applied to element types. Elements of a
which this exception is applied cannot be moved in any direction with the	type to which this exception is applied cannot be resized vertically
mouse. Their children elements cannot be moved either.	with the mouse. Their children elements cannot be resized either.</dd>
</dd>	<dt><tt>NoResize</tt></dt>
<dt><tt>NoHResize</tt></dt>	<dd>This exception can only be applied to element types. Elements of a
<dd>	type to which this exception is applied cannot be resized in any
This exception can only be applied to element types. Elements of a type to	direction with the mouse. Their children elements cannot be resized
which this exception is applied cannot be resized horizontally with the mouse.	either.</dd>
Their children elements cannot be resized either.	<dt><tt>MoveResize</tt></dt>
</dd>	<dd>This exception can only be applied to element types. Elements of a
<dt><tt>NoVResize</tt></dt>	type to which this exception is applied can be moved and resized in any
<dd>	direction with the mouse, even if one of their ancestor element has an
This exception can only be applied to element types. Elements of a type to	exception that prevents moving or resizing. Their children elements can
which this exception is applied cannot be resized vertically with the mouse.	also be resized or moved.</dd>
Their children elements cannot be resized either.	<dt><tt>NewWidth</tt></dt>
</dd>	<dd>This exception can only be applied to numeric attributes. If the
<dt><tt>NoResize</tt></dt>	width of an element which has this attribute is modified with the mouse,
<dd>	the value of the new width will be assigned to the attribute.</dd>
This exception can only be applied to element types. Elements of a type to	<dt><tt>NewHeight</tt></dt>
which this exception is applied cannot be resized in any direction with the	<dd>This exception can only be applied to numeric attributes. If the
mouse. Their children elements cannot be resized either.	height of an element which has this attribute is modified with the
</dd>	mouse, the value of the new height will be assigned to the
<dt><tt>MoveResize</tt></dt>	attribute.</dd>
<dd>	<dt><tt>NewHPos</tt></dt>
This exception can only be applied to element types. Elements of a type to	<dd>This exception can only be applied to numeric attributes. If the
which this exception is applied can be moved and resized in any direction with	horizontal position of an element which has this attribute is modified
the mouse, even if one of their ancestor element has an exception that	with the mouse, the value of the new horizontal position will be
prevents moving or resizing. Their children elements can also be resized or	assigned to the attribute.</dd>
moved.	<dt><tt>NewVPos</tt></dt>
</dd>	<dd>This exception can only be applied to numeric attributes. If the
<dt><tt>NewWidth</tt></dt>	vertical position of an element which has this attribute is modified
<dd>	with the mouse, the value of the new vertical position will be assigned
This exception can only be applied to numeric attributes. If the width of an	to the attribute.</dd>
element which has this attribute is modified with the mouse, the value of the	<dt><tt>Invisible</tt></dt>
new width will be assigned to the attribute.	<dd>This exception can only be applied to attributes, but can be applied
</dd>	to all attribute types. It indicates that the attribute must not be
<dt><tt>NewHeight</tt></dt>	seen by the user and that its value must not be changed directly. This
<dd>	exception is usually used when another exception manipulates the value
This exception can only be applied to numeric attributes. If the height of an	of an attribute.</dd>
element which has this attribute is modified with the mouse, the value of the	<dt><tt>NoSelect</tt></dt>
new height will be assigned to the attribute.	<dd>This exception can only be applied to element types. Elements of a
</dd>	type to which this exception is applied cannot be selected directly
<dt><tt>NewHPos</tt></dt>	with the mouse, but they can be selected by other methods provided by
<dd>	the editor.</dd>
This exception can only be applied to numeric attributes. If the horizontal	<dt>NoSpellCheck</dt>
position of an element which has this attribute is modified with the mouse,	<dd>This exception can only be applied to element types. Elements of a
the value of the new horizontal position will be assigned to the attribute.	type to which this exception is applied are not taken into account by
</dd>	the spell checker.</dd>
<dt><tt>NewVPos</tt></dt>	<dt><tt>Hidden</tt></dt>
<dd>	<dd>This exception can only be applied to element types. It indicates
This exception can only be applied to numeric attributes. If the vertical	that elements of this type, although present in the document's
position of an element which has this attribute is modified with the mouse,	structure, must not be shown to the user of the editor. In particular,
the value of the new vertical position will be assigned to the attribute.	the creation menus must not propose this type and the selection message
</dd>	must not pick it.</dd>
<dt><tt>Invisible</tt></dt>	<dt><tt>ActiveRef</tt></dt>
<dd>	<dd>This exception can only be applied to attributes of the reference
This exception can only be applied to attributes, but can be applied to all	type. It indicates that when the user of the editor makes a double
attribute types. It indicates that the attribute must not be seen by the user	click on an element which possesses a reference attribute having this
and that its value must not be changed directly. This exception is usually	exception, the element designated by the reference attribute will be
used when another exception manipulates the value of an attribute.	selected.</dd>
</dd>	<dt><tt>ImportLine</tt></dt>
<dt><tt>NoSelect</tt></dt>	<dd>This exception can only be applied to element types. It indicates
<dd>	that elements of this type should receive the content of imported text
This exception can only be applied to element types. Elements of a type to	files. An element is created for each line of the imported file. A
which this exception is applied cannot be selected directly with the mouse,	structure schema cannot contain several exceptions <tt>ImportLine</tt>
but they can be selected by other methods provided by the editor.	and, if it contains one, it should not contain any exception
</dd>	<tt>ImportParagraph</tt>.</dd>
<dt>NoSpellCheck</dt>	<dt><tt>ImportParagraph</tt></dt>
<dd>	<dd>This exception can only be applied to element types. It indicates
This exception can only be applied to element types. Elements of a type to	that elements of this type should receive the content of imported text
which this exception is applied are not taken into account by the spell	files. An element is created for each paragraph of the imported file.
checker.	A paragraph is a sequence of lines without any empty line. A structure
</dd>	schema cannot contain several exceptions <tt>ImportParagraph</tt> and,
<dt><tt>Hidden</tt></dt>	if it contains one, it should not contain any exception
<dd>	<tt>ImportLine</tt>.</dd>
This exception can only be applied to element types. It indicates that	<dt><tt>NoPaginate</tt></dt>
elements of this type, although present in the document's structure, must not	<dd>This exception can only be applied to the root element, i.e. the name
be shown to the user of the editor. In particular, the creation menus must	that appear after the keyword <tt>STRUCTURE</tt> at the beginning of the
not propose this type and the selection message must not pick it.	structure schema. It indicates that the editor should not allow the
</dd>	user to paginate documents of that type.</dd>
<dt><tt>ActiveRef</tt></dt>	<dt><tt>ParagraphBreak</tt></dt>
<dd>	<dd>This exception can only be applied to element types. When the caret
This exception can only be applied to attributes of the reference type. It	is within an element of a type to which this exception is applied, it is
indicates that when the user of the editor makes a double click on an element	that element that will be split when the user hits the Return key.</dd>
which possesses a reference attribute having this exception, the element	<dt><tt>ReturnCreateNL</tt></dt>
designated by the reference attribute will be selected.	<dd>This exception can only be applied to element types. When the caret
</dd>	is within an element of a type to which this exception is applied, the
<dt><tt>ImportLine</tt></dt>	Return key simply inserts a New line character (code \212) at the
<dd>	current position. The Return key does not create a new element; it does
This exception can only be applied to element types. It indicates that	not split the current element either.</dd>
elements of this type should receive the content of imported text files. An	<dt><tt>ReturnCreateWithin</tt></dt>
element is created for each line of the imported file. A structure schema	<dd>This exception can only be applied to element types. When the caret
cannot contain several exceptions <tt>ImportLine</tt> and, if it contains one,	is within an element of a type to which this exception is applied, the
it should not contain any exception <tt>ImportParagraph</tt>.	Return key will create a new element within that element, not a sibling
</dd>	after that element.</dd>
<dt><tt>ImportParagraph</tt></dt>	<dt><tt>HighlightChildren</tt></dt>
<dd>	<dd>This exception can only be applied to element types. Elements of a
This exception can only be applied to element types. It indicates that	type to which this exception is applied are not highlighted themselves
elements of this type should receive the content of imported text files. An	when they are selected, but all their children are highlighted
element is created for each paragraph of the imported file. A paragraph is a	instead.</dd>
sequence of lines without any empty line. A structure schema cannot contain	<dt><tt>ExtendedSelection</tt></dt>
several exceptions <tt>ImportParagraph</tt> and, if it contains one, it should	<dd>This exception can only be applied to element types. The selection
not contain any exception <tt>ImportLine</tt>.	extension command (middle button of the mouse) only add the clicked
</dd>	element (if it has that exception) to the current selection, without
<dt><tt>NoPaginate</tt></dt>	selecting other elements between the current selection and the clicked
<dd>	element.</dd>
This exception can only be applied to the root element, i.e. the name that	<dt>IsDraw, IsTable, IsColHead, IsRow, IsCell</dt>
appear after the keyword <tt>STRUCTURE</tt> at the beginning of the structure	<dd>These exceptions can only be applied to element types. Elements of a
schema. It indicates that the editor should not allow the user to paginate	type to which these exceptions are applied are identified as Draws,
documents of that type.	Tables, Colheads, Rows or Cells and specific processing are applied to
</dd>	them.</dd>
<dt><tt>ParagraphBreak</tt></dt>	<dt>ColRef</dt>
<dd>	<dd>This exception can only be applied to attributes of the reference
This exception can only be applied to element types. When the caret is within	type. It indicates that this attribute refers to the column head (see
an element of a type to which this exception is applied, it is that element	exception IsColHead) which the element belongs to.</dd>
that will be split when the user hits the Return key.	<dt>ColSpan, RowSpan</dt>
</dd>	<dd>These exceptions can only be applied to numeric attributes of cells.
<dt><tt>ReturnCreateNL</tt></dt>	They indicate that attribute values give how many columns or rows the
<dd>	element spans.</dd>
This exception can only be applied to element types. When the caret is within	<dt>Shadow</dt>
an element of a type to which this exception is applied, the Return key simply	<dd>This exception can only be applied to element types. Text of elements
inserts a New line character (code \212) at the current position. The Return	of a type to which this exception is applied are displayed and printed
key does not create a new element; it does not split the current element	as a set of stars ('*').</dd>
either.
</dd>
<dt><tt>ReturnCreateWithin</tt></dt>
<dd>
This exception can only be applied to element types. When the caret is within
an element of a type to which this exception is applied, the Return key will
create a new element within that element, not a sibling after that element.
</dd>
<dt><tt>HighlightChildren</tt></dt>
<dd>
This exception can only be applied to element types. Elements of a type to
which this exception is applied are not highlighted themselves when they are
selected, but all their children are highlighted instead.
</dd>
<dt><tt>ExtendedSelection</tt></dt>
<dd>
This exception can only be applied to element types. The selection extension
command (middle button of the mouse) only add the clicked element (if it has
that exception) to the current selection, without selecting other elements
between the current selection and the clicked element.
</dd>
<dt>IsDraw, IsTable, IsColHead, IsRow, IsCell</dt>
<dd>
These exceptions can only be applied to element types. Elements of a type to
which these exceptions are applied are identified as Draws, Tables, Colheads,
Rows or Cells and specific processing are applied to them.
</dd>
<dt>ColRef</dt>
<dd>
This exception can only be applied to attributes of the reference type. It
indicates that this attribute refers to the column head (see exception
IsColHead) which the element belongs to.
</dd>
<dt>ColSpan, RowSpan</dt>
<dd>
These exceptions can only be applied to numeric attributes of cells. They
indicate that attribute values give how many columns or rows the element
spans.
</dd>
<dt>Shadow</dt>
<dd>
This exception can only be applied to element types. Text of elements of a
type to which this exception is applied are displayed and printed as a set of
stars ('*').
</dd>
</dl>	</dl>

<blockquote class="example">	<blockquote class="example">
<p>	<p><strong>Example:</strong></p>
<strong>Example:</strong></p>
<p>	<p>Consider a structure schema for object-style graphics which defines the
Consider a structure schema for object-style graphics which defines the	Graphic_object element type with the associated Height and Weight numeric
Graphic_object element type with the associated Height and Weight numeric	attributes. Suppose that we want documents of this class to have the
attributes. Suppose that we want documents of this class to have the	following qualities:</p>
following qualities:</p>	<ul>
<ul>	<li>Whenever the width or height of an object is changed using the mouse,
<li>	the new values are stored in the object's Width and Height
Whenever the width or height of an object is changed using the mouse, the new	attributes.</li>
values are stored in the object's Width and Height attributes.	<li>The user should not be able to change the values of the Width and
</li>	Height attributes via the Attributes menu of the Thot editor.</li>
<li>	</ul>
The user should not be able to change the values of the Width and Height
attributes via the Attributes menu of the Thot editor.	<p>The following exceptions will produce this effect.</p>
</li>	<pre>STRUCT
</ul>
<p>
The following exceptions will produce this effect.</p>
<pre>STRUCT
...	...
Graphics_object (ATTR Height = Integer; Width = Integer)	Graphics_object (ATTR Height = Integer; Width = Integer)
= GRAPHICS with Height ?= 10, Width ?= 10;	= GRAPHICS with Height ?= 10, Width ?= 10;
Line 2535 EXCEPT	Line 2144 EXCEPT
</div>	</div>

<div class="section">	<div class="section">

<h2><a name="sectb33">Some examples</a></h2>	<h2><a name="sectb33">Some examples</a></h2>
<p>
In order to illustrate the principles of the document model and the syntax of
the S language, this section presents two examples of structure schemas. One
defines a class of documents, the other defines a class of objects.</p>

<div class="subsection">	<p>In order to illustrate the principles of the document model and the syntax
	of the S language, this section presents two examples of structure schemas.
	One defines a class of documents, the other defines a class of objects.</p>

	<div class="subsection">
<h3><a name="sectc331">A class of documents: articles</a></h3>	<h3><a name="sectc331">A class of documents: articles</a></h3>
<p>
This example shows a possible structure for articles published in a journal.	<p>This example shows a possible structure for articles published in a
Text between braces is comments.</p>	journal. Text between braces is comments.</p>
<pre>STRUCTURE Article; { This schema defines the Article class }	<pre>STRUCTURE Article; { This schema defines the Article class }
DEFPRES ArticleP; { The default presentation schema is	DEFPRES ArticleP; { The default presentation schema is
ArticleP }	ArticleP }
Line 2658 EXPORT { Skeleton elements }	Line 2265 EXPORT { Skeleton elements }
Section With Section_title;	Section With Section_title;

END { End of the structure schema }</pre>	END { End of the structure schema }</pre>
<p>
This schema is very complete since it defines both paragraphs and	<p>This schema is very complete since it defines both paragraphs and
bibliographic citations. These element types could just as well be defined in	bibliographic citations. These element types could just as well be defined in
other structure schemas, as is the case with the <tt>Formula</tt> class. All	other structure schemas, as is the case with the <tt>Formula</tt> class. All
sorts of other elements can be inserted into an article, since a paragraph can	sorts of other elements can be inserted into an article, since a paragraph can
contain any type of unit. Similarly, figures can be any class of document or	contain any type of unit. Similarly, figures can be any class of document or
object that the user chooses.</p>	object that the user chooses.</p>
<p>
Generally, an article doesn't contain appendices, but it is possible to add	<p>Generally, an article doesn't contain appendices, but it is possible to add
them on explicit request: this is the effect of the question mark before the	them on explicit request: this is the effect of the question mark before the
word Appendices.</p>	word Appendices.</p>
<p>
The Figure, Biblio_citation and Note elements are associated elements. Thus,	<p>The Figure, Biblio_citation and Note elements are associated elements.
they are only used in <tt>REFERENCE</tt> statements.</p>	Thus, they are only used in <tt>REFERENCE</tt> statements.</p>
<p>
Various types of cross-references can be put in paragraphs. They can also be	<p>Various types of cross-references can be put in paragraphs. They can also
placed the objects which are part of the article, since the cross-references	be placed the objects which are part of the article, since the
are defined as units (<tt>UNITS</tt>).</p>	cross-references are defined as units (<tt>UNITS</tt>).</p>
<p>
There is a single restriction to prevent the creation of Ref_note elements	<p>There is a single restriction to prevent the creation of Ref_note elements
within notes.</p>	within notes.</p>
<p>
It is worth noting that the S language permits the definition of recursive	<p>It is worth noting that the S language permits the definition of recursive
structures like sections: a section can contain other sections (which are thus	structures like sections: a section can contain other sections (which are thus
at the next lower level of the document tree). Paragraphs are also recursive	at the next lower level of the document tree). Paragraphs are also recursive
elements, since a paragraph can contain an enumeration in which each element	elements, since a paragraph can contain an enumeration in which each element
Line 2688 elements, since a paragraph can contain	Line 2295 elements, since a paragraph can contain
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc332">A class of objects: mathematical formulas</a></h3>	<h3><a name="sectc332">A class of objects: mathematical formulas</a></h3>
<p>
The example below defines the <tt>Formula</tt> class which is used in Article	<p>The example below defines the <tt>Formula</tt> class which is used in
documents. This class represents mathematical formulas with a rather simple	Article documents. This class represents mathematical formulas with a rather
structure, but sufficient to produce a correct rendition on the screen or	simple structure, but sufficient to produce a correct rendition on the screen
printer. To support more elaborate operations (formal or numeric	or printer. To support more elaborate operations (formal or numeric
calculations), a finer structure should be defined. This class doesn't use any	calculations), a finer structure should be defined. This class doesn't use any
other class and doesn't define any associated elements or units.</p>	other class and doesn't define any associated elements or units.</p>
<pre>STRUCTURE Formula;	<pre>STRUCTURE Formula;
Line 2742 STRUCT	Line 2348 STRUCT
END;	END;
END; { End of Choice Constructor }	END; { End of Choice Constructor }
END { End of Structure Schema }</pre>	END { End of Structure Schema }</pre>
<p>
This schema defines a single global attribute which allows functions and	<p>This schema defines a single global attribute which allows functions and
variables to be distinguished. In the presentation schema, this attribute can	variables to be distinguished. In the presentation schema, this attribute can
be used to choose between roman (for functions) and italic characters (for	be used to choose between roman (for functions) and italic characters (for
variables).</p>	variables).</p>
<p>
A formula's structure is that of a mathematical expression, which is itself a	<p>A formula's structure is that of a mathematical expression, which is itself
sequence of mathematical constructions. A mathematical construction can be	a sequence of mathematical constructions. A mathematical construction can be
either a simple character string, an index, an exponent, a fraction, a root,	either a simple character string, an index, an exponent, a fraction, a root,
etc. Each of these mathematical constructions has a sensible structure which	etc. Each of these mathematical constructions has a sensible structure which
generally includes one or more expressions, thus making the formula class's	generally includes one or more expressions, thus making the formula class's
structure definition recursive.</p>	structure definition recursive.</p>
<p>
In most cases, the roots which appear in the formulas are square roots and	<p>In most cases, the roots which appear in the formulas are square roots and
their order (2) is not specified. This is why the Order component is marked	their order (2) is not specified. This is why the Order component is marked
optional by a question mark. When explicitly requested, it is possible to add	optional by a question mark. When explicitly requested, it is possible to add
an order to a root, for example for cube roots (order = 3).</p>	an order to a root, for example for cube roots (order = 3).</p>
<p>
An integral is formed by an integration symbol, chosen by the user (simple	<p>An integral is formed by an integration symbol, chosen by the user (simple
integral, double, curvilinear, etc.), and two bounds. A more fine-grained	integral, double, curvilinear, etc.), and two bounds. A more fine-grained
schema would add components for the integrand and the integration variable.	schema would add components for the integrand and the integration variable.
Similarly, the Block_Parentheses construction leaves the choice of opening and	Similarly, the Block_Parentheses construction leaves the choice of opening and
Line 2769 etc.</p>	Line 2375 etc.</p>
</div>	</div>
</div>	</div>
<hr>	<hr>

</div>	</div>

<div class="chapter">	<div class="chapter">

<h1><a name="sect4">The P Language</a></h1>	<h1><a name="sect4">The P Language</a></h1>

<div class="section">	<div class="section">

<h2><a name="sectb41">Document presentation</a></h2>	<h2><a name="sectb41">Document presentation</a></h2>
<p>
Because of the model adopted for Thot, the presentation of documents is	<p>Because of the model adopted for Thot, the presentation of documents is
clearly separated from their structure and content. After having presented	clearly separated from their structure and content. After having presented
the logical structure of documents, we now detail the principles implemented	the logical structure of documents, we now detail the principles implemented
for their presentation. The concept of <em>presentation</em> encompasses what	for their presentation. The concept of <em>presentation</em> encompasses what
Line 2790 on paper. Like logical structure, docum	Line 2393 on paper. Like logical structure, docum
generically with the help of a language, called P.</p>	generically with the help of a language, called P.</p>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc411">Two levels of presentation</a></h3>	<h3><a name="sectc411">Two levels of presentation</a></h3>
<p>
The link between structure and presentation is clear: the logical organization	<p>The link between structure and presentation is clear: the logical
of a document is used to carry out its presentation, since the purpose of the	organization of a document is used to carry out its presentation, since the
presentation is to make evident the organization of the document. But the	purpose of the presentation is to make evident the organization of the
presentation is equally dependent on the device used to render the document.	document. But the presentation is equally dependent on the device used to
Certain presentation effects, notably changes of font or character set, cannot	render the document. Certain presentation effects, notably changes of font or
be performed on all printers or on all screens. This is why Thot uses a	character set, cannot be performed on all printers or on all screens. This is
two-level approach, where the presentation is first described in abstract	why Thot uses a two-level approach, where the presentation is first described
terms, without taking into account each particular device, and then the	in abstract terms, without taking into account each particular device, and
presentation is realized within the constraints of a given device.</p>	then the presentation is realized within the constraints of a given
<p>	device.</p>
Thus, presentation is only described as a function of the structure of the
	<p>Thus, presentation is only described as a function of the structure of the
documents and the image that would be produced on an idealized device. For	documents and the image that would be produced on an idealized device. For
this reason, presentation descriptions do not refer to any device	this reason, presentation descriptions do not refer to any device
characteristics: they describe <em>abstract presentations</em> which can be	characteristics: they describe <em>abstract presentations</em> which can be
concretized on different devices.</p>	concretized on different devices.</p>
<p>
A presentation description also defines a <em>generic presentation</em>, since	<p>A presentation description also defines a <em>generic presentation</em>,
it describes the appearance of a class of documents or objects. This generic	since it describes the appearance of a class of documents or objects. This
presentation must also be applied to document and object instances, each	generic presentation must also be applied to document and object instances,
conforming to its generic logical structure, but with all the allowances that	each conforming to its generic logical structure, but with all the allowances
were called to mind above: missing elements, constructed elements with other	that were called to mind above: missing elements, constructed elements with
logical structures, etc.</p>	other logical structures, etc.</p>
<p>
In order to preserve the homogeneity between documents and objects,	<p>In order to preserve the homogeneity between documents and objects,
presentation is described with a single set of tools which support the layout	presentation is described with a single set of tools which support the layout
of a large document as well as the composition of objects like a graphical	of a large document as well as the composition of objects like a graphical
figure or mathematical formula. This unity of presentation description tools	figure or mathematical formula. This unity of presentation description tools
Line 2827 justification, font changes, etc.</p>	Line 2430 justification, font changes, etc.</p>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc412">Boxes</a></h3>	<h3><a name="sectc412">Boxes</a></h3>
<p>
To assure the homogeneity of tools, all presentation in Thot, for documents as	<p>To assure the homogeneity of tools, all presentation in Thot, for documents
well as for the objects which they contain, is based on the notion of the	as well as for the objects which they contain, is based on the notion of the
<em>box</em>, such as was implemented in T<sub><big>E</big></sub>X.</p>	<em>box</em>, such as was implemented in T<sub><big>E</big></sub>X.</p>
<p>
Corresponding to each element of the document is a box, which is the	<p>Corresponding to each element of the document is a box, which is the
rectangle enclosing the element on the display device (screen or sheet of	rectangle enclosing the element on the display device (screen or sheet of
paper); the outline of this rectangle is not visible, except when a <a	paper); the outline of this rectangle is not visible, except when a <a
href="#sectc4230a"><tt>ShowBox</tt> rule</a> applies to the element. The sides	href="#sectc4230a"><tt>ShowBox</tt> rule</a> applies to the element. The sides
of the box are parallel to the sides of the screen or the sheet of paper. By	of the box are parallel to the sides of the screen or the sheet of paper. By
way of example, a box is associated with a character string, a line of text, a	way of example, a box is associated with a character string, a line of text, a
page, a paragraph, a title, a mathematical formula, or a table cell.</p>	page, a paragraph, a title, a mathematical formula, or a table cell.</p>
<p>
Whatever element it corresponds to, each box possesses four sides and four	<p>Whatever element it corresponds to, each box possesses four sides and four
axes, which we designate as follows (<a href="#boxes">see figure</a>):</p>	axes, which we designate as follows (<a href="#boxes">see figure</a>):</p>
<dl>	<dl>
<dt><tt>Top</tt></dt>	<dt><tt>Top</tt></dt>
<dd>	<dd>the upper side,</dd>
the upper side,	<dt><tt>Bottom</tt></dt>
</dd>	<dd>the lower side,</dd>
<dt><tt>Bottom</tt></dt>	<dt><tt>Left</tt></dt>
<dd>	<dd>the left side,</dd>
the lower side,	<dt><tt>Right</tt></dt>
</dd>	<dd>the right side,</dd>
<dt><tt>Left</tt></dt>	<dt><tt>VMiddle</tt></dt>
<dd>	<dd>the vertical axis passing through the center of the box,</dd>
the left side,	<dt><tt>HMiddle</tt></dt>
</dd>	<dd>the horizontal axis passing through the center of the box,</dd>
<dt><tt>Right</tt></dt>	<dt><tt>VRef</tt></dt>
<dd>	<dd>the vertical reference axis,</dd>
the right side,	<dt><tt>HRef</tt></dt>
</dd>	<dd>the horizontal reference axis.</dd>
<dt><tt>VMiddle</tt></dt>
<dd>
the vertical axis passing through the center of the box,
</dd>
<dt><tt>HMiddle</tt></dt>
<dd>
the horizontal axis passing through the center of the box,
</dd>
<dt><tt>VRef</tt></dt>
<dd>
the vertical reference axis,
</dd>
<dt><tt>HRef</tt></dt>
<dd>
the horizontal reference axis.
</dd>
</dl>	</dl>

<div class="figure">	<div class="figure">
<hr>	<hr>

<pre> Left VRef VMiddle Right	<pre> Left VRef VMiddle Right
: :	: :
Top -----------------------------	Top -----------------------------
Line 2898 HMiddle ..\|...........................\|.	Line 2483 HMiddle ..\|...........................\|.
\| : : \|	\| : : \|
Bottom -----------------------------	Bottom -----------------------------
: :</pre>	: :</pre>
<p align="center">
<em><a name="boxes">The sides and axes of boxes</a><em></em></em></p>
<hr>

	<p align="center"><em><a name="boxes">The sides and axes of
	boxes</a><em></em></em></p>
	<hr>
</div>	</div>
<p>
The principal role of boxes is to set the extent and position of the images of	<p>The principal role of boxes is to set the extent and position of the images
the different elements of a document with respect to each other on the	of the different elements of a document with respect to each other on the
reproduction device. This is done by defining relations between the boxes of	reproduction device. This is done by defining relations between the boxes of
different elements which give relative extents and positions to these	different elements which give relative extents and positions to these
boxes.</p>	boxes.</p>
<p>
There are three types of boxes:</p>	<p>There are three types of boxes:</p>
<ul>	<ul>
<li>	<li>boxes corresponding to structural elements of the document,</li>
boxes corresponding to structural elements of the document,	<li>presentation boxes,</li>
</li>	<li>page layout boxes.</li>
<li>
presentation boxes,
</li>
<li>
page layout boxes.
</li>
</ul>	</ul>
<p>
<strong>Boxes corresponding to structural elements of the document</strong>	<p><strong>Boxes corresponding to structural elements of the document</strong>
are those which linked to each of the elements (base or structured) of the	are those which linked to each of the elements (base or structured) of the
logical structure of the document. Such a box contains all the contents of	logical structure of the document. Such a box contains all the contents of
the element to which it corresponds (there is an exception: see <a	the element to which it corresponds (there is an exception: see <a
Line 2935 On the other hand, there are no predefin	Line 2514 On the other hand, there are no predefin
the included boxes. If they are at the same level, they can overlap, be	the included boxes. If they are at the same level, they can overlap, be
contiguous, or be disjoint. The rules expressed in the generic presentation	contiguous, or be disjoint. The rules expressed in the generic presentation
specify their relative positions.</p>	specify their relative positions.</p>
<p>
<strong>Presentation boxes</strong> represent elements which are not found in	<p><strong>Presentation boxes</strong> represent elements which are not found
the logical structure of the document but which are added to meet the needs of	in the logical structure of the document but which are added to meet the needs
presentation. These boxes are linked to the elements of the logical structure	of presentation. These boxes are linked to the elements of the logical
that are best suited to bringing them out. For example, they are used to add	structure that are best suited to bringing them out. For example, they are
the character string ``Summary:'' before the summary in the presentation of a	used to add the character string ``Summary:'' before the summary in the
report or to represent the fraction bar in a formula, or also to make the	presentation of a report or to represent the fraction bar in a formula, or
title of a field in a form appear. These elements have no role in the logical	also to make the title of a field in a form appear. These elements have no
structure of the document: the presence of a Summary element in the document	role in the logical structure of the document: the presence of a Summary
does not require the creation of another structural object to hold the word	element in the document does not require the creation of another structural
``Summary''. Similarly, if a Fraction element contains both a Numerator	object to hold the word ``Summary''. Similarly, if a Fraction element contains
element and a Denominator element, the fraction bar has no purpose	both a Numerator element and a Denominator element, the fraction bar has no
structurally. On the other hand, these elements of the presentation are	purpose structurally. On the other hand, these elements of the presentation
important for the reader of the reproduced document or for the user of an	are important for the reader of the reproduced document or for the user of an
editor. This is why they must appear in the document's image. It is the	editor. This is why they must appear in the document's image. It is the
generic presentation which specifies the presentation boxes to add by	generic presentation which specifies the presentation boxes to add by
indicating their content (a base element for which the value is specified) and	indicating their content (a base element for which the value is specified) and
the position that they must take in the tree of boxes. During editing, these	the position that they must take in the tree of boxes. During editing, these
boxes cannot be modified by the user.</p>	boxes cannot be modified by the user.</p>
<p>
<strong>Page layout boxes</strong> are boxes created implicitly by the page	<p><strong>Page layout boxes</strong> are boxes created implicitly by the page
layout rules. These rules indicate how the contents of a structured element	layout rules. These rules indicate how the contents of a structured element
must be broken into lines and pages. In contrast to presentation boxes, these	must be broken into lines and pages. In contrast to presentation boxes, these
line and page boxes do not depend on the logical structure of the document,	line and page boxes do not depend on the logical structure of the document,
Line 2964 height and width of the window on the sc	Line 2543 height and width of the window on the sc
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc413">Views and visibility</a></h3>	<h3><a name="sectc413">Views and visibility</a></h3>
<p>
One of the operations that one might wish to perform on a document is to view	<p>One of the operations that one might wish to perform on a document is to
it is different ways. For this reason, it is possible to define several	view it is different ways. For this reason, it is possible to define several
<em>views</em> for the same document, or better yet, for all documents of the	<em>views</em> for the same document, or better yet, for all documents of the
same class. A view is not a different presentation of the document, but	same class. A view is not a different presentation of the document, but
rather a filter which only allows the display of certain parts of the	rather a filter which only allows the display of certain parts of the
Line 2978 document. Such a view could be called a	Line 2556 document. Such a view could be called a
be desirable to see only the mathematical formulas of a document in order to	be desirable to see only the mathematical formulas of a document in order to
avoid being distracted by the non-mathematical aspects of the document. A	avoid being distracted by the non-mathematical aspects of the document. A
``mathematics'' view could provide this service.</p>	``mathematics'' view could provide this service.</p>
<p>
Views, like presentation, are based on the generic logical structure. Each	<p>Views, like presentation, are based on the generic logical structure. Each
document class, and each generic presentation, can be provided with views	document class, and each generic presentation, can be provided with views
which are particularly useful for that class or presentation. For each view,	which are particularly useful for that class or presentation. For each view,
the <em>visibility</em> of elements is defined, indicated whether or not the	the <em>visibility</em> of elements is defined, indicated whether or not the
Line 2991 hierarchical level could be used to make	Line 2569 hierarchical level could be used to make
certain threshold level. By varying this threshold, the granularity of the	certain threshold level. By varying this threshold, the granularity of the
view can be varied. In the ``mathematics'' view, only Formula elements would	view can be varied. In the ``mathematics'' view, only Formula elements would
be made visible, no matter what their hierarchical level.</p>	be made visible, no matter what their hierarchical level.</p>
<p>
Because views are especially useful for producing a synthetic image of the	<p>Because views are especially useful for producing a synthetic image of the
document, it is necessary to adapt the presentation of the elements to the	document, it is necessary to adapt the presentation of the elements to the
view in which they appear. For example, it is inappropriate to have a page	view in which they appear. For example, it is inappropriate to have a page
break before every chapter title in the table of contents. Thus, generic	break before every chapter title in the table of contents. Thus, generic
presentations take into account the possible views and permit each element	presentations take into account the possible views and permit each element
type's presentation to vary according the view in which its image appears.</p>	type's presentation to vary according the view in which its image appears.</p>
<p>
<a name="views">Views</a> are also used, when editing documents, to display	<p><a name="views">Views</a> are also used, when editing documents, to display
the associated elements. So, in addition to the primary view of the document,	the associated elements. So, in addition to the primary view of the document,
there can be a ``notes'' view and a ``figures'' view which contain,	there can be a ``notes'' view and a ``figures'' view which contain,
respectively, the associated elements of the Note and Figure types. In this	respectively, the associated elements of the Note and Figure types. In this
Line 3009 printed.</p>	Line 2587 printed.</p>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc414">Pages</a></h3>	<h3><a name="sectc414">Pages</a></h3>
<p>
Presentation schemas can be defined which display the document as a long	<p>Presentation schemas can be defined which display the document as a long
scroll, without page breaks. This type of schema is particularly well-suited	scroll, without page breaks. This type of schema is particularly well-suited
to the initial phase of work on a document, where jumps from page to page	to the initial phase of work on a document, where jumps from page to page
would hinder composing and reading the document on a screen. In this case,	would hinder composing and reading the document on a screen. In this case,
Line 3021 page footer, are presented in a separate	Line 2598 page footer, are presented in a separate
written, it may be desirable to display the document on the screen in the same	written, it may be desirable to display the document on the screen in the same
manner in which it will be printed. So, the presentation schema must define	manner in which it will be printed. So, the presentation schema must define
pages.</p>	pages.</p>
<p>
The P language permits the specification of the dimensions of pages as well as	<p>The P language permits the specification of the dimensions of pages as well
their composition. It is possible to generate running titles, page numbers,	as their composition. It is possible to generate running titles, page
zones at the bottom of the page for notes, etc. The editor follows this model	numbers, zones at the bottom of the page for notes, etc. The editor follows
and inserts page break marks in the document which are used during printing,	this model and inserts page break marks in the document which are used during
insuring that the pages on paper are the same as on the screen.</p>	printing, insuring that the pages on paper are the same as on the screen.</p>
<p>
Once a document has been edited with a presentation schema defining pages, it	<p>Once a document has been edited with a presentation schema defining pages,
contains page marks. But it is always possible to edit the document using a	it contains page marks. But it is always possible to edit the document using
schema without pages. In this case, the page marks are simply ignored by the	a schema without pages. In this case, the page marks are simply ignored by
editor. They are considered again as soon as a schema with pages is used.	the editor. They are considered again as soon as a schema with pages is used.
Thus, the user is free to choose between schemas with and without pages.</p>	Thus, the user is free to choose between schemas with and without pages.</p>
<p>
Thot treats the page break, rather than the page itself, as a box. This page	<p>Thot treats the page break, rather than the page itself, as a box. This
break box contains all the elements of one page's footer, a rule marking the	page break box contains all the elements of one page's footer, a rule marking
edge of this page, and all the elements of the next page's header. The	the edge of this page, and all the elements of the next page's header. The
elements of the header and footer can be running titles, page number,	elements of the header and footer can be running titles, page number,
associated elements (notes, for example), etc. All these elements, as well as	associated elements (notes, for example), etc. All these elements, as well as
their content and graphical appearance, are defined by the generic	their content and graphical appearance, are defined by the generic
Line 3044 presentation.</p>	Line 2621 presentation.</p>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc415">Numbering</a></h3>	<h3><a name="sectc415">Numbering</a></h3>
<p>
Many elements are numbered in documents: pages, chapters, sections, formulas,	<p>Many elements are numbered in documents: pages, chapters, sections,
theorems, notes, figures, bibliographic references, exercises, examples,	formulas, theorems, notes, figures, bibliographic references, exercises,
lemmas, etc. Because Thot has a notion of logical structure, all of these	examples, lemmas, etc. Because Thot has a notion of logical structure, all of
numbers (with the exception of pages) are redundant with information implicit	these numbers (with the exception of pages) are redundant with information
in the logical structure of the document. Such numbers are simply a way to	implicit in the logical structure of the document. Such numbers are simply a
make the structure of the document more visible. So, they are part of the	way to make the structure of the document more visible. So, they are part of
document's presentation and are calculated by the editor from the logical	the document's presentation and are calculated by the editor from the logical
structure. The structure does not contain numbers as such; it only defines	structure. The structure does not contain numbers as such; it only defines
relative structural positions between elements, which serve as ordering	relative structural positions between elements, which serve as ordering
relations on these elements.</p>	relations on these elements.</p>
<p>
If the structure schema defines the body of a document as a sequence of at	<p>If the structure schema defines the body of a document as a sequence of at
least two chapters:</p>	least two chapters:</p>
<pre>Body = LIST [2..*] OF Chapter;</pre>	<pre>Body = LIST [2..*] OF Chapter;</pre>
<p>
the sequence defined by the list constructor is ordered and each chapter can	<p>the sequence defined by the list constructor is ordered and each chapter
be assigned a number based on its rank in the Body list. Therefore, all	can be assigned a number based on its rank in the Body list. Therefore, all
elements contained in lists a the structure of a document can be numbered, but	elements contained in lists a the structure of a document can be numbered, but
they are not the only ones. The tree structure induced by the aggregate,	they are not the only ones. The tree structure induced by the aggregate,
list, and choice constructors (excluding references) defines a total order on	list, and choice constructors (excluding references) defines a total order on
Line 3075 a chapter in the same sequence of number	Line 2651 a chapter in the same sequence of number
same list constructor and appear at different levels of the document's tree.	same list constructor and appear at different levels of the document's tree.
By changing the filter, they can be numbered separately: one sequence of	By changing the filter, they can be numbered separately: one sequence of
numbers for theorems, another for the lemmas.</p>	numbers for theorems, another for the lemmas.</p>
<p>
Associated elements pose a special problem, since they are not part of the	<p>Associated elements pose a special problem, since they are not part of the
document's primary structure, but are attached only by references, which	document's primary structure, but are attached only by references, which
violate the total order of the document. Then, these associated elements are	violate the total order of the document. Then, these associated elements are
frequently numbered, precisely because the number is an effective way to	frequently numbered, precisely because the number is an effective way to
Line 3084 visualize the reference. In order to re	Line 2660 visualize the reference. In order to re
defines a list constructor for each type of associated element, gathering	defines a list constructor for each type of associated element, gathering
together (and ordering) these elements. Thus, the associated elements can be	together (and ordering) these elements. Thus, the associated elements can be
numbered by type.</p>	numbered by type.</p>
<p>
Since they are calculated from the document's logical structure and only for	<p>Since they are calculated from the document's logical structure and only
the needs of the presentation, numbers are presentation elements, described by	for the needs of the presentation, numbers are presentation elements,
presentation boxes, just like the fraction bar or the word ``Summary''.	described by presentation boxes, just like the fraction bar or the word
Nevertheless, numbers differ from these other boxes because their content	``Summary''. Nevertheless, numbers differ from these other boxes because their
varies from instance to instance, even though they are of the same type,	content varies from instance to instance, even though they are of the same
whereas all fraction bars are horizontal lines and the same word ``Summary''	type, whereas all fraction bars are horizontal lines and the same word
appears at the head of every document's summary.</p>	``Summary'' appears at the head of every document's summary.</p>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc416">Presentation parameters</a></h3>	<h3><a name="sectc416">Presentation parameters</a></h3>
<p>
The principal parameters which determine document presentation are the	<p>The principal parameters which determine document presentation are the
<em>positions</em> and <em>dimensions</em> of boxes, the <em>font</em>, the	<em>positions</em> and <em>dimensions</em> of boxes, the <em>font</em>, the
<em>style</em>, the <em>size</em>, the <em>underlining</em> and the	<em>style</em>, the <em>size</em>, the <em>underlining</em> and the
<em>color</em> of their content. From these parameters, and some others of	<em>color</em> of their content. From these parameters, and some others of
Line 3106 less importance, it is possible to repre	Line 2681 less importance, it is possible to repre
for the textual parts of the document. These same parameters can be used to	for the textual parts of the document. These same parameters can be used to
describe the geometry of the non-textual elements, even though they are	describe the geometry of the non-textual elements, even though they are
two-dimensional elements unlike the text, which is linear.</p>	two-dimensional elements unlike the text, which is linear.</p>
<p>
As we have already seen, the positions of the boxes always respect the rule	<p>As we have already seen, the positions of the boxes always respect the
of enclosure: a box in the tree encloses all the boxes of the next lower level	rule of enclosure: a box in the tree encloses all the boxes of the next lower
which are attached to it. The positional parameters permit the specification	level which are attached to it. The positional parameters permit the
of the position of each box in relation to the enclosing box or to its sibling	specification of the position of each box in relation to the enclosing box or
boxes (boxes directly attached to the same enclosing box in the tree of	to its sibling boxes (boxes directly attached to the same enclosing box in the
boxes).</p>	tree of boxes).</p>
<p>
The presentation parameters also provide control over the dimensions of the	<p>The presentation parameters also provide control over the dimensions of the
boxes. The dimensions of a box can depend either on its content or on its	boxes. The dimensions of a box can depend either on its content or on its
context (its sibling boxes and the enclosing box). Each dimension (height or	context (its sibling boxes and the enclosing box). Each dimension (height or
width) can be defined independently of the other.</p>	width) can be defined independently of the other.</p>
<p>
Because of the position and dimension parameters, it is possible to do the	<p>Because of the position and dimension parameters, it is possible to do the
same things that are normally done in typography by changing margins, line	same things that are normally done in typography by changing margins, line
lengths, and vertical or horizontal skips. This approach can also align or	lengths, and vertical or horizontal skips. This approach can also align or
center elements and groups of elements.</p>	center elements and groups of elements.</p>
<p>
In contrast to the position and dimension parameters, the font, style, size,	<p>In contrast to the position and dimension parameters, the font, style,
underlining, and color do not concern the box itself (the rectangle delimiting	size, underlining, and color do not concern the box itself (the rectangle
the element), but its content. These parameters indicate the typographic	delimiting the element), but its content. These parameters indicate the
attributes which must be applied to the text contained in the box, and by	typographic attributes which must be applied to the text contained in the box,
extension, to all base elements.</p>	and by extension, to all base elements.</p>
<p>
For text, the font parameter is used to change the family of characters	<p>For text, the font parameter is used to change the family of characters
(Times, Helvetica, Courier, etc.); the style is used to obtain italic or	(Times, Helvetica, Courier, etc.); the style is used to obtain italic or
roman, bold or light characters; the size determines the point size of the	roman, bold or light characters; the size determines the point size of the
characters; underlining defines the type and thickness of the lines drawn	characters; underlining defines the type and thickness of the lines drawn
above, below, or through the characters.</p>	above, below, or through the characters.</p>
<p>
For graphics, the line style parameter can be either solid, dotted, or dashed;	<p>For graphics, the line style parameter can be either solid, dotted, or
the line thickness parameter controls the width of the lines; the fill pattern	dashed; the line thickness parameter controls the width of the lines; the fill
parameter determines how closed geometric figures must be filled.</p>	pattern parameter determines how closed geometric figures must be filled.</p>
<p>
While some of the parameters which determine the appearance of a box's	<p>While some of the parameters which determine the appearance of a box's
contents make sense only for one content type (text or graphic), other	contents make sense only for one content type (text or graphic), other
parameters apply to all content types: these are the color parameters. These	parameters apply to all content types: these are the color parameters. These
indicate the color of lines and the background color.</p>	indicate the color of lines and the background color.</p>
Line 3148 indicate the color of lines and the back	Line 2723 indicate the color of lines and the back
</div>	</div>

<div class="section">	<div class="section">

<h2><a name="sectb42">Presentation description language</a></h2>	<h2><a name="sectb42">Presentation description language</a></h2>
<p>
A generic presentation defines the values of presentation parameters (or the	<p>A generic presentation defines the values of presentation parameters (or
way to calculate those values) for a generic structure, or more precisely, for	the way to calculate those values) for a generic structure, or more precisely,
all the element types and all the global and local attributes defined in that	for all the element types and all the global and local attributes defined in
generic structure. This definition of the presentation parameters is made	that generic structure. This definition of the presentation parameters is
with the P language. A program written in this language, that is a generic	made with the P language. A program written in this language, that is a
presentation expressed in P, is call a <em>presentation schema</em>. This	generic presentation expressed in P, is call a <em>presentation schema</em>.
section describes the syntax and semantics of the language, using the same <a	This section describes the syntax and semantics of the language, using the
href="#sectc321">meta-language</a> as was used for the definition of the S	same <a href="#sectc321">meta-language</a> as was used for the definition of
language.</p>	the S language.</p>
<p>
Recall that it is possible to write many different presentation schemas for	<p>Recall that it is possible to write many different presentation schemas for
the same class of documents or objects. This allows users to choose for a	the same class of documents or objects. This allows users to choose for a
document the graphical appearance which best suits their type of work or	document the graphical appearance which best suits their type of work or
their personal taste.</p>	their personal taste.</p>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc421">The organization of a presentation schema</a></h3>	<h3><a name="sectc421">The organization of a presentation schema</a></h3>
<p>
A presentation schema begins with the word <tt>PRESENTATION</tt> and ends with	<p>A presentation schema begins with the word <tt>PRESENTATION</tt> and ends
the word <tt>END</tt>. The word <tt>PRESENTATION</tt> is followed by the name	with the word <tt>END</tt>. The word <tt>PRESENTATION</tt> is followed by the
of the generic structure to which the presentation will be applied. This name	name of the generic structure to which the presentation will be applied. This
must be the same as that which follows the keyword <tt>STRUCTURE</tt> in the	name must be the same as that which follows the keyword <tt>STRUCTURE</tt> in
structure schema associated with the presentation schema.</p>	the structure schema associated with the presentation schema.</p>
<p>
After this declaration of the name of the structure, the following sections	<p>After this declaration of the name of the structure, the following sections
appear (in order):</p>	appear (in order):</p>
<ul>	<ul>
<li>	<li>Declarations of
Declarations of	<ul>
<ul>	<li>all views,</li>
<li>	<li>printed views,</li>
all views,	<li>counters,</li>
</li>	<li>presentation constants,</li>
<li>	<li>variables,</li>
printed views,	</ul>
</li>	</li>
<li>	<li>default presentation rules,</li>
counters,	<li>presentation box and page layout box definitions,</li>
</li>	<li>presentation rules for structured elements,</li>
<li>	<li>presentation rules for attributes,</li>
presentation constants,	<li>rules for transmitting values to attributes of included documents.</li>
</li>
<li>
variables,
</li>
</ul>
</li>
<li>
default presentation rules,
</li>
<li>
presentation box and page layout box definitions,
</li>
<li>
presentation rules for structured elements,
</li>
<li>
presentation rules for attributes,
</li>
<li>
rules for transmitting values to attributes of included documents.
</li>
</ul>	</ul>
<p>
Each of these sections is introduced by a keyword which is followed by a	<p>Each of these sections is introduced by a keyword which is followed by a
sequence of declarations. Every section is optional.</p>	sequence of declarations. Every section is optional.</p>
<pre> SchemaPres ='PRESENTATION' ElemID ';'	<pre> SchemaPres ='PRESENTATION' ElemID ';'
[ 'VIEWS' ViewSeq ]	[ 'VIEWS' ViewSeq ]
Line 3234 sequence of declarations. Every section	Line 2786 sequence of declarations. Every section
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc422">Views</a></h3>	<h3><a name="sectc422">Views</a></h3>
<p>
Each of the possible views must be declared in the presentation schema. As	<p>Each of the possible views must be declared in the presentation schema. As
has <a href="#views">already been described</a>, the presentation rules for an	has <a href="#views">already been described</a>, the presentation rules for an
element type can vary according to the view in which the element appears. The	element type can vary according to the view in which the element appears. The
name of the view is used to designate the view to which the presentation rules	name of the view is used to designate the view to which the presentation rules
Line 3246 definition of the view's contents are di	Line 2797 definition of the view's contents are di
rules attached to the different element types and attributes. The	rules attached to the different element types and attributes. The
<tt>VIEWS</tt> section is simply a sequence of view names separated by commas	<tt>VIEWS</tt> section is simply a sequence of view names separated by commas
and terminated by a semi-colon.</p>	and terminated by a semi-colon.</p>
<p>
One of the view names (and only one) can be followed by the keyword	<p>One of the view names (and only one) can be followed by the keyword
<tt>EXPORT</tt>. This keyword identifies the view which presents the members	<tt>EXPORT</tt>. This keyword identifies the view which presents the members
of the document class in <a href="#sectc3213">skeleton form</a>. The	of the document class in <a href="#sectc3213">skeleton form</a>. The
graphical appearance and the content of this view is defined just as with	graphical appearance and the content of this view is defined just as with
other views, but it is useless to specify presentation rules concerning this	other views, but it is useless to specify presentation rules concerning this
view for the elements which are not loaded in the skeleton form.</p>	view for the elements which are not loaded in the skeleton form.</p>
<p>
It is not necessary to declare any views; in this case there is a single	<p>It is not necessary to declare any views; in this case there is a single
unnamed view. If many views are declared, the first view listed is considered	unnamed view. If many views are declared, the first view listed is considered
the principal view. The principal view is the one to which all rules that are	the principal view. The principal view is the one to which all rules that are
not preceded by an indication of a view will apply (see the <a	not preceded by an indication of a view will apply (see the <a
href="#inkeyword">instruction <tt>IN</tt></a>).</p>	href="#inkeyword">instruction <tt>IN</tt></a>).</p>
<p>
The principal view is the the one which the editor presents on the screen when	<p>The principal view is the the one which the editor presents on the screen
the user asks to create or edit a document. Thus, it makes sense to put the	when the user asks to create or edit a document. Thus, it makes sense to put
most frequently used view at the head of the list. But if the structure	the most frequently used view at the head of the list. But if the structure
schema contains <a href="#sectc3213">skeleton elements</a> and is loaded in	schema contains <a href="#sectc3213">skeleton elements</a> and is loaded in
its skeleton form, the view whose name is followed by the keyword	its skeleton form, the view whose name is followed by the keyword
<tt>EXPORT</tt> will be opened and no other views can be opened.</p>	<tt>EXPORT</tt> will be opened and no other views can be opened.</p>
<pre> 'VIEWS' ViewSeq	<pre> 'VIEWS' ViewSeq
ViewSeq = ViewDeclaration	ViewSeq = ViewDeclaration
< ',' ViewDeclaration > ';' .	< ',' ViewDeclaration > ';' .
ViewDeclaration = ViewID [ 'EXPORT' ] .	ViewDeclaration = ViewID [ 'EXPORT' ] .
ViewID = NAME .</pre>	ViewID = NAME .</pre>

<blockquote class="example">	<blockquote class="example">
<p>	<p><strong>Example:</strong></p>
<strong>Example:</strong></p>
<p>	<p>When editing a report, it might be useful have views of the table of
When editing a report, it might be useful have views of the table of contents	contents and of the mathematical formulas, in addition to the principal view
and of the mathematical formulas, in addition to the principal view which	which shows the document in its entirety. To achieve this, a presentation
shows the document in its entirety. To achieve this, a presentation schema	schema for the Report class would have the following <tt>VIEWS</tt>
for the Report class would have the following <tt>VIEWS</tt> section:</p>	section:</p>
<pre>VIEWS	<pre>VIEWS
Full_text, Table_of_contents, Formulas;</pre>	Full_text, Table_of_contents, Formulas;</pre>
<p>
The contents of these views are specified in the presentation rules of the	<p>The contents of these views are specified in the presentation rules of
schema.</p>	the schema.</p>
</blockquote>	</blockquote>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc423">Print Views</a></h3>	<h3><a name="sectc423">Print Views</a></h3>
<p>
When editing a document, each view is presented in a different window. In	<p>When editing a document, each view is presented in a different window. In
addition to the views specified by the <tt>VIEWS</tt> instruction, the user	addition to the views specified by the <tt>VIEWS</tt> instruction, the user
can display the associated elements with one window for each type of	can display the associated elements with one window for each type of
associated element.</p>	associated element.</p>
<p>
When printing a document, it is possible to print any number of views, chosen	<p>When printing a document, it is possible to print any number of views,
from among all the views which the editor can display (views in the strict	chosen from among all the views which the editor can display (views in the
sense or associated elements). Print views, as well as the order in which	strict sense or associated elements). Print views, as well as the order in
they must be printed, are indicated by the <tt>PRINT</tt> instruction. It	which they must be printed, are indicated by the <tt>PRINT</tt> instruction.
appears after the <tt>VIEWS</tt> instruction and is formed of the keyword	It appears after the <tt>VIEWS</tt> instruction and is formed of the keyword
<tt>PRINT</tt> followed by the ordered list of print view names. The print	<tt>PRINT</tt> followed by the ordered list of print view names. The print
view names are separated by commas and followed by a semi-colon. A print view	view names are separated by commas and followed by a semi-colon. A print view
name is either a view name declared in the <tt>VIEWS</tt> instruction or the	name is either a view name declared in the <tt>VIEWS</tt> instruction or the
Line 3308 name of an associated element type (with	Line 2859 name of an associated element type (with
associated element must have been declared in the <tt>ASSOC</tt> section of	associated element must have been declared in the <tt>ASSOC</tt> section of
the structure schema.</p>	the structure schema.</p>
<pre> 'PRINT' PrintViewSeq	<pre> 'PRINT' PrintViewSeq
PrintViewSeq = PrintView < ',' PrintView > ';' .	PrintViewSeq = PrintView < ',' PrintView > ';' .
PrintView = ViewID / ElemID .</pre>	PrintView = ViewID / ElemID .</pre>
<p>
If the <tt>PRINT</tt> instruction is absent, the printing program will print	<p>If the <tt>PRINT</tt> instruction is absent, the printing program will
only the principal view (the first view specified by the <tt>VIEWS</tt>	print only the principal view (the first view specified by the <tt>VIEWS</tt>
instruction or the single, unnamed view when there is no <tt>VIEWS</tt>	instruction or the single, unnamed view when there is no <tt>VIEWS</tt>
instruction).</p>	instruction).</p>

<blockquote class="example">	<blockquote class="example">
<p>	<p><strong>Example:</strong></p>
<strong>Example:</strong></p>
<p>	<p>Consider a Report presentation using the view declarations from the
Consider a Report presentation using the view declarations from the preceding	preceding example. Suppose we want to print the full text and table of
example. Suppose we want to print the full text and table of contents views,	contents views, but not the Formulas view, which is only useful when
but not the Formulas view, which is only useful when editing. In addition,	editing. In addition, suppose that we also want to print the bibliographic
suppose that we also want to print the bibliographic citations, which are	citations, which are associated elements (of type <tt>Citation</tt>). A
associated elements (of type <tt>Citation</tt>). A sensible printing order	sensible printing order would be to print the full text then the
would be to print the full text then the bibliography and finally the table of	bibliography and finally the table of contents. To obtain this result when
contents. To obtain this result when printing, the presentation schema would	printing, the presentation schema would say:</p>
say:</p>	<pre>PRINT
<pre>PRINT
Full_text, Citations, Table_of_contents;</pre>	Full_text, Citations, Table_of_contents;</pre>
</blockquote>	</blockquote>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc424">Counters</a></h3>	<h3><a name="sectc424">Counters</a></h3>
<p>
A presentation has a <em>counter</em> for each type of number in the	<p>A presentation has a <em>counter</em> for each type of number in the
presentation. All counters, and therefore all types of numbers, used in the	presentation. All counters, and therefore all types of numbers, used in the
schema must be declared after the <tt>COUNTERS</tt> keyword.</p>	schema must be declared after the <tt>COUNTERS</tt> keyword.</p>
<p>
Each counter declaration is composed of a name identifying the counter	<p>Each counter declaration is composed of a name identifying the counter
followed by a colon and the counting function to be applied to the counter.	followed by a colon and the counting function to be applied to the counter.
The counter declaration ends with a semi-colon.</p>	The counter declaration ends with a semi-colon.</p>
<p>
The counting function indicates how the counter values will be calculated.	<p>The counting function indicates how the counter values will be calculated.
Three types of counting functions are available. The first type is used to	Three types of counting functions are available. The first type is used to
count the elements of a list or aggregate: it assigns to the counter the rank	count the elements of a list or aggregate: it assigns to the counter the rank
of the element in the list or aggregate. More precisely, the function</p>	of the element in the list or aggregate. More precisely, the function</p>
<pre>RANK OF ElemID [ LevelAsc ] [ INIT AttrID ]	<pre>RANK OF ElemID [ LevelAsc ] [ INIT AttrID ]
[ 'REINIT' AttrID ]</pre>	[ 'REINIT' AttrID ]</pre>
<p>
indicates that when an element creates, by a creation rule (see the <a	<p>indicates that when an element creates, by a creation rule (see the <a
href="#sectc4232"><tt>Create</tt> instructions</a>), a presentation box	href="#sectc4232"><tt>Create</tt> instructions</a>), a presentation box
containing the counter value, this value is the rank of the creating element,	containing the counter value, this value is the rank of the creating element,
if it is of type <tt>ElemID</tt>, otherwise the rank of the first element of	if it is of type <tt>ElemID</tt>, otherwise the rank of the first element of
type <tt>ElemID</tt> which encloses the creating element in the logical	type <tt>ElemID</tt> which encloses the creating element in the logical
structure of the document.</p>	structure of the document.</p>
<p>
The type name can be preceded by a star in the special case where the	<p>The type name can be preceded by a star in the special case where the
structure schema defines an element of whose <tt>ElemID</tt> is the same as	structure schema defines an element of whose <tt>ElemID</tt> is the same as
that of an <a href="#sectd3284">inclusion</a> without expansion or with	that of an <a href="#sectd3284">inclusion</a> without expansion or with
partial expansion. To resolve this ambiguity, the <tt>ElemID</tt> alone	partial expansion. To resolve this ambiguity, the <tt>ElemID</tt> alone
refers to the type defined in the structure schema while the <tt>ElemID</tt>	refers to the type defined in the structure schema while the <tt>ElemID</tt>
preceded by a star refers to the included type.</p>	preceded by a star refers to the included type.</p>
<p>
The type name <tt>ElemID</tt> can be followed by an integer. That number	<p>The type name <tt>ElemID</tt> can be followed by an integer. That number
represents the relative level, among the ancestors of the creating element, of	represents the relative level, among the ancestors of the creating element, of
the element whose rank is asked. If that relative level <i>n</i> is unsigned,	the element whose rank is asked. If that relative level <i>n</i> is unsigned,
the <i>n</i><sup>th</sup> element of type <tt>ElemID</tt> encountered when	the <i>n</i><sup>th</sup> element of type <tt>ElemID</tt> encountered when
Line 3373 travelling the logical structure from th	Line 2923 travelling the logical structure from th
taken into account. If the relative level is negative, the logical structure	taken into account. If the relative level is negative, the logical structure
is travelled in the other direction, from the creating element to the	is travelled in the other direction, from the creating element to the
root.</p>	root.</p>
<p>
The function can end with the keyword <tt>INIT</tt> followed by the name of a	<p>The function can end with the keyword <tt>INIT</tt> followed by the name of
numeric attribute (and only a numeric attribute). Then, the rank of the first	a numeric attribute (and only a numeric attribute). Then, the rank of the
element of the list or aggregate is considered to be the value of this	first element of the list or aggregate is considered to be the value of this
attribute, rather than the default value of 1, and the rank of the other	attribute, rather than the default value of 1, and the rank of the other
elements is shifted accordingly. The attribute which determines the initial	elements is shifted accordingly. The attribute which determines the initial
value is searched on the element itself and on its ancestors.</p>	value is searched on the element itself and on its ancestors.</p>
<p>
The function can end with the keyword <tt>REINIT</tt> followed by the name of	<p>The function can end with the keyword <tt>REINIT</tt> followed by the name
a numeric attribute (and only a numeric attribute). Then, if an element to be	of a numeric attribute (and only a numeric attribute). Then, if an element to
counted has this attribute, the counter value for this element is the	be counted has this attribute, the counter value for this element is the
attribute value and the following elements are numbered starting from this	attribute value and the following elements are numbered starting from this
value.</p>	value.</p>
<p>
When the <tt>RANK</tt> function is written</p>	<p>When the <tt>RANK</tt> function is written</p>
<pre>RANK OF Page [ ViewID ] [ INIT AttrID ]</pre>	<pre>RANK OF Page [ ViewID ] [ INIT AttrID ]</pre>
<p>
(<tt>Page</tt>is a keyword of the P language), the counter takes as its value	<p>(<tt>Page</tt>is a keyword of the P language), the counter takes as its
the number of the page on which the element which creates the presentation box	value the number of the page on which the element which creates the
containing the number appears. This is done as if the pages of the document	presentation box containing the number appears. This is done as if the pages
form a list for each view. The counter only takes into account the pages of	of the document form a list for each view. The counter only takes into
the relevant view, that is the view displaying the presentation box whose	account the pages of the relevant view, that is the view displaying the
contents take the value of the number. However, if the keyword <tt>Page</tt>	presentation box whose contents take the value of the number. However, if the
is followed by the name of a view (between parentheses), it is the pages of	keyword <tt>Page</tt> is followed by the name of a view (between parentheses),
that view that are taken into account. As in the preceding form, the	it is the pages of that view that are taken into account. As in the preceding
<tt>RANK</tt> function applied to pages can end with the <tt>INIT</tt> keyword	form, the <tt>RANK</tt> function applied to pages can end with the
followed by the name of a numeric attribute which sets the value of the first	<tt>INIT</tt> keyword followed by the name of a numeric attribute which sets
page's number. This attribute must be a local attribute of the document	the value of the first page's number. This attribute must be a local
itself, and not of one of its components.</p>	attribute of the document itself, and not of one of its components.</p>
<p>
The second counting function is used to count the occurrences of a certain	<p>The second counting function is used to count the occurrences of a certain
element type in a specified context. The instruction</p>	element type in a specified context. The instruction</p>
<pre>SET n ON Type1 ADD m ON Type2 [ INIT AttrID ]</pre>	<pre>SET n ON Type1 ADD m ON Type2 [ INIT AttrID ]</pre>
<p>
says that when the document is traversed from beginning to end (in the order	<p>says that when the document is traversed from beginning to end (in the
induced by the logical structure), the counter is assigned the value	order induced by the logical structure), the counter is assigned the value
<tt>n</tt> each time an element of type <tt>Type1</tt> is encountered, no	<tt>n</tt> each time an element of type <tt>Type1</tt> is encountered, no
matter what the current value of the counter, and the value <tt>m</tt> is	matter what the current value of the counter, and the value <tt>m</tt> is
added to the current value of the counter each time an element of type	added to the current value of the counter each time an element of type
<tt>Type2</tt> is encountered.</p>	<tt>Type2</tt> is encountered.</p>
<p>
As with the <tt>RANK</tt> function, the type names can be preceded by a star	<p>As with the <tt>RANK</tt> function, the type names can be preceded by a
to resolve the ambiguity of included elements.</p>	star to resolve the ambiguity of included elements.</p>
<p>
If the function ends with the keyword <tt>INIT</tt> followed by the name of an	<p>If the function ends with the keyword <tt>INIT</tt> followed by the name of
attribute and if the document possesses this attribute, the value of this	an attribute and if the document possesses this attribute, the value of this
attribute is used in place of <tt>n</tt>. The attribute must be numeric. It	attribute is used in place of <tt>n</tt>. The attribute must be numeric. It
is searched on the element itself and on its ancestors.</p>	is searched on the element itself and on its ancestors.</p>
<p>
This function can also be used with the <tt>Page</tt> keyword in the place of	<p>This function can also be used with the <tt>Page</tt> keyword in the place
<tt>Type1</tt> or <tt>Type2</tt>. In the first case, the counter is	of <tt>Type1</tt> or <tt>Type2</tt>. In the first case, the counter is
reinitialized on each page with the value <tt>n</tt>, while in the second	reinitialized on each page with the value <tt>n</tt>, while in the second
case, it is incremented by <tt>m</tt> on each page. As with the preceding	case, it is incremented by <tt>m</tt> on each page. As with the preceding
counting function, the word <tt>Page</tt> can be followed by a name between	counting function, the word <tt>Page</tt> can be followed by a name between
parentheses. In this case, the name specifies a view whose pages are taken	parentheses. In this case, the name specifies a view whose pages are taken
into account.</p>	into account.</p>
<p>
The definition of a counter can contain several <tt>SET</tt> functions and	<p>The definition of a counter can contain several <tt>SET</tt> functions and
several <tt>ADD</tt> functions, each with a different value. The total number	several <tt>ADD</tt> functions, each with a different value. The total number
of counting functions must not be greater than 6.</p>	of counting functions must not be greater than 6.</p>
<p>
The third counting function is used to count the elements of a certain type	<p>The third counting function is used to count the elements of a certain type
encountered when travelling from the creating element to the root of the	encountered when travelling from the creating element to the root of the
logical structure. The creating element is included if it is of that type.	logical structure. The creating element is included if it is of that type.
That function is written</p>	That function is written</p>
<pre>RLEVEL OF Type</pre>	<pre>RLEVEL OF Type</pre>
<p>
where <tt>Type</tt> represents the type of the elements to be counted.</p>	<p>where <tt>Type</tt> represents the type of the elements to be counted.</p>
<p>
The formal definition of counter declarations is:</p>	<p>The formal definition of counter declarations is:</p>
<pre> 'COUNTERS' CounterSeq	<pre> 'COUNTERS' CounterSeq
CounterSeq = Counter < Counter > .	CounterSeq = Counter < Counter > .
Counter = CounterID ':' CounterFunc ';' .	Counter = CounterID ':' CounterFunc ';' .
CounterID = NAME .	CounterID = NAME .
CounterFunc = 'RANK' 'OF' TypeOrPage [ SLevelAsc ]	CounterFunc = 'RANK' 'OF' TypeOrPage [ SLevelAsc ]
[ 'INIT' AttrID ] [ 'REINIT' AttrID ] /	[ 'INIT' AttrID ] [ 'REINIT' AttrID ] /
SetFunction < SetFunction >	SetFunction < SetFunction >
AddFunction < AddFunction >	AddFunction < AddFunction >
[ 'INIT' AttrID ] /	[ 'INIT' AttrID ] /
'RLEVEL' 'OF' ElemID .	'RLEVEL' 'OF' ElemID .
SLevelAsc = [ '-' ] LevelAsc .	SLevelAsc = [ '-' ] LevelAsc .
Line 3460 The formal definition of counter declara	Line 3010 The formal definition of counter declara
TypeOrPage = 'Page' [ '(' ViewID ')' ] /	TypeOrPage = 'Page' [ '(' ViewID ')' ] /
[ '*' ] ElemID .	[ '*' ] ElemID .
CounterValue = NUMBER .</pre>	CounterValue = NUMBER .</pre>

<blockquote class="example">	<blockquote class="example">
<p>	<p><strong>Example:</strong></p>
<strong>Example:</strong></p>
<p>	<p>If the body of a chapter is defined as a sequence of sections in the
If the body of a chapter is defined as a sequence of sections in the structure	structure schema:</p>
schema:</p>	<pre>Chapter_body = LIST OF (Section =
<pre>Chapter_body = LIST OF (Section =
BEGIN	BEGIN
Section_Title = Text;	Section_Title = Text;
Section_Body = Paragraphs;	Section_Body = Paragraphs;
END	END
);</pre>	);</pre>
<p>
the section counter is declared:</p>	<p>the section counter is declared:</p>
<pre>SectionCtr : RANK OF Section;</pre>	<pre>SectionCtr : RANK OF Section;</pre>
<p>
and the display of the section number before the section title is obtained by	<p>and the display of the section number before the section title is
a <a href="#sectc4232"><tt>CreateBefore</tt> rule</a> attached the	obtained by a <a href="#sectc4232"><tt>CreateBefore</tt> rule</a> attached
<tt>Section_Title</tt> type, which creates a presentation box whose content is	the <tt>Section_Title</tt> type, which creates a presentation box whose
the value of the <tt>SectionCtr</tt> counter (see the <a	content is the value of the <tt>SectionCtr</tt> counter (see the <a
href="#sectc4231"><tt>Content</tt> instruction</a>).</p>	href="#sectc4231"><tt>Content</tt> instruction</a>).</p>
<p>
In order to number the formulas separately within each chapter, the formula	<p>In order to number the formulas separately within each chapter, the
counter is declared:</p>	formula counter is declared:</p>
<pre>FormulaCtr : SET 0 ON Chapter ADD 1 ON Formula;</pre>	<pre>FormulaCtr : SET 0 ON Chapter ADD 1 ON Formula;</pre>
<p>
and the display of the formula number in the right margin, alongside each	<p>and the display of the formula number in the right margin, alongside each
formula, is obtained by a <tt>CreateAfter</tt> instruction attached to the	formula, is obtained by a <tt>CreateAfter</tt> instruction attached to the
<tt>Formula</tt> type, which creates a presentation box whose content is the	<tt>Formula</tt> type, which creates a presentation box whose content is the
value of the <tt>FormulaCtr</tt> counter.</p>	value of the <tt>FormulaCtr</tt> counter.</p>
<p>
To number the page chapter by chapter, with the first page of each chapter	<p>To number the page chapter by chapter, with the first page of each
having the number 1, the counter definition would be</p>	chapter having the number 1, the counter definition would be</p>
<pre>ChapterPageCtr : SET 0 ON Chapter ADD 1 ON Page;</pre>	<pre>ChapterPageCtr : SET 0 ON Chapter ADD 1 ON Page;</pre>
<p>
If there is also a chapter counter</p>	<p>If there is also a chapter counter</p>
<pre>ChapterCtr : RANK OF Chapter;</pre>	<pre>ChapterCtr : RANK OF Chapter;</pre>
<p>
the <a href="#sectc4231">content</a> of a presentation box created at the top	<p>the <a href="#sectc4231">content</a> of a presentation box created at the
of each page could be defined as:</p>	top of each page could be defined as:</p>
<pre>Content : (VALUE(ChapterCtr, URoman) TEXT '-'	<pre>Content : (VALUE(ChapterCtr, URoman) TEXT '-'
VALUE(ChapterPageCtr, Arabic));</pre>	VALUE(ChapterPageCtr, Arabic));</pre>
<p>
Thus, the presentation box contains the number of the chapter in upper-case	<p>Thus, the presentation box contains the number of the chapter in
roman numerals followed by a hyphen and the number of the page within the	upper-case roman numerals followed by a hyphen and the number of the page
chapter in arabic numerals.</p>	within the chapter in arabic numerals.</p>
</blockquote>	</blockquote>

<blockquote class="example">	<blockquote class="example">
<p>	<p><strong>Example:</strong></p>
<strong>Example:</strong></p>
<p>	<p>To count tables and figures together in a document of the chapter type, a
To count tables and figures together in a document of the chapter type, a	counter could be defined using:</p>
counter could be defined using:</p>	<pre>CommonCtr : SET 0 ON Chapter ADD 1 ON Table
<pre>CommonCtr : SET 0 ON Chapter ADD 1 ON Table
ADD 1 ON Figure;</pre>	ADD 1 ON Figure;</pre>
</blockquote>	</blockquote>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc425">Presentation constants</a></h3>	<h3><a name="sectc425">Presentation constants</a></h3>
<p>
Presentation constants are used in the definition of the content of	<p>Presentation constants are used in the definition of the content of
presentation boxes. This content is used in <a href="#sectc426">variable	presentation boxes. This content is used in <a href="#sectc426">variable
definitions</a> and in the <a href="#sectc4231"><tt>Content</tt> rule</a>. The	definitions</a> and in the <a href="#sectc4231"><tt>Content</tt> rule</a>. The
only presentation constants which can be used are character strings,	only presentation constants which can be used are character strings,
mathematical symbols, graphical elements, and pictures, that is to say, base	mathematical symbols, graphical elements, and pictures, that is to say, base
elements.</p>	elements.</p>
<p>
Constants can be defined directly in the variables or presentation boxes	<p>Constants can be defined directly in the variables or presentation boxes
(<tt>Content</tt> rule) which use them. But it is only necessary them to	(<tt>Content</tt> rule) which use them. But it is only necessary them to
declare once, in the constant declaration section, even though they are used	declare once, in the constant declaration section, even though they are used
in many variables or boxes. Thus, each declared constant has a name, which	in many variables or boxes. Thus, each declared constant has a name, which
allows it to be designated whenever it is used, a type (one of the four base	allows it to be designated whenever it is used, a type (one of the four base
types) and a value (a character string or a single character for mathematical	types) and a value (a character string or a single character for mathematical
symbols and graphical elements).</p>	symbols and graphical elements).</p>
<p>
The constant declarations appear after the keyword <tt>CONST</tt>. Each	<p>The constant declarations appear after the keyword <tt>CONST</tt>. Each
declaration is composed of the name of the constant, an equals sign, a keyword	declaration is composed of the name of the constant, an equals sign, a keyword
representing its type (<tt>Text</tt>, <tt>Symbol</tt>, <tt>Graphics</tt> or	representing its type (<tt>Text</tt>, <tt>Symbol</tt>, <tt>Graphics</tt> or
<tt>Picture</tt>) and the string representing its value. A semi-colon	<tt>Picture</tt>) and the string representing its value. A semi-colon
terminates each declaration.</p>	terminates each declaration.</p>
<p>
In the case of a character string, the keyword <tt>Text</tt> can be followed	<p>In the case of a character string, the keyword <tt>Text</tt> can be
by the name of an alphabet (for example, <tt>Greek</tt> or <tt>Latin</tt>) in	followed by the name of an alphabet (for example, <tt>Greek</tt> or
which the constant's text should be expressed. If the alphabet name is	<tt>Latin</tt>) in which the constant's text should be expressed. If the
absent, the Latin alphabet is used. When the alphabet name is present, only	alphabet name is absent, the Latin alphabet is used. When the alphabet name
the first letter of the alphabet name is interpreted. Thus, the words	is present, only the first letter of the alphabet name is interpreted. Thus,
<tt>Greek</tt> and <tt>Grec</tt> designate the same alphabet. In current	the words <tt>Greek</tt> and <tt>Grec</tt> designate the same alphabet. In
versions of Thot, only the Greek and Latin alphabets are available.</p>	current versions of Thot, only the Greek and Latin alphabets are
	available.</p>
<pre> 'CONST' ConstSeq	<pre> 'CONST' ConstSeq
ConstSeq = Const < Const > .	ConstSeq = Const < Const > .
Const = ConstID '=' ConstType ConstValue ';' .	Const = ConstID '=' ConstType ConstValue ';' .
ConstID = NAME .	ConstID = NAME .
ConstType ='Text' [ Alphabet ] / 'Symbol' /	ConstType ='Text' [ Alphabet ] / 'Symbol' /
'Graphics' / 'Picture' .	'Graphics' / 'Picture' .
ConstValue = STRING .	ConstValue = STRING .
Alphabet = NAME .</pre>	Alphabet = NAME .</pre>
<p>
For character strings in the Latin alphabet (ISO Latin-1 character set),	<p>For character strings in the Latin alphabet (ISO Latin-1 character set),
characters having codes higher than 127 (decimal) are represented by their	characters having codes higher than 127 (decimal) are represented by their
code in octal.</p>	code in octal.</p>
<p>
In the case of a symbol or graphical element, the value only contains a single	<p>In the case of a symbol or graphical element, the value only contains a
character, between apostrophes, which indicates the form of the element which	single character, between apostrophes, which indicates the form of the element
must be drawn in the box whose content is the constant. The symbol or	which must be drawn in the box whose content is the constant. The symbol or
graphical element takes the dimensions of the box, which are determined by the	graphical element takes the dimensions of the box, which are determined by the
<tt>Height</tt> and <tt>Width</tt> rules. See <a href="#sectb72">table of	<tt>Height</tt> and <tt>Width</tt> rules. See <a href="#sectb72">table of
codes</a> for the symbols and graphical elements.</p>	codes</a> for the symbols and graphical elements.</p>

<blockquote class="example">	<blockquote class="example">
<p>	<p><strong>Example:</strong></p>
<strong>Example:</strong></p>
<p>	<p>The constants ``Summary:'' and fraction bar, which were described
The constants ``Summary:'' and fraction bar, which were described earlier, are	earlier, are declared:</p>
declared:</p>	<pre>CONST
<pre>CONST
SummaryConst = Text 'Summary:';	SummaryConst = Text 'Summary:';
Bar = Graphics 'h';</pre>	Bar = Graphics 'h';</pre>
</blockquote>	</blockquote>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc426">Variables</a></h3>	<h3><a name="sectc426">Variables</a></h3>
<p>
Variables permit the definition of computed content for presentation boxes. A	<p>Variables permit the definition of computed content for presentation boxes.
variable is associated with a presentation box by a <tt>Content</tt> rule; but	A variable is associated with a presentation box by a <tt>Content</tt> rule;
before being used in a <tt>Content</tt> rule, a variable can be defined in the	but before being used in a <tt>Content</tt> rule, a variable can be defined in
<tt>VAR</tt> section. It is also possible to define a variable at the time of	the <tt>VAR</tt> section. It is also possible to define a variable at the
its use in a <tt>Content</tt> rule, as can be done with a constant.</p>	time of its use in a <tt>Content</tt> rule, as can be done with a
<p>	constant.</p>
A variable has a name and a value which is a character string resulting from
the concatenation of the values of a sequence of functions. Each variable	<p>A variable has a name and a value which is a character string resulting
declaration is composed of the variable name followed by a colon and the	from the concatenation of the values of a sequence of functions. Each
sequence of functions which produces its value, separated by spaces. Each	variable declaration is composed of the variable name followed by a colon and
	the sequence of functions which produces its value, separated by spaces. Each
declaration is terminated by a semi-colon.</p>	declaration is terminated by a semi-colon.</p>
<pre> 'VAR' VarSeq	<pre> 'VAR' VarSeq
VarSeq = Variable < Variable > .	VarSeq = Variable < Variable > .
Variable = VarID ':' FunctionSeq ';' .	Variable = VarID ':' FunctionSeq ';' .
VarID = NAME .	VarID = NAME .
FunctionSeq = Function < Function > .</pre>	FunctionSeq = Function < Function > .</pre>
<p>
Several functions are available. The first two return, in the form of a	<p>Several functions are available. The first two return, in the form of a
character string, the current date. <tt>DATE</tt> returns the date in	character string, the current date. <tt>DATE</tt> returns the date in
English, while <tt>FDATE</tt> returns the date in french.</p>	English, while <tt>FDATE</tt> returns the date in french.</p>
<p>
Two other functions, <tt>DocName</tt> and <tt>DirName</tt>, return the	<p>Two other functions, <tt>DocName</tt> and <tt>DirName</tt>, return the
document name and the directory where the document is stored.</p>	document name and the directory where the document is stored.</p>
<p>
Function <tt>ElemName</tt> returns the type of the element which created the	<p>Function <tt>ElemName</tt> returns the type of the element which created
presentation box whose contents are the variable.</p>	the presentation box whose contents are the variable.</p>
<p>
Another function simply returns the value of a presentation constant. For any	<p>Another function simply returns the value of a presentation constant. For
constant declared in the <tt>CONST</tt> section, it is sufficient to give the	any constant declared in the <tt>CONST</tt> section, it is sufficient to give
name of the constant. Otherwise, the type and value of the constant must be	the name of the constant. Otherwise, the type and value of the constant must
given, using the same form as in a <a href="#sectc425">constant	be given, using the same form as in a <a href="#sectc425">constant
declaration</a>. If the constant is not of type text, (types <tt>Symbol</tt>,	declaration</a>. If the constant is not of type text, (types <tt>Symbol</tt>,
<tt>Graphics</tt> or <tt>Picture</tt>), it must be alone in the variable	<tt>Graphics</tt> or <tt>Picture</tt>), it must be alone in the variable
definition; only constants of type <tt>Text</tt> can be mixed with other	definition; only constants of type <tt>Text</tt> can be mixed with other
functions.</p>	functions.</p>
<p>
It is also possible to obtain the value of an attribute, simply by mentioning	<p>It is also possible to obtain the value of an attribute, simply by
the attribute's name. The value of this function is the value of the	mentioning the attribute's name. The value of this function is the value of
attribute for the element which created the presentation box whose contents	the attribute for the element which created the presentation box whose
are the variable. If the creating element does not have the indicated	contents are the variable. If the creating element does not have the
attribute, the value is an empty string. In the case of a numeric attribute,	indicated attribute, the value is an empty string. In the case of a numeric
the attribute is translated into a decimal number in arabic numerals. If	attribute, the attribute is translated into a decimal number in arabic
another form is desired, the <tt>VALUE</tt> function must be used.</p>	numerals. If another form is desired, the <tt>VALUE</tt> function must be
<p>	used.</p>
The last available function returns, as a character string, the value of a
	<p>The last available function returns, as a character string, the value of a
counter, an attribute or a page number. This value can be presented in	counter, an attribute or a page number. This value can be presented in
different styles. The keyword <tt>VALUE</tt> is followed (between	different styles. The keyword <tt>VALUE</tt> is followed (between
parentheses) by the name of the counter, the name of the attribute, or the	parentheses) by the name of the counter, the name of the attribute, or the
Line 3639 value should be presented in arabic nume	Line 3190 value should be presented in arabic nume
roman numerals (<tt>LRoman</tt>), or upper-case roman numerals	roman numerals (<tt>LRoman</tt>), or upper-case roman numerals
(<tt>URoman</tt>), or by an upper-case letter (<tt>Uppercase</tt>) or	(<tt>URoman</tt>), or by an upper-case letter (<tt>Uppercase</tt>) or
lower-case letter (<tt>Lowercase</tt>).</p>	lower-case letter (<tt>Lowercase</tt>).</p>
<p>
For a page counter, the keyword <tt>PageNumber</tt> can be followed, between	<p>For a page counter, the keyword <tt>PageNumber</tt> can be followed,
parentheses, by the name of the view from which to obtain the page number. By	between parentheses, by the name of the view from which to obtain the page
default, the first view declared in the <tt>VIEWS</tt> section is used. The	number. By default, the first view declared in the <tt>VIEWS</tt> section is
value obtained is the number of the page on which is found the element that is	used. The value obtained is the number of the page on which is found the
using the variable in a <tt>Content</tt> rule.</p>	element that is using the variable in a <tt>Content</tt> rule.</p>
<p>
For an ordinary counter, the name of the counter can be preceded by the	<p>For an ordinary counter, the name of the counter can be preceded by the
keyword <tt>MaxRangeVal</tt> or <tt>MinRangeVal</tt>. These keywords mean	keyword <tt>MaxRangeVal</tt> or <tt>MinRangeVal</tt>. These keywords mean
that the value returned by the function is the maximum (minimum resp.) value	that the value returned by the function is the maximum (minimum resp.) value
taken by the counter in the whole document, not the value for the element	taken by the counter in the whole document, not the value for the element
Line 3663 concerned by the function.</p>	Line 3214 concerned by the function.</p>
CounterStyle = 'Arabic' / 'LRoman' / 'URoman' /	CounterStyle = 'Arabic' / 'LRoman' / 'URoman' /
'Uppercase' / 'Lowercase' .	'Uppercase' / 'Lowercase' .
MinMax = 'MaxRangeVal' / 'MinRangeVal' .</pre>	MinMax = 'MaxRangeVal' / 'MinRangeVal' .</pre>

<blockquote class="example">	<blockquote class="example">
<p>	<p><strong>Example:</strong></p>
<strong>Example:</strong></p>
<p>	<p>To make today's date appear at the top of the first page of a report, a
To make today's date appear at the top of the first page of a report, a <a	<a href="#sectc4232"><tt>CREATE</tt> rule</a> associated with the
href="#sectc4232"><tt>CREATE</tt> rule</a> associated with the Report_Title	Report_Title element type generates a presentation box whose content
element type generates a presentation box whose content (specified by the	(specified by the <tt>Content</tt> rule of that presentation box) is the
<tt>Content</tt> rule of that presentation box) is the variable:</p>	variable:</p>
<pre>VAR	<pre>VAR
Todays_date : TEXT 'Version of ' DATE;</pre>	Todays_date : TEXT 'Version of ' DATE;</pre>
<p>
To produce, before each section title, the chapter number (in upper-case roman	<p>To produce, before each section title, the chapter number (in upper-case
numerals) followed by the section number (in arabic numerals), two counters	roman numerals) followed by the section number (in arabic numerals), two
must be defined:</p>	counters must be defined:</p>
<pre>COUNTERS	<pre>COUNTERS
ChapterCtr : RANK OF Chapter;	ChapterCtr : RANK OF Chapter;
SectionCtr : RANK OF Section;</pre>	SectionCtr : RANK OF Section;</pre>
<p>
and the Section_Title element must create a presentation box whose content is	<p>and the Section_Title element must create a presentation box whose
the variable</p>	content is the variable</p>
<pre>VAR	<pre>VAR
SectionNum : VALUE (ChapterCtr, URoman) TEXT '-'	SectionNum : VALUE (ChapterCtr, URoman) TEXT '-'
VALUE (SectionCtr, Arabic);</pre>	VALUE (SectionCtr, Arabic);</pre>
<p>
In order to make the page number on which each section begins appear in the	<p>In order to make the page number on which each section begins appear in
table of contents view next to the section title, each Section_Title element	the table of contents view next to the section title, each Section_Title
must create a presentation box, visible only in the table of contents view,	element must create a presentation box, visible only in the table of
whose content is the variable:</p>	contents view, whose content is the variable:</p>
<pre>VAR	<pre>VAR
TitlePageNume :	TitlePageNume :
VALUE (PageNumber(Full_text), Arabic);</pre>	VALUE (PageNumber(Full_text), Arabic);</pre>
</blockquote>	</blockquote>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc427">Default presentation rules</a></h3>	<h3><a name="sectc427">Default presentation rules</a></h3>
<p>
In order to avoid having to specify, for each element type defined in the	<p>In order to avoid having to specify, for each element type defined in the
structure schema, values for every one of the numerous presentation	structure schema, values for every one of the numerous presentation
parameters, the presentation schema allows the definition of a set of default	parameters, the presentation schema allows the definition of a set of default
presentation rules. These rules apply to all the boxes of the elements	presentation rules. These rules apply to all the boxes of the elements
defined in the structure schema and to the presentation boxes and page layout	defined in the structure schema and to the presentation boxes and page layout
boxes defined in the presentation schema. Only rules which differ from these	boxes defined in the presentation schema. Only rules which differ from these
default need to be specified in other sections of the presentation schema.</p>	default need to be specified in other sections of the presentation schema.</p>
<p>
For the primary view, the default rules can define every presentation	<p>For the primary view, the default rules can define every presentation
parameter, but not the <a href="#presfunct">presentation functions</a> or the	parameter, but not the <a href="#presfunct">presentation functions</a> or the
<a href="#sectc4223">linebreaking conditions</a> (the <tt>NoBreak1</tt>,	<a href="#sectc4223">linebreaking conditions</a> (the <tt>NoBreak1</tt>,
<tt>NoBreak2</tt>, and <tt>Gather</tt> rules).</p>	<tt>NoBreak2</tt>, and <tt>Gather</tt> rules).</p>
<p>
In a presentation schema, the default presentation rules section is optional;	<p>In a presentation schema, the default presentation rules section is
in this case, the <tt>DEFAULT</tt> keyword is also absent and the following	optional; in this case, the <tt>DEFAULT</tt> keyword is also absent and the
rules are considered to be the default rules:</p>	following rules are considered to be the default rules:</p>
<pre> Visibility: Enclosing =;	<pre> Visibility: Enclosing =;
VertRef: * . Left;	VertRef: * . Left;
HorizRef: Enclosed . HRef;	HorizRef: Enclosed . HRef;
Line 3766 rules are considered to be the default r	Line 3317 rules are considered to be the default r
FillPattern: Enclosing =;	FillPattern: Enclosing =;
Background: Enclosing =;	Background: Enclosing =;
Foreground: Enclosing =;</pre>	Foreground: Enclosing =;</pre>
<p>
If other values are desired for the default rules, they must be defined	<p>If other values are desired for the default rules, they must be defined
explicitly in the default rules section. In fact, it is only necessary to	explicitly in the default rules section. In fact, it is only necessary to
define those default rules which differ from the ones above, since the rules	define those default rules which differ from the ones above, since the rules
above will be used whenever a rule is not explicitly named.</p>	above will be used whenever a rule is not explicitly named.</p>
<p>
Default rules for views other than the primary view can also be specified.	<p>Default rules for views other than the primary view can also be specified.
Otherwise, the default rules for the primary views are applied to the other	Otherwise, the default rules for the primary views are applied to the other
views.</p>	views.</p>
<p>
Default rules are expressed in the same way as <a href="#sectc4215">explicit	<p>Default rules are expressed in the same way as <a
rules for document elements</a>.</p>	href="#sectc4215">explicit rules for document elements</a>.</p>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc428">Presentation and page layout boxes</a></h3>	<h3><a name="sectc428">Presentation and page layout boxes</a></h3>
<p>
The presentation process uses elements which are not part of the logical	<p>The presentation process uses elements which are not part of the logical
structure of the document, such as pages (which are the page layout boxes) or	structure of the document, such as pages (which are the page layout boxes) or
alternatively, rules, numbers, or words introducing certain parts of the	alternatively, rules, numbers, or words introducing certain parts of the
document, such as ``Summary'', ``Appendices'', ``Bibliography'', etc. (which	document, such as ``Summary'', ``Appendices'', ``Bibliography'', etc. (which
are presentation boxes).</p>	are presentation boxes).</p>
<p>
After the word <tt>BOXES</tt>, each presentation or page layout box is defined	<p>After the word <tt>BOXES</tt>, each presentation or page layout box is
by its name and a sequence of presentation rules which indicate how they must	defined by its name and a sequence of presentation rules which indicate how
be displayed. These rules are the same as those which define the boxes	they must be displayed. These rules are the same as those which define the
associated with element of the logical structure of the document, with a	boxes associated with element of the logical structure of the document, with a
single exception, the <a href="#sectc4231"><tt>Content</tt> rule</a> which is	single exception, the <a href="#sectc4231"><tt>Content</tt> rule</a> which is
used only to specify the content of presentation boxes. The content of boxes	used only to specify the content of presentation boxes. The content of boxes
associated with elements of the document structure is defined in each document	associated with elements of the document structure is defined in each document
or object and thus is not specified in the presentation schema, which applies	or object and thus is not specified in the presentation schema, which applies
to all documents or objects of a class.</p>	to all documents or objects of a class.</p>
<p>
Among the rules which define a presentation box, certain ones can refer to	<p>Among the rules which define a presentation box, certain ones can refer to
another presentation box (for example, in their positional rules). If the	another presentation box (for example, in their positional rules). If the
designated box is defined after the box which designates it, a	designated box is defined after the box which designates it, a
<tt>FORWARD</tt> instruction followed by the name of the designated box must	<tt>FORWARD</tt> instruction followed by the name of the designated box must
appear before the designation.</p>	appear before the designation.</p>
<pre> 'BOXES' BoxSeq	<pre> 'BOXES' BoxSeq
BoxSeq = Box < Box > .	BoxSeq = Box < Box > .
Box ='FORWARD' BoxID ';' /	Box ='FORWARD' BoxID ';' /
BoxID ':' ViewRuleSeq .	BoxID ':' ViewRuleSeq .
BoxID = NAME .</pre>	BoxID = NAME .</pre>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc429">Presentation of structured elements</a></h3>	<h3><a name="sectc429">Presentation of structured elements</a></h3>
<p>
After the words <tt>RULES</tt>, the presentation schema gives the presentation	<p>After the words <tt>RULES</tt>, the presentation schema gives the
rules that apply to the elements whose types are defined in the structure	presentation rules that apply to the elements whose types are defined in the
schema. Only those rules which differ from the <a	structure schema. Only those rules which differ from the <a
href="#sectc427">default</a> must be specified in the <tt>RULES</tt>	href="#sectc427">default</a> must be specified in the <tt>RULES</tt>
section.</p>	section.</p>
<p>
The rule definitions for each element type are composed of the name of the	<p>The rule definitions for each element type are composed of the name of the
element type (as specified in the structure schema) followed by a colon and	element type (as specified in the structure schema) followed by a colon and
the set of rules specific to that type.</p>	the set of rules specific to that type.</p>
<p>
The type name can be preceded by a star in the special case where the	<p>The type name can be preceded by a star in the special case where the
structure schema defines an <a href="#sectd3284">inclusion</a> without	structure schema defines an <a href="#sectd3284">inclusion</a> without
expansion (or with partial expansion) of a type with the same name as an	expansion (or with partial expansion) of a type with the same name as an
element of defined in the structure schema.</p>	element of defined in the structure schema.</p>
<p>
In the case where the element is a <a href="#sectd3285">mark pair</a>, but	<p>In the case where the element is a <a href="#sectd3285">mark pair</a>, but
only in this case, the type name can be preceded by the keywords	only in this case, the type name can be preceded by the keywords
<tt>First</tt> or <tt>Second</tt>. These keywords indicate whether the rules	<tt>First</tt> or <tt>Second</tt>. These keywords indicate whether the rules
that follow apply to the first or second mark of the pair.</p>	that follow apply to the first or second mark of the pair.</p>
<pre> 'RULES' PresentSeq	<pre> 'RULES' PresentSeq
PresentSeq = Present < Present > .	PresentSeq = Present < Present > .
Present = [ '*' ] [ FirstSec ] ElemID ':'	Present = [ '*' ] [ FirstSec ] ElemID ':'
ViewRuleSeq .	ViewRuleSeq .
FirstSec = 'First' / 'Second' .</pre>	FirstSec = 'First' / 'Second' .</pre>
<p>
A presentation schema can define presentation rules for base elements, which	<p>A presentation schema can define presentation rules for base elements,
are defined implicitly in the structure schemas. In the English version of	which are defined implicitly in the structure schemas. In the English version
the presentation schema compiler, the base type names are the same as in the S	of the presentation schema compiler, the base type names are the same as in
language, but they are terminated by the <tt>_UNIT</tt> suffix:	the S language, but they are terminated by the <tt>_UNIT</tt> suffix:
<tt>TEXT_UNIT</tt>, <tt>PICTURE_UNIT</tt>, <tt>SYMBOL_UNIT</tt>,	<tt>TEXT_UNIT</tt>, <tt>PICTURE_UNIT</tt>, <tt>SYMBOL_UNIT</tt>,
<tt>GRAPHICS_UNIT</tt>. The base type names are written in upper-case	<tt>GRAPHICS_UNIT</tt>. The base type names are written in upper-case
letters.</p>	letters.</p>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc4210">Logical attribute presentation</a></h3>	<h3><a name="sectc4210">Logical attribute presentation</a></h3>
<p>
After the keyword <tt>ATTRIBUTES</tt>, all attributes which are to have some	<p>After the keyword <tt>ATTRIBUTES</tt>, all attributes which are to have
effect on the presentation of the element to which they are attached must be	some effect on the presentation of the element to which they are attached must
mentioned, along with the corresponding presentation rules. This is true for	be mentioned, along with the corresponding presentation rules. This is true
both global attributes (which can be attached to all element types) and local	for both global attributes (which can be attached to all element types) and
attributes (which can only be attached to certain element types).</p>	local attributes (which can only be attached to certain element types).</p>
<p>
Also mentioned in this section are attributes which imply an effect on	<p>Also mentioned in this section are attributes which imply an effect on
elements in the subtree of the element to which they are attached. The	elements in the subtree of the element to which they are attached. The
presentation of these descendants can be modified as a function of the value	presentation of these descendants can be modified as a function of the value
of the attribute which they inherit, just as if it was attached to them	of the attribute which they inherit, just as if it was attached to them
directly.</p>	directly.</p>
<p>
The specification for each attribute includes the attribute's name, followed	<p>The specification for each attribute includes the attribute's name,
by an optional value specification and, after a colon, a set of rules. The	followed by an optional value specification and, after a colon, a set of
set of rules must contain at least one rule.</p>	rules. The set of rules must contain at least one rule.</p>
<p>
When there is no value specification, the rules are applied to all elements	<p>When there is no value specification, the rules are applied to all elements
which carry the attribute, no matter what their value. When the rules must	which carry the attribute, no matter what their value. When the rules must
only apply when the attribute has certain values, these values must be	only apply when the attribute has certain values, these values must be
specified. Thus, the same attribute can appear in the <tt>ATTRIBUTES</tt>	specified. Thus, the same attribute can appear in the <tt>ATTRIBUTES</tt>
section several times, with each appearance having a different value	section several times, with each appearance having a different value
specification. However, reference attributes never have a value specification	specification. However, reference attributes never have a value specification
and, as a result, can only appear once in the <tt>ATTRIBUTES</tt> section.</p>	and, as a result, can only appear once in the <tt>ATTRIBUTES</tt> section.</p>
<p>
To specify that the presentation rules apply to some of the descendants of the	<p>To specify that the presentation rules apply to some of the descendants of
element having the attribute, the name of the affected element type is given,	the element having the attribute, the name of the affected element type is
between parentheses, after the attribute name. This way, the presentation	given, between parentheses, after the attribute name. This way, the
rules for the attribute will be applied to the element having the attribute,	presentation rules for the attribute will be applied to the element having the
if it is of the given type, and to all of its descendants of the given type.	attribute, if it is of the given type, and to all of its descendants of the
In the case where this type is a <a href="#sectd3285">mark pair</a>, but only	given type. In the case where this type is a <a href="#sectd3285">mark
in this case, the type name can be preceded by the keywords <tt>First</tt> or	pair</a>, but only in this case, the type name can be preceded by the keywords
<tt>Second</tt>. These keywords indicate whether the rules that follow apply	<tt>First</tt> or <tt>Second</tt>. These keywords indicate whether the rules
to the first or second mark of the pair. If the rule must apply to several	that follow apply to the first or second mark of the pair. If the rule must
different element types, the specification must be repeated for each element	apply to several different element types, the specification must be repeated
type.</p>	for each element type.</p>
<p>
The specification of values for which the presentation rules will be applied	<p>The specification of values for which the presentation rules will be
varies according to the type of the attribute:</p>	applied varies according to the type of the attribute:</p>
<dl>	<dl>
<dt>numeric attribute</dt>	<dt>numeric attribute</dt>
<dd>	<dd>If the rules are to apply for one value of the attribute, then the
If the rules are to apply for one value of the attribute, then the attribute	attribute name is followed by an equals sign and this value. If the
name is followed by an equals sign and this value. If the rules are to apply	rules are to apply for all values less than (or greater than) a
for all values less than (or greater than) a threshold value, non-inclusive,	threshold value, non-inclusive, the attribute name followed by a '<'
the attribute name followed by a '<' sign (or a '>' sign, respectively) and	sign (or a '>' sign, respectively) and the threshold value. If the
the threshold value. If the rules must apply to a range of values, the	rules must apply to a range of values, the attribute name is followed by
attribute name is followed by the word '<tt>IN</tt>' and the two bounds of the	the word '<tt>IN</tt>' and the two bounds of the range, enclosed in
range, enclosed in brackets and separated by two periods ('<tt>..</tt>'). In	brackets and separated by two periods ('<tt>..</tt>'). In the case of
the case of ranges, the values of the bounds are included in the range.	ranges, the values of the bounds are included in the range.
<p>	<p>The threshold value in the comparisons can be the value of an
The threshold value in the comparisons can be the value of an attribute	attribute attached to an ancestor element. In this case, the attribute
attached to an ancestor element. In this case, the attribute name is given	name is given instead of a constant value.</p>
instead of a constant value.</p>	<p>It is also possible to write rules which apply only when a comparison
<p>	between two different attributes of the element's ancestors is true. In
It is also possible to write rules which apply only when a comparison between	this case, the first attribute name is followed by a comparison keyword
two different attributes of the element's ancestors is true. In this case, the	and the name of the second attribute. The comparison keywords are
first attribute name is followed by a comparison keyword and the name of the	<tt>EQUAL</tt> (simple equality), <tt>LESS</tt> (non-inclusive less
second attribute. The comparison keywords are <tt>EQUAL</tt> (simple	than), and <tt>GREATER</tt> (non-inclusive greater than).</p>
equality), <tt>LESS</tt> (non-inclusive less than), and <tt>GREATER</tt>	</dd>
(non-inclusive greater than).</p>	<dt>text attribute</dt>
</dd>	<dd>If the rules are to apply for one value of the attribute, then the
<dt>text attribute</dt>	attribute name is followed by an equals sign and this value.</dd>
<dd>	<dt>reference attribute</dt>
If the rules are to apply for one value of the attribute, then the attribute	<dd>There is never a value specification; the rules apply no matter what
name is followed by an equals sign and this value.	element is designated by the attribute.</dd>
</dd>	<dt>enumerated attribute</dt>
<dt>reference attribute</dt>	<dd>If the rules are to apply for one value of the attribute, then the
<dd>	attribute name is followed by an equals sign and this value.</dd>
There is never a value specification; the rules apply no matter what element
is designated by the attribute.
</dd>
<dt>enumerated attribute</dt>
<dd>
If the rules are to apply for one value of the attribute, then the attribute
name is followed by an equals sign and this value.
</dd>
</dl>	</dl>
<p>
The order in which the rules associated with a numeric attribute are defined	<p>The order in which the rules associated with a numeric attribute are
is important. When multiple sets of rules can be applied, the first set	defined is important. When multiple sets of rules can be applied, the first
declared is the one used.</p>	set declared is the one used.</p>
<p>
Rules for attributes have priority over both default rules and rules	<p>Rules for attributes have priority over both default rules and rules
associated with element types. The attribute rules apply to the element to	associated with element types. The attribute rules apply to the element to
which the attribute is attached. It is the rules which apply to the	which the attribute is attached. It is the rules which apply to the
surrounding elements (and especially to the descendants) which determine the	surrounding elements (and especially to the descendants) which determine the
effect of the attribute rules on the environment ( and especially on the	effect of the attribute rules on the environment ( and especially on the
terminal elements of the structure).</p>	terminal elements of the structure).</p>
<pre> 'ATTRIBUTES' PresAttrSeq	<pre> 'ATTRIBUTES' PresAttrSeq
PresAttrSeq = PresAttr < PresAttr > .	PresAttrSeq = PresAttr < PresAttr > .
PresAttr = AttrID [ '(' [ FirstSec ] ElemID ')' ]	PresAttr = AttrID [ '(' [ FirstSec ] ElemID ')' ]
[ AttrRelation ] ':' ViewRuleSeq .	[ AttrRelation ] ':' ViewRuleSeq .
AttrID = NAME .	AttrID = NAME .
AttrRelation ='=' AttrVal /	AttrRelation ='=' AttrVal /
'>' [ '-' ] MinValue /	'>' [ '-' ] MinValue /
'<' [ '-' ] MaxValue /	'<' [ '-' ] MaxValue /
'IN' '[' [ '-' ] LowerBound '..'	'IN' '[' [ '-' ] LowerBound '..'
[ '-' ] UpperBound ']' /	[ '-' ] UpperBound ']' /
Line 3964 terminal elements of the structure).</p>	Line 3504 terminal elements of the structure).</p>
EqualNum = NUMBER .	EqualNum = NUMBER .
EqualText = STRING .	EqualText = STRING .
AttrValue = NAME .</pre>	AttrValue = NAME .</pre>
<p>
In presentation rules associated with a numeric attribute (and only in such	<p>In presentation rules associated with a numeric attribute (and only in such
rules), the attribute name can be used in place of a numeric value. In this	rules), the attribute name can be used in place of a numeric value. In this
case, the value of the attribute is used in the application of the rule. Thus,	case, the value of the attribute is used in the application of the rule. Thus,
the attribute can represent a relation between the size of two boxes, the	the attribute can represent a relation between the size of two boxes, the
Line 3973 height and width of a box, the height of	Line 3513 height and width of a box, the height of
prohibited, the distance between two boxes, the position of the reference axis	prohibited, the distance between two boxes, the position of the reference axis
of a box, the interline spacing, the indentation of the first line, the	of a box, the interline spacing, the indentation of the first line, the
visibility, the depth (z-order), or the character set.</p>	visibility, the depth (z-order), or the character set.</p>
<p>
The presentation rules associated with reference attributes, it is possible to	<p>The presentation rules associated with reference attributes, it is possible
use the element designated by the attribute as a reference box in a positional	to use the element designated by the attribute as a reference box in a
or extent rule. This element is represented in the <a	positional or extent rule. This element is represented in the <a
href="#sectc4218">position</a> or <a href="#sectc4219">extent</a> rule by the	href="#sectc4218">position</a> or <a href="#sectc4219">extent</a> rule by the
keyword <tt>Referred</tt>.</p>	keyword <tt>Referred</tt>.</p>

<blockquote class="example">	<blockquote class="example">
<p>	<p><strong>Example:</strong></p>
<strong>Example:</strong></p>
<p>	<p>In all structure schemas, there is a global Language attribute defined as
In all structure schemas, there is a global Language attribute defined as	follows:</p>
follows:</p>	<pre>ATTR
<pre>ATTR
Language = TEXT;</pre>	Language = TEXT;</pre>
<p>
The following rules would make French text be displayed in roman characters	<p>The following rules would make French text be displayed in roman
and English text be displayed in italics:</p>	characters and English text be displayed in italics:</p>
<pre>ATTRIBUTES	<pre>ATTRIBUTES
Language = 'French' :	Language = 'French' :
Style : Roman;	Style : Roman;
Language = 'English' :	Language = 'English' :
Style : Italics;</pre>	Style : Italics;</pre>
<p>
Using these rules, when the user puts the Language attribute with the value	<p>Using these rules, when the user puts the Language attribute with the
'English' on the summary of a document, every character string (terminal	value 'English' on the summary of a document, every character string
elements) contained in the summary are displayed in italics. See the <a	(terminal elements) contained in the summary are displayed in italics. See
href="#sectd42252"><tt>Style</tt> rule</a>.</p>	the <a href="#sectd42252"><tt>Style</tt> rule</a>.</p>
</blockquote>	</blockquote>

<blockquote class="example">	<blockquote class="example">
<p>	<p><strong>Example:</strong></p>
<strong>Example:</strong></p>
<p>	<p>A numeric attribute representing the importance of the part of the
A numeric attribute representing the importance of the part of the document to	document to which it is attached can be defined:</p>
which it is attached can be defined:</p>	<pre>ATTR
<pre>ATTR
Importance = INTEGER;</pre>	Importance = INTEGER;</pre>
<p>
In the presentation schema, the importance of an element is reflected in the	<p>In the presentation schema, the importance of an element is reflected in
choice of character size, using the following rules.</p>	the choice of character size, using the following rules.</p>
<pre>ATTRIBUTES	<pre>ATTRIBUTES
Importance < 2 :	Importance < 2 :
Size : 1;	Size : 1;
Importance IN [2..4] :	Importance IN [2..4] :
Size : Importance;	Size : Importance;
Importance = 10 :	Importance = 10 :
Size : 5;	Size : 5;
Importance > 4 :	Importance > 4 :
Size : 4;</pre>	Size : 4;</pre>
<p>
Thus, the character size corresponds to the value of the Importance attribute;	<p>Thus, the character size corresponds to the value of the Importance
its value is</p>	attribute; its value is</p>
<ul>	<ul>
<li>	<li>the value of the Importance attribute when the value is between 2 and
the value of the Importance attribute when the value is between 2 and 4	4 (inclusive),</li>
(inclusive),	<li>1, when the value of the Importance attribute is less than 2,</li>
</li>	<li>4, when the value of the Importance attribute is greater than 4,</li>
<li>	<li>5, when the value of the Importance attribute is 10.</li>
1, when the value of the Importance attribute is less than 2,	</ul>
</li>
<li>	<p>The last case (value 5) must be defined before the case which handles all
4, when the value of the Importance attribute is greater than 4,	Importance values greater than 4, because the two rules are not disjoint and
</li>	the first one defined will have priority. Otherwise, when the Importance
<li>	attribute has value 10, the font size will be 4.</p>
5, when the value of the Importance attribute is 10.
</li>
</ul>
<p>
The last case (value 5) must be defined before the case which handles all
Importance values greater than 4, because the two rules are not disjoint and
the first one defined will have priority. Otherwise, when the Importance
attribute has value 10, the font size will be 4.</p>
</blockquote>	</blockquote>

<blockquote class="example">	<blockquote class="example">
<p>	<p><strong>Example:</strong></p>
<strong>Example:</strong></p>
<p>	<p>Suppose the structure defines a list element which can have an attribute
Suppose the structure defines a list element which can have an attribute	defining the type of list (numbered or not):</p>
defining the type of list (numbered or not):</p>	<pre>STRUCT
<pre>STRUCT
list (ATTR list_type = enumeration, dash)	list (ATTR list_type = enumeration, dash)
= LIST OF (list_item = TEXT);</pre>	= LIST OF (list_item = TEXT);</pre>
<p>
Then, the presentation schema could use the attribute placed on the list	<p>Then, the presentation schema could use the attribute placed on the list
element to put either a dash or a number before the each element of the	element to put either a dash or a number before the each element of the
list:</p>	list:</p>
<pre>ATTRIBUTES	<pre>ATTRIBUTES
list_type (list_item) = enumeration :	list_type (list_item) = enumeration :
CreateBefore (NumberBox);	CreateBefore (NumberBox);
list_type (list_item) = dash :	list_type (list_item) = dash :
CreateBefore (DashBox);</pre>	CreateBefore (DashBox);</pre>
</blockquote>	</blockquote>

<blockquote class="example">	<blockquote class="example">
<p>	<p><strong>Example:</strong></p>
<strong>Example:</strong></p>
<p>	<p>Suppose that two attributes are defined in the structure schema. The
Suppose that two attributes are defined in the structure schema. The first is	first is a numeric global attribute called ``version''. The other is a
a numeric global attribute called ``version''. The other is a local attribute	local attribute defined on the root of the document called
defined on the root of the document called ``Document_version'':</p>	``Document_version'':</p>
<pre>STRUCTURE Document	<pre>STRUCTURE Document
ATTR	ATTR
version = INTEGER;	version = INTEGER;
STRUCT	STRUCT
Line 4082 STRUCT	Line 3615 STRUCT
SomeOtherElement ;	SomeOtherElement ;
END ;	END ;
...</pre>	...</pre>
<p>
These attributes can be used in the presentation schema to place change bars	<p>These attributes can be used in the presentation schema to place change
in the margin next to elements whose version attribute has a value equal to	bars in the margin next to elements whose version attribute has a value
the Document_version attribute of the root and to place a star in margin of	equal to the Document_version attribute of the root and to place a star in
elements whose version attribute is less than the value of the root's	margin of elements whose version attribute is less than the value of the
Document_version attribute:</p>	root's Document_version attribute:</p>
<pre>ATTRIBUTES	<pre>ATTRIBUTES
version EQUAL Document_version :	version EQUAL Document_version :
CreateBefore (ChangeBarBox) ;	CreateBefore (ChangeBarBox) ;
version LESS Document_version :	version LESS Document_version :
Line 4097 Document_version attribute:</p>	Line 3630 Document_version attribute:</p>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc4212">Value transmission rules</a></h3>	<h3><a name="sectc4212">Value transmission rules</a></h3>
<p>
The last section of a presentation schema, which is optional, serves to	<p>The last section of a presentation schema, which is optional, serves to
defines the way in which a document transmits certain values to its	defines the way in which a document transmits certain values to its
sub-documents. A sub-document is an document <a	sub-documents. A sub-document is an document <a
href="#inclusion">included</a> without expansion or with partial expansion.	href="#inclusion">included</a> without expansion or with partial expansion.
The primary document can transmit to its sub-documents the values of certain	The primary document can transmit to its sub-documents the values of certain
counters or the textual content of certain of its elements, as a function of	counters or the textual content of certain of its elements, as a function of
their type.</p>	their type.</p>
<p>
The sub-documents receive these values in attributes which must be defined in	<p>The sub-documents receive these values in attributes which must be defined
their structure schema as local attributes of the root element. The types of	in their structure schema as local attributes of the root element. The types
these attributes must correspond to the type of the value which they receive:	of these attributes must correspond to the type of the value which they
numeric attributes for receiving the value of a counter, textual attributes	receive: numeric attributes for receiving the value of a counter, textual
for receiving the content of an element.</p>	attributes for receiving the content of an element.</p>
<p>
In the structure schema of the primary document, there appears at the end,	<p>In the structure schema of the primary document, there appears at the end,
after the <tt>TRANSMIT</tt> keyword, a sequence of transmission rules. Each	after the <tt>TRANSMIT</tt> keyword, a sequence of transmission rules. Each
rule begins with the name of the counter to transmit or of the element type	rule begins with the name of the counter to transmit or of the element type
whose textual content will be transmitted. This name is followed by the	whose textual content will be transmitted. This name is followed by the
Line 4122 keyword <tt>To</tt> and the name of the	Line 3654 keyword <tt>To</tt> and the name of the
the value is transmitted. The sub-document class is indicated between	the value is transmitted. The sub-document class is indicated between
parentheses after the name of the attribute. The transmission rule ends with	parentheses after the name of the attribute. The transmission rule ends with
a semicolon.</p>	a semicolon.</p>
<pre> TransmitSeq = Transmit < Transmit > .	<pre> TransmitSeq = Transmit < Transmit > .
Transmit = TypeOrCounter 'To' ExternAttr	Transmit = TypeOrCounter 'To' ExternAttr
'(' ElemID ')' ';' .	'(' ElemID ')' ';' .
TypeOrCounter = CounterID / ElemID .	TypeOrCounter = CounterID / ElemID .
ExternAttr = NAME .</pre>	ExternAttr = NAME .</pre>

<blockquote class="example">	<blockquote class="example">
<p>	<p><strong>Example:</strong></p>
<strong>Example:</strong></p>
<p>	<p>Consider a Book document class which includes instances of the Chapter
Consider a Book document class which includes instances of the Chapter	document class. These classes might have the following schemas:</p>
document class. These classes might have the following schemas:</p>	<pre>STRUCTURE Book
<pre>STRUCTURE Book
STRUCT	STRUCT
Book = BEGIN	Book = BEGIN
Title = Text;	Title = Text;
Line 4151 STRUCT	Line 3683 STRUCT
...	...
END;	END;
...</pre>	...</pre>
<p>
Then the presentation schema for books could define chapter and page counters.	<p>Then the presentation schema for books could define chapter and page
The following transmission rules in the book presentation schema would	counters. The following transmission rules in the book presentation schema
transmit values for the three attributes defined at the root of each chapter	would transmit values for the three attributes defined at the root of each
sub-document.</p>	chapter sub-document.</p>
<pre>PRESENTATION Book;	<pre>PRESENTATION Book;
VIEWS	VIEWS
Full_text;	Full_text;
COUNTERS	COUNTERS
Line 4168 TRANSMIT	Line 3700 TRANSMIT
ChapterCtr TO ChapterNum(Chapter);	ChapterCtr TO ChapterNum(Chapter);
Title TO CurrentTitle(Chapter);	Title TO CurrentTitle(Chapter);
END</pre>	END</pre>
<p>
Thus, each chapter included in a book can number its pages as a function of	<p>Thus, each chapter included in a book can number its pages as a function
the number of pages preceding it in the book, can make the chapter's number	of the number of pages preceding it in the book, can make the chapter's
appear before the number of each of its sections, or can place the title of	number appear before the number of each of its sections, or can place the
the book at the top of each page.</p>	title of the book at the top of each page.</p>
</blockquote>	</blockquote>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc4213">Presentation rules</a></h3>	<h3><a name="sectc4213">Presentation rules</a></h3>
<p>
Whether defining the appearance of a presentation or page layout box, an	<p>Whether defining the appearance of a presentation or page layout box, an
element type, or an attribute value, the set of presentation rules that apply	element type, or an attribute value, the set of presentation rules that apply
is always defined in the same way.</p>	is always defined in the same way.</p>
<p>
Normally, a set of presentation rules is placed between the keywords	<p>Normally, a set of presentation rules is placed between the keywords
<tt>BEGIN</tt> and <tt>END</tt>, the keyword <tt>END</tt> being followed by a	<tt>BEGIN</tt> and <tt>END</tt>, the keyword <tt>END</tt> being followed by a
semicolon. The first section of this block defines the rules that apply to	semicolon. The first section of this block defines the rules that apply to
the primary view, if the <a href="#sectc427">default rules</a> are not	the primary view, if the <a href="#sectc427">default rules</a> are not
Line 4194 satisfactory. If the default rules are	Line 3725 satisfactory. If the default rules are
there will not be any specific rules for these views. If there is only one	there will not be any specific rules for these views. If there is only one
rule which applies to all views then the keywords <tt>BEGIN</tt> and	rule which applies to all views then the keywords <tt>BEGIN</tt> and
<tt>END</tt> need not appear.</p>	<tt>END</tt> need not appear.</p>
<p>
For each view, it is only necessary to specify those rules which differ from	<p>For each view, it is only necessary to specify those rules which differ
the default rules for the view, so that for certain views (or even all views),	from the default rules for the view, so that for certain views (or even all
there may be no specific rules.</p>	views), there may be no specific rules.</p>
<p>
The specific rules for a non-primary view are introduced by the <a	<p>The specific rules for a non-primary view are introduced by the <a
name="inkeyword"><tt>IN</tt> keyword</a>, followed by the view name. The	name="inkeyword"><tt>IN</tt> keyword</a>, followed by the view name. The
rules for that view follow, delimited by the keywords <tt>BEGIN</tt> and	rules for that view follow, delimited by the keywords <tt>BEGIN</tt> and
<tt>END</tt>, or without these two keywords when there is only one rule.</p>	<tt>END</tt>, or without these two keywords when there is only one rule.</p>
<p>
<strong>Note:</strong> the view name which follows the <tt>IN</tt> keyword	<p><strong>Note:</strong> the view name which follows the <tt>IN</tt> keyword
must not be the name of the primary view, since the rules for that view are	must not be the name of the primary view, since the rules for that view are
found before the rules for the other views.</p>	found before the rules for the other views.</p>
<p>
Within each block concerning a view, other blocks can appear, delimited by the	<p>Within each block concerning a view, other blocks can appear, delimited by
same keywords <tt>BEGIN</tt> and <tt>END</tt>. Each of these blocks gathers	the same keywords <tt>BEGIN</tt> and <tt>END</tt>. Each of these blocks
the presentation rules that apply, for a given view, only when a given	gathers the presentation rules that apply, for a given view, only when a given
condition is satisfied. Each block is preceded by a condition introduced by	condition is satisfied. Each block is preceded by a condition introduced by
the <tt>IF</tt> keyword. If such a conditional block contains only one rule,	the <tt>IF</tt> keyword. If such a conditional block contains only one rule,
the keywords <tt>BEGIN</tt> and <tt>END</tt> can be omitted.</p>	the keywords <tt>BEGIN</tt> and <tt>END</tt> can be omitted.</p>
<p>
Although the syntax allows any presentation rule to appear in a conditional	<p>Although the syntax allows any presentation rule to appear in a conditional
block, only <a href="#sectc4232">creation rules</a> are allowed after any	block, only <a href="#sectc4232">creation rules</a> are allowed after any
condition; other rules are allowed only after conditions <tt>Within</tt> and	condition; other rules are allowed only after conditions <tt>Within</tt> and
ElemID. In addition, the following rules cannot be conditional:	ElemID. In addition, the following rules cannot be conditional:
<tt>PageBreak, LineBreak, Inline, Gather</tt>.</p>	<tt>PageBreak, LineBreak, Inline, Gather</tt>.</p>
<p>
For a given view, the rules that apply without any condition must appear	<p>For a given view, the rules that apply without any condition must appear
before the first conditional block. If some rules apply only when none of the	before the first conditional block. If some rules apply only when none of the
specified condition holds, they are grouped in a block preceded by the keyword	specified condition holds, they are grouped in a block preceded by the keyword
<tt>Otherwise</tt>, and that block must appear after the last conditionnal	<tt>Otherwise</tt>, and that block must appear after the last conditionnal
block concerning the same view.</p>	block concerning the same view.</p>
<pre> ViewRuleSeq = 'BEGIN' < RulesAndCond > < ViewRules >	<pre> ViewRuleSeq = 'BEGIN' < RulesAndCond > < ViewRules >
'END' ';' /	'END' ';' /
ViewRules / CondRules / Rule .	ViewRules / CondRules / Rule .
RulesAndCond = CondRules / Rule .	RulesAndCond = CondRules / Rule .
ViewRules = 'IN' ViewID CondRuleSeq .	ViewRules = 'IN' ViewID CondRuleSeq .
CondRuleSeq = 'BEGIN' < RulesAndCond > 'END' ';' /	CondRuleSeq = 'BEGIN' < RulesAndCond > 'END' ';' /
CondRules / Rule .	CondRules / Rule .
CondRules = CondRule < CondRule >	CondRules = CondRule < CondRule >
[ 'Otherwise' RuleSeq ] .	[ 'Otherwise' RuleSeq ] .
CondRule = 'IF' ConditionSeq RuleSeq .	CondRule = 'IF' ConditionSeq RuleSeq .
RulesSeq = 'BEGIN' Rule < Rule > 'END' ';' /	RulesSeq = 'BEGIN' Rule < Rule > 'END' ';' /
Rule .</pre>	Rule .</pre>

<blockquote class="example">	<blockquote class="example">
<p>	<p><strong>Example:</strong></p>
<strong>Example:</strong></p>
<p>	<p>The following rules for a report's title make the title visible in the
The following rules for a report's title make the title visible in the primary	primary view and invisible in the table of contents and in the formula views
view and invisible in the table of contents and in the formula views (see the	(see the <a href="#sectc4224"><tt>Visibility</tt> rule</a>).</p>
<a href="#sectc4224"><tt>Visibility</tt> rule</a>).</p>	<pre>Title : BEGIN
<pre>Title : BEGIN
Visibility : 1;	Visibility : 1;
... {Other rules for the primary view}	... {Other rules for the primary view}
IN Table_of_contents	IN Table_of_contents
Line 4257 view and invisible in the table of conte	Line 3788 view and invisible in the table of conte
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc4214">Conditions applying to presentation rules</a></h3>	<h3><a name="sectc4214">Conditions applying to presentation rules</a></h3>
<p>
Many conditions can be applied to presentation rules. Conditions allow	<p>Many conditions can be applied to presentation rules. Conditions allow
certain presentation rules to apply only in certain cases. These conditions	certain presentation rules to apply only in certain cases. These conditions
can be based on the structural position of the element. They can be based on	can be based on the structural position of the element. They can be based on
whether the element has references, and what type of references, whether the	whether the element has references, and what type of references, whether the
element has attributes, whether the element is empty or not. They can also be	element has attributes, whether the element is empty or not. They can also be
based on the value of a counter.</p>	based on the value of a counter.</p>
<p>
It is possible to specify several conditions which must all be true for the	<p>It is possible to specify several conditions which must all be true for the
rules to apply.</p>	rules to apply.</p>
<p>
A set of conditions is specified by the <tt>IF</tt> keyword. This keyword is	<p>A set of conditions is specified by the <tt>IF</tt> keyword. This keyword
followed by the sequence of conditions, separated by the <tt>AND</tt> keyword.	is followed by the sequence of conditions, separated by the <tt>AND</tt>
Each condition is specified by a keyword which defines the condition type. In	keyword. Each condition is specified by a keyword which defines the condition
some cases, the keyword is followed by other data, which specify the condition	type. In some cases, the keyword is followed by other data, which specify the
more precisely.</p>	condition more precisely.</p>
<p>
An elementary condition can be negative; it is then preceded by the	<p>An elementary condition can be negative; it is then preceded by the
<tt>NOT</tt> keyword.</p>	<tt>NOT</tt> keyword.</p>
<p>
When the presentation rule(s) controlled by the condition apply to a reference	<p>When the presentation rule(s) controlled by the condition apply to a
element or a reference attribute, an elementary condition can also apply to	reference element or a reference attribute, an elementary condition can also
element referred by this reference. The <tt>Target</tt> keyword is used for	apply to element referred by this reference. The <tt>Target</tt> keyword is
that purpose. It must appear before the keyword defining the condition	used for that purpose. It must appear before the keyword defining the
type.</p>	condition type.</p>
<pre> CondRule ='IF' ConditionSeq RuleSeq .	<pre> CondRule ='IF' ConditionSeq RuleSeq .
ConditionSeq = Condition < 'AND' Condition > .	ConditionSeq = Condition < 'AND' Condition > .
Condition = [ 'NOT' ] [ 'Target' ] ConditionElem .	Condition = [ 'NOT' ] [ 'Target' ] ConditionElem .
ConditionElem ='First' / 'Last' /	ConditionElem ='First' / 'Last' /
[ 'Immediately' ] 'Within' [ NumParent ]	[ 'Immediately' ] 'Within' [ NumParent ]
Line 4299 type.</p>	Line 3829 type.</p>
'(' [ MinMax ] CounterName CounterCond ')' /	'(' [ MinMax ] CounterName CounterCond ')' /
CondPage '(' CounterID ')' .	CondPage '(' CounterID ')' .
NumParent = [ GreaterLess ] NParent .	NumParent = [ GreaterLess ] NParent .
GreaterLess ='>' / '<' .	GreaterLess ='>' / '<' .
NParent = NUMBER.	NParent = NUMBER.
ExtStruct ='(' ElemID ')' .	ExtStruct ='(' ElemID ')' .
CounterCond ='<' MaxCtrVal / '>' MinCtrVal /	CounterCond ='<' MaxCtrVal / '>' MinCtrVal /
'=' EqCtrVal /	'=' EqCtrVal /
'IN' '[' ['-'] MinCtrBound '.' '.'	'IN' '[' ['-'] MinCtrBound '.' '.'
['-'] MaxCtrBound ']' .	['-'] MaxCtrBound ']' .
Line 4314 type.</p>	Line 3844 type.</p>
MinCtrBound = NUMBER .</pre>	MinCtrBound = NUMBER .</pre>

<div class="subsubsection">	<div class="subsubsection">

<h4><a name="sectd42141">Conditions based on the logical position of the	<h4><a name="sectd42141">Conditions based on the logical position of the
element</a></h4>	element</a></h4>
<p>
The condition can be on the position of the element in the document's logical	<p>The condition can be on the position of the element in the document's
structure tree. It is possible to test whether the element is the first	logical structure tree. It is possible to test whether the element is the
(<tt>First</tt>) or last (<tt>Last</tt>) among its siblings or if it is not	first (<tt>First</tt>) or last (<tt>Last</tt>) among its siblings or if it is
the first (<tt>NOT First</tt>) or not the last (<tt>NOT Last</tt>). These	not the first (<tt>NOT First</tt>) or not the last (<tt>NOT Last</tt>). These
conditions can be associated only with <a href="#sectc4232">creation	conditions can be associated only with <a href="#sectc4232">creation
rules</a>.</p>	rules</a>.</p>
<p>
It is also possible to test if the element is contained in an element of a	<p>It is also possible to test if the element is contained in an element of a
given type (<tt>Within</tt>) or if it is not (<tt>NOT Within</tt>). The type	given type (<tt>Within</tt>) or if it is not (<tt>NOT Within</tt>). The type
is indicated after the keyword <tt>Within</tt>. If that element type is	is indicated after the keyword <tt>Within</tt>. If that element type is
defined in a structure schema which is not the one which corresponds to the	defined in a structure schema which is not the one which corresponds to the
presentation schema, the type name of this element must be followed, between	presentation schema, the type name of this element must be followed, between
parentheses, by the name of the structure schema which defines it.</p>	parentheses, by the name of the structure schema which defines it.</p>
<p>
If the keyword <tt>Within</tt> is preceded by <tt>Immediately</tt>, the	<p>If the keyword <tt>Within</tt> is preceded by <tt>Immediately</tt>, the
condition is satisfied only if the <em>parent</em> element has the type	condition is satisfied only if the <em>parent</em> element has the type
indicated. If the word <tt>Immediately</tt> is missing, the condition is	indicated. If the word <tt>Immediately</tt> is missing, the condition is
satisfied if any <em>ancestor</em> has the type indicated.</p>	satisfied if any <em>ancestor</em> has the type indicated.</p>
<p>
An integer <i>n</i> can appear between the keyword <tt>Within</tt> and the	<p>An integer <i>n</i> can appear between the keyword <tt>Within</tt> and the
type. It specifies the number of ancestors of the indicated type that must be	type. It specifies the number of ancestors of the indicated type that must be
present for the condition to be satisfied. If the keyword	present for the condition to be satisfied. If the keyword
<tt>Immediately</tt> is also present, the <i>n</i> immediate ancestors of the	<tt>Immediately</tt> is also present, the <i>n</i> immediate ancestors of the
element must have the indicated type. The integer <i>n</i> must be positive	element must have the indicated type. The integer <i>n</i> must be positive
or zero. It can be preceded by <tt><</tt> or <tt>></tt> to indicate a	or zero. It can be preceded by <tt><</tt> or <tt>></tt> to indicate a
maximum or minimum number of ancestors. If these symbols are missing, the	maximum or minimum number of ancestors. If these symbols are missing, the
condition is satisfied only if it exists exactly <i>n</i> ancestors. When	condition is satisfied only if it exists exactly <i>n</i> ancestors. When
this number is missing, it is equivalent to > 0.</p>	this number is missing, it is equivalent to > 0.</p>
<p>
If the condition applies to presentation rules associated with an attribute,	<p>If the condition applies to presentation rules associated with an
in the <tt>ATTRIBUTES</tt> section of the presentation schema, the condition	attribute, in the <tt>ATTRIBUTES</tt> section of the presentation schema, the
can be simply an element name. Presentation rules are then executed only if	condition can be simply an element name. Presentation rules are then executed
the attribute is attached to an element of that type. The keyword <tt>NOT</tt>	only if the attribute is attached to an element of that type. The keyword
before the element name indicates that the presentation rules must be executed	<tt>NOT</tt> before the element name indicates that the presentation rules
only if the element is not of the type indicated.</p>	must be executed only if the element is not of the type indicated.</p>
</div>	</div>

<div class="subsubsection">	<div class="subsubsection">

<h4><a name="sectd42142">Conditions on references</a></h4>	<h4><a name="sectd42142">Conditions on references</a></h4>
<p>
References may be taken into account in conditions, which can be based on the	<p>References may be taken into account in conditions, which can be based on
fact that the element, or one of its ancestors, is designated by a at least	the fact that the element, or one of its ancestors, is designated by a at
one reference (<tt>Referred</tt>) or by none (<tt>NOT Referred</tt>).</p>	least one reference (<tt>Referred</tt>) or by none (<tt>NOT
<p>	Referred</tt>).</p>
If the element or attribute to which the condition is attached is a reference,
the condition can be based on the fact that it acts as the first reference to	<p>If the element or attribute to which the condition is attached is a
the designated element (<tt>FirstRef</tt>), or as the last (<tt>LastRef</tt>),	reference, the condition can be based on the fact that it acts as the first
or as a reference to an element located in another document	reference to the designated element (<tt>FirstRef</tt>), or as the last
(<tt>ExternalRef</tt>) or in the same document (<tt>InternalRef</tt>).</p>	(<tt>LastRef</tt>), or as a reference to an element located in another
<p>	document (<tt>ExternalRef</tt>) or in the same document
The condition can also be based on the fact that the element is an <a	(<tt>InternalRef</tt>).</p>

	<p>The condition can also be based on the fact that the element is an <a
href="#inclusion">inclusion</a>. This is noted (<tt>CopyRef</tt>).</p>	href="#inclusion">inclusion</a>. This is noted (<tt>CopyRef</tt>).</p>
<p>
Like all conditions, conditions on references can be inverted by the	<p>Like all conditions, conditions on references can be inverted by the
<tt>NOT</tt> keyword. These conditions can be associated only with <a	<tt>NOT</tt> keyword. These conditions can be associated only with <a
href="#sectc4232">creation rules</a>.</p>	href="#sectc4232">creation rules</a>.</p>
</div>	</div>

<div class="subsubsection">	<div class="subsubsection">

<h4><a name="sectd42143">Conditions on logical attributes</a></h4>	<h4><a name="sectd42143">Conditions on logical attributes</a></h4>
<p>
The condition can be based on the presence or absence of attributes associated	<p>The condition can be based on the presence or absence of attributes
with the element, no matter what the attributes or their values. The	associated with the element, no matter what the attributes or their values.
<tt>AnyAttributes</tt> keyword expresses this condition.</p>	The <tt>AnyAttributes</tt> keyword expresses this condition.</p>
<p>
If the condition appears in the presentation rules of an attribute, the	<p>If the condition appears in the presentation rules of an attribute, the
<tt>FirstAttr</tt> and <tt>LastAttr</tt> keywords can be used to indicate that	<tt>FirstAttr</tt> and <tt>LastAttr</tt> keywords can be used to indicate that
the rules must only be applied if this attribute is the first attribute for	the rules must only be applied if this attribute is the first attribute for
the element or if it is the last (respectively). These conditions can also be	the element or if it is the last (respectively). These conditions can also be
inverted by the <tt>NOT</tt> keyword. These conditions can be associated only	inverted by the <tt>NOT</tt> keyword. These conditions can be associated only
with <a href="#sectc4232">creation rules</a>.</p>	with <a href="#sectc4232">creation rules</a>.</p>
<p>
It is also possible to apply certain presentation rules only when the element	<p>It is also possible to apply certain presentation rules only when the
being processed or one of its ancestors has a certain attribute, perhaps with	element being processed or one of its ancestors has a certain attribute,
a certain value. This can be done in the <a	perhaps with a certain value. This can be done in the <a
href="#sectc4210"><tt>ATTRIBUTES</tt> section</a>.</p>	href="#sectc4210"><tt>ATTRIBUTES</tt> section</a>.</p>
</div>	</div>

<div class="subsubsection">	<div class="subsubsection">

<h4><a name="sectd42144">Conditions on page breaks</a></h4>	<h4><a name="sectd42144">Conditions on page breaks</a></h4>
<p>
The page break base type (and only this type) can use the following	<p>The page break base type (and only this type) can use the following
conditions: <tt>ComputedPage</tt>, <tt>StartPage</tt>, and <tt>UserPage</tt>.	conditions: <tt>ComputedPage</tt>, <tt>StartPage</tt>, and <tt>UserPage</tt>.
The <tt>ComputedPage</tt> condition indicates that the presentation rule(s)	The <tt>ComputedPage</tt> condition indicates that the presentation rule(s)
should apply if the page break was created automatically by Thot; the	should apply if the page break was created automatically by Thot; the
<tt>StartPage</tt> condition is true if the page break is generated before the	<tt>StartPage</tt> condition is true if the page break is generated before the
element by the <tt>Page</tt> rule; and the <tt>UserPage</tt> condition applies	element by the <tt>Page</tt> rule; and the <tt>UserPage</tt> condition applies
if the page break was inserted by the user.</p>	if the page break was inserted by the user.</p>
<p>
These conditions can be associated only with <a href="#sectc4232">creation	<p>These conditions can be associated only with <a href="#sectc4232">creation
rules</a>.</p>	rules</a>.</p>
</div>	</div>

<div class="subsubsection">	<div class="subsubsection">

<h4><a name="sectd42145">Conditions on the element's content</a></h4>	<h4><a name="sectd42145">Conditions on the element's content</a></h4>
<p>
The condition can be based on whether or not the element is empty. An element	<p>The condition can be based on whether or not the element is empty. An
which has no children or whose leaves are all empty is considered to be empty	element which has no children or whose leaves are all empty is considered to
itself. This condition is expressed by the <tt>Empty</tt> keyword, optionally	be empty itself. This condition is expressed by the <tt>Empty</tt> keyword,
preceded by the <tt>NOT</tt> keyword. This condition can be associated only	optionally preceded by the <tt>NOT</tt> keyword. This condition can be
with <a href="#sectc4232">creation rules</a>.</p>	associated only with <a href="#sectc4232">creation rules</a>.</p>
</div>	</div>

<div class="subsubsection">	<div class="subsubsection">

<h4><a name="sectd42146">Conditions on counters</a></h4>	<h4><a name="sectd42146">Conditions on counters</a></h4>
<p>
Presentation rules can apply when the counter's value is one, is even or odd,	<p>Presentation rules can apply when the counter's value is one, is even or
is equal, greater than or less than a given value or falls in a range of	odd, is equal, greater than or less than a given value or falls in a range of
values. This is particularly useful for creating header and footer boxes.	values. This is particularly useful for creating header and footer boxes.
These conditions can be associated only with <a href="#sectc4232">creation	These conditions can be associated only with <a href="#sectc4232">creation
rules</a>.</p>	rules</a>.</p>
<p>
To compare the value of a counter to a given value, a comparison is given	<p>To compare the value of a counter to a given value, a comparison is given
between parentheses. The comparison is composed of the counter name followed	between parentheses. The comparison is composed of the counter name followed
by an equals, greater than, or less than sign and the value to which the	by an equals, greater than, or less than sign and the value to which the
counter will be compared. A test for whether or not a counter's value falls	counter will be compared. A test for whether or not a counter's value falls
Line 4443 in a range also appears within parenthes	Line 3969 in a range also appears within parenthes
followed by the <tt>IN</tt> keyword and the range definition within brackets.	followed by the <tt>IN</tt> keyword and the range definition within brackets.
The <tt>Even</tt>, <tt>Odd</tt> and <tt>One</tt> are used to test a counter's	The <tt>Even</tt>, <tt>Odd</tt> and <tt>One</tt> are used to test a counter's
value and are followed by the counter name between parentheses.</p>	value and are followed by the counter name between parentheses.</p>
<p>
The list of possible conditions on counters is:</p>	<p>The list of possible conditions on counters is:</p>
<dl>	<dl>
<dt><tt>Even (Counter)</tt></dt>	<dt><tt>Even (Counter)</tt></dt>
<dd>	<dd>the box is created only if the counter has an even value.</dd>
the box is created only if the counter has an even value.	<dt><tt>Odd (Counter)</tt></dt>
</dd>	<dd>the box is created only if the counter has an odd value.</dd>
<dt><tt>Odd (Counter)</tt></dt>	<dt><tt>One (Counter)</tt></dt>
<dd>	<dd>the box is created only the counter's value is 1.</dd>
the box is created only if the counter has an odd value.	<dt><tt>NOT One (Counter)</tt></dt>
</dd>	<dd>the box is created, unless the counter's value is 1.</dd>
<dt><tt>One (Counter)</tt></dt>	<dt><tt>(Counter < Value)</tt></dt>
<dd>	<dd>the box is created only if the counter's value is less than
the box is created only the counter's value is 1.	Value.</dd>
</dd>	<dt><tt>(Counter > Value)</tt></dt>
<dt><tt>NOT One (Counter)</tt></dt>	<dd>the box is created only if the counter's value is greater than
<dd>	Value.</dd>
the box is created, unless the counter's value is 1.	<dt><tt>(Counter = Value)</tt></dt>
</dd>	<dd>the box is created only if the counter's value is equal to Value.</dd>
<dt><tt>(Counter < Value)</tt></dt>	<dt><tt>NOT (Counter = Value)</tt></dt>
<dd>	<dd>the is created only if the counter's value is different than
the box is created only if the counter's value is less than Value.	Value.</dd>
</dd>	<dt><tt>(Counter IN [MinValue..MaxValue])</tt></dt>
<dt><tt>(Counter > Value)</tt></dt>	<dd>the box is created only if the counter's value falls in the range
<dd>	bounded by MinValue and MaxValue (inclusive).</dd>
the box is created only if the counter's value is greater than Value.	<dt><tt>NOT (Counter IN [MinValue..MaxValue])</tt></dt>
</dd>	<dd>the box is created only if the value of the counter does not fall in
<dt><tt>(Counter = Value)</tt></dt>	the range bounded by MinValue and MaxValue (inclusive).</dd>
<dd>
the box is created only if the counter's value is equal to Value.
</dd>
<dt><tt>NOT (Counter = Value)</tt></dt>
<dd>
the is created only if the counter's value is different than Value.
</dd>
<dt><tt>(Counter IN [MinValue..MaxValue])</tt></dt>
<dd>
the box is created only if the counter's value falls in the range bounded by
MinValue and MaxValue (inclusive).
</dd>
<dt><tt>NOT (Counter IN [MinValue..MaxValue])</tt></dt>
<dd>
the box is created only if the value of the counter does not fall in the range
bounded by MinValue and MaxValue (inclusive).
</dd>
</dl>	</dl>
<p>
<strong>Note:</strong> the <tt>NOT Even</tt> and <tt>NOT Odd</tt> conditions	<p><strong>Note:</strong> the <tt>NOT Even</tt> and <tt>NOT Odd</tt>
are syntactically correct but can be expressed more simply by <tt>Odd</tt> and	conditions are syntactically correct but can be expressed more simply by
<tt>Even</tt>, respectively.</p>	<tt>Odd</tt> and <tt>Even</tt>, respectively.</p>
</div>	</div>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc4215">A presentation rule</a></h3>	<h3><a name="sectc4215">A presentation rule</a></h3>
<p>
A presentation rule defines either a presentation parameter or presentation	<p>A presentation rule defines either a presentation parameter or presentation
function. The parameters are:</p>	function. The parameters are:</p>
<ul>	<ul>
<li>	<li>the position of the vertical and horizontal reference axes of the
the position of the vertical and horizontal reference axes of the box,	box,</li>
</li>	<li>the position of the box in relation to other boxes,</li>
<li>	<li>the height or width of the box, with overflow exceptions,</li>
the position of the box in relation to other boxes,	<li>the margins, padding and borders of the box,</li>
</li>	<li>the characteristics of the lines contained in the box: linespacing,
<li>	indentation of the first line, justification, hyphenation,</li>
the height or width of the box, with overflow exceptions,	<li>the conditions for breaking the box across pages,</li>
</li>	<li>the characteristics of the characters contained in the box: size, font,
<li>	style, underlining,</li>
the margins, padding and borders of the box,	<li>the depth of the box among overlapping boxes (often called stacking
</li>	order),</li>
<li>	<li>the characteristics of graphic elements contained in the box: style and
the characteristics of the lines contained in the box: linespacing,	thickness of lines, fill pattern for closed objects,</li>
indentation of the first line, justification, hyphenation,	<li>the colors in text, graphics, pictures, and symbols contained in the box
</li>	are displayed or printed,</li>
<li>	<li>for presentation boxes only, the contents of the box.</li>
the conditions for breaking the box across pages,	</ul>
</li>
<li>	<p>The <a name="presfunct">presentation functions</a> are:</p>
the characteristics of the characters contained in the box: size, font, style,	<ul>
underlining,	<li>the creation of a presentation box</li>
</li>	<li>the line-breaking or page-breaking style,</li>
<li>	<li>the copying of another box,</li>
the depth of the box among overlapping boxes (often called stacking order),	<li>the display of the box background and border,</li>
</li>	<li>the display of a background picture and its aspect.</li>
<li>	</ul>
the characteristics of graphic elements contained in the box: style and
thickness of lines, fill pattern for closed objects,	<p>For each box and each view, every presentation parameter is defined once
</li>	and only once, either explicitly or by the <a href="#sectc427">default
<li>	rules</a>. In contrast, presentation functions are not obligatory and can
the colors in text, graphics, pictures, and symbols contained in the box are	appear many times for the same element. for example an element can create
displayed or printed,	many presentation boxes. Another element may not use any presentation
</li>
<li>
for presentation boxes only, the contents of the box.
</li>
</ul>
<p>
The <a name="presfunct">presentation functions</a> are:</p>
<ul>
<li>
the creation of a presentation box
</li>
<li>
the line-breaking or page-breaking style,
</li>
<li>
the copying of another box,
</li>
<li>
the display of the box background and border,
</li>
<li>
the display of a background picture and its aspect.
</li>
</ul>
<p>
For each box and each view, every presentation parameter is defined once and
only once, either explicitly or by the <a href="#sectc427">default rules</a>.
In contrast, presentation functions are not obligatory and can appear many
times for the same element. for example an element can create many
presentation boxes. Another element may not use any presentation
functions.</p>	functions.</p>
<p>
Each rule defining a presentation parameter begins with a keyword followed by	<p>Each rule defining a presentation parameter begins with a keyword followed
a colon. The keyword indicates the parameter which is the subject of the	by a colon. The keyword indicates the parameter which is the subject of the
rule. After the keyword and the colon, the remainder of the rule varies. All	rule. After the keyword and the colon, the remainder of the rule varies. All
rules are terminated by a semicolon.</p>	rules are terminated by a semicolon.</p>
<pre> Rule = PresParam ';' / PresFunc ';' .	<pre> Rule = PresParam ';' / PresFunc ';' .
Line 4637 rules are terminated by a semicolon.</p>	Line 4115 rules are terminated by a semicolon.</p>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc4216">Box axes</a></h3>	<h3><a name="sectc4216">Box axes</a></h3>
<p>
The position of the middle axes <tt>VMiddle</tt> and <tt>HMiddle</tt> in	<p>The position of the middle axes <tt>VMiddle</tt> and <tt>HMiddle</tt> in
relation to their box is always calculated automatically as a function of the	relation to their box is always calculated automatically as a function of the
height and width of the box and is not specified by the presentation rules. In	height and width of the box and is not specified by the presentation rules. In
the presentation schema, these middle axes are used only to position their box	the presentation schema, these middle axes are used only to position their box
with respect to another by specifying the distance between the middle axis and	with respect to another by specifying the distance between the middle axis and
an axis or a side of another box (see the <a href="#sectc4218">relative	an axis or a side of another box (see the <a href="#sectc4218">relative
position</a>).</p>	position</a>).</p>
<p>
The reference axes of a box are also used to position their box in relation to	<p>The reference axes of a box are also used to position their box in relation
another, but in contrast to the middle axes, the presentation schema must make	to another, but in contrast to the middle axes, the presentation schema must
their position explicit, either in relation to a side or the middle axis of	make their position explicit, either in relation to a side or the middle axis
the box itself, or in relation to an axis of an enclosed box.</p>	of the box itself, or in relation to an axis of an enclosed box.</p>
<p>
Only boxes of base elements have predefined reference axes. For character	<p>Only boxes of base elements have predefined reference axes. For character
string boxes, the horizontal reference axis is the baseline of the characters	string boxes, the horizontal reference axis is the baseline of the characters
(the line which passes immediately under the upper-case letters, ignoring the	(the line which passes immediately under the upper-case letters, ignoring the
letter Q) and the vertical reference axis is at the left edge of the first	letter Q) and the vertical reference axis is at the left edge of the first
character of the string.</p>	character of the string.</p>
<p>
The positions of a box's reference axes are defined by the <tt>VertRef</tt>	<p>The positions of a box's reference axes are defined by the <tt>VertRef</tt>
and <tt>HorizRef</tt> rules which specify the <a href="#distance">distance</a>	and <tt>HorizRef</tt> rules which specify the <a href="#distance">distance</a>
between the reference axis and an axis or parallel side of the same box or of	between the reference axis and an axis or parallel side of the same box or of
an enclosed box.</p>	an enclosed box.</p>
<pre> 'VertRef' ':' PositionHoriz	<pre> 'VertRef' ':' PositionHoriz
'HorizRef' ':' PositionVert</pre>	'HorizRef' ':' PositionVert</pre>

<blockquote class="example">	<blockquote class="example">
<p>	<p><strong>Example:</strong></p>
<strong>Example:</strong></p>
<p>	<p>If, in the structure schema for mathematical formulas, the fraction
If, in the structure schema for mathematical formulas, the fraction element is	element is defined by</p>
defined by</p>	<pre>Fraction = BEGIN
<pre>Fraction = BEGIN
Numerator = Expression;	Numerator = Expression;
Denominator = Expression;	Denominator = Expression;
END;</pre>	END;</pre>
<p>
then the horizontal reference axis of the fraction can be positioned on top of	<p>then the horizontal reference axis of the fraction can be positioned on
the denominator by the rule:</p>	top of the denominator by the rule:</p>
<pre>Fraction :	<pre>Fraction :
BEGIN	BEGIN
HorizRef : Enclosed Denominator . Top;	HorizRef : Enclosed Denominator . Top;
...	...
END;</pre>	END;</pre>
<p>
To put the horizontal reference axis of a column at its middle:</p>	<p>To put the horizontal reference axis of a column at its middle:</p>
<pre>Column :	<pre>Column :
BEGIN	BEGIN
HorizRef : * . HMiddle;	HorizRef : * . HMiddle;
...	...
Line 4694 To put the horizontal reference axis of	Line 4171 To put the horizontal reference axis of
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc4217">Distance units</a></h3>	<h3><a name="sectc4217">Distance units</a></h3>
<p>
Some distances and dimensions appear in many rules of a presentation schema,	<p>Some distances and dimensions appear in many rules of a presentation
especially in position rules (<tt>VertPos, HorizPos</tt>), in extent rules for	schema, especially in position rules (<tt>VertPos, HorizPos</tt>), in extent
boxes (<tt>Height, Width</tt>), in rules defining lines (<tt>LineSpacing,	rules for boxes (<tt>Height, Width</tt>), in rules defining lines
Indent</tt>), in rules controlling pagination (<tt>NoBreak1, NoBreak2</tt>)	(<tt>LineSpacing, Indent</tt>), in rules controlling pagination (<tt>NoBreak1,
and in rules specifying the thickness of strokes (<tt>LineWeight</tt>).</p>	NoBreak2</tt>) and in rules specifying the thickness of strokes
<p>	(<tt>LineWeight</tt>).</p>
In all these rules, the distance or extent can be expressed</p>
<ul>	<p>In all these rules, the distance or extent can be expressed</p>
<li>	<ul>
either in relative units, which depend on the size of the characters in the	<li>either in relative units, which depend on the size of the characters in
current font: height of the element's font or height of the letter 'x',	the current font: height of the element's font or height of the letter
</li>	'x',</li>
<li>	<li>or in absolute units: centimeter, millimeter, inch, typographer's point,
or in absolute units: centimeter, millimeter, inch, typographer's point, pica	pica or pixel.</li>
or pixel.	</ul>
</li>
</ul>	<p>Units can be chosen freely. Thus, it is possible to use relative units in
<p>	one rule, centimeters in the next rule, and typographer's points in
Units can be chosen freely. Thus, it is possible to use relative units in one	another.</p>
rule, centimeters in the next rule, and typographer's points in another.</p>
<p>	<p>Absolute units are used to set rigid rules for the appearance of documents.
Absolute units are used to set rigid rules for the appearance of documents. In	In contrast, relative units allow changes of scale. The editor lets the value
contrast, relative units allow changes of scale. The editor lets the value of	of relative units be changed dynamically. Such changes affect every box using
relative units be changed dynamically. Such changes affect every box using
relative units simultaneously and in the same proportion. Changing the value	relative units simultaneously and in the same proportion. Changing the value
of the relative units affects the size of the characters and graphical	of the relative units affects the size of the characters and graphical
elements, and the size of the boxes and the distances between them.</p>	elements, and the size of the boxes and the distances between them.</p>
<p>
A <a name="distance">distance</a> or extent is specified by a number, which	<p>A <a name="distance">distance</a> or extent is specified by a number, which
may be followed by one or more spaces and a units keyword. When there is no	may be followed by one or more spaces and a units keyword. When there is no
units keyword, the number specifies the number of relative units, where a	units keyword, the number specifies the number of relative units, where a
relative unit is the height of a character in the current font (an em). When	relative unit is the height of a character in the current font (an em). When
the number is followed by a units keyword, the keyword indicates the type of	the number is followed by a units keyword, the keyword indicates the type of
absolute units:</p>	absolute units:</p>
<ul>	<ul>
<li>	<li><tt>em</tt>: height of the element's font,</li>
<tt>em</tt>: height of the element's font,	<li><tt>ex</tt>: height of the letter 'x',</li>
</li>	<li><tt>cm</tt>: centimeter,</li>
<li>	<li><tt>mm</tt>: millimeter,</li>
<tt>ex</tt>: height of the letter 'x',	<li><tt>in</tt>: inch (1 in = 2.54 cm),</li>
</li>	<li><tt>pt</tt>: point (1 pt = 1/72 in),</li>
<li>	<li><tt>pc</tt>: pica (1 pc = 12 pt),</li>
<tt>cm</tt>: centimeter,	<li><tt>px</tt>: pixel.</li>
</li>
<li>
<tt>mm</tt>: millimeter,
</li>
<li>
<tt>in</tt>: inch (1 in = 2.54 cm),
</li>
<li>
<tt>pt</tt>: point (1 pt = 1/72 in),
</li>
<li>
<tt>pc</tt>: pica (1 pc = 12 pt),
</li>
<li>
<tt>px</tt>: pixel.
</li>
</ul>	</ul>
<p>
Whatever the chosen unit, relative or absolute, the number is not necessarily	<p>Whatever the chosen unit, relative or absolute, the number is not
an integer and may be expressed in fixed point notation (using the American	necessarily an integer and may be expressed in fixed point notation (using the
convention of a period to express the decimal point).</p>	American convention of a period to express the decimal point).</p>
<p>
If the distance appears in a presentation rule for a numeric attribute, the	<p>If the distance appears in a presentation rule for a numeric attribute, the
number can be replaced by the name of an attribute. In this case, the value	number can be replaced by the name of an attribute. In this case, the value
of the attribute is used. Obviously, the attribute name cannot be followed by	of the attribute is used. Obviously, the attribute name cannot be followed by
a decimal point and a fractional part, but it can be followed a units keyword.	a decimal point and a fractional part, but it can be followed a units keyword.
Line 4776 However, the choice of units is limited	Line 4235 However, the choice of units is limited
DecimalPart = NUMBER .	DecimalPart = NUMBER .
Unit ='em' / 'ex' / 'cm' / 'mm' / 'in' / 'pt' /	Unit ='em' / 'ex' / 'cm' / 'mm' / 'in' / 'pt' /
'pc' / 'px' / '%' .</pre>	'pc' / 'px' / '%' .</pre>

<blockquote class="example">	<blockquote class="example">
<p>	<p><strong>Example:</strong></p>
<strong>Example:</strong></p>
<p>	<p>The following rules specify that a box has a height of 10.5 centimeters
The following rules specify that a box has a height of 10.5 centimeters and a	and a width of 5.3 ems:</p>
width of 5.3 ems:</p>	<pre>Height : 10.5 cm;
<pre>Height : 10.5 cm;
Width : 5.3;</pre>	Width : 5.3;</pre>
</blockquote>	</blockquote>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc4218">Relative positions</a></h3>	<h3><a name="sectc4218">Relative positions</a></h3>
<p>
The positioning of boxes uses the eight axes and sides, the sides generally	<p>The positioning of boxes uses the eight axes and sides, the sides generally
being used to define the juxtapositioning (vertical or horizontal) of boxes,	being used to define the juxtapositioning (vertical or horizontal) of boxes,
the middle axes being used to define centering, and the reference axes being	the middle axes being used to define centering, and the reference axes being
used for alignment.</p>	used for alignment.</p>
<p>
Two rules allow a box to be placed relative to other boxes. The	<p>Two rules allow a box to be placed relative to other boxes. The
<tt>VertPos</tt> rule positions the box vertically. The <tt>HorizPos</tt>	<tt>VertPos</tt> rule positions the box vertically. The <tt>HorizPos</tt>
rule positions the box horizontally. It is possible that a box's position	rule positions the box horizontally. It is possible that a box's position
could be entirely determined by other boxes positioned relative to it. In this	could be entirely determined by other boxes positioned relative to it. In this
Line 4815 box.</p>	Line 4273 box.</p>
[ 'UserSpecified' ].	[ 'UserSpecified' ].
VertAxis = 'Left' / 'VMiddle' / 'VRef' / 'Right' .	VertAxis = 'Left' / 'VMiddle' / 'VRef' / 'Right' .
HorizAxis = 'Top' / 'HMiddle' / 'HRef' / 'Bottom' .</pre>	HorizAxis = 'Top' / 'HMiddle' / 'HRef' / 'Bottom' .</pre>
<p>
The reference box is an adjacent box: enclosing, enclosed or adjacent. When a	<p>The reference box is an adjacent box: enclosing, enclosed or adjacent. When
rule is associated with a reference type attribute (and only in this case), it	a rule is associated with a reference type attribute (and only in this case),
can be a box of the element designated by the attribute. The reference box	it can be a box of the element designated by the attribute. The reference box
can be either a presentation box previously defined in the <tt>BOXES</tt>	can be either a presentation box previously defined in the <tt>BOXES</tt>
section of the schema and created by a creation function, or the box	section of the schema and created by a creation function, or the box
associated with a structured element.</p>	associated with a structured element.</p>
<p>
The structural position of the reference box (relative to the box for which	<p>The structural position of the reference box (relative to the box for which
the rule is being written) is indicated by a keyword: <tt>Enclosing</tt>,	the rule is being written) is indicated by a keyword: <tt>Enclosing</tt>,
<tt>Enclosed</tt>, or, for sibling boxes, <tt>Previous</tt> or <tt>Next</tt>.	<tt>Enclosed</tt>, or, for sibling boxes, <tt>Previous</tt> or <tt>Next</tt>.
The reference attributes, or presentation boxes created by a reference	The reference attributes, or presentation boxes created by a reference
Line 4832 which the reference points to. The keyw	Line 4290 which the reference points to. The keyw
rules for presentation boxes to designate the box of the element which created	rules for presentation boxes to designate the box of the element which created
the presentation box. Finally, the <tt>Root</tt> keyword can be used to	the presentation box. Finally, the <tt>Root</tt> keyword can be used to
designate the root of the document.</p>	designate the root of the document.</p>
<p>
When the keyword is ambiguous, it is followed by the name of an element type	<p>When the keyword is ambiguous, it is followed by the name of an element
or presentation box which resolves the ambiguity (the <tt>Creator</tt> and	type or presentation box which resolves the ambiguity (the <tt>Creator</tt>
<tt>Root</tt> keywords are never ambiguous). If this name is not given, then	and <tt>Root</tt> keywords are never ambiguous). If this name is not given,
the first box encountered is used as the reference box. It is also possible to	then the first box encountered is used as the reference box. It is also
use just the name of an element type or presentation box without an initial	possible to use just the name of an element type or presentation box without
keyword. In this case, a sibling having that name will be used. If the name	an initial keyword. In this case, a sibling having that name will be used. If
is preceded by the keyword <tt>NOT</tt>, then the reference box will be the	the name is preceded by the keyword <tt>NOT</tt>, then the reference box will
first box whose type is not the named one.</p>	be the first box whose type is not the named one.</p>
<p>
In place of the box or type name, the keywords <tt>AnyElem</tt>,	<p>In place of the box or type name, the keywords <tt>AnyElem</tt>,
<tt>AnyBox</tt> and <tt>ElemWithAttr</tt> can be used, representing	<tt>AnyBox</tt> and <tt>ElemWithAttr</tt> can be used, representing
respectively, any structured element box, any presentation box, and the box	respectively, any structured element box, any presentation box, and the box
corresponding to any structured element having a particular attribute,	corresponding to any structured element having a particular attribute,
whatever its value; the name of this attribute must follow the keyword	whatever its value; the name of this attribute must follow the keyword
<tt>ElemWithAttr</tt>.</p>	<tt>ElemWithAttr</tt>.</p>
<p>
A type name may be preceded by a star in order to resolve the ambiguity in the	<p>A type name may be preceded by a star in order to resolve the ambiguity in
special case where the structure schema defines an <a	the special case where the structure schema defines an <a
href="#sectd3284">inclusion</a> without expansion (or with partial expansion)	href="#sectd3284">inclusion</a> without expansion (or with partial expansion)
of the same type as an element of the scheme. For mark pairs (and only for <a	of the same type as an element of the scheme. For mark pairs (and only for <a
href="#sectd3285">mark pairs</a>) the type name <em>must</em> be preceded by	href="#sectd3285">mark pairs</a>) the type name <em>must</em> be preceded by
the <tt>First</tt> or <tt>Second</tt> keyword, which indicates which of the	the <tt>First</tt> or <tt>Second</tt> keyword, which indicates which of the
two marks of the pair should be used as the reference box.</p>	two marks of the pair should be used as the reference box.</p>
<p>
The star character ('<tt>*</tt>') used alone designates the box to which the	<p>The star character ('<tt>*</tt>') used alone designates the box to which
rule applies (in this case, it is obviously useless to specify the type of the	the rule applies (in this case, it is obviously useless to specify the type of
reference box).</p>	the reference box).</p>
<p>
The keywords <tt>Enclosing</tt> and <tt>Enclosed</tt> can be used no matter	<p>The keywords <tt>Enclosing</tt> and <tt>Enclosed</tt> can be used no matter
what constructor defines the type to which the rule applies. When applied to	what constructor defines the type to which the rule applies. When applied to
the element which represents the entire document, <tt>Enclosing</tt>	the element which represents the entire document, <tt>Enclosing</tt>
designates the window or page in which the document's image is displayed for	designates the window or page in which the document's image is displayed for
Line 4871 aggregate. It can also be used to desig	Line 4329 aggregate. It can also be used to desig
box. The keywords <tt>Previous</tt> and <tt>Next</tt> are primarily used to	box. The keywords <tt>Previous</tt> and <tt>Next</tt> are primarily used to
denote list elements, but can also be used to denote elements of an	denote list elements, but can also be used to denote elements of an
aggregate.</p>	aggregate.</p>
<p>
In the position rule, the structural position relative to the reference box is	<p>In the position rule, the structural position relative to the reference box
followed, after a period, by the name of an axis or side. The rule specifies	is followed, after a period, by the name of an axis or side. The rule
its node's position as being some distance from this axis or side of the	specifies its node's position as being some distance from this axis or side of
reference box. If this distance is zero, then the distance does not appear in	the reference box. If this distance is zero, then the distance does not
the rule. Otherwise, it does appear as a positive or negative number (the	appear in the rule. Otherwise, it does appear as a positive or negative
sign is required for negative numbers). The sign takes into account the	number (the sign is required for negative numbers). The sign takes into
orientation of the coordinate axes: for top to bottom for the vertical axis	account the orientation of the coordinate axes: for top to bottom for the
and from left to right for the horizontal axis. Thus, a negative distance in	vertical axis and from left to right for the horizontal axis. Thus, a
a vertical position indicates that the side or axis specified in the rule is	negative distance in a vertical position indicates that the side or axis
above the side or axis of the reference box.</p>	specified in the rule is above the side or axis of the reference box.</p>
<p>
The distance can be followed by the <tt>UserSpecified</tt> keyword (even if	<p>The distance can be followed by the <tt>UserSpecified</tt> keyword (even if
the distance is nil and does not appear, the <tt>UserSpecified</tt> keyword	the distance is nil and does not appear, the <tt>UserSpecified</tt> keyword
can be used). It indicates that when the element to which the rule applies is	can be used). It indicates that when the element to which the rule applies is
being created, the editor will ask the user to specify the distance himself,	being created, the editor will ask the user to specify the distance himself,
Line 4907 rule, the horizontal position rule, or b	Line 4365 rule, the horizontal position rule, or b
'AnyElem' / 'AnyBox' /	'AnyElem' / 'AnyBox' /
'ElemWithAttr' AttrID .	'ElemWithAttr' AttrID .
BoxTypeNot = [ 'NOT' ] BoxOrType .</pre>	BoxTypeNot = [ 'NOT' ] BoxOrType .</pre>

<blockquote class="example">	<blockquote class="example">
<p>	<p><strong>Example:</strong></p>
<strong>Example:</strong></p>
<p>	<p>If a <a name="expos1">report</a> is defined by the following structure
If a <a name="expos1">report</a> is defined by the following structure	schema:</p>
schema:</p>	<pre>Report = BEGIN
<pre>Report = BEGIN
Title = Text;	Title = Text;
Summary = Text;	Summary = Text;
Keywords = Text;	Keywords = Text;
...	...
END;</pre>	END;</pre>
<p>
then the presentation schema could contain the rules:</p>	<p>then the presentation schema could contain the rules:</p>
<pre>Report : BEGIN	<pre>Report : BEGIN
VertPos : Top = Enclosing . Top;	VertPos : Top = Enclosing . Top;
HorizPos : Left = Enclosing . Left;	HorizPos : Left = Enclosing . Left;
...	...
END;</pre>	END;</pre>
<p>
These rules place the <a name="reportexample">report</a> in the upper left	<p>These rules place the <a name="reportexample">report</a> in the upper
corner of the enclosing box, which is the window in which the document is	left corner of the enclosing box, which is the window in which the document
being edited.</p>	is being edited.</p>
<pre>Title : BEGIN	<pre>Title : BEGIN
VertPos : Top = Enclosing . Top + 1;	VertPos : Top = Enclosing . Top + 1;
HorizPos : VMiddle = Enclosing . VMiddle;	HorizPos : VMiddle = Enclosing . VMiddle;
...	...
END;</pre>	END;</pre>
<p>
The top of the title is one line (a line has the height of the characters of	<p>The top of the title is one line (a line has the height of the characters
the title) from the top of the report, which is also the top of the editing	of the title) from the top of the report, which is also the top of the
window. The title is centered horizontally in the window (see <a	editing window. The title is centered horizontally in the window (see <a
href="#posdim">figure</a>).</p>	href="#posdim">figure</a>).</p>
<pre>Summary : BEGIN	<pre>Summary : BEGIN
VertPos : Top = Title . Bottom + 1.5;	VertPos : Top = Title . Bottom + 1.5;
HorizPos : Left = Enclosing . Left + 2 cm;	HorizPos : Left = Enclosing . Left + 2 cm;
...	...
END;</pre>	END;</pre>
<p>
The top of the summary is place a line and a half below the bottom of the	<p>The top of the summary is place a line and a half below the bottom of the
title and is shifted two centimeters from the side of the window.</p>	title and is shifted two centimeters from the side of the window.</p>
</blockquote>	</blockquote>

<blockquote class="example">	<blockquote class="example">
<p>	<p><strong>Example:</strong></p>
<strong>Example:</strong></p>
<p>	<p>Suppose there is a <a name="expos2">Design</a> logical structure which
Suppose there is a <a name="expos2">Design</a> logical structure which	contains graphical elements:</p>
contains graphical elements:</p>	<pre>Design = LIST OF (ElemGraph = GRAPHICS);</pre>
<pre>Design = LIST OF (ElemGraph = GRAPHICS);</pre>
<p>	<p>The following rules allow the user to freely choose the position of each
The following rules allow the user to freely choose the position of each	element when it is created:</p>
element when it is created:</p>	<pre>ElemGraph =
<pre>ElemGraph =
BEGIN	BEGIN
VertPos : Top = Enclosing . Top + 1 cm UserSpecified;	VertPos : Top = Enclosing . Top + 1 cm UserSpecified;
HorizPos: Left = Enclosing . Left UserSpecified;	HorizPos: Left = Enclosing . Left UserSpecified;
...	...
END;</pre>	END;</pre>
<p>
Thus, when a graphical element is created, its default placement is at the	<p>Thus, when a graphical element is created, its default placement is at
left of the window and 1 cm from the top, but the user can move it	the left of the window and 1 cm from the top, but the user can move it
immediately, simply by moving the mouse.</p>	immediately, simply by moving the mouse.</p>
</blockquote>	</blockquote>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc4219">Box extents</a></h3>	<h3><a name="sectc4219">Box extents</a></h3>
<p>
The extents (height and width) of each box are defined by the two rules	<p>The extents (height and width) of each box are defined by the two rules
<tt>Height</tt> and <tt>Width</tt>. There are three types of extents: fixed,	<tt>Height</tt> and <tt>Width</tt>. There are three types of extents: fixed,
relative, and elastic.</p>	relative, and elastic.</p>

<div class="subsubsection">	<div class="subsubsection">

<h4><a name="sectd42191">Fixed extents</a></h4>	<h4><a name="sectd42191">Fixed extents</a></h4>
<p>
A fixed dimension sets the height or width of the box independently of all	<p>A fixed dimension sets the height or width of the box independently of all
other boxes. It is expressed in <a href="#sectc4217">distance units</a>. The	other boxes. It is expressed in <a href="#sectc4217">distance units</a>. The
extent can be followed by the <tt>UserSpecified</tt> keyword which indicates	extent can be followed by the <tt>UserSpecified</tt> keyword which indicates
that when the element to which the rule applies is being created, the editor	that when the element to which the rule applies is being created, the editor
Line 4992 will ask the user to specify the extent	Line 4448 will ask the user to specify the extent
case, the extent specified in the rule is a default extent which is suggested	case, the extent specified in the rule is a default extent which is suggested
to the user but can be modified. The <tt>UserSpecified</tt> keyword can be	to the user but can be modified. The <tt>UserSpecified</tt> keyword can be
used either in the <tt>Height</tt> rule, the <tt>Width</tt> rule, or both.</p>	used either in the <tt>Height</tt> rule, the <tt>Width</tt> rule, or both.</p>
<p>
A fixed extent rule can be ended by the <tt>Min</tt> keyword, which signifies	<p>A fixed extent rule can be ended by the <tt>Min</tt> keyword, which
that the indicated value is a minimum, and that, if the contents of the box	signifies that the indicated value is a minimum, and that, if the contents of
require it, a larger extent is possible.</p>	the box require it, a larger extent is possible.</p>
<pre> 'Height' ':' Dimension	<pre> 'Height' ':' Dimension
'Width' ':' Dimension	'Width' ':' Dimension
Dimension = AbsDist [ 'UserSpecified' ] [ 'Min' ] /	Dimension = AbsDist [ 'UserSpecified' ] [ 'Min' ] /
...</pre>	...</pre>

<blockquote class="example">	<blockquote class="example">
<p>	<p><strong>Example:</strong></p>
<strong>Example:</strong></p>
<p>	<p>Continuing with the <a href="#expos2">previous example</a>, it is
Continuing with the <a href="#expos2">previous example</a>, it is possible to	possible to allow the user to choose the size of each graphical element as
allow the user to choose the size of each graphical element as it is	it is created:</p>
created:</p>	<pre>ElemGraph : BEGIN
<pre>ElemGraph : BEGIN
Width : 2 cm UserSpecified;	Width : 2 cm UserSpecified;
Height : 1 cm UserSpecified;	Height : 1 cm UserSpecified;
...	...
END;</pre>	END;</pre>
<p>
Thus, when a graphical element is create, it is drawn by default with a width	<p>Thus, when a graphical element is create, it is drawn by default with a
of 2 cm and a height of 1 cm, but the user is free to resize it immediately	width of 2 cm and a height of 1 cm, but the user is free to resize it
with the mouse.</p>	immediately with the mouse.</p>
<pre>Summary : BEGIN	<pre>Summary : BEGIN
Height : 5 cm Min;	Height : 5 cm Min;
...	...
END;	END;
Line 5028 Keywords : BEGIN	Line 4484 Keywords : BEGIN
</div>	</div>

<div class="subsubsection">	<div class="subsubsection">

<h4><a name="sectd42192">Relative extents</a></h4>	<h4><a name="sectd42192">Relative extents</a></h4>
<p>
A relative extent determines the extent as a function of the extent of another	<p>A relative extent determines the extent as a function of the extent of
box, just as a relative position places a box in relation to another. The	another box, just as a relative position places a box in relation to another.
reference box in an extent rule is designated using the same syntax as is used	The reference box in an extent rule is designated using the same syntax as is
in a relative position rule. It is followed by a period and a <tt>Height</tt>	used in a relative position rule. It is followed by a period and a
or <tt>Width</tt> keyword, depending on the extent being referred to. Next	<tt>Height</tt> or <tt>Width</tt> keyword, depending on the extent being
comes the relation between the extent being defined and the extent of the	referred to. Next comes the relation between the extent being defined and the
reference box. This relation can be either a percentage or a difference.</p>	extent of the reference box. This relation can be either a percentage or a
<p>	difference.</p>
A percentage is indicated by a star (the multiplication symbol) followed by
	<p>A percentage is indicated by a star (the multiplication symbol) followed by
the numeric percentage value (which may be greater than or less than 100) and	the numeric percentage value (which may be greater than or less than 100) and
the percent (`%') character. A difference is simply indicated by a signed	the percent (`%') character. A difference is simply indicated by a signed
difference.</p>	difference.</p>
<p>
If the rule appears in the presentation rules of a numeric attribute, the	<p>If the rule appears in the presentation rules of a numeric attribute, the
percentage value can be replaced by the name of the attribute. This attribute	percentage value can be replaced by the name of the attribute. This attribute
is then used as a percentage. The attribute can also be used as part of a <a	is then used as a percentage. The attribute can also be used as part of a <a
href="#distance">difference</a>.</p>	href="#distance">difference</a>.</p>
<p>
Just as with a fixed extent, a relative extent rule can end with the	<p>Just as with a fixed extent, a relative extent rule can end with the
<tt>Min</tt> keyword, which signifies that the extent is a minimum and that,	<tt>Min</tt> keyword, which signifies that the extent is a minimum and that,
if the contents of the box require it, a larger extent is possible.</p>	if the contents of the box require it, a larger extent is possible.</p>
<p>
A special case of relative extent rules is:</p>	<p>A special case of relative extent rules is:</p>
<pre>Height : Enclosed . Height;</pre>	<pre>Height : Enclosed . Height;</pre>
<p>
or</p>	<p>or</p>
<pre>Width : Enclosed . Width;</pre>	<pre>Width : Enclosed . Width;</pre>
<p>
which specifies that the box has a height (or width) such that it encloses all	<p>which specifies that the box has a height (or width) such that it encloses
the boxes which it contains, excluding boxes having a rule <tt>VertOverflow:	all the boxes which it contains, excluding boxes having a rule
Yes;</tt> or <tt>HorizOverflow: Yes;</tt>.</p>	<tt>VertOverflow: Yes;</tt> or <tt>HorizOverflow: Yes;</tt>.</p>
<p>
<strong>Note:</strong> character strings (type <tt>TEXT_UNIT</tt>) generally	<p><strong>Note:</strong> character strings (type <tt>TEXT_UNIT</tt>)
must use the sum of the widths of the characters which compose them as their	generally must use the sum of the widths of the characters which compose them
width, which is expressed by the rule:</p>	as their width, which is expressed by the rule:</p>
<pre>TEXT_UNIT :	<pre>TEXT_UNIT :
Width : Enclosed . Width;</pre>	Width : Enclosed . Width;</pre>
<p>
If this rule is not the default <tt>Width</tt> rule, it must be given	<p>If this rule is not the default <tt>Width</tt> rule, it must be given
explicitly in the <tt>RULES</tt> section which defines the presentation rules	explicitly in the <tt>RULES</tt> section which defines the presentation rules
of the logical elements.</p>	of the logical elements.</p>
<pre> 'Height' ':' Extent	<pre> 'Height' ':' Extent
Line 5080 of the logical elements.</p>	Line 4536 of the logical elements.</p>
Relation ='*' ExtentAttr '%' / Distance .	Relation ='*' ExtentAttr '%' / Distance .
ExtentAttr = ExtentVal / AttrID .	ExtentAttr = ExtentVal / AttrID .
ExtentVal = NUMBER .</pre>	ExtentVal = NUMBER .</pre>

<blockquote class="example">	<blockquote class="example">
<p>	<p><strong>Example:</strong></p>
<strong>Example:</strong></p>
<p>	<p>Completing the <a href="#expos1">above example</a>, it is possible to
Completing the <a href="#expos1">above example</a>, it is possible to specify	specify that the report takes its width from the editing window and its
that the report takes its width from the editing window and its height from	height from the size of its contents (this can obviously be greater than
the size of its contents (this can obviously be greater than that of the	that of the window):</p>
window):</p>	<pre>Report : BEGIN
<pre>Report : BEGIN
Width : Enclosing . Width;	Width : Enclosing . Width;
Height : Enclosed . Height;	Height : Enclosed . Height;
...	...
END;</pre>	END;</pre>
<p>
Then, the following rules make the title occupy 60% of the width of the report	<p>Then, the following rules make the title occupy 60% of the width of the
(which is that of the window) and is broken into centered lines of this width	report (which is that of the window) and is broken into centered lines of
(see the <a href="#sectc4222"><tt>Line</tt> rule</a>).</p>	this width (see the <a href="#sectc4222"><tt>Line</tt> rule</a>).</p>
<pre>Title : BEGIN	<pre>Title : BEGIN
Width : Enclosing . Width * 60%;	Width : Enclosing . Width * 60%;
Height : Enclosed . Height;	Height : Enclosed . Height;
Line;	Line;
Adjust : VMiddle;	Adjust : VMiddle;
...	...
END;</pre>	END;</pre>
<p>
The summary occupy the entire width of the window, with the exception of a 2	<p>The summary occupy the entire width of the window, with the exception of
cm margin reserved by the horizontal position rule:</p>	a 2 cm margin reserved by the horizontal position rule:</p>
<pre>Summary : BEGIN	<pre>Summary : BEGIN
Width : Enclosing . Width - 2 cm;	Width : Enclosing . Width - 2 cm;
Height : Enclosed . Height;	Height : Enclosed . Height;
...	...
END;</pre>	END;</pre>
<p>
This set of rules, plus the <a href="#reportexample">position rules given
above</a>, produce the layout of boxes shown in the following<a
href="#posdim">figure</a>.</p>

<div class="figure">
<hr>

<pre>-------------------------------------------------------------	<p>This set of rules, plus the <a href="#reportexample">position rules given
	above</a>, produce the layout of boxes shown in the following<a
	href="#posdim">figure</a>.</p>

	<div class="figure">
	<hr>
	<pre>-------------------------------------------------------------
\| Window and Report ^ \|	\| Window and Report ^ \|
\| \| 1 line \|	\| \| 1 line \|
\| v \|	\| v \|
\| ------------------------------------- \|	\| ------------------------------------- \|
\| \| \| \|	\| \| \| \|
: 20% : Title : 20% :	: 20% : Title : 20% :
:<--------->: :<--------->:	:<--------->: :<--------->:
: : 60% : :	: : 60% : :
: :<--------------------------------->: :	: :<--------------------------------->: :
\| \| \| \|	\| \| \| \|
\| ------------------------------------- \|	\| ------------------------------------- \|
\| ^ \|	\| ^ \|
Line 5138 href="#posdim">figure</a>.</p>	Line 4593 href="#posdim">figure</a>.</p>
\| v \|	\| v \|
\| ---------------------------------------------------\|	\| ---------------------------------------------------\|
\| 2 cm \| \|	\| 2 cm \| \|
\|<------>\| Summary \|	\|<------>\| Summary \|
: : :</pre>	: : :</pre>
<p align="center">
<em><a name="posdim">Box position and extent</a><em></em></em></p>
<hr>

</div>	<p align="center"><em><a name="posdim">Box position and
	extent</a><em></em></em></p>
	<hr>
	</div>
</blockquote>	</blockquote>
</div>	</div>

<div class="subsubsection">	<div class="subsubsection">

<h4><a name="sectd42193">Elastic extents</a></h4>	<h4><a name="sectd42193">Elastic extents</a></h4>
<p>
The last type of extent is the elastic extent. Either one or both extents can	<p>The last type of extent is the elastic extent. Either one or both extents
be elastic. A box has an elastic extent when two opposite sides are linked by	can be elastic. A box has an elastic extent when two opposite sides are
distance constraints to two sides or axes of other boxes.</p>	linked by distance constraints to two sides or axes of other boxes.</p>
<p>
One of the sides of the elastic box is linked by a position rule	<p>One of the sides of the elastic box is linked by a position rule
(<tt>VertPos</tt> or <tt>HorizPos</tt>) to a neighboring box. The other side	(<tt>VertPos</tt> or <tt>HorizPos</tt>) to a neighboring box. The other side
is link to another box by a <tt>Height</tt> or <tt>Width</tt> rule, which	is link to another box by a <tt>Height</tt> or <tt>Width</tt> rule, which
takes the same form as the position rule. For the elastic box itself, the	takes the same form as the position rule. For the elastic box itself, the
Line 5168 in the position and extent rule are oppo	Line 4622 in the position and extent rule are oppo
<pre> 'Height' ':' Extent	<pre> 'Height' ':' Extent
'Width' ':' Extent	'Width' ':' Extent
Extent = HPos / VPos / ...</pre>	Extent = HPos / VPos / ...</pre>

<blockquote class="example">	<blockquote class="example">
<p>	<p><strong>Example:</strong></p>
<strong>Example:</strong></p>
<p>	<p>Suppose we want to draw an elastic arrow or line between the middle of
Suppose we want to draw an elastic arrow or line between the middle of the	the bottom side of box A and the upper left corner of box B. To do this, we
bottom side of box A and the upper left corner of box B. To do this, we would	would define a graphics box whose upper left corner coincides with the
define a graphics box whose upper left corner coincides with the middle of the	middle of the bottom side of A (a position rule) and whose lower right
bottom side of A (a position rule) and whose lower right corner coincides with	corner coincides with with the upper left corner of B (dimension rules):</p>
with the upper left corner of B (dimension rules):</p>	<pre>LinkedBox :
<pre>LinkedBox :
BEGIN	BEGIN
VertPos : Top = A .Bottom;	VertPos : Top = A .Bottom;
HorizPos : Left = A . VMiddle;	HorizPos : Left = A . VMiddle;
Line 5185 with the upper left corner of B (dimensi	Line 4639 with the upper left corner of B (dimensi
Width : Right = B . Left;	Width : Right = B . Left;
END;</pre>	END;</pre>
</blockquote>	</blockquote>

<blockquote class="example">	<blockquote class="example">
<p>	<p><strong>Example:</strong></p>
<strong>Example:</strong></p>
<p>	<p>The element SectionTitle creates a presentation box called SectionNum
The element SectionTitle creates a presentation box called SectionNum which	which contains the number of the section. Suppose we want to align the
contains the number of the section. Suppose we want to align the SectionNum	SectionNum and SectionTitle horizontally, have the SectionNum take its width
and SectionTitle horizontally, have the SectionNum take its width from its	from its contents (the section number), have the SectionTitle box begin 0.5
contents (the section number), have the SectionTitle box begin 0.5 cm to the	cm to the right of the SectionNum box and end at the right edge of its
right of the SectionNum box and end at the right edge of its enclosing box.	enclosing box. This would make the SectionTitle box elastic, since its width
This would make the SectionTitle box elastic, since its width is defined by	is defined by the position of its left and right sides. The following rules
the position of its left and right sides. The following rules produce this	produce this effect:</p>
effect:</p>	<pre>SectionNum :
<pre>SectionNum :
BEGIN	BEGIN
HorizPos : Left = Enclosing . Left;	HorizPos : Left = Enclosing . Left;
Width : Enclosed . Width;	Width : Enclosed . Width;
Line 5215 SectionTitle :	Line 4669 SectionTitle :
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc4220">Overflow</a></h3>	<h3><a name="sectc4220">Overflow</a></h3>
<p>
A boxes corresponding to a structural element normally contain all boxes	<p>A boxes corresponding to a structural element normally contain all boxes
corresponding to the elements of its subtree. However, in some cases, it	corresponding to the elements of its subtree. However, in some cases, it
could be necessary to allow a box to jut out from its parent box. Two	could be necessary to allow a box to jut out from its parent box. Two
presentation rules indicate that such an overflow is allowed, one for	presentation rules indicate that such an overflow is allowed, one for
horizontal overflow, one for vertical overflow.</p>	horizontal overflow, one for vertical overflow.</p>
<p>
Each of these rules is expressed by a keyword followed by a colon and the	<p>Each of these rules is expressed by a keyword followed by a colon and the
keyword <tt>Yes</tt> or <tt>No</tt>.</p>	keyword <tt>Yes</tt> or <tt>No</tt>.</p>
<pre> 'VertOverflow' ':' Boolean /	<pre> 'VertOverflow' ':' Boolean /
'HorizOverflow' ':' Boolean .	'HorizOverflow' ':' Boolean .
Boolean = 'Yes' / 'No' .</pre>	Boolean = 'Yes' / 'No' .</pre>
</div>	</div>

<p>@@@@@ ****** </p>	<p>@@@@@ ******</p>

<p>Explain Margin, Padding and Border. Refer to CSS2.</p>	<p>Explain Margin, Padding and Border. Refer to CSS2.</p>
<pre> 'MarginTop' ':' MarginWidth /	<pre> 'MarginTop' ':' MarginWidth /
'MarginRight' ':' MarginWidth /	'MarginRight' ':' MarginWidth /
Line 5264 BorderStyle = InheritParent /	Line 4718 BorderStyle = InheritParent /
'Double' / 'Groove' / 'Ridge' / 'Inset' / 'Outset' .	'Double' / 'Groove' / 'Ridge' / 'Inset' / 'Outset' .
InheritParent = 'Enclosing' '=' / 'Creator' '=' .	InheritParent = 'Enclosing' '=' / 'Creator' '=' .
ColorName = NAME .</pre>	ColorName = NAME .</pre>
<p>@@@@@ ****** </p>

<div class="subsection">	<p>@@@@@ ******</p>

	<div class="subsection">
<h3><a name="sectc4221">Inheritance</a></h3>	<h3><a name="sectc4221">Inheritance</a></h3>
<p>
A presentation parameter can be defined by reference to the same parameter of	<p>A presentation parameter can be defined by reference to the same parameter
another box in the tree of boxes. These structural links are expressed by	of another box in the tree of boxes. These structural links are expressed by
kinship. The reference box can be that of the element immediately above in	kinship. The reference box can be that of the element immediately above in
the structure (<tt>Enclosing</tt>), two levels above (<tt>GrandFather</tt>),	the structure (<tt>Enclosing</tt>), two levels above (<tt>GrandFather</tt>),
immediately below (<tt>Enclosed</tt>) or immediately before	immediately below (<tt>Enclosed</tt>) or immediately before
(<tt>Previous</tt>). In the case of a presentation box, and only in that	(<tt>Previous</tt>). In the case of a presentation box, and only in that
case, the reference box may be the element which created the presentation box	case, the reference box may be the element which created the presentation box
(<tt>Creator</tt>).</p>	(<tt>Creator</tt>).</p>
<p>
Kinship is expressed in terms of the logical structure of the document and not	<p>Kinship is expressed in terms of the logical structure of the document and
in terms of the tree of boxes. The presentation box cannot transmit any of	not in terms of the tree of boxes. The presentation box cannot transmit any
their parameters by inheritance; only structured element boxes can do so. As	of their parameters by inheritance; only structured element boxes can do so.
an example, consider an element B which follows an element A in the logical	As an example, consider an element B which follows an element A in the logical
structure. The element B creates a presentation box P in front of itself,	structure. The element B creates a presentation box P in front of itself,
using the <tt>CreateBefore</tt> rule (see the <a href="#sectc4232">creation	using the <tt>CreateBefore</tt> rule (see the <a href="#sectc4232">creation
rules</a>). If element B's box inherits its character style using the	rules</a>). If element B's box inherits its character style using the
<tt>Previous</tt> kinship operation, it gets its character style from A's box,	<tt>Previous</tt> kinship operation, it gets its character style from A's box,
not from P's box. Inheritance works differently for positions and extents,	not from P's box. Inheritance works differently for positions and extents,
which can refer to presentation boxes.</p>	which can refer to presentation boxes.</p>
<p>
The inherited parameter value can be the same as that of the reference box.	<p>The inherited parameter value can be the same as that of the reference box.
This is indicated by an equals sign. However, for numeric parameters, a	This is indicated by an equals sign. However, for numeric parameters, a
different value can be obtained by adding or subtracting a number from the	different value can be obtained by adding or subtracting a number from the
reference box's parameter value. Addition is indicated by a plus sign before	reference box's parameter value. Addition is indicated by a plus sign before
the number, while subtraction is specified with a minus sign. The value of a	the number, while subtraction is specified with a minus sign. The value of a
parameter can also be given a maximum (if the sign is a plus) or minimum (if	parameter can also be given a maximum (if the sign is a plus) or minimum (if
the sign is a minus).</p>	the sign is a minus).</p>
<p>
If the rule is being applied to a numeric attribute, the number to add or	<p>If the rule is being applied to a numeric attribute, the number to add or
subtract can be replaced by the attribute name. The value of a maximum or	subtract can be replaced by the attribute name. The value of a maximum or
minimum may also be replaced by an attribute name. In these cases, the value	minimum may also be replaced by an attribute name. In these cases, the value
of the attribute is used.</p>	of the attribute is used.</p>
Line 5316 of the attribute is used.</p>	Line 4770 of the attribute is used.</p>
maximum = NUMBER .	maximum = NUMBER .
minimumA = minimum / AttrID .	minimumA = minimum / AttrID .
minimum = NUMBER .</pre>	minimum = NUMBER .</pre>
<p>
The parameters which can be obtained by inheritance are justification,	<p>The parameters which can be obtained by inheritance are justification,
hyphenation, interline spacing, character font (font family), font style, font	hyphenation, interline spacing, character font (font family), font style, font
size, visibility, indentation, underlining, alignment of text, stacking order	size, visibility, indentation, underlining, alignment of text, stacking order
of objects, the style and thickness of lines, fill pattern and the colors of	of objects, the style and thickness of lines, fill pattern and the colors of
Line 5325 lines and characters.</p>	Line 4779 lines and characters.</p>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc4222">Line breaking</a></h3>	<h3><a name="sectc4222">Line breaking</a></h3>
<p>
The <tt>Line</tt> rule specifies that the contents of the box should be broken	<p>The <tt>Line</tt> rule specifies that the contents of the box should be
into lines: the boxes included in the box to which this rule is attached are	broken into lines: the boxes included in the box to which this rule is
displayed one after the other, from left to right, with their horizontal	attached are displayed one after the other, from left to right, with their
reference axes aligned so that they form a series of lines. The length of	horizontal reference axes aligned so that they form a series of lines. The
these lines is equal to the width of the box to which the <tt>Line</tt> rule	length of these lines is equal to the width of the box to which the
is attached.</p>	<tt>Line</tt> rule is attached.</p>
<p>
When an included box overflows the current line, it is either carried forward	<p>When an included box overflows the current line, it is either carried
to the next line, cur, or left the way it is. The <a	forward to the next line, cur, or left the way it is. The <a
href="#sectc4223"><tt>LineBreak</tt> rule</a> is used to allow or prevent the	href="#sectc4223"><tt>LineBreak</tt> rule</a> is used to allow or prevent the
breaking of included boxes. If the included box is not breakable but is	breaking of included boxes. If the included box is not breakable but is
longer than the space remaining on the line, it is left as is. When a	longer than the space remaining on the line, it is left as is. When a
Line 5346 box is breakable, the box is transparent	Line 4799 box is breakable, the box is transparent
included in the compound box are treated just like included boxes which have	included in the compound box are treated just like included boxes which have
the <tt>LineBreak</tt> rule. Thus, it is possible to traverse a complete	the <tt>LineBreak</tt> rule. Thus, it is possible to traverse a complete
subtree of boxes to line break the text leaves of a complex structure.</p>	subtree of boxes to line break the text leaves of a complex structure.</p>
<p>
The relative position rules of the included boxes are ignored, since the boxes	<p>The relative position rules of the included boxes are ignored, since the
will be placed according to the line breaking rules.</p>	boxes will be placed according to the line breaking rules.</p>
<p>
The <tt>Line</tt> rule does not have a parameter. The characteristics of the	<p>The <tt>Line</tt> rule does not have a parameter. The characteristics of
lines that will be constructed are determined by the <tt>LineSpacing</tt>,	the lines that will be constructed are determined by the <tt>LineSpacing</tt>,
<tt>Indent</tt>, <tt>Adjust</tt>, <tt>Justify</tt>, and <tt>Hyphenate</tt>	<tt>Indent</tt>, <tt>Adjust</tt>, <tt>Justify</tt>, and <tt>Hyphenate</tt>
rules. Moreover, the <a href="#insectd42226"><tt>Inline</tt> rule</a> permits	rules. Moreover, the <a href="#insectd42226"><tt>Inline</tt> rule</a> permits
the exclusion of certain elements from the line breaking process.</p>	the exclusion of certain elements from the line breaking process.</p>
<p>
When the <tt>Line</tt> rule appears in the rules sequence of a non-primary	<p>When the <tt>Line</tt> rule appears in the rules sequence of a non-primary
view, it applies only to that view, but when the <tt>Line</tt> rule appears in	view, it applies only to that view, but when the <tt>Line</tt> rule appears in
the rules sequence of the primary view, it also applies to the other views by	the rules sequence of the primary view, it also applies to the other views by
default, except for those views which explicitly invoke the <tt>NoLine</tt>	default, except for those views which explicitly invoke the <tt>NoLine</tt>
Line 5369 rule does not take any parameters.</p>	Line 4822 rule does not take any parameters.</p>
'NoLine'</pre>	'NoLine'</pre>

<div class="subsubsection">	<div class="subsubsection">

<h4><a name="sectd42221">Line spacing</a></h4>	<h4><a name="sectd42221">Line spacing</a></h4>
<p>
The <tt>LineSpacing</tt> rule defines the line spacing to be used in the line	<p>The <tt>LineSpacing</tt> rule defines the line spacing to be used in the
breaking process. The line spacing is the distance between the baselines	line breaking process. The line spacing is the distance between the baselines
(horizontal reference axis) of the successive lines produced by the	(horizontal reference axis) of the successive lines produced by the
<tt>Line</tt> rule. The value of the line spacing can be specified as a	<tt>Line</tt> rule. The value of the line spacing can be specified as a
constant or by inheritance. It is expressed in any of the available <a	constant or by inheritance. It is expressed in any of the available <a
href="#sectc4217">distance units</a>.</p>	href="#sectc4217">distance units</a>.</p>
<p>
Inheritance allows the value to be obtained from a relative in the structure	<p>Inheritance allows the value to be obtained from a relative in the
tree, either without change (an equals sign appears after the inheritance	structure tree, either without change (an equals sign appears after the
keyword), with a positive difference (a plus sign), or a negative difference	inheritance keyword), with a positive difference (a plus sign), or a negative
(a minus sign). When the rule uses a difference, the value of the difference	difference (a minus sign). When the rule uses a difference, the value of the
follows the sign and is expressed as a <a href="#sectc4217">distance</a>.</p>	difference follows the sign and is expressed as a <a
	href="#sectc4217">distance</a>.</p>
<pre> 'LineSpacing' ':' DistOrInherit	<pre> 'LineSpacing' ':' DistOrInherit
DistOrInherit = Kinship InheritedDist / Distance .	DistOrInherit = Kinship InheritedDist / Distance .
InheritedDist = '=' / '+' AbsDist / '-' AbsDist .</pre>	InheritedDist = '=' / '+' AbsDist / '-' AbsDist .</pre>
<p>
When the line spacing value (or its difference from another element) is	<p>When the line spacing value (or its difference from another element) is
expressed in relative units, it changes with the size of the characters. Thus,	expressed in relative units, it changes with the size of the characters. Thus,
when a larger font is chosen for a part of the document, the line spacing of	when a larger font is chosen for a part of the document, the line spacing of
that part expands proportionally. In contrast, when the line spacing value is	that part expands proportionally. In contrast, when the line spacing value is
Line 5399 depending on the desired effect.</p>	Line 4852 depending on the desired effect.</p>
</div>	</div>

<div class="subsubsection">	<div class="subsubsection">

<h4><a name="sectd42222">First line indentation</a></h4>	<h4><a name="sectd42222">First line indentation</a></h4>
<p>
The <tt>Indent</tt> rule is used to specify the indentation of the first line	<p>The <tt>Indent</tt> rule is used to specify the indentation of the first
of the elements broken into lines by the <tt>Line</tt> function. The	line of the elements broken into lines by the <tt>Line</tt> function. The
indentation determines how far the first line of the element is shifted with	indentation determines how far the first line of the element is shifted with
respect to the other lines of the same element. It can be specified as a	respect to the other lines of the same element. It can be specified as a
constant or by inheritance. The constant value is a positive integer (shifted	constant or by inheritance. The constant value is a positive integer (shifted
to the right; the sign is optional), a negative integer (shifted to the left)	to the right; the sign is optional), a negative integer (shifted to the left)
or zero (no shift). All available <a href="#sectc4217">units</a> can be	or zero (no shift). All available <a href="#sectc4217">units</a> can be
used.</p>	used.</p>
<p>
Indentation can be defined for any box, regardless of whether the box is line	<p>Indentation can be defined for any box, regardless of whether the box is
broken, and transmitted by inheritance to elements that are line broken. The	line broken, and transmitted by inheritance to elements that are line broken.
size of the indentation is specified in the same manner as the <a	The size of the indentation is specified in the same manner as the <a
href="#sectd42221">line spacing</a>.</p>	href="#sectd42221">line spacing</a>.</p>
<pre> 'Indent' ':' DistOrInherit</pre>	<pre> 'Indent' ':' DistOrInherit</pre>
</div>	</div>

<div class="subsubsection">	<div class="subsubsection">

<h4><a name="sectd42223">Alignment</a></h4>	<h4><a name="sectd42223">Alignment</a></h4>
<p>
The alignment style of the lines constructed during line breaking is defined	<p>The alignment style of the lines constructed during line breaking is
by the <tt>Adjust</tt> rule. The alignment value can be a constant or	defined by the <tt>Adjust</tt> rule. The alignment value can be a constant or
inherited. A constant value is specified by a keyword:</p>	inherited. A constant value is specified by a keyword:</p>
<ul>	<ul>
<li>	<li><tt>Left</tt>: at the left edge,</li>
<tt>Left</tt>: at the left edge,	<li><tt>Right</tt>: at the right edge,</li>
</li>	<li><tt>VMiddle</tt>: centered</li>
<li>	<li><tt>LeftWithDots</tt>: at the left edge with a dotted line filling out
<tt>Right</tt>: at the right edge,	the last line up to the right edge of the line breaking box.</li>
</li>
<li>
<tt>VMiddle</tt>: centered
</li>
<li>
<tt>LeftWithDots</tt>: at the left edge with a dotted line filling out the
last line up to the right edge of the line breaking box.
</li>
</ul>	</ul>
<p>
An inherited value can only be the same as that of the reference box and is	<p>An inherited value can only be the same as that of the reference box and is
specified by a kinship keyword followed by an equals sign.</p>	specified by a kinship keyword followed by an equals sign.</p>
<pre> 'Adjust' ':' AlignOrInherit	<pre> 'Adjust' ':' AlignOrInherit
AlignOrInherit = Kinship '=' / Alignment .	AlignOrInherit = Kinship '=' / Alignment .
Line 5450 specified by a kinship keyword followed	Line 4893 specified by a kinship keyword followed
</div>	</div>

<div class="subsubsection">	<div class="subsubsection">

<h4><a name="sectd42224">Justification</a></h4>	<h4><a name="sectd42224">Justification</a></h4>
<p>
The <tt>Justify</tt> rule indicates whether the lines contained in the box and	<p>The <tt>Justify</tt> rule indicates whether the lines contained in the box
produced by a <tt>Line</tt> rule should be extended horizontally to occupy the	and produced by a <tt>Line</tt> rule should be extended horizontally to occupy
entire width of their enclosing box. The first and last lines are treated	the entire width of their enclosing box. The first and last lines are treated
specially: the position of the beginning of the first line is fixed by the	specially: the position of the beginning of the first line is fixed by the
<tt>Indent</tt> rule and last line is not extended. The justification	<tt>Indent</tt> rule and last line is not extended. The justification
parameter defined by this rule takes a boolean value, which can be a constant	parameter defined by this rule takes a boolean value, which can be a constant
Line 5466 followed by an equals sign.</p>	Line 4908 followed by an equals sign.</p>
<pre> 'Justify' ':' BoolInherit	<pre> 'Justify' ':' BoolInherit
BoolInherit = Boolean / Kinship '=' .	BoolInherit = Boolean / Kinship '=' .
Boolean ='Yes' / 'No' .</pre>	Boolean ='Yes' / 'No' .</pre>
<p>
When the lines are justified, the alignment parameter specified in the	<p>When the lines are justified, the alignment parameter specified in the
<tt>Adjust</tt> rule has no influence, other than on the last line produced.	<tt>Adjust</tt> rule has no influence, other than on the last line produced.
This occurs because, when the other are extended to the limits of the box, the	This occurs because, when the other are extended to the limits of the box, the
alignment style is no longer perceptible.</p>	alignment style is no longer perceptible.</p>

<blockquote class="example">	<blockquote class="example">
<p>	<p><strong>Example:</strong></p>
<strong>Example:</strong></p>
<p>	<p>An important use of inheritance is to vary the characteristics of lines
An important use of inheritance is to vary the characteristics of lines for an	for an element type (for example, Paragraph) according to the enclosing
element type (for example, Paragraph) according to the enclosing environment	environment (for example, Summary or Section), and thus obtain different
(for example, Summary or Section), and thus obtain different line breaking	line breaking styles for the same elements when they appear in different
styles for the same elements when they appear in different environments. The	environments. The following rules specify that paragraphs inherit their
following rules specify that paragraphs inherit their alignment,	alignment, justification, and line spacing:</p>
justification, and line spacing:</p>	<pre>Paragraph :
<pre>Paragraph :
BEGIN	BEGIN
Justify : Enclosing = ;	Justify : Enclosing = ;
LineSpacing : Enclosing = ;	LineSpacing : Enclosing = ;
Adjust : Enclosing =;	Adjust : Enclosing =;
Line;	Line;
END;</pre>	END;</pre>
<p>
If the alignment, justification, and line spacing of the Section and Summary	<p>If the alignment, justification, and line spacing of the Section and
elements is fixed:</p>	Summary elements is fixed:</p>
<pre>Section :	<pre>Section :
BEGIN	BEGIN
Adjust : Left;	Adjust : Left;
Justify : Yes;	Justify : Yes;
Line 5503 Summary :	Line 4945 Summary :
Justify : No;	Justify : No;
LineSpacing : 1.3;	LineSpacing : 1.3;
END;</pre>	END;</pre>
<p>
then the paragraphs appearing in sections are justified with a simple line	<p>then the paragraphs appearing in sections are justified with a simple
spacing while those appearing in summaries are centered and not justified and	line spacing while those appearing in summaries are centered and not
have a larger line spacing. These are nevertheless the very same type of	justified and have a larger line spacing. These are nevertheless the very
paragraph defined in the logical structure schema.</p>	same type of paragraph defined in the logical structure schema.</p>
</blockquote>	</blockquote>
</div>	</div>

<div class="subsubsection">	<div class="subsubsection">

<h4><a name="sectd42225">Hyphenation</a></h4>	<h4><a name="sectd42225">Hyphenation</a></h4>
<p>
The <tt>Hyphenate</tt> rule indicates whether or not words should be broken by	<p>The <tt>Hyphenate</tt> rule indicates whether or not words should be broken
hyphenation at the end of lines. It affects the lines produced by the	by hyphenation at the end of lines. It affects the lines produced by the
<tt>Line</tt> rule and contained in the box carrying the <tt>Hyphenate</tt>	<tt>Line</tt> rule and contained in the box carrying the <tt>Hyphenate</tt>
rule.</p>	rule.</p>
<p>
The hyphenation parameter takes a boolean value, which can be either constant	<p>The hyphenation parameter takes a boolean value, which can be either
or inherited. A constant boolean value is expressed by either the	constant or inherited. A constant boolean value is expressed by either the
<tt>Yes</tt> or the <tt>No</tt> keyword. An inherited value can only be the	<tt>Yes</tt> or the <tt>No</tt> keyword. An inherited value can only be the
same as that of the reference box and is specified by a kinship keyword	same as that of the reference box and is specified by a kinship keyword
followed by an equals sign.</p>	followed by an equals sign.</p>
Line 5531 followed by an equals sign.</p>	Line 4972 followed by an equals sign.</p>
</div>	</div>

<div class="subsubsection">	<div class="subsubsection">

<h4><a name="sectd42226">Avoiding line breaking</a></h4>	<h4><a name="sectd42226">Avoiding line breaking</a></h4>
<p>
The <tt>InLine</tt> rule is used to specify that a box that would otherwise	<p>The <tt>InLine</tt> rule is used to specify that a box that would otherwise
participate in line breaking asked for by the <tt>Line</tt> rule of an	participate in line breaking asked for by the <tt>Line</tt> rule of an
enclosing box, instead avoids the line breaking process and positions itself	enclosing box, instead avoids the line breaking process and positions itself
according to the <tt>HorizPos</tt> and <tt>VertPos</tt> rules that apply to	according to the <tt>HorizPos</tt> and <tt>VertPos</tt> rules that apply to
it. When the <tt>InLine</tt> rule applies to a box which would not be line	it. When the <tt>InLine</tt> rule applies to a box which would not be line
broken, it has no effect.</p>	broken, it has no effect.</p>
<p>
The rule is expressed by the <tt>InLine</tt> keyword followed by a colon and	<p>The rule is expressed by the <tt>InLine</tt> keyword followed by a colon
the keyword <tt>Yes</tt>, if the box should participate in line breaking, or	and the keyword <tt>Yes</tt>, if the box should participate in line breaking,
the keyword <tt>No</tt>, if it should not. This is the only form possible:	or the keyword <tt>No</tt>, if it should not. This is the only form possible:
this rule cannot be inherited. Moreover, it can only appear in the rules of	this rule cannot be inherited. Moreover, it can only appear in the rules of
the primary view and applies to all views defined in the presentation	the primary view and applies to all views defined in the presentation
schema.</p>	schema.</p>
<pre> 'InLine' ':' Boolean .	<pre> 'InLine' ':' Boolean .
Boolean = 'Yes' / 'No' .</pre>	Boolean = 'Yes' / 'No' .</pre>

<blockquote class="example">	<blockquote class="example">
<p>	<p><strong>Example:</strong></p>
<strong>Example:</strong></p>
<p>	<p>Suppose the structure schema defines a logical attribute called
Suppose the structure schema defines a logical attribute called <tt>New</tt>	<tt>New</tt> which is used to identify the passages in a document which were
which is used to identify the passages in a document which were recently	recently modified. It would be nice to have the presentation schema make a
modified. It would be nice to have the presentation schema make a bar appear	bar appear in the left margin next to each passage having the <tt>New</tt>
in the left margin next to each passage having the <tt>New</tt> attribute. A	attribute. A new passage can be an entire element, such as a paragraph or
new passage can be an entire element, such as a paragraph or section, or it	section, or it can be some words in the middle of a paragraph. To produce
can be some words in the middle of a paragraph. To produce the desired	the desired effect, the <tt>New</tt> attribute is given a creation rule
effect, the <tt>New</tt> attribute is given a creation rule which generates a	which generates a <tt>VerticalBar</tt> presentation box.</p>
<tt>VerticalBar</tt> presentation box.</p>
<p>	<p>When the <tt>New</tt> attribute is attached to a character string which
When the <tt>New</tt> attribute is attached to a character string which is	is inside a line broken element (inside a paragraph, for example), the bar
inside a line broken element (inside a paragraph, for example), the bar is one	is one of the elements which participates in line breaking and it is placed
of the elements which participates in line breaking and it is placed normally	normally in the current line, at the end of the character string which has
in the current line, at the end of the character string which has the	the attribute. To avoid this, the <tt>InLine</tt> rule is used in the
attribute. To avoid this, the <tt>InLine</tt> rule is used in the following	following way:</p>
way:</p>	<pre>BOXES
<pre>BOXES
VerticalBar:	VerticalBar:
BEGIN	BEGIN
Content: Graphics 'l';	Content: Graphics 'l';
Line 5590 ATTRIBUTES	Line 5030 ATTRIBUTES
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc4223">Page breaking and line breaking conditions</a></h3>	<h3><a name="sectc4223">Page breaking and line breaking conditions</a></h3>
<p>
Pages are constructed by the editor in accordance with the model specified by	<p>Pages are constructed by the editor in accordance with the model specified
a <a href="#sectc4233"><tt>Page</tt> rule</a>. The page model describes only	by a <a href="#sectc4233"><tt>Page</tt> rule</a>. The page model describes
the composition of the pages but does not give any rules for breaking	only the composition of the pages but does not give any rules for breaking
different element types across pages. Now, it is possible that certain	different element types across pages. Now, it is possible that certain
elements must not be cut by page breaks, while others can be cut anywhere. The	elements must not be cut by page breaks, while others can be cut anywhere. The
<tt>PageBreak</tt>, <tt>NoBreak1</tt>, and <tt>NoBreak2</tt> rules are used to	<tt>PageBreak</tt>, <tt>NoBreak1</tt>, and <tt>NoBreak2</tt> rules are used to
specify the conditions under which each element type can be cut.</p>	specify the conditions under which each element type can be cut.</p>
<p>
The <tt>PageBreak</tt> rule is used to indicate whether or not the box can be	<p>The <tt>PageBreak</tt> rule is used to indicate whether or not the box can
cut during the construction of pages. If cutting is authorized, the box can	be cut during the construction of pages. If cutting is authorized, the box
be cut, with one part appearing at the bottom of a page and the other part	can be cut, with one part appearing at the bottom of a page and the other part
appearing at the top of the next page. The rule is formed by the	appearing at the top of the next page. The rule is formed by the
<tt>PageBreak</tt> keyword followed by a colon and a constant boolean value	<tt>PageBreak</tt> keyword followed by a colon and a constant boolean value
(<tt>Yes</tt> or <tt>No</tt>). This is the only form possible: this rule	(<tt>Yes</tt> or <tt>No</tt>). This is the only form possible: this rule
cannot be inherited. Moreover, it can only appear in the rules of the primary	cannot be inherited. Moreover, it can only appear in the rules of the primary
view and applies to all views defined in the presentation schema.</p>	view and applies to all views defined in the presentation schema.</p>
<p>
Whether objects can be cut by line breaks can be controlled in a similar way	<p>Whether objects can be cut by line breaks can be controlled in a similar
using the <tt>LineBreak</tt> rule. This rule allows the specification of	way using the <tt>LineBreak</tt> rule. This rule allows the specification of
whether or not the box can be cut during the construction of lines. If	whether or not the box can be cut during the construction of lines. If
cutting is authorized, the box can be cut, with one part appearing at the end	cutting is authorized, the box can be cut, with one part appearing at the end
of a line and the other part appearing at the beginning of the next line. The	of a line and the other part appearing at the beginning of the next line. The
Line 5623 schema.</p>	Line 5062 schema.</p>
<pre> 'PageBreak' ':' Boolean .	<pre> 'PageBreak' ':' Boolean .
'LineBreak' ':' Boolean .	'LineBreak' ':' Boolean .
Boolean = 'Yes' / 'No' .</pre>	Boolean = 'Yes' / 'No' .</pre>
<p>
When a box can be cut by a page break, it is possible that a page break will	<p>When a box can be cut by a page break, it is possible that a page break
fall an inappropriate spot, creating, for example, a widow or orphan, or	will fall an inappropriate spot, creating, for example, a widow or orphan, or
separating the title of a section from the first paragraph of the section. The	separating the title of a section from the first paragraph of the section. The
<tt>NoBreak1</tt> and <tt>NoBreak2</tt> rules are used to avoid this. They	<tt>NoBreak1</tt> and <tt>NoBreak2</tt> rules are used to avoid this. They
specify that the box of the element to which they apply cannot be cut within a	specify that the box of the element to which they apply cannot be cut within a
certain zone at the top (<tt>NoBreak1</tt> rule) or at the bottom	certain zone at the top (<tt>NoBreak1</tt> rule) or at the bottom
(<tt>NoBreak2</tt> rule). These two rules specify the height of the zones in	(<tt>NoBreak2</tt> rule). These two rules specify the height of the zones in
which page breaks are prohibited.</p>	which page breaks are prohibited.</p>
<p>
The <tt>NoBreak1</tt> and <tt>NoBreak2</tt> rules give the height of the zone	<p>The <tt>NoBreak1</tt> and <tt>NoBreak2</tt> rules give the height of the
in which page breaking is prohibited. The height is given as a constant value	zone in which page breaking is prohibited. The height is given as a constant
using any of the <a href="#sectc4217">available units</a>, absolute or	value using any of the <a href="#sectc4217">available units</a>, absolute or
relative. The value may not be inherited.</p>	relative. The value may not be inherited.</p>
<pre> 'NoBreak1' ':' AbsDist .	<pre> 'NoBreak1' ':' AbsDist .
'NoBreak2' ':' AbsDist .</pre>	'NoBreak2' ':' AbsDist .</pre>

<blockquote class="example">	<blockquote class="example">
<p>	<p><strong>Example:</strong></p>
<strong>Example:</strong></p>
<p>	<p>The following rules prevent widows and orphans in a paragraph:</p>
The following rules prevent widows and orphans in a paragraph:</p>	<pre>Paragraph :
<pre>Paragraph :
BEGIN	BEGIN
NoBreak1 : 2;	NoBreak1 : 2;
NoBreak2 : 2;	NoBreak2 : 2;
END;</pre>	END;</pre>
<p>
This rule prevents a section title from becoming separated from the first	<p>This rule prevents a section title from becoming separated from the first
paragraph of the section by prohibiting page breaks at the beginning of the	paragraph of the section by prohibiting page breaks at the beginning of the
section rule:</p>	section rule:</p>
<pre>Section :	<pre>Section :
NoBreak1 : 1.5 cm;</pre>	NoBreak1 : 1.5 cm;</pre>
<p>
Finally, this rule prevents a figure from being page broken in any way:</p>	<p>Finally, this rule prevents a figure from being page broken in any
<pre>Figure :	way:</p>
	<pre>Figure :
PageBreak : No;</pre>	PageBreak : No;</pre>
</blockquote>	</blockquote>
<p>
The Thot editor constructs the document images displayed on the screen	<p>The Thot editor constructs the document images displayed on the screen
dynamically. As the user moves in the document or makes the document scroll	dynamically. As the user moves in the document or makes the document scroll
in a window, the editor constructs the image to be displayed in little bits,	in a window, the editor constructs the image to be displayed in little bits,
filling the gaps which are produced in the course of these operations. It	filling the gaps which are produced in the course of these operations. It
Line 5672 reached. For example, an element might	Line 5112 reached. For example, an element might
the last element displayed, but its image was not constructed. The user will	the last element displayed, but its image was not constructed. The user will
not know whether the element is really absent or if its image has simply not	not know whether the element is really absent or if its image has simply not
been constructed.</p>	been constructed.</p>
<p>
The <tt>Gather</tt> rule is used to remedy this problem. When the rule	<p>The <tt>Gather</tt> rule is used to remedy this problem. When the rule
<tt>Gather : Yes;</tt> is associated with an element type, the image of such	<tt>Gather : Yes;</tt> is associated with an element type, the image of such
elements is constructed as a block by the editor: it is never split up.</p>	elements is constructed as a block by the editor: it is never split up.</p>
<p>
The <tt>Gather</tt> rule may not appear in the <a href="#sectc427">default	<p>The <tt>Gather</tt> rule may not appear in the <a href="#sectc427">default
rules</a>. Elements which do not have the <tt>Gather</tt> rule are considered	rules</a>. Elements which do not have the <tt>Gather</tt> rule are considered
susceptible to being split up during display. Thus, it is not necessary to	susceptible to being split up during display. Thus, it is not necessary to
use the <tt>Gather : No;</tt> form. This rule must be used prudently and only	use the <tt>Gather : No;</tt> form. This rule must be used prudently and only
for those elements which truly need it. If used incorrectly, it can	for those elements which truly need it. If used incorrectly, it can
pointlessly increase the size of the image constructed by the editor and lead	pointlessly increase the size of the image constructed by the editor and lead
to excessive memory consumption by the editor.</p>	to excessive memory consumption by the editor.</p>
<p>
Like the <tt>PageBreak</tt> and <tt>LineBreak</tt> rules, the <tt>Gather</tt>	<p>Like the <tt>PageBreak</tt> and <tt>LineBreak</tt> rules, the
rule can only appear in rules of the primary view and applies to all views	<tt>Gather</tt> rule can only appear in rules of the primary view and applies
defined in the presentation schema.</p>	to all views defined in the presentation schema.</p>
<pre> 'Gather' ':' Boolean .</pre>	<pre> 'Gather' ':' Boolean .</pre>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc4224">Visibility</a></h3>	<h3><a name="sectc4224">Visibility</a></h3>
<p>
The visibility parameter is used to control which elements should or should	<p>The visibility parameter is used to control which elements should or should
not be displayed, based on context. An element can have different	not be displayed, based on context. An element can have different
visibilities in different views. If an element's visibility is zero for a	visibilities in different views. If an element's visibility is zero for a
view, that element is not displayed in that view and does not occupy any space	view, that element is not displayed in that view and does not occupy any space
(its extents are zero).</p>	(its extents are zero).</p>
<p>
Visibility takes non-negative integer values (positive or zero). If values	<p>Visibility takes non-negative integer values (positive or zero). If values
greater than 1 are used, they allow the user to choose a degree of visibility	greater than 1 are used, they allow the user to choose a degree of visibility
and, thus, to see only those boxes whose visibility parameter exceeds a	and, thus, to see only those boxes whose visibility parameter exceeds a
certain threshold. This gives the user control over the granularity of the	certain threshold. This gives the user control over the granularity of the
displayed pictures.</p>	displayed pictures.</p>
<p>
The visibility parameter can be defined as a constant or by inheritance. If	<p>The visibility parameter can be defined as a constant or by inheritance. If
defined by inheritance, it cannot be based on the value of the next or	defined by inheritance, it cannot be based on the value of the next or
previous box. Visibility can only be inherited from above.</p>	previous box. Visibility can only be inherited from above.</p>
<p>
If it is a numeric attribute's presentation rule, the visibility can be	<p>If it is a numeric attribute's presentation rule, the visibility can be
specified by the attribute's name, in which case the value of the attribute is	specified by the attribute's name, in which case the value of the attribute is
used.</p>	used.</p>
<pre> 'Visibility' ':' NumberInherit	<pre> 'Visibility' ':' NumberInherit
NumberInherit = Integer / AttrID / Inheritance .	NumberInherit = Integer / AttrID / Inheritance .
Integer = NUMBER .</pre>	Integer = NUMBER .</pre>

<blockquote class="example">	<blockquote class="example">
<p>	<p><strong>Example:</strong></p>
<strong>Example:</strong></p>
<p>	<p>Suppose that only <tt>Formula</tt> elements should be displayed in the
Suppose that only <tt>Formula</tt> elements should be displayed in the	<tt>MathView</tt> view. Then, the default rules should include:</p>
<tt>MathView</tt> view. Then, the default rules should include:</p>	<pre>DEFAULT
<pre>DEFAULT
IN MathView Visibility:0;</pre>	IN MathView Visibility:0;</pre>
<p>
which makes all elements invisible in the <tt>MathView</tt> view. However,	<p>which makes all elements invisible in the <tt>MathView</tt> view.
the <tt>Formula</tt> element also has a <tt>Visibility</tt> rule:</p>	However, the <tt>Formula</tt> element also has a <tt>Visibility</tt>
<pre>Formula :	rule:</p>
	<pre>Formula :
IN MathView Visibility:5;</pre>	IN MathView Visibility:5;</pre>
<p>
which makes formulas, and only formulas, visible.</p>	<p>which makes formulas, and only formulas, visible.</p>
</blockquote>	</blockquote>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc4225">Character style parameters</a></h3>	<h3><a name="sectc4225">Character style parameters</a></h3>
<p>
Four parameters are used to determine which characters are used to display	<p>Four parameters are used to determine which characters are used to display
text. They are size, font, style, and underlining.</p>	text. They are size, font, style, and underlining.</p>

<div class="subsubsection">	<div class="subsubsection">

<h4><a name="sectd42251">Character size</a></h4>	<h4><a name="sectd42251">Character size</a></h4>
<p>
The size parameter has two effects. First, it is used to specify the actual	<p>The size parameter has two effects. First, it is used to specify the
size and distance units for boxes defined in <a href="#sectc4217">relative	actual size and distance units for boxes defined in <a
units</a>. Second, it defines the size of the characters contained in the	href="#sectc4217">relative units</a>. Second, it defines the size of the
box.</p>	characters contained in the box.</p>
<p>
As a distance or length, the size can be expressed in abstract or absolute	<p>As a distance or length, the size can be expressed in abstract or absolute
units. It can also be inherited. If it is not inherited, it is expressed	units. It can also be inherited. If it is not inherited, it is expressed
simply as an integer followed by the <tt>pt</tt> keyword, which indicates that	simply as an integer followed by the <tt>pt</tt> keyword, which indicates that
the size is expressed in typographer's points. The absence of the <tt>pt</tt>	the size is expressed in typographer's points. The absence of the <tt>pt</tt>
Line 5760 the smallest size while the value 16 is	Line 5198 the smallest size while the value 16 is
between these abstract sizes and the real character sizes is controlled by a	between these abstract sizes and the real character sizes is controlled by a
table which can be modified statically or even dynamically during the	table which can be modified statically or even dynamically during the
execution of the Thot editor.</p>	execution of the Thot editor.</p>
<p>
If the <tt>Size</tt> rule is a numeric attribute's presentation rule, the	<p>If the <tt>Size</tt> rule is a numeric attribute's presentation rule, the
value of the size parameter can be specified by the attribute's name, in	value of the size parameter can be specified by the attribute's name, in which
which case the value of the attribute is used.</p>	case the value of the attribute is used.</p>
<p>
<strong>Note:</strong> the only unit available for defining an absolute size	<p><strong>Note:</strong> the only unit available for defining an absolute
is the typographer's point. Centimeters and inches may not be used.</p>	size is the typographer's point. Centimeters and inches may not be used.</p>
<p>
If the size is inherited, the rule must specify the relative from which to	<p>If the size is inherited, the rule must specify the relative from which to
inherit and any percentage or difference from that relative's value.	inherit and any percentage or difference from that relative's value. A
A percentage is indicated by a <tt>*</tt> followed by the value of the	percentage is indicated by a <tt>*</tt> followed by the value of the
percentage and a <tt>%</tt>.	percentage and a <tt>%</tt>. A difference can be expressed in either
A difference can be expressed in either typographer's points or in abstract	typographer's points or in abstract units and the maximum or minimum size can
units and the maximum or minimum size can be specified, but without	be specified, but without specifying the unit: it is the same as was specified
specifying the unit: it is the same as was specified for the difference.</p>	for the difference.</p>
<p>
In a numeric attribute's presentation rule, the difference in size or the	<p>In a numeric attribute's presentation rule, the difference in size or the
percentage can be indicated by the attribute's name instead of the numeric	percentage can be indicated by the attribute's name instead of the numeric
value, which means that the attribute's value should be used as the difference	value, which means that the attribute's value should be used as the difference
or percentage. The attribute can also be used as the minimum or maximum size	or percentage. The attribute can also be used as the minimum or maximum size
Line 5798 for a difference.</p>	Line 5236 for a difference.</p>
MinSize = NUMBER .	MinSize = NUMBER .
PercentSizeAttr = PercentSize / AttrID .	PercentSizeAttr = PercentSize / AttrID .
PercentSize = NUMBER .</pre>	PercentSize = NUMBER .</pre>

<blockquote class="example">	<blockquote class="example">
<p>	<p><strong>Example:</strong></p>
<strong>Example:</strong></p>
<p>	<p>The rule</p>
The rule</p>	<pre>Size : Enclosing - 2 pt Min 7;</pre>
<pre>Size : Enclosing - 2 pt Min 7;</pre>
<p>	<p>states that the character size is 2 points less than that of the
states that the character size is 2 points less than that of the enclosing	enclosing box, but that it may not be less than 7 points, whatever the
box, but that it may not be less than 7 points, whatever the enclosing box's	enclosing box's value.</p>
value.</p>
<p>	<p>The following rules make the text of a report be displayed with
The following rules make the text of a report be displayed with medium-sized	medium-sized characters (for example, size 5), while the title is displayed
characters (for example, size 5), while the title is displayed with larger	with larger characters and the summary is displayed with smaller
characters and the summary is displayed with smaller characters:</p>	characters:</p>
<pre>Report :	<pre>Report :
Size : 5;	Size : 5;
Title :	Title :
Size : Enclosing + 2;	Size : Enclosing + 2;
Summary :	Summary :
Size : Enclosing - 1;</pre>	Size : Enclosing - 1;</pre>
<p>
Thus, the character sizes in the entire document can be changed by changing	<p>Thus, the character sizes in the entire document can be changed by
the size parameter of the Report element, while preserving the relationships	changing the size parameter of the Report element, while preserving the
between the sizes of the different elements.</p>	relationships between the sizes of the different elements.</p>
</blockquote>	</blockquote>
</div>	</div>

<div class="subsubsection">	<div class="subsubsection">

<h4><a name="sectd42252">Font and character style</a></h4>	<h4><a name="sectd42252">Font and character style</a></h4>
<p>
The <tt>Font</tt> rule determines the font family to be used to display the	<p>The <tt>Font</tt> rule determines the font family to be used to display the
characters contained in the box, while the <tt>Style</tt> rule determines	characters contained in the box, while the <tt>Style</tt> rule determines
their style and the <tt>Weight</tt> rule determines their weight. Thot	their style and the <tt>Weight</tt> rule determines their weight. Thot
recognizes three character fonts (Times, Helvetica, and Courier), three	recognizes three character fonts (Times, Helvetica, and Courier), three
styles: Roman, Italics, and Oblique, and two weights: Normal and Bold.</p>	styles: Roman, Italics, and Oblique, and two weights: Normal and Bold.</p>
<p>
The font family, style and weight can be specified by a named constant or	<p>The font family, style and weight can be specified by a named constant or
can be inherited. For the name of the font family only the first character	can be inherited. For the name of the font family only the first character is
is used.</p>	used.</p>
<p>
Only identical inheritance is allowed: the box takes the same font, style or	<p>Only identical inheritance is allowed: the box takes the same font, style
weight as the box from which it inherits. This is indicated by an equals	or weight as the box from which it inherits. This is indicated by an equals
sign after the kinship specification.</p>	sign after the kinship specification.</p>
<pre> 'Font' ':' NameInherit /	<pre> 'Font' ':' NameInherit /
'Style' ':' StyleInherit /	'Style' ':' StyleInherit /
Line 5852 StyleInherit = Kinship '=' /	Line 5290 StyleInherit = Kinship '=' /
'Roman' / 'Italics' / 'Oblique' .	'Roman' / 'Italics' / 'Oblique' .
WeightInherit = Kinship '=' /	WeightInherit = Kinship '=' /
'Normal' / 'Bold' .</pre>	'Normal' / 'Bold' .</pre>

<blockquote class="example">	<blockquote class="example">
<p>	<p><strong>Example:</strong></p>
<strong>Example:</strong></p>
<p>	<p>To specify that the summary uses the font family of the rest of the
To specify that the summary uses the font family of the rest of the document,	document, but in the italic style, the following rules are used:</p>
but in the italic style, the following rules are used:</p>	<pre>Summary :
<pre>Summary :
BEGIN	BEGIN
Font : Enclosing =;	Font : Enclosing =;
Style : Italics;	Style : Italics;
Line 5867 but in the italic style, the following r	Line 5305 but in the italic style, the following r
</div>	</div>

<div class="subsubsection">	<div class="subsubsection">

<h4><a name="sectd42253">Underlining</a></h4>	<h4><a name="sectd42253">Underlining</a></h4>
<p>
The <tt>Underline</tt> rule is used to specify if the characters contained in	<p>The <tt>Underline</tt> rule is used to specify if the characters contained
a box should have lines drawn on or near them. There are four underlining	in a box should have lines drawn on or near them. There are four underlining
styles: <tt>Underlined</tt>, <tt>Overlined</tt>, <tt>CrossedOut</tt>, and	styles: <tt>Underlined</tt>, <tt>Overlined</tt>, <tt>CrossedOut</tt>, and
<tt>NoUnderline</tt>. The <tt>Thickness</tt> rule specifies the thickness of	<tt>NoUnderline</tt>. The <tt>Thickness</tt> rule specifies the thickness of
the line, <tt>Thin</tt> or <tt>Thick</tt>.</p>	the line, <tt>Thin</tt> or <tt>Thick</tt>.</p>
<p>
As with font family and style, only identical inheritance is allowed: the box	<p>As with font family and style, only identical inheritance is allowed: the
has the same underlining type as the box from which it inherits the value.	box has the same underlining type as the box from which it inherits the value.
This is indicated by an equals sign after the kinship specification.</p>	This is indicated by an equals sign after the kinship specification.</p>
<pre> 'Underline' ':' UnderLineInherit /	<pre> 'Underline' ':' UnderLineInherit /
'Thickness' ':' ThicknessInherit /	'Thickness' ':' ThicknessInherit /
Line 5890 ThicknessInherit = Kinship '=' / 'Thick'	Line 5327 ThicknessInherit = Kinship '=' / 'Thick'
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc4226">Stacking order</a></h3>	<h3><a name="sectc4226">Stacking order</a></h3>
<p>
The <tt>Depth</tt> rule is used to define the stacking order of terminal boxes	<p>The <tt>Depth</tt> rule is used to define the stacking order of terminal
when multiple boxes at least partially overlap. This rule defines how the	boxes when multiple boxes at least partially overlap. This rule defines how
depth parameter, which is zero or a positive integer, is calculated. The	the depth parameter, which is zero or a positive integer, is calculated. The
depth parameter has a value for all boxes. For terminal boxes in the	depth parameter has a value for all boxes. For terminal boxes in the
structure and for presentation boxes, the depth value is used during display	structure and for presentation boxes, the depth value is used during display
and printing: the boxes with the lowest value overlap those with higher	and printing: the boxes with the lowest value overlap those with higher
depths. For non-terminal boxes, the depth is not interpreted during display,	depths. For non-terminal boxes, the depth is not interpreted during display,
but it is used to calculate the depth of terminal boxes by inheritance.</p>	but it is used to calculate the depth of terminal boxes by inheritance.</p>
<p>
Like most other rules, the depth rule is defined in the <a	<p>Like most other rules, the depth rule is defined in the <a
href="#sectc427">default rules</a> of each presentation schema. Thus, there	href="#sectc427">default rules</a> of each presentation schema. Thus, there
is always a depth value, even when it is not necessary because there is no	is always a depth value, even when it is not necessary because there is no
overlapping. To avoid useless operations, a zero value can be given to the	overlapping. To avoid useless operations, a zero value can be given to the
depth parameter, which signifies that overlapping is never a problem.</p>	depth parameter, which signifies that overlapping is never a problem.</p>
<p>
The depth rule has the same form as the <a href="#sectc4224">visibility	<p>The depth rule has the same form as the <a href="#sectc4224">visibility
rule</a>. It can be defined by inheritance or by a constant numeric value.	rule</a>. It can be defined by inheritance or by a constant numeric value.
When the rule is attached to a numeric attribute, it can take the value of	When the rule is attached to a numeric attribute, it can take the value of
that attribute.</p>	that attribute.</p>
<pre> 'Depth' ':' NumberInherit</pre>	<pre> 'Depth' ':' NumberInherit</pre>

<blockquote class="example">	<blockquote class="example">
<p>	<p><strong>Example:</strong></p>
<strong>Example:</strong></p>
<p>	<p>For a purely textual document, in which overlapping never poses a
For a purely textual document, in which overlapping never poses a problem, a	problem, a single default <tt>Depth</tt> rule in the presentation schema is
single default <tt>Depth</tt> rule in the presentation schema is	sufficient:</p>
sufficient:</p>	<pre>DEFAULT
<pre>DEFAULT
Depth : 0;	Depth : 0;
...</pre>	...</pre>
<p>
To make the text of examples appear on a light blue background, a presentation	<p>To make the text of examples appear on a light blue background, a
box is defined:</p>	presentation box is defined:</p>
<pre>BOXES	<pre>BOXES
BlueBG :	BlueBG :
BEGIN	BEGIN
Content : Graphics 'R';	Content : Graphics 'R';
Line 5935 box is defined:</p>	Line 5371 box is defined:</p>
Depth : 2;	Depth : 2;
...	...
END;</pre>	END;</pre>
<p>
and is created by the <tt>Example</tt> element, which has the rules:</p>	<p>and is created by the <tt>Example</tt> element, which has the rules:</p>
<pre>RULES	<pre>RULES
Example :	Example :
BEGIN	BEGIN
CreateFirst (BlueBG);	CreateFirst (BlueBG);
Depth : 1;	Depth : 1;
...	...
END;</pre>	END;</pre>
<p>
In this way, the text of an example (if it inherits its depth from its	<p>In this way, the text of an example (if it inherits its depth from its
ancestor) will be superimposed on a light blue background, and not the	ancestor) will be superimposed on a light blue background, and not the
reverse).</p>	reverse).</p>
</blockquote>	</blockquote>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc4227">Line style</a></h3>	<h3><a name="sectc4227">Line style</a></h3>
<p>
The <tt>LineStyle</tt> rule determines the style of line which should be used	<p>The <tt>LineStyle</tt> rule determines the style of line which should be
to draw all the elements contained in the box and the box itself, if it has a	used to draw all the elements contained in the box and the box itself, if it
<a href="#sectc4230a"><tt>ShowBox</tt> rule</a>. The line style can be	has a <a href="#sectc4230a"><tt>ShowBox</tt> rule</a>. The line style can be
indicated by a name (<tt>Solid</tt>, <tt>Dashed</tt>, <tt>Dotted</tt>) or it	indicated by a name (<tt>Solid</tt>, <tt>Dashed</tt>, <tt>Dotted</tt>) or it
can be inherited. All elements of the graphic base type are affected by this	can be inherited. All elements of the graphic base type are affected by this
rule, but it can be attached to any box and transmitted by inheritance to the	rule, but it can be attached to any box and transmitted by inheritance to the
graphic elements. The border of elements having a <a	graphic elements. The border of elements having a <a
href="#sectc4230a"><tt>ShowBox</tt> rule</a> is drawn according to the line	href="#sectc4230a"><tt>ShowBox</tt> rule</a> is drawn according to the line
style specified by this rule.</p>	style specified by this rule.</p>
<p>
Only identical inheritance is allowed: the box takes the same line style as	<p>Only identical inheritance is allowed: the box takes the same line style as
the box from which it inherits. This is indicated by an equals sign after the	the box from which it inherits. This is indicated by an equals sign after the
kinship specification.</p>	kinship specification.</p>
<pre> 'LineStyle' ':' LineStyleInherit	<pre> 'LineStyle' ':' LineStyleInherit
LineStyleInherit = Kinship '=' /	LineStyleInherit = Kinship '=' /
'Solid' / 'Dashed' / 'Dotted' .</pre>	'Solid' / 'Dashed' / 'Dotted' .</pre>

<blockquote class="example">	<blockquote class="example">
<p>	<p><strong>Example:</strong></p>
<strong>Example:</strong></p>
<p>	<p>To specify that, in Figures, the graphical parts should be drawn in solid
To specify that, in Figures, the graphical parts should be drawn in solid	lines, the Figure element is given a rule using the <tt>Solid</tt> name:</p>
lines, the Figure element is given a rule using the <tt>Solid</tt> name:</p>	<pre>Figure :
<pre>Figure :
LineStyle : Solid;</pre>	LineStyle : Solid;</pre>
<p>
and the elements composing figures are given an inheritance rule:</p>	<p>and the elements composing figures are given an inheritance rule:</p>
<pre> LineStyle : Enclosing =;</pre>	<pre> LineStyle : Enclosing =;</pre>
</blockquote>	</blockquote>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc4228">Line thickness</a></h3>	<h3><a name="sectc4228">Line thickness</a></h3>
<p>
The <tt>LineWeight</tt> rule determines the thickness of the lines of all	<p>The <tt>LineWeight</tt> rule determines the thickness of the lines of all
graphical elements which appear in the box, no matter what their line style.	graphical elements which appear in the box, no matter what their line style.
Line thickness can be specified by a constant value or by inheritance. A	Line thickness can be specified by a constant value or by inheritance. A
constant value is a positive number followed by an optional unit specification	constant value is a positive number followed by an optional unit specification
Line 5997 constant value is a positive number foll	Line 5431 constant value is a positive number foll
href="#sectc4217">distance units</a> can be used. Line thickness is expressed	href="#sectc4217">distance units</a> can be used. Line thickness is expressed
in the same way as <a href="#sectd42221">line spacing</a>.</p>	in the same way as <a href="#sectd42221">line spacing</a>.</p>
<pre> 'LineWeight' ':' DistOrInherit</pre>	<pre> 'LineWeight' ':' DistOrInherit</pre>
<p>
All elements of the graphic base type are affected by this rule, but it can be	<p>All elements of the graphic base type are affected by this rule, but it can
attached to any box and transmitted by inheritance to the graphic elements.	be attached to any box and transmitted by inheritance to the graphic elements.
The border of element having a <a href="#sectc4230a"><tt>ShowBox</tt> rule</a>	The border of element having a <a href="#sectc4230a"><tt>ShowBox</tt> rule</a>
is also drawn according to the thickness specified by this rule.</p>	is also drawn according to the thickness specified by this rule.</p>

<blockquote class="example">	<blockquote class="example">
<p>	<p><strong>Example:</strong></p>
<strong>Example:</strong></p>
<p>	<p>To specify that, in Figures, the graphical parts should be drawn with
To specify that, in Figures, the graphical parts should be drawn with lines	lines 0.3 pt thick, the Figure element is given this rule:</p>
0.3 pt thick, the Figure element is given this rule:</p>	<pre>Figure :
<pre>Figure :
LineWeight : 0.3 pt;</pre>	LineWeight : 0.3 pt;</pre>
<p>
and the elements composing figures are given an inheritance rule:</p>	<p>and the elements composing figures are given an inheritance rule:</p>
<pre> LineWeight : Enclosing =;</pre>	<pre> LineWeight : Enclosing =;</pre>
</blockquote>	</blockquote>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc4229">Fill pattern</a></h3>	<h3><a name="sectc4229">Fill pattern</a></h3>
<p>
The <tt>FillPattern</tt> rule determines the pattern used to fill closed	<p>The <tt>FillPattern</tt> rule determines the pattern used to fill closed
graphical elements (circles, rectangles, etc.) which appear in the box. This	graphical elements (circles, rectangles, etc.) which appear in the box. This
rule also specifies the pattern used to fill the box associated with elements	rule also specifies the pattern used to fill the box associated with elements
having a <a href="#sectc4230a"><tt>ShowBox</tt> rule</a><a>. This pattern can	having a <a href="#sectc4230a"><tt>ShowBox</tt> rule</a><a>. This pattern can
Line 6030 patterns are: nopattern, foregroundcolor	Line 5463 patterns are: nopattern, foregroundcolor
gray3, gray4, gray5, gray6, gray7, horiz1, horiz2, horiz3, vert1, vert2,	gray3, gray4, gray5, gray6, gray7, horiz1, horiz2, horiz3, vert1, vert2,
vert3, left1, left2, left3, right1, right2, right3, square1, square2, square3,	vert3, left1, left2, left3, right1, right2, right3, square1, square2, square3,
lozenge, brick, tile, sea, basket.</a></p>	lozenge, brick, tile, sea, basket.</a></p>
<p>
Like the other rules peculiar to graphics, <tt>LineStyle</tt> and	<p>Like the other rules peculiar to graphics, <tt>LineStyle</tt> and
<tt>LineWeight</tt>, only elements of the graphic base type are affected by	<tt>LineWeight</tt>, only elements of the graphic base type are affected by
the <tt>FillPattern</tt> rule, but the rule can be attached to any box and	the <tt>FillPattern</tt> rule, but the rule can be attached to any box and
transmitted by inheritance to the graphic elements. As with the other rules	transmitted by inheritance to the graphic elements. As with the other rules
specific to graphics, only identical inheritance is allowed.</p>	specific to graphics, only identical inheritance is allowed.</p>
<p>
The <tt>FillPattern</tt> rule can also be used to determine whether or not	<p>The <tt>FillPattern</tt> rule can also be used to determine whether or not
text characters, symbols and pictures should be colored. For these element	text characters, symbols and pictures should be colored. For these element
types (text, symbols, and pictures), the only valid values are	types (text, symbols, and pictures), the only valid values are
<tt>nopattern</tt>, <tt>foregroundcolor</tt>, and <tt>backgroundcolor</tt>.	<tt>nopattern</tt>, <tt>foregroundcolor</tt>, and <tt>backgroundcolor</tt>.
Line 6049 these same elements are given the color	Line 5482 these same elements are given the color
href="#sectc4230"><tt>Foreground</tt> rule</a> which applies to these	href="#sectc4230"><tt>Foreground</tt> rule</a> which applies to these
elements. In all other case, text characters are not colored.</p>	elements. In all other case, text characters are not colored.</p>
<pre> 'FillPattern' ':' NameInherit</pre>	<pre> 'FillPattern' ':' NameInherit</pre>

<blockquote class="example">	<blockquote class="example">
<p>	<p><strong>Example:</strong></p>
<strong>Example:</strong></p>
<p>	<p>To specify that, in Figures, the closed graphical elements should be
To specify that, in Figures, the closed graphical elements should be filled	filled with a pattern resembling a brick wall, the Figure element is given
with a pattern resembling a brick wall, the Figure element is given this	this rule:</p>
rule:</p>	<pre>Figure :
<pre>Figure :
FillPattern : brick;</pre>	FillPattern : brick;</pre>
<p>
and the elements composing figures are given an inheritance rule:</p>	<p>and the elements composing figures are given an inheritance rule:</p>
<pre> FillPattern : Enclosing =;</pre>	<pre> FillPattern : Enclosing =;</pre>
</blockquote>	</blockquote>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc4230">Colors</a></h3>	<h3><a name="sectc4230">Colors</a></h3>
<p>
The <tt>Foreground</tt> and <tt>Background</tt> rules determine the foreground	<p>The <tt>Foreground</tt> and <tt>Background</tt> rules determine the
and background colors of the base elements which appear in the box. They also	foreground and background colors of the base elements which appear in the box.
control the color of boxes associated with elements having a <a	They also control the color of boxes associated with elements having a <a
href="#sectc4230a"><tt>ShowBox</tt> rule</a>. These colors can be specified	href="#sectc4230a"><tt>ShowBox</tt> rule</a>. These colors can be specified
with a named constant or by inheritance. The named constants specify one of	with a named constant or by inheritance. The named constants specify one of
the available colors in Thot. The available color names can be found in the	the available colors in Thot. The available color names can be found in the
file <tt>thot.color</tt>.</p>	file <tt>thot.color</tt>. In addition to those names, you can use the keyword
<p>	<code>Transparent</code>, to not draw anything.</p>
The color rules affect the same way all base elements and elements having a <a
href="#sectc4230a"><tt>ShowBox</tt> rule</a>, no matter what their type (text,	<p>The color rules affect the same way all base elements and elements having a
graphics, pictures, symbols). The color rules can be associated with any box	<a href="#sectc4230a"><tt>ShowBox</tt> rule</a>, no matter what their type
and can be transmitted by inheritance to the base elements or the elements	(text, graphics, pictures, symbols). The color rules can be associated with
having a <a href="#sectc4230a"><tt>ShowBox</tt> rule</a>. Like the preceding	any box and can be transmitted by inheritance to the base elements or the
rules, only inheritance of the same value is allowed.</p>	elements having a <a href="#sectc4230a"><tt>ShowBox</tt> rule</a>. Like the
<pre> 'Foreground' ':' NameInherit	preceding rules, only inheritance of the same value is allowed.</p>
'Background' ':' NameInherit</pre>	<pre> 'Foreground' ':' Color
<p>	'Background' ':' Color
<strong>Note:</strong> text colors only appear for text elements whose <a	Color = 'Transparent' / Link '=' / FontColorName .</pre>

	<p><strong>Note:</strong> text colors only appear for text elements whose <a
href="#sectc4229">fill pattern</a> does not prevent the use of color.</p>	href="#sectc4229">fill pattern</a> does not prevent the use of color.</p>

<blockquote class="example">	<blockquote class="example">
<p>	<p><strong>Example:</strong></p>
<strong>Example:</strong></p>
<p>	<p>To specify that, in Figures, everything must be drawn in blue on a
To specify that, in Figures, everything must be drawn in blue on a background	background of yellow, the Figure element is given these rules:</p>
of yellow, the Figure element is given these rules:</p>	<pre>Figure :
<pre>Figure :
BEGIN	BEGIN
Foreground : Blue;	Foreground : Blue;
Background : Yellow;	Background : Yellow;
Fillpattern : backgroundcolor;	Fillpattern : backgroundcolor;
END;</pre>	END;</pre>
<p>
and the elements composing figures are given inheritance rules:</p>	<p>and the elements composing figures are given inheritance rules:</p>
<pre> Foreground : Enclosing =;	<pre> Foreground : Enclosing =;
Background : Enclosing =;	Background : Enclosing =;
FillPattern : Enclosing =;</pre>	FillPattern : Enclosing =;</pre>
</blockquote>	</blockquote>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc4230a">Background color and border</a></h3>	<h3><a name="sectc4230a">Background color and border</a></h3>
<p>
Boxes associated with structural elements are normally not visible, but it is	<p>Boxes associated with structural elements are normally not visible, but it
possible to draw their border and/or to paint their area when it is needed.	is possible to draw their border and/or to paint their area when it is needed.
This is achieved by associating the <tt>ShowBox</tt> rule with the concerned	This is achieved by associating the <tt>ShowBox</tt> rule with the concerned
element. This rule has no parameter and no value. It is simply written	element. This rule has no parameter and no value. It is simply written
<tt>Showbox;</tt>. It is not inherited nor transmitted to any other element.	<tt>Showbox;</tt>. It is not inherited nor transmitted to any other element.
It applies only to the element with which it is associated.</p>	It applies only to the element with which it is associated.</p>
<pre> 'ShowBox'</pre>	<pre> 'ShowBox'</pre>
<p>
When an element has a <tt>ShowBox</tt> rule, the border is drawn only if the	<p>When an element has a <tt>ShowBox</tt> rule, the border is drawn only if
<tt>LineWeight</tt> rule that applies to that element has a non-zero value	the <tt>LineWeight</tt> rule that applies to that element has a non-zero value
(this value can be inherited). The color, style and thickness of the border	(this value can be inherited). The color, style and thickness of the border
are defined by the <tt>Foreground</tt>, <tt>LineStyle</tt>, and	are defined by the <tt>Foreground</tt>, <tt>LineStyle</tt>, and
<tt>LineWeight</tt> rules that apply to the element.</p>	<tt>LineWeight</tt> rules that apply to the element.</p>
<p>
When an element has a <tt>ShowBox</tt> rule, the background of this element is	<p>When an element has a <tt>ShowBox</tt> rule, the background of this element
paint only if the value of the <tt>FillPattern</tt> rule that applies to that	is paint only if the value of the <tt>FillPattern</tt> rule that applies to
element is not <tt>nopattern</tt>. The pattern and color(s) of the background	that element is not <tt>nopattern</tt>. The pattern and color(s) of the
are defined by the <tt>FillPattern</tt>, <tt>Background</tt>, and	background are defined by the <tt>FillPattern</tt>, <tt>Background</tt>, and
<tt>Foreground</tt> rules that apply to the element.</p>	<tt>Foreground</tt> rules that apply to the element.</p>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc4230b">Background pictures</a></h3>	<h3><a name="sectc4230b">Background pictures</a></h3>
<p>
The <tt>BackgroundPicture</tt> rule allows to display a picture as the	<p>The <tt>BackgroundPicture</tt> rule allows to display a picture as the
background of an element. It has a single parameter, the file name of the	background of an element. It has a single parameter, the file name of the
picture. This is a string delimited by single quotes. If the first character	picture. This is a string delimited by single quotes. If the first character
in this string is '/', it is considered as an absolute path, otherwise the	in this string is '/', it is considered as an absolute path, otherwise the
file is searched for along the schema directory path. This file may contain a	file is searched for along the schema directory path. This file may contain a
picture in any format accepted by Thot (xbm, xpm, gif, jpeg, png, etc.)</p>	picture in any format accepted by Thot (xbm, xpm, gif, jpeg, png, etc.)</p>
<p>
The <tt>BackgroundPicture</tt> and <tt>PictureMode</tt> rules apply only to	<p>The <tt>BackgroundPicture</tt> and <tt>PictureMode</tt> rules apply only to
the element with which they are associated. They are not inherited nor	the element with which they are associated. They are not inherited nor
transmitted to children elements.</p>	transmitted to children elements.</p>
<p>
The background picture has not always the same size as the element's box.	<p>The background picture has not always the same size as the element's box.
There are diffrent ways to fill the element box with the picture. This is	There are diffrent ways to fill the element box with the picture. This is
specified by the <tt>PictureMode</tt> rule, which should be associated to the	specified by the <tt>PictureMode</tt> rule, which should be associated to the
same element. This rule may take one of the following values:</p>	same element. This rule may take one of the following values:</p>
<dl>	<dl>
<dt><tt>NormalSize</tt></dt>	<dt><tt>NormalSize</tt></dt>
<dd>	<dd>The picture is centered in the box, and clipped if it is too
The picture is centered in the box, and clipped if it is too large.	large.</dd>
</dd>	<dt><tt>Scale</tt></dt>
<dt><tt>Scale</tt></dt>	<dd>The picture is zoomed to fit the box size.</dd>
<dd>	<dt><tt>RepeatX</tt></dt>
The picture is zoomed to fit the box size.	<dd>The picture is repeated horizontally to fit the box width.</dd>
</dd>	<dt><tt>RepeatY</tt></dt>
<dt><tt>RepeatX</tt></dt>	<dd>The picture is repeated vertically to fit the box height.</dd>
<dd>	<dt><tt>RepeatXY</tt></dt>
The picture is repeated horizontally to fit the box width.	<dd>The picture is repeated both horizontally and vertically to fill the
</dd>	box.</dd>
<dt><tt>RepeatY</tt></dt>
<dd>
The picture is repeated vertically to fit the box height.
</dd>
<dt><tt>RepeatXY</tt></dt>
<dd>
The picture is repeated both horizontally and vertically to fill the box.
</dd>
</dl>	</dl>
<p>
If an element has a <tt>BackgroundPicture</tt> rule and no	<p>If an element has a <tt>BackgroundPicture</tt> rule and no
<tt>PictureMode</tt> rule, the <tt>NormalSize</tt> value is assumed.</p>	<tt>PictureMode</tt> rule, the <tt>NormalSize</tt> value is assumed.</p>
<pre> 'BackgroundPicture' ':' FileName /	<pre> 'BackgroundPicture' ':' FileName /
'PictureMode' ':' PictMode .	'PictureMode' ':' PictMode .

FileName = STRING .	FileName = STRING .
PictMode = 'NormalSize' / 'Scale' / 'RepeatXY' / 'RepeatX' / 'RepeatY' .</pre>	PictMode = 'NormalSize' / 'Scale' / 'RepeatXY' / 'RepeatX' / 'RepeatY' .</pre>
<p>
The <tt>BackgroundPicture</tt> and <tt>PictureMode</tt> rules apply only to	<p>The <tt>BackgroundPicture</tt> and <tt>PictureMode</tt> rules apply only to
the element with which they are associated. They are not inherited nor	the element with which they are associated. They are not inherited nor
transmitted to children elements.</p>	transmitted to children elements.</p>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc4231">Presentation box content</a></h3>	<h3><a name="sectc4231">Presentation box content</a></h3>
<p>
The <tt>Content</tt> rule applies to presentation boxes. It indicates the	<p>The <tt>Content</tt> rule applies to presentation boxes. It indicates the
content given to a box. This content is either a variable's value or a	content given to a box. This content is either a variable's value or a
constant value. In the special case of <a href="#sectc4233">header or footer	constant value. In the special case of <a href="#sectc4233">header or footer
boxes</a>, the content can also be a structured element type.</p>	boxes</a>, the content can also be a structured element type.</p>
<p>
If the content is a constant, it can be specified, as in a variable	<p>If the content is a constant, it can be specified, as in a variable
declaration, either by the name of a constant declared in the <tt>CONST</tt>	declaration, either by the name of a constant declared in the <tt>CONST</tt>
section or by direct specification of the type and value of the box's	section or by direct specification of the type and value of the box's
content.</p>	content.</p>
<p>
Similarly, if it is a variable, the name of a variable declared in	<p>Similarly, if it is a variable, the name of a variable declared in
<tt>VAR</tt> section can be given or the variable may be defined within	<tt>VAR</tt> section can be given or the variable may be defined within
parentheses. The content inside the parentheses has the same syntax as a <a	parentheses. The content inside the parentheses has the same syntax as a <a
href="#sectc426">variable declaration</a>.</p>	href="#sectc426">variable declaration</a>.</p>
<p>
When the content is a structured element type, the name of the element type is	<p>When the content is a structured element type, the name of the element type
given after the colon. In this case, the box's content is all elements of	is given after the colon. In this case, the box's content is all elements of
the named type which are designated by references which are part of the page	the named type which are designated by references which are part of the page
on which the header or footer with this <tt>Content</tt> rule appears. Only	on which the header or footer with this <tt>Content</tt> rule appears. Only
associated elements can appear in a <tt>Content</tt> rule and the structure	associated elements can appear in a <tt>Content</tt> rule and the structure
Line 6218 view.</p>	Line 5641 view.</p>
VarConst = ConstID / ConstType ConstValue /	VarConst = ConstID / ConstType ConstValue /
VarID / '(' FunctionSeq ')' /	VarID / '(' FunctionSeq ')' /
ElemID .</pre>	ElemID .</pre>
<p>
A presentation box can have only one <tt>Content</tt> rule, which means that	<p>A presentation box can have only one <tt>Content</tt> rule, which means
the content of a presentation box cannot vary from view to view. However, such	that the content of a presentation box cannot vary from view to view. However,
an effect can be achieved by creating several presentation boxes, each with	such an effect can be achieved by creating several presentation boxes, each
different content and visible in different views.</p>	with different content and visible in different views.</p>
<p>
The <tt>Content</tt> rule also applies to elements defined as references in	<p>The <tt>Content</tt> rule also applies to elements defined as references in
the structure schema. In this case, the content defined by the rule must be	the structure schema. In this case, the content defined by the rule must be
a constant. It is this content which appears on the screen or paper to	a constant. It is this content which appears on the screen or paper to
represent references of the type to which the rule applies. A reference can	represent references of the type to which the rule applies. A reference can
Line 6232 have a <tt>Content</tt> rule or a <a hre	Line 5655 have a <tt>Content</tt> rule or a <a hre
for each view. If neither of these rules appears, the reference is displayed	for each view. If neither of these rules appears, the reference is displayed
as <tt>[*]</tt>, which is equivalent to the rule:</p>	as <tt>[*]</tt>, which is equivalent to the rule:</p>
<pre> Content: Text '[*]';</pre>	<pre> Content: Text '[*]';</pre>

<blockquote class="example">	<blockquote class="example">
<p>	<p><strong>Example:</strong></p>
<strong>Example:</strong></p>
<p>	<p>The content of the presentation box created to make the chapter number
The content of the presentation box created to make the chapter number and	and section number appear before each section title can be defined by:</p>
section number appear before each section title can be defined by:</p>	<pre>BOXES
<pre>BOXES
SectionNumBox :	SectionNumBox :
BEGIN	BEGIN
Content : NumSection;	Content : NumSection;
...	...
END;</pre>	END;</pre>
<p>
if the <tt>NumSection</tt> variable has been defined in the variable	<p>if the <tt>NumSection</tt> variable has been defined in the variable
definition section of the presentation schema. Otherwise the <tt>Content</tt>	definition section of the presentation schema. Otherwise the
would be written:</p>	<tt>Content</tt> would be written:</p>
<pre>BOXES	<pre>BOXES
SectionNumBox :	SectionNumBox :
BEGIN	BEGIN
Content : (VALUE (ChapterCtr, Roman) TEXT '.'	Content : (VALUE (ChapterCtr, Roman) TEXT '.'
VALUE (SectionCtr, Arabic));	VALUE (SectionCtr, Arabic));
...	...
END;</pre>	END;</pre>
<p>
To specify that a page footer should contain all elements of the <tt>Note</tt>	<p>To specify that a page footer should contain all elements of the
type are referred to in the page, the following rule is written:</p>	<tt>Note</tt> type are referred to in the page, the following rule is
<pre>BOXES	written:</p>
	<pre>BOXES
NotesFooterBox :	NotesFooterBox :
BEGIN	BEGIN
Content : Note;	Content : Note;
...	...
END;</pre>	END;</pre>
<p>
<tt>Note</tt> is defined as an associated element in the structure schema and	<p><tt>Note</tt> is defined as an associated element in the structure schema
NotesFooterBox is created by a page box of the primary view.</p>	and NotesFooterBox is created by a page box of the primary view.</p>
</blockquote>	</blockquote>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc4232">Presentation box creation</a></h3>	<h3><a name="sectc4232">Presentation box creation</a></h3>
<p>
A creation rule specifies that a presentation box should be created when an	<p>A creation rule specifies that a presentation box should be created when an
element of the type to which the rule is attached appears in the document.</p>	element of the type to which the rule is attached appears in the document.</p>
<p>
A keyword specifies the position, relative to the creating box, at which the	<p>A keyword specifies the position, relative to the creating box, at which
created box will be placed in the structure:</p>	the created box will be placed in the structure:</p>
<dl>	<dl>
<dt><tt>CreateFirst</tt></dt>	<dt><tt>CreateFirst</tt></dt>
<dd>	<dd>specifies that the box should be created as the first box of the next
specifies that the box should be created as the first box of the next lower	lower level, before any already existing boxes, and only if the
level, before any already existing boxes, and only if the beginning of the	beginning of the creating element is visible;</dd>
creating element is visible;	<dt><tt>CreateLast</tt></dt>
</dd>	<dd>specifies that the box should be created as the last box of the next
<dt><tt>CreateLast</tt></dt>	lower level, after any existing boxes, and only if the end of the
<dd>	creating element is visible;</dd>
specifies that the box should be created as the last box of the next lower	<dt><tt>CreateBefore</tt></dt>
level, after any existing boxes, and only if the end of the creating element	<dd>specifies that the box should be created before the creating box, on
is visible;	the same level as the creating box, and only if the beginning of the
</dd>	creating element is visible;</dd>
<dt><tt>CreateBefore</tt></dt>	<dt><tt>CreateAfter</tt></dt>
<dd>	<dd>specifies that the box should be created after the creating box, on
specifies that the box should be created before the creating box, on the same	the same level as the creating box, and only if the beginning of the
level as the creating box, and only if the beginning of the creating element	creating element is visible;</dd>
is visible;	<dt><tt>CreateEnclosing</tt></dt>
</dd>	<dd>specifies that the box should be created at the upper level relatively
<dt><tt>CreateAfter</tt></dt>	to the creating box, and that it must contain that creating box and all
<dd>	presentation boxes created by the same creating box.</dd>
specifies that the box should be created after the creating box, on the same
level as the creating box, and only if the beginning of the creating element
is visible;
</dd>
<dt><tt>CreateEnclosing</tt></dt>
<dd>
specifies that the box should be created at the upper level relatively to the
creating box, and that it must contain that creating box and all presentation
boxes created by the same creating box.
</dd>
</dl>	</dl>
<p>
This keyword can be followed by the <tt>Repeated</tt> keyword to indicate that	<p>This keyword can be followed by the <tt>Repeated</tt> keyword to indicate
the box must be created for each part of the creating element. These parts	that the box must be created for each part of the creating element. These
result from the division of the element by page breaks or column changes. If	parts result from the division of the element by page breaks or column
the <tt>Repeated</tt> keyword is missing, the box is only created for the	changes. If the <tt>Repeated</tt> keyword is missing, the box is only created
first part of the creating element (<tt>CreateFirst</tt> and	for the first part of the creating element (<tt>CreateFirst</tt> and
<tt>CreateBefore</tt> rules) or for the last part (<tt>CreateLast</tt> and	<tt>CreateBefore</tt> rules) or for the last part (<tt>CreateLast</tt> and
<tt>CreateAfter</tt> rules).</p>	<tt>CreateAfter</tt> rules).</p>
<p>
The type of presentation to be created is specified at the end of the rule	<p>The type of presentation to be created is specified at the end of the rule
between parentheses.</p>	between parentheses.</p>
<p>
Creation rules cannot appear in the <a href="#sectc427">default presentation	<p>Creation rules cannot appear in the <a href="#sectc427">default
rules</a>. The boxes being created should have a <tt>Content</tt> rule which	presentation rules</a>. The boxes being created should have a
indicates their <a href="#sectc4231">content</a>.</p>	<tt>Content</tt> rule which indicates their <a
<p>	href="#sectc4231">content</a>.</p>
Creation rules can only appear in the block of rules for the primary view;
	<p>Creation rules can only appear in the block of rules for the primary view;
creation is provoked by a document element for all views. However, for each	creation is provoked by a document element for all views. However, for each
view, the presentation box is only created if the creating element is itself a	view, the presentation box is only created if the creating element is itself a
box in the view. Moreover, the visibility parameter of the presentation box	box in the view. Moreover, the visibility parameter of the presentation box
Line 6338 basis.</p>	Line 5752 basis.</p>
Create ='CreateFirst' / 'CreateLast' /	Create ='CreateFirst' / 'CreateLast' /
'CreateBefore' / 'CreateAfter' /	'CreateBefore' / 'CreateAfter' /
'CreateEnclosing' .</pre>	'CreateEnclosing' .</pre>

<blockquote class="example">	<blockquote class="example">
<p>	<p><strong>Example:</strong></p>
<strong>Example:</strong></p>
<p>
Let us define an object type, called Table, which is composed of a sequence of
columns, all having the same fixed width, where the columns are separated by
vertical lines. There is a line to the left of the first column and one to
the right of the last. Each column has a variable number of cells, placed one
on top of the other and separated by horizontal lines. There are no
horizontal lines above the first cell or below the last cell. The text
contained in each cell is broken into lines and these lines are centered
horizontally in the cell. The logical structure of this object is defined
by:</p>
<pre>Table = LIST OF (Column);
Column = LIST OF (Cell = Text);</pre>

<div class="figure">	<p>Let us define an object type, called Table, which is composed of a
<hr>	sequence of columns, all having the same fixed width, where the columns are
	separated by vertical lines. There is a line to the left of the first
	column and one to the right of the last. Each column has a variable number
	of cells, placed one on top of the other and separated by horizontal lines.
	There are no horizontal lines above the first cell or below the last cell.
	The text contained in each cell is broken into lines and these lines are
	centered horizontally in the cell. The logical structure of this object is
	defined by:</p>
	<pre>Table = LIST OF (Column);
	Column = LIST OF (Cell = Text);</pre>

<pre>\| \| \| \|	<div class="figure">
	<hr>
	<pre>\| \| \| \|
\| xx xxxx xxxx \|x xxxx xxx xxxxx\| x xxx x xxx \|	\| xx xxxx xxxx \|x xxxx xxx xxxxx\| x xxx x xxx \|
\| xxx xxx xxxx x \| x xx x xxx \| xxxxx xxxx xx \|	\| xxx xxx xxxx x \| x xx x xxx \| xxxxx xxxx xx \|
\| xxxxx xxxx \|----------------\| xxx xxxxx x \|	\| xxxxx xxxx \|----------------\| xxx xxxxx x \|
Line 6369 Column = LIST OF (Cell = Text);</pre>	Line 5782 Column = LIST OF (Cell = Text);</pre>
\|----------------\| xxx xxxxx xxxx \| xxxx xxxx xxx \|	\|----------------\| xxx xxxxx xxxx \| xxxx xxxx xxx \|
\| xxxxx xxx xxxx \| xxxx xx x xx \| xxxxx xxx \|	\| xxxxx xxx xxxx \| xxxx xx x xx \| xxxxx xxx \|
\|xxxx xx x xxxxxx\| xxxx xx xxxxxx \| xxxxx xxxxx \|</pre>	\|xxxx xx x xxxxxx\| xxxx xx xxxxxx \| xxxxx xxxxx \|</pre>
<p align="center">
<em><a name="table">The design of a table</a></em></p>
<hr>

</div>	<p align="center"><em><a name="table">The design of a table</a></em></p>
<p>	<hr>
The presentation of the table should resemble the design of the above <a	</div>
href="#table">figure</a>. It is defined by the following presentation schema
fragment:</p>	<p>The presentation of the table should resemble the design of the above <a
<pre>BOXES	href="#table">figure</a>. It is defined by the following presentation
	schema fragment:</p>
	<pre>BOXES
VertLine : BEGIN	VertLine : BEGIN
Width : 0.3 cm;	Width : 0.3 cm;
Height : Enclosing . Height;	Height : Enclosing . Height;
Line 6414 RULES	Line 5826 RULES
Line;	Line;
Adjust : VMiddle;	Adjust : VMiddle;
END;</pre>	END;</pre>
<p>
It is useful to note that the horizontal position rule of the first vertical	<p>It is useful to note that the horizontal position rule of the first
line will not be applied, since there is no preceding box. In this case, the	vertical line will not be applied, since there is no preceding box. In this
box is simply placed on the left side of the enclosing box.</p>	case, the box is simply placed on the left side of the enclosing box.</p>
</blockquote>	</blockquote>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc4233">Page layout</a></h3>	<h3><a name="sectc4233">Page layout</a></h3>
<p>
The page models specified in the <tt>Page</tt> rule are defined by boxes	<p>The page models specified in the <tt>Page</tt> rule are defined by boxes
declared in the <tt>BOXES</tt> section of the presentation schema. Pages are	declared in the <tt>BOXES</tt> section of the presentation schema. Pages are
not described as frames which will be filled by the document's text, but as	not described as frames which will be filled by the document's text, but as
element are inserted in the flow of the document and which mark the page	element are inserted in the flow of the document and which mark the page
Line 6435 page. The page box itself is the simple	Line 5846 page. The page box itself is the simple
screen. Both the footer and header boxes placed themselves with respect to	screen. Both the footer and header boxes placed themselves with respect to
this page box, with the footer being placed above it and the header boxes	this page box, with the footer being placed above it and the header boxes
being placed above it.</p>	being placed above it.</p>
<p>
The boxes created by a page box are headers and footers and can only place	<p>The boxes created by a page box are headers and footers and can only place
themselves vertically with respect to the page box itself (which is in fact	themselves vertically with respect to the page box itself (which is in fact
the separation between two pages). Besides, it is their vertical position	the separation between two pages). Besides, it is their vertical position
rule which determines whether they are header or footer boxes. Header and	rule which determines whether they are header or footer boxes. Header and
footer boxes must have an explicit vertical position rule (they must not use	footer boxes must have an explicit vertical position rule (they must not use
the default rule).</p>	the default rule).</p>
<p>
Footer boxes must have an absolute height or inherit the height of their	<p>Footer boxes must have an absolute height or inherit the height of their
contents:</p>	contents:</p>
<pre>Height : Enclosed . Height;</pre>	<pre>Height : Enclosed . Height;</pre>
<p>
A page box must have height and width rules and these two rules must be	<p>A page box must have height and width rules and these two rules must be
specified with constant values, expressed in centimeters, inches, or	specified with constant values, expressed in centimeters, inches, or
typographer's points. These two rules are interpreted in a special way for	typographer's points. These two rules are interpreted in a special way for
page boxes: they determine the width of the page and the vertical distance	page boxes: they determine the width of the page and the vertical distance
between two page separators, which is the height of the page and its header	between two page separators, which is the height of the page and its header
and footer together.</p>	and footer together.</p>
<p>
A page box should also have vertical and horizontal position rules and these	<p>A page box should also have vertical and horizontal position rules and
two rules should specify the position on the sheet of paper of the rectangle	these two rules should specify the position on the sheet of paper of the
enclosing the page's contents. These two rules must position the upper left	rectangle enclosing the page's contents. These two rules must position the
corner of the enclosing rectangle in relation to the upper left corner of the	upper left corner of the enclosing rectangle in relation to the upper left
sheet of paper, considered to be the enclosing element. In both rules,	corner of the sheet of paper, considered to be the enclosing element. In both
distances must be expressed in fixed units: centimeters (<tt>cm</tt>), inches	rules, distances must be expressed in fixed units: centimeters (<tt>cm</tt>),
(<tt>in</tt>), or typographer's points (<tt>pt</tt>). Thus, rules similar to	inches (<tt>in</tt>), or typographer's points (<tt>pt</tt>). Thus, rules
the following should be found in the rules for a page box:</p>	similar to the following should be found in the rules for a page box:</p>
<pre>BOXES	<pre>BOXES
ThePage :	ThePage :
BEGIN	BEGIN
Line 6470 the following should be found in the rul	Line 5881 the following should be found in the rul
Width : 16 cm;	Width : 16 cm;
Height : 22.5 cm;	Height : 22.5 cm;
END;</pre>	END;</pre>
<p>
When a document must be page broken, the page models to be constructed are	<p>When a document must be page broken, the page models to be constructed are
defined in the <tt>BOXES</tt> section of the presentation schema by declaring	defined in the <tt>BOXES</tt> section of the presentation schema by declaring
page boxes and header and footer boxes. Also, the <tt>Page</tt> rule is used	page boxes and header and footer boxes. Also, the <tt>Page</tt> rule is used
to specify to which parts of the document and to which views each model should	to specify to which parts of the document and to which views each model should
be applied.</p>	be applied.</p>
<p>
The <tt>Page</tt> rule has only one parameter, given between parentheses after	<p>The <tt>Page</tt> rule has only one parameter, given between parentheses
the <tt>Page</tt> keyword. This parameter is the name of the box which must	after the <tt>Page</tt> keyword. This parameter is the name of the box which
serve as the model for page construction. When a <tt>Page</tt> rule is	must serve as the model for page construction. When a <tt>Page</tt> rule is
attached to an element type, each time such an element appears in a document,	attached to an element type, each time such an element appears in a document,
a page break takes place and the page model indicated in the rule is applied	a page break takes place and the page model indicated in the rule is applied
to all following pages, until reaching the next element which has a	to all following pages, until reaching the next element which has a
<tt>Page</tt> rule.</p>	<tt>Page</tt> rule.</p>
<p>
The <tt>Page</tt> rule applies to only one view; if it appears in the primary	<p>The <tt>Page</tt> rule applies to only one view; if it appears in the
view's block of rules, a <tt>Page</tt> rule applies only to that view. Thus,	primary view's block of rules, a <tt>Page</tt> rule applies only to that view.
different page models can be defined for the full document and for its table	Thus, different page models can be defined for the full document and for its
of contents, which is another view of the same document. Some views can be	table of contents, which is another view of the same document. Some views can
specified with pages, and other views of the same document can be specified	be specified with pages, and other views of the same document can be specified
without pages.</p>	without pages.</p>
<pre> 'Page' '(' BoxID ')'</pre>	<pre> 'Page' '(' BoxID ')'</pre>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc4234">Box copies</a></h3>	<h3><a name="sectc4234">Box copies</a></h3>
<p>
The <tt>Copy</tt> rule can be used for an element which is defined as a	<p>The <tt>Copy</tt> rule can be used for an element which is defined as a
reference in the structure schema. In this case, the rule specifies, between	reference in the structure schema. In this case, the rule specifies, between
parenthesis, the name of the box (declared in the <tt>BOXES</tt> section)	parenthesis, the name of the box (declared in the <tt>BOXES</tt> section)
which must be produced when this reference appears in the structure of a	which must be produced when this reference appears in the structure of a
Line 6507 presentation) of the box type indicated	Line 5917 presentation) of the box type indicated
and which is in the element designated by the reference. The name of a box	and which is in the element designated by the reference. The name of a box
can be replaced by type name. Then what is copied is the contents of the	can be replaced by type name. Then what is copied is the contents of the
element of this type which is inside the referenced element.</p>	element of this type which is inside the referenced element.</p>
<p>
Whether a box name or type name is given, it may be followed by the name of a	<p>Whether a box name or type name is given, it may be followed by the name of
structure schema between parentheses. This signifies that the box or type is	a structure schema between parentheses. This signifies that the box or type
defined in the indicated structure schema and not in the structure schema with	is defined in the indicated structure schema and not in the structure schema
which the rule's presentation schema is associated.</p>	with which the rule's presentation schema is associated.</p>
<p>
The <tt>Copy</tt> rule can also be applied to a presentation box. If the	<p>The <tt>Copy</tt> rule can also be applied to a presentation box. If the
presentation box was created by a reference attribute, the rule is applied as	presentation box was created by a reference attribute, the rule is applied as
in the case of a reference element: the contents of the box having the	in the case of a reference element: the contents of the box having the
<tt>Copy</tt> rule are based on the element designated by the reference	<tt>Copy</tt> rule are based on the element designated by the reference
Line 6529 footers.</p>	Line 5939 footers.</p>
BoxTypeToCopy = BoxID [ ExtStruct ] /	BoxTypeToCopy = BoxID [ ExtStruct ] /
ElemID [ ExtStruct ] .	ElemID [ ExtStruct ] .
ExtStruct = '(' ElemID ')' .</pre>	ExtStruct = '(' ElemID ')' .</pre>
<p>
Like the creation rules, the <tt>Copy</tt> rule cannot appear in the <a	<p>Like the creation rules, the <tt>Copy</tt> rule cannot appear in the <a
href="#sectc427">default presentation rules</a>. Moreover, this rule can only	href="#sectc427">default presentation rules</a>. Moreover, this rule can only
appear in the primary view's block of rules; the copy rule is applied to all	appear in the primary view's block of rules; the copy rule is applied to all
views.</p>	views.</p>

<blockquote class="example">	<blockquote class="example">
<p>	<p><strong>Example:</strong></p>
<strong>Example:</strong></p>
<p>	<p>If the following definitions are in the structure schema:</p>
If the following definitions are in the structure schema:</p>	<pre>Body = LIST OF (Chapter =
<pre>Body = LIST OF (Chapter =
BEGIN	BEGIN
ChapterTitle = Text;	ChapterTitle = Text;
ChapterBody = SectionSeq;	ChapterBody = SectionSeq;
END);	END);
RefChapter = REFERENCE (Chapter);</pre>	RefChapter = REFERENCE (Chapter);</pre>
<p>
then the following presentation rules (among many other rules in the	<p>then the following presentation rules (among many other rules in the
presentation schema) can be specified:</p>	presentation schema) can be specified:</p>
<pre>COUNTERS	<pre>COUNTERS
ChapterCtr : RANK OF Chapter;	ChapterCtr : RANK OF Chapter;
BOXES	BOXES
ChapterNumber :	ChapterNumber :
Line 6567 RULES	Line 5977 RULES
Copy (ChapterNumber);	Copy (ChapterNumber);
...	...
END;</pre>	END;</pre>
<p>
which makes the number of the chapter designated by the reference appear in	<p>which makes the number of the chapter designated by the reference appear
uppercase roman numerals, in place of the reference to a chapter itself.	in uppercase roman numerals, in place of the reference to a chapter itself.
Alternatively, the chapter title can be made to appear in place of the	Alternatively, the chapter title can be made to appear in place of the
reference by writing this <tt>Copy</tt>rule:</p>	reference by writing this <tt>Copy</tt>rule:</p>
<pre> Copy (ChapterTitle);</pre>	<pre> Copy (ChapterTitle);</pre>
<p>
To define a header box, named <tt>RunningTitle</tt>, which contains the title	<p>To define a header box, named <tt>RunningTitle</tt>, which contains the
of the current chapter, the box's contents are defined in this way:</p>	title of the current chapter, the box's contents are defined in this
<pre>BOXES	way:</p>
	<pre>BOXES
RunningTitle :	RunningTitle :
Copy (ChapterTitle);</pre>	Copy (ChapterTitle);</pre>
</blockquote>	</blockquote>
</div>	</div>
</div>	</div>
<hr>	<hr>

</div>	</div>

<div class="chapter">	<div class="chapter">

<h1><a name="sect5">The T language</a></h1>	<h1><a name="sect5">The T language</a></h1>

<div class="section">	<div class="section">

<h2><a name="sectb51">Document translation</a></h2>	<h2><a name="sectb51">Document translation</a></h2>
<p>
Because of its document model, Thot can produce documents in a high-level	<p>Because of its document model, Thot can produce documents in a high-level
abstract form. This form, called the <em>canonical form</em> is specific to	abstract form. This form, called the <em>canonical form</em> is specific to
Thot; it is well suited to the editor's manipulations, but it does not	Thot; it is well suited to the editor's manipulations, but it does not
necessarily suit other operations which might be applied to documents. Because	necessarily suit other operations which might be applied to documents. Because
Line 6605 also be used to export documents from Th	Line 6013 also be used to export documents from Th
formalisms.</p>	formalisms.</p>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc511">Translation principles</a></h3>	<h3><a name="sectc511">Translation principles</a></h3>
<p>
Document translation allows the export of documents to other systems which do	<p>Document translation allows the export of documents to other systems which
not accept Thot's canonical form. Translation can be used to export document	do not accept Thot's canonical form. Translation can be used to export
to source-based formatters like T<sub><big>E</big></sub>X,	document to source-based formatters like T<sub><big>E</big></sub>X,
L<sup>A</sup>T<sub><big>E</big></sub>X, and <tt>troff</tt>. It can also be	L<sup>A</sup>T<sub><big>E</big></sub>X, and <tt>troff</tt>. It can also be
used to translate documents into interchange formats like SGML or HTML. To	used to translate documents into interchange formats like SGML or HTML. To
allow the widest range of possible exports, Thot does not limit the choice of	allow the widest range of possible exports, Thot does not limit the choice of
translations, but rather allows the user to define the formalisms into which	translations, but rather allows the user to define the formalisms into which
documents can be translated.</p>	documents can be translated.</p>
<p>
For each document or object class, a set of translation rules can be defined,	<p>For each document or object class, a set of translation rules can be
specifying how the canonical form should be transformed into a given	defined, specifying how the canonical form should be transformed into a given
formalism. These translation rules are grouped into <em>translation	formalism. These translation rules are grouped into <em>translation
schemas</em>, each schema containing the rules necessary to translate a	schemas</em>, each schema containing the rules necessary to translate a
generic logical structure (document or object structure) into a particular	generic logical structure (document or object structure) into a particular
formalism. The same generic logical structure can have several different	formalism. The same generic logical structure can have several different
translation schemas, each defining translation rules for a different	translation schemas, each defining translation rules for a different
formalism.</p>	formalism.</p>
<p>
Like presentation schemas, translation schemas are generic. Thus, they apply	<p>Like presentation schemas, translation schemas are generic. Thus, they
to an entire object or document class and permit translation of all documents	apply to an entire object or document class and permit translation of all
or objects of that class.</p>	documents or objects of that class.</p>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc512">Translation procedure</a></h3>	<h3><a name="sectc512">Translation procedure</a></h3>
<p>
The translator works on the specific logical structure of the document being	<p>The translator works on the specific logical structure of the document
translated. It traverses the primary tree of this logical structure in	being translated. It traverses the primary tree of this logical structure in
pre-order and, at each node encountered, it applies the corresponding	pre-order and, at each node encountered, it applies the corresponding
translation rules defined in the translation schema. Translation can be	translation rules defined in the translation schema. Translation can be
associated:</p>	associated:</p>
<ul>	<ul>
<li>	<li>with element types defined in the structure schema,</li>
with element types defined in the structure schema,	<li>with global or local attributes defined in the structure schema,</li>
</li>	<li>with specific presentation rules,</li>
<li>	<li>with the content of the leaves of the structure (characters, symbols
with global or local attributes defined in the structure schema,	and graphical elements)</li>
</li>
<li>
with specific presentation rules,
</li>
<li>
with the content of the leaves of the structure (characters, symbols and
graphical elements)
</li>
</ul>	</ul>
<p>
Thus, for each node, the translator applies all rules associated with the	<p>Thus, for each node, the translator applies all rules associated with the
element type, all rules associated with each attribute (local or global)	element type, all rules associated with each attribute (local or global)
carried by the element, and if the element is a leaf of the tree, it also	carried by the element, and if the element is a leaf of the tree, it also
applies translation rules for characters, symbols, or graphical elements,	applies translation rules for characters, symbols, or graphical elements,
depending on the type of the leaf.</p>	depending on the type of the leaf.</p>
<p>
Rules associated with the content of leaves are different from all other	<p>Rules associated with the content of leaves are different from all other
rules: they specify only how to translate character strings, symbols, and	rules: they specify only how to translate character strings, symbols, and
graphical elements. All other rules, whether associated with element types,	graphical elements. All other rules, whether associated with element types,
with specific presentation rules or with attributes, are treated similarly.	with specific presentation rules or with attributes, are treated similarly.
These rules primarily allow:</p>	These rules primarily allow:</p>
<ul>	<ul>
<li>	<li>generation of a text constant or variable before or after the contents
generation of a text constant or variable before or after the contents of an	of an element,</li>
element,	<li>modification of the order in which elements appear after
</li>	translation,</li>
<li>	<li>removal of an element in the translated document,</li>
modification of the order in which elements appear after translation,	<li>and writing messages on the user's terminal during translation.</li>
</li>
<li>
removal of an element in the translated document,
</li>
<li>
and writing messages on the user's terminal during translation.
</li>
</ul>	</ul>
</div>	</div>
</div>	</div>

<div class="section">	<div class="section">

<h2><a name="sectb52">Translation definition language</a></h2>	<h2><a name="sectb52">Translation definition language</a></h2>
<p>
Translation schemas are written in a custom language, called T, which is	<p>Translation schemas are written in a custom language, called T, which is
described in the rest of this chapter. The grammar of T is specified using	described in the rest of this chapter. The grammar of T is specified using
the same <a href="#sectc321">meta-language</a> as was used for the S and P	the same <a href="#sectc321">meta-language</a> as was used for the S and P
languages and the translation schemas are written using the same conventions	languages and the translation schemas are written using the same conventions
Line 6700 identifiers created by the programmer mu	Line 6090 identifiers created by the programmer mu
way.</p>	way.</p>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc521">Organization of a translation schema</a></h3>	<h3><a name="sectc521">Organization of a translation schema</a></h3>
<p>
A translation schema is begun by the <tt>TRANSLATION</tt> keyword and is	<p>A translation schema is begun by the <tt>TRANSLATION</tt> keyword and is
terminated by the <tt>END</tt> keyword. The <tt>TRANSLATION</tt> keyword is	terminated by the <tt>END</tt> keyword. The <tt>TRANSLATION</tt> keyword is
followed by the name of the generic structure for which a translation is being	followed by the name of the generic structure for which a translation is being
defined and a semicolon. This name must be identical to the name which	defined and a semicolon. This name must be identical to the name which
appears after the <tt>STRUCTURE</tt> keyword in the corresponding structure	appears after the <tt>STRUCTURE</tt> keyword in the corresponding structure
schema.</p>	schema.</p>
<p>
After this declaration of the structure, the following material appears in	<p>After this declaration of the structure, the following material appears in
order:</p>	order:</p>
<ul>	<ul>
<li>	<li>the length of lines produced by the translation,</li>
the length of lines produced by the translation,	<li>the character delimiting the end of the line,</li>
</li>	<li>the character string which the translator will insert if it must
<li>	line-break the translated text,</li>
the character delimiting the end of the line,	<li>declarations of
</li>	<ul>
<li>	<li>buffers,</li>
the character string which the translator will insert if it must line-break	<li>counters,</li>
the translated text,	<li>constants,</li>
</li>	<li>variables,</li>
<li>	</ul>
declarations of	</li>
<ul>	<li>translation rules associated with element types,</li>
<li>	<li>translation rules associated with attributes,</li>
buffers,	<li>translation rules associated with specific presentation rules,</li>
</li>	<li>translation rules associated with characters strings, symbols and
<li>	graphical elements.</li>
counters,
</li>
<li>
constants,
</li>
<li>
variables,
</li>
</ul>	</ul>
</li>
<li>	<p>Each of these sections is introduced by a keyword followed by a sequence of
translation rules associated with element types,
</li>
<li>
translation rules associated with attributes,
</li>
<li>
translation rules associated with specific presentation rules,
</li>
<li>
translation rules associated with characters strings, symbols and graphical
elements.
</li>
</ul>
<p>
Each of these sections is introduced by a keyword followed by a sequence of
declarations. All of these sections are optional, expect for the translation	declarations. All of these sections are optional, expect for the translation
rules associated with element types. Many <tt>TEXTTRANSLATE</tt> sections can	rules associated with element types. Many <tt>TEXTTRANSLATE</tt> sections can
appear, each defining the rules for translating character strings of a	appear, each defining the rules for translating character strings of a
Line 6771 particular alphabet.</p>	Line 6137 particular alphabet.</p>
'RULES' ElemSeq	'RULES' ElemSeq
[ 'ATTRIBUTES' AttrSeq ]	[ 'ATTRIBUTES' AttrSeq ]
[ 'PRESENTATION' PresSeq ]	[ 'PRESENTATION' PresSeq ]
< 'TEXTTRANSLATE' TextTransSeq >	< 'TEXTTRANSLATE' TextTransSeq >
[ 'SYMBTRANSLATE' TransSeq ]	[ 'SYMBTRANSLATE' TransSeq ]
[ 'GRAPHTRANSLATE' TransSeq ]	[ 'GRAPHTRANSLATE' TransSeq ]
'END' .</pre>	'END' .</pre>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc522">Line length</a></h3>	<h3><a name="sectc522">Line length</a></h3>
<p>
If a <tt>LINELENGTH</tt> instruction is present after the structure	<p>If a <tt>LINELENGTH</tt> instruction is present after the structure
declaration, the translator divides the text it produces into lines, each line	declaration, the translator divides the text it produces into lines, each line
having a length less than or equal to the integer which follows the	having a length less than or equal to the integer which follows the
<tt>LINELENGTH</tt> keyword. This maximum line length is expressed as a	<tt>LINELENGTH</tt> keyword. This maximum line length is expressed as a
Line 6789 number of characters. The end of the li	Line 6154 number of characters. The end of the li
by the <tt>LINEEND</tt> instruction. When the translator breaks the lines on	by the <tt>LINEEND</tt> instruction. When the translator breaks the lines on
a space character in generated text, this space will be replaced by the	a space character in generated text, this space will be replaced by the
character string defined by the <tt>LINEENDINSERT</tt> instruction.</p>	character string defined by the <tt>LINEENDINSERT</tt> instruction.</p>
<p>
If the <tt>LINEEND</tt> instruction is not defined then the linefeed character	<p>If the <tt>LINEEND</tt> instruction is not defined then the linefeed
(octal code 12) is used as the default line end character. If the	character (octal code 12) is used as the default line end character. If the
<tt>LINEENDINSERT</tt> instruction is not defined, the linefeed character is	<tt>LINEENDINSERT</tt> instruction is not defined, the linefeed character is
inserted at the end of the produced lines. If there is no <tt>LINELENGTH</tt>	inserted at the end of the produced lines. If there is no <tt>LINELENGTH</tt>
instruction, the translated text is not divided into lines. Otherwise, if the	instruction, the translated text is not divided into lines. Otherwise, if the
Line 6799 translation rules generate line end mark	Line 6164 translation rules generate line end mark
translated text, but the length of the lines is not controlled by the	translated text, but the length of the lines is not controlled by the
translator.</p>	translator.</p>
<pre> LineLength = NUMBER .</pre>	<pre> LineLength = NUMBER .</pre>

<blockquote class="example">	<blockquote class="example">
<p>	<p><strong>Example:</strong></p>
<strong>Example:</strong></p>
<p>	<p>To limit the lines produced by the translator to a length of 80
To limit the lines produced by the translator to a length of 80 characters,	characters, the following rule is written at the beginning of the
the following rule is written at the beginning of the translation schema.</p>	translation schema.</p>
<pre>LineLength 80;</pre>	<pre>LineLength 80;</pre>
</blockquote>	</blockquote>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc523">Buffers</a></h3>	<h3><a name="sectc523">Buffers</a></h3>
<p>
A buffer is a unit of memory managed by the translator, which can either	<p>A buffer is a unit of memory managed by the translator, which can either
contain text read from the terminal during the translation (see the <a	contain text read from the terminal during the translation (see the <a
href="#sectc5212"><tt>Read</tt> rule</a>), or the name of the last picture	href="#sectc5212"><tt>Read</tt> rule</a>), or the name of the last picture
(bit-map) encountered by the translator in its traversal of the document.	(bit-map) encountered by the translator in its traversal of the document.
Remember the pictures are stored in files that are separate for the document	Remember the pictures are stored in files that are separate for the document
files and that the canonical form contains only the names of the files in	files and that the canonical form contains only the names of the files in
which the pictures are found.</p>	which the pictures are found.</p>
<p>
Thus, there are two types of buffers: buffers for reading from the terminal	<p>Thus, there are two types of buffers: buffers for reading from the
(filled by the <tt>Read</tt> rule) and the buffer of picture names (containing	terminal (filled by the <tt>Read</tt> rule) and the buffer of picture names
the name of the last picture encountered). A translation schema can use	(containing the name of the last picture encountered). A translation schema
either type, one or several read buffers and one (and only one) picture name	can use either type, one or several read buffers and one (and only one)
buffer.</p>	picture name buffer.</p>
<p>
If any buffers are used, the <tt>BUFFERS</tt> keyword must be present,	<p>If any buffers are used, the <tt>BUFFERS</tt> keyword must be present,
followed by declarations of every buffer used in the translation schema. Each	followed by declarations of every buffer used in the translation schema. Each
buffer declaration is composed only of the name of the buffer, chosen freely	buffer declaration is composed only of the name of the buffer, chosen freely
by the programmer. The picture name buffer is identified by the	by the programmer. The picture name buffer is identified by the
<tt>Picture</tt> keyword, between parentheses, following the buffer name. The	<tt>Picture</tt> keyword, between parentheses, following the buffer name. The
<tt>Picture</tt> keyword may only appear once. Each buffer declaration is	<tt>Picture</tt> keyword may only appear once. Each buffer declaration is
terminated by a semicolon.</p>	terminated by a semicolon.</p>
<pre> BufferSeq = Buffer < Buffer > .	<pre> BufferSeq = Buffer < Buffer > .
Buffer = BufferID [ '(' 'Picture' ')' ] ';' .	Buffer = BufferID [ '(' 'Picture' ')' ] ';' .
BufferID = NAME .</pre>	BufferID = NAME .</pre>

<blockquote class="example">	<blockquote class="example">
<p>	<p><strong>Example:</strong></p>
<strong>Example:</strong></p>
<p>	<p>The following buffer declarations create a picture name buffer named
The following buffer declarations create a picture name buffer named	<tt>pictureName</tt> and a read buffer named <a
<tt>pictureName</tt> and a read buffer named <a	name="destname"><tt>DestName</tt></a>:</p>
name="destname"><tt>DestName</tt></a>:</p>	<pre>BUFFERS
<pre>BUFFERS
pictureName (Picture); DestName;</pre>	pictureName (Picture); DestName;</pre>
</blockquote>	</blockquote>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc524">Counters</a></h3>	<h3><a name="sectc524">Counters</a></h3>
<p>
Certain translation rules generate text that varies according to the context	<p>Certain translation rules generate text that varies according to the
of the element to which the rules apply. Variable text is defined either in	context of the element to which the rules apply. Variable text is defined
the <a href="#sectc526"><tt>VAR</tt> section</a> of the translation schema or	either in the <a href="#sectc526"><tt>VAR</tt> section</a> of the translation
in the rule itself (see the <tt>Create</tt> and <tt>Write</tt> rules). Both	schema or in the rule itself (see the <tt>Create</tt> and <tt>Write</tt>
types of definition rely on counters for the calculation of variable	rules). Both types of definition rely on counters for the calculation of
material.</p>	variable material.</p>
<p>
There are two types of counter: counters whose value is explicitely computed	<p>There are two types of counter: counters whose value is explicitely
by applying <a href="#sectc5221"><tt>Set</tt> and <tt>Add</tt> rules</a>, and	computed by applying <a href="#sectc5221"><tt>Set</tt> and <tt>Add</tt>
counters whose value is computed by a function associated with the counter.	rules</a>, and counters whose value is computed by a function associated with
Those functions allow the same calculations as can be used in presentation	the counter. Those functions allow the same calculations as can be used in
schemas. As in a presentation schema, counters must be defined in the	presentation schemas. As in a presentation schema, counters must be defined in
<tt>COUNTERS</tt> section of the translation schema before they are used.</p>	the <tt>COUNTERS</tt> section of the translation schema before they are
<p>	used.</p>
When counters are used in a translation schema, the <tt>COUNTERS</tt> keyword
is followed by the declarations of every counter used. Each declaration is	<p>When counters are used in a translation schema, the <tt>COUNTERS</tt>
composed of the counter's name possibly followed by a colon and the counting	keyword is followed by the declarations of every counter used. Each
function to be used for the counter. The declaration is terminated by a	declaration is composed of the counter's name possibly followed by a colon and
semi-colon. If the counter is explicitely computed by <tt>Set</tt> and	the counting function to be used for the counter. The declaration is
<tt>Add</tt> rules, no counting function is indicated. If a counting function	terminated by a semi-colon. If the counter is explicitely computed by
is indicated, <tt>Set</tt> and <tt>Add</tt> rules cannot be applied to that	<tt>Set</tt> and <tt>Add</tt> rules, no counting function is indicated. If a
counter.</p>	counting function is indicated, <tt>Set</tt> and <tt>Add</tt> rules cannot be
<p>	applied to that counter.</p>
The counting function indicates how the counter's value will be computed.
	<p>The counting function indicates how the counter's value will be computed.
Three functions are available: <tt>Rank</tt>, <tt>Rlevel</tt>, and	Three functions are available: <tt>Rank</tt>, <tt>Rlevel</tt>, and
<tt>Set</tt>.</p>	<tt>Set</tt>.</p>
<ul>	<ul>
<li>	<li><tt>Rank of ElemID</tt> indicates that the counter's value is the rank
<tt>Rank of ElemID</tt> indicates that the counter's value is the rank of the	of the element of type <tt>ElemID</tt> which encloses the element for
element of type <tt>ElemID</tt> which encloses the element for which the	which the counter is being evaluated. For the purposes of this function,
counter is being evaluated. For the purposes of this function, an element of	an element of type <tt>ElemID</tt> is considered to enclose itself. This
type <tt>ElemID</tt> is considered to enclose itself. This function is	function is primarily used when the element of type <tt>ElemID</tt> is
primarily used when the element of type <tt>ElemID</tt> is part of an	part of an aggregate or list, in which case the counter's value is the
aggregate or list, in which case the counter's value is the element's rank in	element's rank in its list or aggregate. Note that, unlike the
its list or aggregate. Note that, unlike the <tt>Rank</tt> function for	<tt>Rank</tt> function for presentation schemas, the <tt>Page</tt> keyword
presentation schemas, the <tt>Page</tt> keyword cannot be used in place of the	cannot be used in place of the <tt>ElemID</tt>.
<tt>ElemID</tt>.	<p>The type name <tt>ElemID</tt> can be followed by an integer. That
<p>	number represents the relative level, among the ancestors of the concerned
The type name <tt>ElemID</tt> can be followed by an integer. That number	element, of the element whose rank is asked. If that relative level
represents the relative level, among the ancestors of the concerned element,	<i>n</i> is unsigned, the <i>n<sup>th</sup></i> element of type
of the element whose rank is asked. If that relative level <i>n</i> is	<tt>ElemID</tt> encountered when travelling the logical structure from the
unsigned, the <i>n<sup>th</sup></i> element of type <tt>ElemID</tt>	root to the concerned element is taken into account. If the relative
encountered when travelling the logical structure from the root to the	level is negative, the logical structure is travelled in the other
concerned element is taken into account. If the relative level is negative,	direction, from the concerned element to the root.</p>
the logical structure is travelled in the other direction, from the concerned	</li>
element to the root.</p>	<li><tt>Rlevel of ElemID</tt> indicates that the counter's values is the
</li>	relative level in the tree of the element for which the counter is being
<li>	evaluated. The counter counts the number of elements of type
<tt>Rlevel of ElemID</tt> indicates that the counter's values is the relative	<tt>ElemID</tt> which are found on the path between the root of the
level in the tree of the element for which the counter is being evaluated. The	document's logical structure tree and the element (inclusive).</li>
counter counts the number of elements of type <tt>ElemID</tt> which are found	<li><tt>Set n on Type1 Add m on Type2</tt> indicates that the counter's
on the path between the root of the document's logical structure tree and the	value is calculated as follows: in traversing the document from the
element (inclusive).	beginning to the element for which the counter is being evaluated, the
</li>	counter is set to the value <tt>n</tt> each time a <tt>Type1</tt> element
<li>	is encountered and is incremented by the amount <tt>m</tt> each time a
<tt>Set n on Type1 Add m on Type2</tt> indicates that the counter's value is	<tt>Type2</tt> element is encountered. The initial value <tt>n</tt> and
calculated as follows: in traversing the document from the beginning to the	the increment <tt>m</tt> are integers.</li>
element for which the counter is being evaluated, the counter is set to the	</ul>
value <tt>n</tt> each time a <tt>Type1</tt> element is encountered and is
incremented by the amount <tt>m</tt> each time a <tt>Type2</tt> element is	<p>As in a presentation schema, the <tt>Rank</tt> and <tt>Set</tt> functions
encountered. The initial value <tt>n</tt> and the increment <tt>m</tt> are	can be modified by a numeric attribute which changes their initial value. This
integers.	is indicated by the <tt>Init</tt> keyword followed by the numeric attribute's
</li>
</ul>
<p>
As in a presentation schema, the <tt>Rank</tt> and <tt>Set</tt> functions can
be modified by a numeric attribute which changes their initial value. This is
indicated by the <tt>Init</tt> keyword followed by the numeric attribute's
name. The <tt>Set</tt> function takes the value of the attribute instead of	name. The <tt>Set</tt> function takes the value of the attribute instead of
the <tt>InitValue</tt> (<tt>n</tt>). For the <tt>Rank</tt> function, the	the <tt>InitValue</tt> (<tt>n</tt>). For the <tt>Rank</tt> function, the
value of the attribute is considered to be the rank of the first element of	value of the attribute is considered to be the rank of the first element of
the list (rather than the normal value of 1). Subsequent items in the list	the list (rather than the normal value of 1). Subsequent items in the list
have their ranks shifted accordingly. In both cases, the attribute must be	have their ranks shifted accordingly. In both cases, the attribute must be
numeric and must be a local attribute of the root of the document itself.</p>	numeric and must be a local attribute of the root of the document itself.</p>
<pre> CounterSeq = Counter < Counter > .	<pre> CounterSeq = Counter < Counter > .
Counter = CounterID [ ':' CounterFunc ] ';' .	Counter = CounterID [ ':' CounterFunc ] ';' .
CounterID = NAME .	CounterID = NAME .
CounterFunc = 'Rank' 'of' ElemID [ SLevelAsc ]	CounterFunc = 'Rank' 'of' ElemID [ SLevelAsc ]
Line 6942 numeric and must be a local attribute of	Line 6301 numeric and must be a local attribute of
Increment = NUMBER .	Increment = NUMBER .
ElemID = NAME .	ElemID = NAME .
AttrID = NAME .</pre>	AttrID = NAME .</pre>

<blockquote class="example">	<blockquote class="example">
<p>	<p><strong>Example:</strong></p>
<strong>Example:</strong></p>
<p>	<p>If the body of a chapter is defined in the structure schema by:</p>
If the body of a chapter is defined in the structure schema by:</p>	<pre>Chapter_Body = LIST OF
<pre>Chapter_Body = LIST OF
(Section = BEGIN	(Section = BEGIN
Section_Title = Text;	Section_Title = Text;
Section_Body = BEGIN	Section_Body = BEGIN
Line 6956 If the body of a chapter is defined in t	Line 6315 If the body of a chapter is defined in t
END;	END;
END	END
);</pre>	);</pre>
<p>
(sections are defined recursively), a counter can be defined giving the <a	<p>(sections are defined recursively), a counter can be defined giving the
name="sectnum">number of a section</a> within its level in the hierarchy:</p>	<a name="sectnum">number of a section</a> within its level in the
<pre>COUNTERS	hierarchy:</p>
	<pre>COUNTERS
SectionNumber : Rank of Section;</pre>	SectionNumber : Rank of Section;</pre>
<p>
A counter holding the hierarchic level of a section:</p>	<p>A counter holding the hierarchic level of a section:</p>
<pre> SectionLevel : Rlevel of Section;</pre>	<pre> SectionLevel : Rlevel of Section;</pre>
<p>
A <a name="uniquenum">counter</a> which sequentially numbers all the	<p>A <a name="uniquenum">counter</a> which sequentially numbers all the
document's sections, whatever their hierarchic level:</p>	document's sections, whatever their hierarchic level:</p>
<pre> UniqueSectNum : Set 0 on Document Add 1 on Section;</pre>	<pre> UniqueSectNum : Set 0 on Document Add 1 on Section;</pre>
</blockquote>	</blockquote>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc525">Constants</a></h3>	<h3><a name="sectc525">Constants</a></h3>
<p>
A common feature of translation rules is the generation of constant text. This	<p>A common feature of translation rules is the generation of constant text.
text can be defined in the rule that generates it (see for example the <a	This text can be defined in the rule that generates it (see for example the <a
href="#sectc5210"><tt>Create</tt></a> and <a	href="#sectc5210"><tt>Create</tt></a> and <a
href="#sectc5211"><tt>Write</tt></a> rules); but it can also be defined once	href="#sectc5211"><tt>Write</tt></a> rules); but it can also be defined once
in the constant declaration section and used many times in different rules.	in the constant declaration section and used many times in different rules.
The latter option is preferable when the same text is used in several rules or	The latter option is preferable when the same text is used in several rules or
several <a href="#sectc526">variables</a>.</p>	several <a href="#sectc526">variables</a>.</p>
<p>
The <tt>CONST</tt> keyword begins the constant declaration section of the	<p>The <tt>CONST</tt> keyword begins the constant declaration section of the
translation schema. It must be omitted if no constants are declared. Each	translation schema. It must be omitted if no constants are declared. Each
constant declaration is composed of the constant name, an equals sign, and the	constant declaration is composed of the constant name, an equals sign, and the
constant's value, which is a character string between apostrophes. A constant	constant's value, which is a character string between apostrophes. A constant
declaration is terminated by a semicolon.</p>	declaration is terminated by a semicolon.</p>
<pre> ConstSeq = Const < Const > .	<pre> ConstSeq = Const < Const > .
Const = ConstID '=' ConstValue ';' .	Const = ConstID '=' ConstValue ';' .
ConstID = NAME .	ConstID = NAME .
ConstValue = STRING .</pre>	ConstValue = STRING .</pre>

<blockquote class="example">	<blockquote class="example">
<p>	<p><strong><a name="levelexample">Example:</a></strong></p>
<strong><a name="levelexample">Example:</a></strong></p>
<p>	<p>The following rule assigns the name <tt>TxtLevel</tt> to the character
The following rule assigns the name <tt>TxtLevel</tt> to the character string	string ``Level'':</p>
``Level'':</p>	<pre>CONST
<pre>CONST
TxtLevel = 'Level';</pre>	TxtLevel = 'Level';</pre>
</blockquote>	</blockquote>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc526">Variables</a></h3>	<h3><a name="sectc526">Variables</a></h3>
<p>
Variables allow to define variable text which is generated by the	<p>Variables allow to define variable text which is generated by the
<tt>Create</tt> and <tt>Write</tt> rules. They are also used to define file	<tt>Create</tt> and <tt>Write</tt> rules. They are also used to define file
names which are used in the <tt>Create</tt>, <tt>ChangeMainFile</tt>,	names which are used in the <tt>Create</tt>, <tt>ChangeMainFile</tt>,
<tt>RemoveFile</tt>, and <tt>Indent</tt> rules. Variables can be defined	<tt>RemoveFile</tt>, and <tt>Indent</tt> rules. Variables can be defined
Line 7017 in the <tt>VAR</tt> section, and when th	Line 6375 in the <tt>VAR</tt> section, and when th
in the translation schema, it makes sense to define it globally in the	in the translation schema, it makes sense to define it globally in the
<tt>VAR</tt> section. This section is only present if at least one variable	<tt>VAR</tt> section. This section is only present if at least one variable
is defined globally.</p>	is defined globally.</p>
<p>
After the <tt>VAR</tt> keyword, each global variable is defined by its name, a	<p>After the <tt>VAR</tt> keyword, each global variable is defined by its
colon separator and a sequence of functions (at least one function). Each	name, a colon separator and a sequence of functions (at least one function).
variable definition is terminated by a semicolon. Functions determine the	Each variable definition is terminated by a semicolon. Functions determine the
different parts which together give the value of the variable. The value is	different parts which together give the value of the variable. The value is
obtained by concatenating the strings produced by each of the functions. Seven	obtained by concatenating the strings produced by each of the functions. Seven
types of functions are available. Each variable definition may use any number	types of functions are available. Each variable definition may use any number
of functions of each type.</p>	of functions of each type.</p>
<ul>	<ul>
<li>	<li>The function <tt>Value(Counter)</tt>returns a string representing the
The function <tt>Value(Counter)</tt>returns a string representing the value	value taken by the counter when it is evaluated for the element in whose
taken by the counter when it is evaluated for the element in whose rule the	rule the variable is used. The counter must have been declared in the
variable is used. The counter must have been declared in the	<tt>COUNTERS</tt> section of the translation schema. When the counter is
<tt>COUNTERS</tt> section of the translation schema. When the counter is	expressed in arabic numerals, the counter name can be followed by a colon
expressed in arabic numerals, the counter name can be followed by a colon and	and an integer indicating a minimum length (number of characters) for the
an integer indicating a minimum length (number of characters) for the string;	string; if the counter's value is normally expressed with fewer characters
if the counter's value is normally expressed with fewer characters than the	than the required minimum, zeroes are added to the front of the string to
required minimum, zeroes are added to the front of the string to achieve the	achieve the minimum length.
minimum length.	<p>By default, the counter value is written in arabic digits. If another
<p>	representation of that value is needed, the counter name must be followed
By default, the counter value is written in arabic digits. If another	by a comma and one of the following keywords:</p>
representation of that value is needed, the counter name must be followed by a	<ul>
comma and one of the following keywords:</p>	<li><tt>Arabic</tt>: arabic numerals (default value),</li>
<ul>	<li><tt>LRoman</tt>: lower-case roman numerals,</li>
<li>	<li><tt>URoman</tt>: upper-case roman numerals,</li>
<tt>Arabic</tt>: arabic numerals (default value),	<li><tt>Uppercase</tt>: upper-case letter,</li>
</li>	<li><tt>Lowercase</tt>: lower-case letter.</li>
<li>	</ul>
<tt>LRoman</tt>: lower-case roman numerals,	</li>
</li>	<li>The function <tt>FileDir</tt>, without parameter, returns a string
<li>	representing the name of the directory of the output file that has been
<tt>URoman</tt>: upper-case roman numerals,	given as a parameter to the translation program. The string includes a
</li>	character '/' at the end.</li>
<li>	<li>The function <tt>FileName</tt>, without parameter, returns a string
<tt>Uppercase</tt>: upper-case letter,	representing the name of the output file that has been given as a
</li>	parameter to the translation program. The file extension (the character
<li>	string that terminate the file name, after a dot) is not part of that
<tt>Lowercase</tt>: lower-case letter.	string.</li>
</li>	<li>The function <tt>Extension</tt>, without parameter, returns a string
</ul>	representing the extension of the file name. That string is empty if the
</li>	file name that has been given as a parameter to the translation program
<li>	has no extension. If there is an extension, its first character is a
The function <tt>FileDir</tt>, without parameter, returns a string	dot.</li>
representing the name of the directory of the output file that has been given	<li>The function <tt>DocumentName</tt>, without parameter, returns a string
as a parameter to the translation program. The string includes a character '/'	representing the name of the document being translated.</li>
at the end.	<li>The function <tt>DocumentDir</tt>, without parameter, returns a string
</li>	representing the directory containing the document being translated.</li>
<li>	<li>The function formed by the name of a constant returns that constant's
The function <tt>FileName</tt>, without parameter, returns a string	value.</li>
representing the name of the output file that has been given as a parameter to	<li>The function formed by a character string between apostrophes returns
the translation program. The file extension (the character string that	that string.</li>
terminate the file name, after a dot) is not part of that string.	<li>The function formed by the name of a buffer returns the contents of that
</li>	buffer. If the named buffer is the picture buffer, then the name of the
<li>	last picture encountered is returned. Otherwise, the buffer is a read
The function <tt>Extension</tt>, without parameter, returns a string	buffer and the value returned is text previously read from the terminal.
representing the extension of the file name. That string is empty if the file	If the buffer is empty (no picture has been encountered or the
name that has been given as a parameter to the translation program has no	<tt>Read</tt> rule has not been executed for the buffer), then the empty
extension. If there is an extension, its first character is a dot.	string is returned.</li>
</li>	<li>The function formed by an attribute name takes the value of the
<li>	indicated attribute for the element to which the variable applies. If the
The function <tt>DocumentName</tt>, without parameter, returns a string	element does not have that attribute, then the element's ancestor are
representing the name of the document being translated.	searched toward the root of the tree. If one of the ancestors does have
</li>	the attribute then its value is used. If no ancestors have the attribute,
<li>	then the value of the function is the empty string.</li>
The function <tt>DocumentDir</tt>, without parameter, returns a string
representing the directory containing the document being translated.
</li>
<li>
The function formed by the name of a constant returns that constant's value.
</li>
<li>
The function formed by a character string between apostrophes returns that
string.
</li>
<li>
The function formed by the name of a buffer returns the contents of that
buffer. If the named buffer is the picture buffer, then the name of the last
picture encountered is returned. Otherwise, the buffer is a read buffer and
the value returned is text previously read from the terminal. If the buffer
is empty (no picture has been encountered or the <tt>Read</tt> rule has not
been executed for the buffer), then the empty string is returned.
</li>
<li>
The function formed by an attribute name takes the value of the indicated
attribute for the element to which the variable applies. If the element does
not have that attribute, then the element's ancestor are searched toward the
root of the tree. If one of the ancestors does have the attribute then its
value is used. If no ancestors have the attribute, then the value of the
function is the empty string.
</li>
</ul>	</ul>
<pre> VariableSeq = Variable < Variable > .	<pre> VariableSeq = Variable < Variable > .
Variable = VarID ':' Function < Function > ';' .	Variable = VarID ':' Function < Function > ';' .
VarID = NAME .	VarID = NAME .
Function ='Value' '(' CounterID [ ':' Length ]	Function ='Value' '(' CounterID [ ':' Length ]
[ ',' CounterStyle ] ')' /	[ ',' CounterStyle ] ')' /
Line 7121 function is the empty string.	Line 6453 function is the empty string.
CounterStyle= 'Arabic' / 'LRoman' / 'URoman' /	CounterStyle= 'Arabic' / 'LRoman' / 'URoman' /
'Uppercase' / 'Lowercase' .	'Uppercase' / 'Lowercase' .
CharString = STRING .</pre>	CharString = STRING .</pre>

<blockquote class="example">	<blockquote class="example">
<p>	<p><strong>Example:</strong></p>
<strong>Example:</strong></p>
<p>	<p>To create, at the beginning of each section of the translated document,
To create, at the beginning of each section of the translated document, text	text composed of the string ``Section'' followed by the section number, the
composed of the string ``Section'' followed by the section number, the	following <a name="varsectexample">variable definition</a> might be
following <a name="varsectexample">variable definition</a> might be used:</p>	used:</p>
<pre>VAR	<pre>VAR
SectionVar : 'Section' Value(SectionNumber);</pre>	SectionVar : 'Section' Value(SectionNumber);</pre>
<p>
(see the definition of <a href="#sectnum"><tt>SectionNumber</tt></a>).</p>	<p>(see the definition of <a
<p>	href="#sectnum"><tt>SectionNumber</tt></a>).</p>
The following variable definition can be used to create, at the beginning of
each section, the text ``Level'' followed by the hierarchical level of the	<p>The following variable definition can be used to create, at the beginning
section. It used the constant defined above.</p>	of each section, the text ``Level'' followed by the hierarchical level of
<pre> LevelVar : TxtLevel Value(SectionLevel);</pre>	the section. It used the constant defined above.</p>
<p>	<pre> LevelVar : TxtLevel Value(SectionLevel);</pre>
(see the definitions of <a href="#sectnum"><tt>SectionLevel</tt></a> and of <a
href="#levelexample"><tt>TxtLevel</tt></a>).</p>	<p>(see the definitions of <a href="#sectnum"><tt>SectionLevel</tt></a> and
<p>	of <a href="#levelexample"><tt>TxtLevel</tt></a>).</p>
To generate the translation of each section in a different file (see <a
href="#sectc5220">rule <tt>ChangeMainFile</tt></a>), the name of these files	<p>To generate the translation of each section in a different file (see <a
might be defined by the following variable:</p>	href="#sectc5220">rule <tt>ChangeMainFile</tt></a>), the name of these files
<pre> VarOutpuFile : FileName Value(SectionNumber)	might be defined by the following variable:</p>
	<pre> VarOutpuFile : FileName Value(SectionNumber)
Extension;</pre>	Extension;</pre>
<p>
If <tt>output.txt</tt> is the name of the <a name="varoutputfile">output	<p>If <tt>output.txt</tt> is the name of the <a name="varoutputfile">output
file</a> specified when starting the translation program, translated sections	file</a> specified when starting the translation program, translated
are written in files <tt>output1.txt</tt>, <tt>output2.txt</tt>, etc.</p>	sections are written in files <tt>output1.txt</tt>, <tt>output2.txt</tt>,
	etc.</p>
</blockquote>	</blockquote>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc527">Translating structure elements</a></h3>	<h3><a name="sectc527">Translating structure elements</a></h3>
<p>
The <tt>RULES</tt> keyword introduces the translation rules which will be	<p>The <tt>RULES</tt> keyword introduces the translation rules which will be
applied to the various structured element types. Translation rules can be	applied to the various structured element types. Translation rules can be
specified for each element type defined in the structure schema, including the	specified for each element type defined in the structure schema, including the
base types defined implicitly, whose names are <tt>TEXT_UNIT</tt>,	base types defined implicitly, whose names are <tt>TEXT_UNIT</tt>,
<tt>PICTURE_UNIT</tt>, <tt>SYMBOL_UNIT</tt>, <tt>GRAPHIC_UNIT</tt> and	<tt>PICTURE_UNIT</tt>, <tt>SYMBOL_UNIT</tt>, <tt>GRAPHIC_UNIT</tt> and
<tt>PAGE_UNIT</tt>. But it is not necessary to specify rules for every	<tt>PAGE_UNIT</tt>. But it is not necessary to specify rules for every
defined type.</p>	defined type.</p>
<p>
If there are no translation rules for an element type, the elements that it	<p>If there are no translation rules for an element type, the elements that it
contains (and which may have rules themselves) will still be translated, but	contains (and which may have rules themselves) will still be translated, but
the translator will produce nothing for the element itself. To make the	the translator will produce nothing for the element itself. To make the
translator completely ignore the content of an element the <a	translator completely ignore the content of an element the <a
href="#sectc5217"><tt>Remove</tt> rule</a> must be used.</p>	href="#sectc5217"><tt>Remove</tt> rule</a> must be used.</p>
<p>
The translation rules for an element type defined in the structure schema are	<p>The translation rules for an element type defined in the structure schema
written using the name of the type followed by a colon and the list of	are written using the name of the type followed by a colon and the list of
applicable rules. When the element type is a <a href="#sectd3285">mark	applicable rules. When the element type is a <a href="#sectd3285">mark
pair</a>, but only in this case, the type name must be preceded by the	pair</a>, but only in this case, the type name must be preceded by the
<tt>First</tt> or <tt>Second</tt> keyword. This keyword indicates whether the	<tt>First</tt> or <tt>Second</tt> keyword. This keyword indicates whether the
rules that follow apply to the first or second mark of the pair.</p>	rules that follow apply to the first or second mark of the pair.</p>
<p>
The list of rules can take several forms. It may be a simple non-conditional	<p>The list of rules can take several forms. It may be a simple
rule. It can also be formed by a condition followed by one or more simple	non-conditional rule. It can also be formed by a condition followed by one or
rules. Or it can be a block of rules beginning with the <tt>BEGIN</tt>	more simple rules. Or it can be a block of rules beginning with the
keyword and ending with the <tt>END</tt> keyword and a semicolon. This block	<tt>BEGIN</tt> keyword and ending with the <tt>END</tt> keyword and a
of rules can contain one or more simple rules and/or one or more conditions,	semicolon. This block of rules can contain one or more simple rules and/or
each followed by one or more simple rules.</p>	one or more conditions, each followed by one or more simple rules.</p>
<pre> ElemSeq = TransType < TransType > .	<pre> ElemSeq = TransType < TransType > .
TransType = [ FirstSec ] ElemID ':' RuleSeq .	TransType = [ FirstSec ] ElemID ':' RuleSeq .
FirstSec = 'First' / 'Second' .	FirstSec = 'First' / 'Second' .
RuleSeq = Rule / 'BEGIN' < Rule > 'END' ';' .	RuleSeq = Rule / 'BEGIN' < Rule > 'END' ';' .
Rule = SimpleRule / ConditionBlock .	Rule = SimpleRule / ConditionBlock .
ConditionBlock = 'IF' ConditionSeq SimpleRuleSeq .	ConditionBlock = 'IF' ConditionSeq SimpleRuleSeq .
SimpleRuleSeq = 'BEGIN' < SimpleRule > 'END' ';' /	SimpleRuleSeq = 'BEGIN' < SimpleRule > 'END' ';' /
SimpleRule .</pre>	SimpleRule .</pre>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc528">Conditional rules</a></h3>	<h3><a name="sectc528">Conditional rules</a></h3>
<p>
In a translation schema, the translation rules are either associated with	<p>In a translation schema, the translation rules are either associated with
element types or with attribute values or with a specific presentation. They	element types or with attribute values or with a specific presentation. They
are applied by the translator each time an element of the corresponding type	are applied by the translator each time an element of the corresponding type
is encountered in the translated document or each time the attribute value is	is encountered in the translated document or each time the attribute value is
Line 7206 carried by an element or also, each time	Line 6539 carried by an element or also, each time
to an element. This systematic application of the rules can be relaxed: it is	to an element. This systematic application of the rules can be relaxed: it is
possible to add a condition to one or more rules, so that these rules are only	possible to add a condition to one or more rules, so that these rules are only
applied when the condition is true.</p>	applied when the condition is true.</p>
<p>
A condition begins with the keyword <tt>IF</tt>, followed by a sequence of	<p>A condition begins with the keyword <tt>IF</tt>, followed by a sequence of
elementary conditions. Elementary conditions are separated from each other by	elementary conditions. Elementary conditions are separated from each other by
the <tt>AND</tt> keyword. If there is only one elementary condition, this	the <tt>AND</tt> keyword. If there is only one elementary condition, this
keyword is absent. The rules are only applied if all the elementary	keyword is absent. The rules are only applied if all the elementary
conditions are true. The elementary condition can be negative; it is then	conditions are true. The elementary condition can be negative; it is then
preceded by the <tt>NOT</tt> keyword.</p>	preceded by the <tt>NOT</tt> keyword.</p>
<p>
When the translation rule(s) controlled by the condition apply to a reference	<p>When the translation rule(s) controlled by the condition apply to a
element or a reference attribute, an elementary condition can also apply to	reference element or a reference attribute, an elementary condition can also
element referred by this reference. The <tt>Target</tt> keyword is used for	apply to element referred by this reference. The <tt>Target</tt> keyword is
that purpose. It must appear before the keyword defining the condition	used for that purpose. It must appear before the keyword defining the
type.</p>	condition type.</p>
<p>
Depending on their type, some conditions may apply either to the element with	<p>Depending on their type, some conditions may apply either to the element
which they are associated, or to one of its ancestor. In the case of an	with which they are associated, or to one of its ancestor. In the case of an
ancestor, the key word <tt>Ancestor</tt> must be used, followed by</p>	ancestor, the key word <tt>Ancestor</tt> must be used, followed by</p>
<ul>	<ul>
<li>	<li>either an integer which represents the number of levels in the tree
either an integer which represents the number of levels in the tree between	between the element and the ancestor of interest,</li>
the element and the ancestor of interest,	<li>or the type name of the ancestor of interest. If that type is defined
</li>	in a separate structure schema, the name of that schema must follow
<li>	between parentheses.</li>
or the type name of the ancestor of interest. If that type is defined in a
separate structure schema, the name of that schema must follow between
parentheses.
</li>
</ul>	</ul>
<p>
There is a special case for the parent element, which can be simply written	<p>There is a special case for the parent element, which can be simply written
<tt>Parent</tt> instead of <tt>Ancestor 1</tt>.</p>	<tt>Parent</tt> instead of <tt>Ancestor 1</tt>.</p>
<p>
Only conditions <tt>First</tt>, <tt>Last</tt>, <tt>Referred</tt>,	<p>Only conditions <tt>First</tt>, <tt>Last</tt>, <tt>Referred</tt>,
<tt>Within</tt>, <tt>Attributes</tt>, <tt>Presentation</tt>, <tt>Comment</tt>	<tt>Within</tt>, <tt>Attributes</tt>, <tt>Presentation</tt>, <tt>Comment</tt>
and those concerning an attribute or a specific presentation can apply to an	and those concerning an attribute or a specific presentation can apply to an
ancestor. Conditions <tt>Defined</tt>, <tt>FirstRef</tt>, <tt>LastRef</tt>,	ancestor. Conditions <tt>Defined</tt>, <tt>FirstRef</tt>, <tt>LastRef</tt>,
Line 7246 ancestor. Conditions <tt>Defined</tt>, <	Line 6575 ancestor. Conditions <tt>Defined</tt>, <
<tt>LastAttr</tt>, <tt>ComputedPage</tt>, <tt>StartPage</tt>,	<tt>LastAttr</tt>, <tt>ComputedPage</tt>, <tt>StartPage</tt>,
<tt>UserPage</tt>, <tt>ReminderPage</tt>, <tt>Empty</tt> cannot be preceded by	<tt>UserPage</tt>, <tt>ReminderPage</tt>, <tt>Empty</tt> cannot be preceded by
keywords <tt>Parent</tt> or <tt>Ancestor</tt>.</p>	keywords <tt>Parent</tt> or <tt>Ancestor</tt>.</p>
<p>
In condition <tt>Referred</tt> and in the condition that applies to a named	<p>In condition <tt>Referred</tt> and in the condition that applies to a named
attribute, a symbol '<tt>*</tt>' can indicate that the condition is related	attribute, a symbol '<tt>*</tt>' can indicate that the condition is related
only to the element itself. If this symbol is not present, not only the	only to the element itself. If this symbol is not present, not only the
element is considered, but also its ancestor, at any level.</p>	element is considered, but also its ancestor, at any level.</p>
<p>
The form of an elementary condition varies according to the type of	<p>The form of an elementary condition varies according to the type of
condition.</p>	condition.</p>

<div class="subsubsection">	<div class="subsubsection">

<h4><a name="sectd5281">Conditions based on the logical position of the	<h4><a name="sectd5281">Conditions based on the logical position of the
element</a></h4>	element</a></h4>
<p>
The condition can be on the position of the element in the document's logical	<p>The condition can be on the position of the element in the document's
structure tree. It is possible to test whether the element is the first	logical structure tree. It is possible to test whether the element is the
(<tt>First</tt>) or last (<tt>Last</tt>) among its siblings or if it is not	first (<tt>First</tt>) or last (<tt>Last</tt>) among its siblings or if it is
the first (<tt>NOT First</tt>) or not the last (<tt>NOT Last</tt>).</p>	not the first (<tt>NOT First</tt>) or not the last (<tt>NOT Last</tt>).</p>
<p>
It is also possible to test if the element is contained in an element of a	<p>It is also possible to test if the element is contained in an element of a
given type (<tt>Within</tt>) or if it is not (<tt>NOT Within</tt>). If that	given type (<tt>Within</tt>) or if it is not (<tt>NOT Within</tt>). If that
element type is defined in a structure schema which is not the one which	element type is defined in a structure schema which is not the one which
corresponds to the translation schema, the type name of this element must be	corresponds to the translation schema, the type name of this element must be
followed, between parentheses, by the name of the structure schema which	followed, between parentheses, by the name of the structure schema which
defines it.</p>	defines it.</p>
<p>
If the keyword <tt>Within</tt> is preceded by <tt>Immediately</tt>, the	<p>If the keyword <tt>Within</tt> is preceded by <tt>Immediately</tt>, the
condition is satisfied only if the <em>parent</em> element has the type	condition is satisfied only if the <em>parent</em> element has the type
indicated. If the word <tt>Immediately</tt> is missing, the condition is	indicated. If the word <tt>Immediately</tt> is missing, the condition is
satisfied if any <em>ancestor</em> has the type indicated.</p>	satisfied if any <em>ancestor</em> has the type indicated.</p>
<p>
An integer <i>n</i> can appear between the keyword <tt>Within</tt> and the	<p>An integer <i>n</i> can appear between the keyword <tt>Within</tt> and the
type. It specifies the number of ancestors of the indicated type that must be	type. It specifies the number of ancestors of the indicated type that must be
present for the condition to be satisfied. If the keyword	present for the condition to be satisfied. If the keyword
<tt>Immediately</tt> is also present, the <i>n</i> immediate ancestors of the	<tt>Immediately</tt> is also present, the <i>n</i> immediate ancestors of the
element must have the indicated type. The integer <i>n</i> must be positive	element must have the indicated type. The integer <i>n</i> must be positive
or zero. It can be preceded by <tt><</tt> or <tt>></tt> to indicate a	or zero. It can be preceded by <tt><</tt> or <tt>></tt> to indicate a
maximum or minimum number of ancestors. If these symbols are missing, the	maximum or minimum number of ancestors. If these symbols are missing, the
condition is satisfied only if it exists exactly <i>n</i> ancestors. When	condition is satisfied only if it exists exactly <i>n</i> ancestors. When
this number is missing, it is equivalent to > 0.</p>	this number is missing, it is equivalent to > 0.</p>
<p>
If the condition applies to translation rules associated with an attribute,	<p>If the condition applies to translation rules associated with an attribute,
i.e. if it is in the <tt>ATTRIBUTES</tt> section of the presentation schema,	i.e. if it is in the <tt>ATTRIBUTES</tt> section of the presentation schema,
the condition can be simply an element name. Translation rules are then	the condition can be simply an element name. Translation rules are then
executed only if the attribute is attached to an element of that type. The	executed only if the attribute is attached to an element of that type. The
Line 7296 rules must be executed only if the eleme	Line 6624 rules must be executed only if the eleme
</div>	</div>

<div class="subsubsection">	<div class="subsubsection">

<h4><a name="sectd5282">Conditions on references</a></h4>	<h4><a name="sectd5282">Conditions on references</a></h4>
<p>
References may be taken into account in conditions, which can be based on the	<p>References may be taken into account in conditions, which can be based on
fact that the element, or one of its ancestors (unless symbol <tt>*</tt> is	the fact that the element, or one of its ancestors (unless symbol <tt>*</tt>
present), is designated by a at least one reference (<tt>Referred</tt>) or by	is present), is designated by a at least one reference (<tt>Referred</tt>) or
none (<tt>NOT Referred</tt>). If the element or attribute to which the	by none (<tt>NOT Referred</tt>). If the element or attribute to which the
condition is attached is a reference, the condition can be based on the fact	condition is attached is a reference, the condition can be based on the fact
that it acts as the first reference to the designated element	that it acts as the first reference to the designated element
(<tt>FirstRef</tt>), or as the last (<tt>LastRef</tt>), or as a reference to	(<tt>FirstRef</tt>), or as the last (<tt>LastRef</tt>), or as a reference to
Line 7312 keyword.</p>	Line 6639 keyword.</p>
</div>	</div>

<div class="subsubsection">	<div class="subsubsection">

<h4><a name="sectd5283">Conditions on the parameters</a></h4>	<h4><a name="sectd5283">Conditions on the parameters</a></h4>
<p>
Elements which are <a href="#sectc326">parameters</a> can be given a	<p>Elements which are <a href="#sectc326">parameters</a> can be given a
particular condition which is based on whether or not the parameter is given a	particular condition which is based on whether or not the parameter is given a
value in the document (<tt>Defined</tt> or <tt>NOT Defined</tt>,	value in the document (<tt>Defined</tt> or <tt>NOT Defined</tt>,
respectively).</p>	respectively).</p>
</div>	</div>

<div class="subsubsection">	<div class="subsubsection">

<h4><a name="sectd5284">Conditions on the alphabets</a></h4>	<h4><a name="sectd5284">Conditions on the alphabets</a></h4>
<p>
The character string base type (and only this type) can use the condition	<p>The character string base type (and only this type) can use the condition
<tt>Alphabet = a</tt> which indicates that the translation rule(s) should only	<tt>Alphabet = a</tt> which indicates that the translation rule(s) should only
apply if the alphabet of the character string is the one whose name appears	apply if the alphabet of the character string is the one whose name appears
after the equals sign (or is not, if there is a preceding <tt>NOT</tt>	after the equals sign (or is not, if there is a preceding <tt>NOT</tt>
keyword). This condition cannot be applied to translation rules of an	keyword). This condition cannot be applied to translation rules of an
attribute.</p>	attribute.</p>
<p>
In the current implementation of Thot, the available alphabets are the	<p>In the current implementation of Thot, the available alphabets are the
<tt>Latin</tt> alphabet and the <tt>Greek</tt> alphabet.</p>	<tt>Latin</tt> alphabet and the <tt>Greek</tt> alphabet.</p>
</div>	</div>

<div class="subsubsection">	<div class="subsubsection">

<h4><a name="sectd5285">Conditions on page breaks</a></h4>	<h4><a name="sectd5285">Conditions on page breaks</a></h4>
<p>
The page break base type (and only this type) can use the following	<p>The page break base type (and only this type) can use the following
conditions: <tt>ComputedPage</tt>, <tt>StartPage</tt>, <tt>UserPage</tt>, and	conditions: <tt>ComputedPage</tt>, <tt>StartPage</tt>, <tt>UserPage</tt>, and
<tt>ReminderPage</tt>. The <tt>ComputedPage</tt> condition indicates that the	<tt>ReminderPage</tt>. The <tt>ComputedPage</tt> condition indicates that the
translation rule(s) should apply if the page break was created automatically	translation rule(s) should apply if the page break was created automatically
Line 7352 of page breaking.</p>	Line 6676 of page breaking.</p>
</div>	</div>

<div class="subsubsection">	<div class="subsubsection">

<h4><a name="sectd5286">Conditions on the element's content</a></h4>	<h4><a name="sectd5286">Conditions on the element's content</a></h4>
<p>
The condition can be based on whether or not the element is empty. An element	<p>The condition can be based on whether or not the element is empty. An
which has no children or whose leaves are all empty is considered to be empty	element which has no children or whose leaves are all empty is considered to
itself. This condition is expressed by the <tt>Empty</tt> keyword, optionally	be empty itself. This condition is expressed by the <tt>Empty</tt> keyword,
preceded by the <tt>NOT</tt> keyword.</p>	optionally preceded by the <tt>NOT</tt> keyword.</p>
</div>	</div>

<div class="subsubsection">	<div class="subsubsection">

<h4><a name="sectd5287">Conditions on the presence of comments</a></h4>	<h4><a name="sectd5287">Conditions on the presence of comments</a></h4>
<p>
The condition can be based on the presence or absence of comments associated	<p>The condition can be based on the presence or absence of comments
with the translated element. This condition is expressed by the keyword	associated with the translated element. This condition is expressed by the
<tt>Comment</tt>, optionally preceded by the keyword <tt>NOT</tt>.</p>	keyword <tt>Comment</tt>, optionally preceded by the keyword <tt>NOT</tt>.</p>
</div>	</div>

<div class="subsubsection">	<div class="subsubsection">

<h4><a name="sectd5288">Conditions on the presence of specific presentation	<h4><a name="sectd5288">Conditions on the presence of specific presentation
rules</a></h4>	rules</a></h4>
<p>
The condition can be based on the presence or absence of specific presentation	<p>The condition can be based on the presence or absence of specific
rules associated with the translated element, whatever the rules, their value	presentation rules associated with the translated element, whatever the rules,
or their number. This condition is expressed by the keyword	their value or their number. This condition is expressed by the keyword
<tt>Presentation</tt>, optionally preceded by the <tt>NOT</tt> keyword.</p>	<tt>Presentation</tt>, optionally preceded by the <tt>NOT</tt> keyword.</p>
</div>	</div>

<div class="subsubsection">	<div class="subsubsection">

<h4><a name="sectd5289">Conditions on the presence of logical	<h4><a name="sectd5289">Conditions on the presence of logical
attributes</a></h4>	attributes</a></h4>
<p>
In the same way, the condition can be based on the presence or absence of	<p>In the same way, the condition can be based on the presence or absence of
attributes associated with the translated elements, no matter what the	attributes associated with the translated elements, no matter what the
attributes or their values. The <tt>Attributes</tt> keyword expresses this	attributes or their values. The <tt>Attributes</tt> keyword expresses this
condition.</p>	condition.</p>
</div>	</div>

<div class="subsubsection">	<div class="subsubsection">

<h4><a name="sectd52810">Conditions on logical attributes</a></h4>	<h4><a name="sectd52810">Conditions on logical attributes</a></h4>
<p>
If the condition appears in the translation rules of an attribute, the	<p>If the condition appears in the translation rules of an attribute, the
<tt>FirstAttr</tt> and <tt>LastAttr</tt> keywords can be used to indicate that	<tt>FirstAttr</tt> and <tt>LastAttr</tt> keywords can be used to indicate that
the rules must only be applied if this attribute is the first attribute for	the rules must only be applied if this attribute is the first attribute for
the translated element or if it is the last (respectively). These conditions	the translated element or if it is the last (respectively). These conditions
can also be inverted by the <tt>NOT</tt> keyword.</p>	can also be inverted by the <tt>NOT</tt> keyword.</p>
<p>
Another type of condition can only be applied to the translation rules when	<p>Another type of condition can only be applied to the translation rules when
the element being processed (or one of its ancestors if symbol <tt>*</tt> is	the element being processed (or one of its ancestors if symbol <tt>*</tt> is
missing) has a certain attribute, perhaps with a certain value or, in	missing) has a certain attribute, perhaps with a certain value or, in
contrast, when the element does not have this attribute with this value. The	contrast, when the element does not have this attribute with this value. The
Line 7414 matter what the attribute's value, the c	Line 6733 matter what the attribute's value, the c
contrast, the condition applies to one or more values of the attribute, these	contrast, the condition applies to one or more values of the attribute, these
are indicated after the name of the attribute, except for reference attributes	are indicated after the name of the attribute, except for reference attributes
which do not have values.</p>	which do not have values.</p>
<p>
The representation of the values of an <a name="relattr">attribute</a> in a	<p>The representation of the values of an <a name="relattr">attribute</a> in a
condition depends on the attribute's type. For attributes with enumerated or	condition depends on the attribute's type. For attributes with enumerated or
textual types, the value (a name or character string between apostrophes,	textual types, the value (a name or character string between apostrophes,
respectively) is simply preceded by an equals sign. For numeric attributes,	respectively) is simply preceded by an equals sign. For numeric attributes,
Line 7423 the condition can be based on a single v	Line 6742 the condition can be based on a single v
case of a unique value, this value (an integer) is simply preceded by an	case of a unique value, this value (an integer) is simply preceded by an
equals sign. Conditions based on ranges of values have several forms:</p>	equals sign. Conditions based on ranges of values have several forms:</p>
<ul>	<ul>
<li>	<li>all values less than a given value (the value is preceded by a ``less
all values less than a given value (the value is preceded by a ``less than''	than'' sign).</li>
sign).	<li>all values greater than a given value (the value is preceded by a
</li>	``greater than'' sign).</li>
<li>	<li>all values falling in an interval, bounds included. The range of values
all values greater than a given value (the value is preceded by a ``greater	is then specified <tt>IN [</tt>Minimum <tt>..</tt>Maximum<tt>]</tt>, where
than'' sign).	Minimum and Maximum are integers.</li>
</li>
<li>
all values falling in an interval, bounds included. The range of values is
then specified <tt>IN [</tt>Minimum <tt>..</tt>Maximum<tt>]</tt>, where
Minimum and Maximum are integers.
</li>
</ul>	</ul>
<p>
All numeric values may be negative. The integer is simply preceded by a minus	<p>All numeric values may be negative. The integer is simply preceded by a
sign.</p>	minus sign.</p>
<p>
Both local and global attributes can be used in conditions.</p>	<p>Both local and global attributes can be used in conditions.</p>
</div>	</div>

<div class="subsubsection">	<div class="subsubsection">

<h4><a name="sectd52811">Conditions on specific presentation rules</a></h4>	<h4><a name="sectd52811">Conditions on specific presentation rules</a></h4>
<p>
It is possible to apply translation rules only when the element being	<p>It is possible to apply translation rules only when the element being
processed has or does not have a specific presentation rule, possibly with a	processed has or does not have a specific presentation rule, possibly with a
certain value. The condition is specified by writing the name of the	certain value. The condition is specified by writing the name of the
presentation rule after the keyword <tt>IF</tt> or <tt>AND</tt>. The	presentation rule after the keyword <tt>IF</tt> or <tt>AND</tt>. The
Line 7458 not have it, if the condition is inverte	Line 6770 not have it, if the condition is inverte
the condition is complete. If, in contrast, the condition applies to one or	the condition is complete. If, in contrast, the condition applies to one or
more values of the rule, these are indicated after the name of the	more values of the rule, these are indicated after the name of the
attribute.</p>	attribute.</p>
<p>
The representation of presentation rule values in a condition is similar to	<p>The representation of presentation rule values in a condition is similar to
that for attribute values. The representation of these values depend on the	that for attribute values. The representation of these values depend on the
type of the presentation rule. There are three categories of presentation	type of the presentation rule. There are three categories of presentation
rules:</p>	rules:</p>
<ul>	<ul>
<li>	<li>those taking numeric values (<tt>Size, Indent, LineSpacing,
those taking numeric values (<tt>Size, Indent, LineSpacing, LineWeight</tt>),	LineWeight</tt>),</li>
</li>	<li>those with values taken from a predefined list (<tt>Adjust, Justify,
<li>	Hyphenate, Style, Weight, Font, UnderLine, Thickness,
those with values taken from a predefined list (<tt>Adjust, Justify,	LineStyle</tt>),</li>
Hyphenate, Style, Weight, Font, UnderLine, Thickness, LineStyle</tt>),	<li>those whose value is a name (<tt>FillPattern, Background,
</li>	Foreground</tt>).</li>
<li>
those whose value is a name (<tt>FillPattern, Background, Foreground</tt>).
</li>
</ul>	</ul>
<p>
For presentation rules which take numeric values, the condition can take a	<p>For presentation rules which take numeric values, the condition can take a
unique value or a range of values. In the case of a unique value, this value	unique value or a range of values. In the case of a unique value, this value
(an integer) is simply preceded by an equals sign. Conditions based on ranges	(an integer) is simply preceded by an equals sign. Conditions based on ranges
of values have several forms:</p>	of values have several forms:</p>
<ul>	<ul>
<li>	<li>all values less than a given value (the value is preceded by a ``less
all values less than a given value (the value is preceded by a ``less than''	than'' sign).</li>
sign).	<li>all values greater than a given value (the value is preceded by a
</li>	``greater than'' sign).</li>
<li>	<li>all values falling in an interval, bounds included. The range of values
all values greater than a given value (the value is preceded by a ``greater	is then specified <tt>IN [</tt>Minimum <tt>..</tt>Maximum<tt>]</tt>, where
than'' sign).	Minimum and Maximum are integers.</li>
</li>
<li>
all values falling in an interval, bounds included. The range of values is
then specified <tt>IN [</tt>Minimum <tt>..</tt>Maximum<tt>]</tt>, where
Minimum and Maximum are integers.
</li>
</ul>	</ul>
<p>
Values for the <tt>Indent</tt>rule may be negative. The integer is then	<p>Values for the <tt>Indent</tt>rule may be negative. The integer is then
simply preceded by a minus sign and represents how far the first line starts	simply preceded by a minus sign and represents how far the first line starts
to the left of the other lines.</p>	to the left of the other lines.</p>
<p>
For presentation rules whose values are taken from predefined lists, the value	<p>For presentation rules whose values are taken from predefined lists, the
which satisfies the condition is indicated by an equals sign followed by the	value which satisfies the condition is indicated by an equals sign followed by
name of the value.</p>	the name of the value.</p>
<p>
For presentation rule whose values are names, the value which satisfies the	<p>For presentation rule whose values are names, the value which satisfies the
condition is indicated by the equals sign followed by the value's name. The	condition is indicated by the equals sign followed by the value's name. The
names of fill patterns (the <tt>FillPattern</tt> rule) and of colors (the	names of fill patterns (the <tt>FillPattern</tt> rule) and of colors (the
<tt>Foreground</tt> and <tt>Background</tt> rules) known to Thot are the same	<tt>Foreground</tt> and <tt>Background</tt> rules) known to Thot are the same
as in the P language.</p>	as in the P language.</p>
<p>
The syntax of conditions based on the specific presentation is the same as the	<p>The syntax of conditions based on the specific presentation is the same as
syntax used to express the <a href="#sectc5224">translation of specific	the syntax used to express the <a href="#sectc5224">translation of specific
presentation rules</a>.</p>	presentation rules</a>.</p>
<p>
When a condition has only one rule, the condition is simply followed by that	<p>When a condition has only one rule, the condition is simply followed by
rule. If it has several rules, they are placed after the condition between	that rule. If it has several rules, they are placed after the condition
the keywords <tt>BEGIN</tt> and <tt>END</tt>.</p>	between the keywords <tt>BEGIN</tt> and <tt>END</tt>.</p>
<pre> ConditionSeq = Condition [ 'AND' Condition ] .	<pre> ConditionSeq = Condition [ 'AND' Condition ] .
Condition = [ 'NOT' ] [ 'Target' ] Cond .	Condition = [ 'NOT' ] [ 'Target' ] Cond .
Cond = CondElem / CondAscend .	Cond = CondElem / CondAscend .
Line 7543 the keywords <tt>BEGIN</tt> and <tt>END<	Line 6846 the keywords <tt>BEGIN</tt> and <tt>END<
PresRule /	PresRule /
'Comment' .	'Comment' .
NumParent = [ GreaterLess ] NParent .	NumParent = [ GreaterLess ] NParent .
GreaterLess = '>' / '<' .	GreaterLess = '>' / '<' .
NParent = NUMBER.	NParent = NUMBER.
ExtStruct = '(' ElemID ')' .	ExtStruct = '(' ElemID ')' .
Alphabet = NAME .	Alphabet = NAME .
RelatAttr ='=' Value /	RelatAttr ='=' Value /
'>' [ '-' ] Minimum /	'>' [ '-' ] Minimum /
'<' [ '-' ] Maximum /	'<' [ '-' ] Maximum /
'IN' '[' [ '-' ] MinInterval '..'	'IN' '[' [ '-' ] MinInterval '..'
[ '-' ] MaxInterval ']' .	[ '-' ] MaxInterval ']' .
Line 7560 the keywords <tt>BEGIN</tt> and <tt>END<	Line 6863 the keywords <tt>BEGIN</tt> and <tt>END<
IntegerVal = NUMBER .	IntegerVal = NUMBER .
TextVal = STRING .	TextVal = STRING .
AttrValue = NAME .</pre>	AttrValue = NAME .</pre>

<blockquote class="example">	<blockquote class="example">
<p>	<p><strong>Example:</strong></p>
<strong>Example:</strong></p>
<p>	<p>Suppose that after each element of type Section_Title it is useful to
Suppose that after each element of type Section_Title it is useful to produce	produce the text <tt>\label{SectX}</tt> where <tt>X</tt> represents the
the text <tt>\label{SectX}</tt> where <tt>X</tt> represents the section	section number, but only if the section is designated by one or more
number, but only if the section is designated by one or more references in the	references in the document. The following conditional rule produces this
document. The following conditional rule produces this effect:</p>	effect:</p>
<pre>RULES	<pre>RULES
Section_Title :	Section_Title :
IF Referred	IF Referred
Create ('\label{Sect' Value(UniqueSectNum) '}\12') After;</pre>	Create ('\label{Sect' Value(UniqueSectNum) '}\12') After;</pre>
<p>
(the declaration of the <a href="#sectc5224"><tt>UniqueSectNum</tt>	<p>(the declaration of the <a href="#sectc5224"><tt>UniqueSectNum</tt>
counter</a> is given above). The string <tt>\12</tt> represents a line	counter</a> is given above). The string <tt>\12</tt> represents a line
break.</p>	break.</p>
</blockquote>	</blockquote>

<blockquote class="example">	<blockquote class="example">
<p>	<p><strong>Example:</strong></p>
<strong>Example:</strong></p>
<p>	<p>Suppose that for elements of the Elmnt type it would be useful to produce
Suppose that for elements of the Elmnt type it would be useful to produce a	a character indicating the value of the numeric attribute Level associated
character indicating the value of the numeric attribute Level associated with	with the element: an ``A'' for all values of Level less than 3, a ``B'' for
the element: an ``A'' for all values of Level less than 3, a ``B'' for values	values between 3 and 10 and a ``C'' for values greater than 10. This can be
between 3 and 10 and a ``C'' for values greater than 10. This can be achieved	achieved by writing the following rules for the Elmnt type:</p>
by writing the following rules for the Elmnt type:</p>	<pre>RULES
<pre>RULES
Elmnt :	Elmnt :
BEGIN	BEGIN
IF Level < 3	IF Level < 3
Create 'A';	Create 'A';
IF Level IN [3..10]	IF Level IN [3..10]
Create 'B';	Create 'B';
IF Level > 10	IF Level > 10
Create 'C';	Create 'C';
END;</pre>	END;</pre>
</blockquote>	</blockquote>
Line 7601 by writing the following rules for the E	Line 6905 by writing the following rules for the E
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc529">Translation rules</a></h3>	<h3><a name="sectc529">Translation rules</a></h3>
<p>
Fifteen types of translation rules can be associated with element types and	<p>Fifteen types of translation rules can be associated with element types and
attribute values. They are the <tt>Create</tt>, <tt>Write</tt>,	attribute values. They are the <tt>Create</tt>, <tt>Write</tt>,
<tt>Read</tt>, <tt>Include</tt>, <tt>Get</tt>, <tt>Copy</tt>, <tt>Use</tt>,	<tt>Read</tt>, <tt>Include</tt>, <tt>Get</tt>, <tt>Copy</tt>, <tt>Use</tt>,
<tt>Remove</tt>, <tt>NoTranslation</tt>, <tt>NoLineBreak</tt>,	<tt>Remove</tt>, <tt>NoTranslation</tt>, <tt>NoLineBreak</tt>,
Line 7634 based on very similar models.</p>	Line 6937 based on very similar models.</p>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc5210">The <tt>Create</tt> rule</a></h3>	<h3><a name="sectc5210">The <tt>Create</tt> rule</a></h3>
<p>
The most frequently used rule is undoubtedly the <tt>Create</tt> rule, which	<p>The most frequently used rule is undoubtedly the <tt>Create</tt> rule,
generates fixed or variable text (called an <em>object</em>) in the output	which generates fixed or variable text (called an <em>object</em>) in the
file. The generated text can be made to appear either before or after the	output file. The generated text can be made to appear either before or after
content of the element to which the rule applies. The rule begins with the	the content of the element to which the rule applies. The rule begins with the
<tt>Create</tt> keyword, followed by a specifier for the object and a keyword	<tt>Create</tt> keyword, followed by a specifier for the object and a keyword
(<tt>Before</tt> or <tt>After</tt>) indicating the position of the generated	(<tt>Before</tt> or <tt>After</tt>) indicating the position of the generated
text (<a href="#sectc5222">before or after</a> the element's content). If the	text (<a href="#sectc5222">before or after</a> the element's content). If the
position is not indicated, the object will be generated before the element's	position is not indicated, the object will be generated before the element's
content. This rule, like all translation rules, is terminated by a	content. This rule, like all translation rules, is terminated by a
semicolon.</p>	semicolon.</p>
<p>
The <tt>Create</tt> keyword can be followed by the <tt>IN</tt> keyword and by	<p>The <tt>Create</tt> keyword can be followed by the <tt>IN</tt> keyword and
the name of a variable. This means that the text generated by the rule must	by the name of a variable. This means that the text generated by the rule
not be written in the main output file, but in the file whose name is	must not be written in the main output file, but in the file whose name is
specified by the variable.</p>	specified by the variable.</p>
<p>
This allows the translation program to generate text in different files during	<p>This allows the translation program to generate text in different files
the same run. These files do not need to be explicitely declared or opened.	during the same run. These files do not need to be explicitely declared or
They do not need to be closed either, but if they contain temporary data, they	opened. They do not need to be closed either, but if they contain temporary
can be removed (see the <a href="#sectc5220a"><tt>RemoveFile</tt> rule</a>).	data, they can be removed (see the <a href="#sectc5220a"><tt>RemoveFile</tt>
As soon as the translation program executes a <tt>Create</tt> rule for a file	rule</a>). As soon as the translation program executes a <tt>Create</tt> rule
that is not yet open, it opens the file. These files are closed when the	for a file that is not yet open, it opens the file. These files are closed
translation is finished.</p>	when the translation is finished.</p>
<pre> 'Create' [ 'IN' VarID ] Object	<pre> 'Create' [ 'IN' VarID ] Object
[ Position ] ';'	[ Position ] ';'
Object = ConstID / CharString /	Object = ConstID / CharString /
BufferID /	BufferID /
VarID /	VarID /
'(' Function < Function > ')' /	'(' Function < Function > ')' /
[ 'Translated' ] AttrID /	[ 'Translated' ] AttrID /
'Value' /	'Value' /
'Content' /	'Content' /
Line 7687 translation is finished.</p>	Line 6989 translation is finished.</p>
'RefId' /	'RefId' /
'DocumentName' /	'DocumentName' /
'DocumentDir' .</pre>	'DocumentDir' .</pre>
<p>
The object to be generated can be:</p>	<p>The object to be generated can be:</p>
<ul>	<ul>
<li>	<li>a constant string, specified by its name if it is declared in the
a constant string, specified by its name if it is declared in the schema's	schema's <tt>CONST</tt> section, or given directly as a value between
<tt>CONST</tt> section, or given directly as a value between apostrophes;	apostrophes;</li>
</li>	<li>the contents of a buffer, designated by the name of the buffer;</li>
<li>	<li>a variable, designated by its name if it is declared in the translation
the contents of a buffer, designated by the name of the buffer;	schema's <tt>VAR</tt> section, or given directly between parentheses. The
</li>	text generated is the value of that variable evaluated for the element to
<li>	which the rule applies.</li>
a variable, designated by its name if it is declared in the translation	<li>the value of an attribute, if the element being translated has this
schema's <tt>VAR</tt> section, or given directly between parentheses. The	attribute. The attribute is specified by its name. If it's a text
text generated is the value of that variable evaluated for the element to	attribute, it can be preceded by the <code>Translated</code> keyword,
which the rule applies.	which causes the attribute value to be recoded using the text translation
</li>	table defined by section <code><a
<li>	href="#sectc5225">TEXTTRANSLATE</a></code>;</li>
the value of an attribute, if the element being translated has this attribute.	<li>the value of a specific presentation rule. This object can only be
The attribute is specified by its name. If it's a text attribute, it can be	generated if the translation rule is for a <a href="#prestransl">specific
preceded by the <code>Translated</code> keyword, which causes the attribute	presentation rule</a>. It is specified by the <tt>Value</tt>
value to be recoded using the text translation table defined by section	keyword;</li>
<code><a href="#sectc5225">TEXTTRANSLATE</a></code>;	<li>the element's content. That is, the content of the leaves of the
</li>	subtree of the translated element. This is specified by the
<li>	<tt>Content</tt> keyword;</li>
the value of a specific presentation rule. This object can only be generated	<li>the comment attached to the element. When the element doesn't have a
if the translation rule is for a <a href="#prestransl">specific presentation	comment, nothing is generated. This is indicated by the <tt>Comment</tt>
rule</a>. It is specified by the <tt>Value</tt> keyword;	keyword;</li>
</li>	<li>the translation of all attributes of the element (which is primarily
<li>	used to apply the attribute translation rules <a
the element's content. That is, the content of the leaves of the subtree of	href="#sectc5222">before</a> those of the element type). This is
the translated element. This is specified by the <tt>Content</tt> keyword;	specified by the <tt>Attributes</tt> keyword.</li>
</li>	<li>the translation of all of the element's specific presentation rules
<li>	(which is primarily used to apply the translation rules for the specific
the comment attached to the element. When the element doesn't have a comment,	presentation rules <a href="#sectc5222">before</a> those of the element or
nothing is generated. This is indicated by the <tt>Comment</tt> keyword;	its attributes). This option is specified by the <tt>Presentation</tt>
</li>	keyword;</li>
<li>	<li>The value of the reference's identifier.<br>
the translation of all attributes of the element (which is primarily used to	Thot associates a unique identifier with each element in a document. This
apply the attribute translation rules <a href="#sectc5222">before</a> those of	identifier (called <em>reference's identifier</em> or <em>label</em>) is a
the element type). This is specified by the <tt>Attributes</tt> keyword.	character string containing the letter `L' followed by digits. Thot uses
</li>	it in references for identifying the referred element.<br>
<li>	The <tt>RefId</tt> keyword produces the reference's identifier of the
the translation of all of the element's specific presentation rules (which is	element to which the translation rule is applied, or the reference's
primarily used to apply the translation rules for the specific presentation	identifier of its first ancestor that is referred by a reference or that
rules <a href="#sectc5222">before</a> those of the element or its attributes).	can be referred by a reference.</li>
This option is specified by the <tt>Presentation</tt> keyword;	<li>the value of a mark pair's unique identifier. This may only be used for
</li>	<a href="#sectd3285">mark pairs</a> and is indicated by the
<li>	<tt>PairId</tt> keyword.</li>
The value of the reference's identifier.<br>	<li>the directory containing the file being generated (this string includes
Thot associates a unique identifier with each element in a document. This	an ending '/', if it is not empty). This is indicated by the
identifier (called <em>reference's identifier</em> or <em>label</em>) is a	<tt>FileDir</tt> keyword.</li>
character string containing the letter `L' followed by digits. Thot uses it	<li>the name of the file being generated (only the name, without the
in references for identifying the referred element.<br>	directory and without the extension). This is indicated by the
The <tt>RefId</tt> keyword produces the reference's identifier of the element	<tt>FileName</tt> keyword.</li>
to which the translation rule is applied, or the reference's identifier of its	<li>the extension of the file being generated (this string starts with a
first ancestor that is referred by a reference or that can be referred by a	dot, if it is not empty). This is indicated by the <tt>Extension</tt>
reference.	keyword.</li>
</li>	<li>the name of the document being translated. This is indicated by the
<li>	<tt>DocumentName</tt> keyword.</li>
the value of a mark pair's unique identifier. This may only be used for <a	<li>the directory containing the document being translated. This is
href="#sectd3285">mark pairs</a> and is indicated by the <tt>PairId</tt>	indicated by the <tt>DocumentDir</tt> keyword.</li>
keyword.
</li>
<li>
the directory containing the file being generated (this string includes an
ending '/', if it is not empty). This is indicated by the <tt>FileDir</tt>
keyword.
</li>
<li>
the name of the file being generated (only the name, without the directory and
without the extension). This is indicated by the <tt>FileName</tt> keyword.
</li>
<li>
the extension of the file being generated (this string starts with a dot, if
it is not empty). This is indicated by the <tt>Extension</tt> keyword.
</li>
<li>
the name of the document being translated. This is indicated by the
<tt>DocumentName</tt> keyword.
</li>
<li>
the directory containing the document being translated. This is indicated by
the <tt>DocumentDir</tt> keyword.
</li>
</ul>	</ul>
<p>
When the rule applies to a reference (an element or an attribute defined as a	<p>When the rule applies to a reference (an element or an attribute defined as
reference in the structure schema), it can generate a text related to the	a reference in the structure schema), it can generate a text related to the
element referred by that reference. The rule name is then followed by the	element referred by that reference. The rule name is then followed by the
<tt>Referred</tt> keyword and a specification of the object to be generated	<tt>Referred</tt> keyword and a specification of the object to be generated
for the referred element. This specification can be:</p>	for the referred element. This specification can be:</p>
<ul>	<ul>
<li>	<li>the name of a variable. The rule generates the value of that variable,
the name of a variable. The rule generates the value of that variable,	computed for the referred element.</li>
computed for the referred element.	<li>an element type. The rule generates the translation of the element of
</li>	that type, which is in the subtree of the referred element. If this
<li>	element is not defined in the structure schema which corresponds to the
an element type. The rule generates the translation of the element of that	translation schema (that is, an object defined in another schema), the
type, which is in the subtree of the referred element. If this element is not	element's type name must be followed by the name of its structure schema
defined in the structure schema which corresponds to the translation schema	between parentheses.</li>
(that is, an object defined in another schema), the element's type name must	<li>the <tt>RefId</tt> keyword. The rule generates the reference's
be followed by the name of its structure schema between parentheses.	identifier of the referred element.</li>
</li>	<li>the <tt>DocumentName</tt> keyword. The rule generates the name of the
<li>	document to which the referred element belongs.</li>
the <tt>RefId</tt> keyword. The rule generates the reference's identifier of	<li>the <tt>DocumentDir</tt> keyword. The rule generates the name of the
the referred element.	directory that contains the document of the referred element.</li>
</li>
<li>
the <tt>DocumentName</tt> keyword. The rule generates the name of the
document to which the referred element belongs.
</li>
<li>
the <tt>DocumentDir</tt> keyword. The rule generates the name of the
directory that contains the document of the referred element.
</li>
</ul>	</ul>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc5211">The <tt>Write</tt> rule</a></h3>	<h3><a name="sectc5211">The <tt>Write</tt> rule</a></h3>
<p>
The <tt>Write</tt> has the same syntax as the <tt>Create</tt> rule. It also	<p>The <tt>Write</tt> has the same syntax as the <tt>Create</tt> rule. It
produces the same effect, but the generated text is displayed on the user's	also produces the same effect, but the generated text is displayed on the
terminal during the translation of the document, instead of being produced in	user's terminal during the translation of the document, instead of being
the translated document. This is useful for helping the user keep track of	produced in the translated document. This is useful for helping the user keep
the progress of the translation and for prompting the user on the terminal for	track of the progress of the translation and for prompting the user on the
input required by the <tt>Read</tt> rule.</p>	terminal for input required by the <tt>Read</tt> rule.</p>
<pre> 'Write' Object [ Position ] ';'</pre>	<pre> 'Write' Object [ Position ] ';'</pre>
<p>
Notice: if the translator is launched by the editor (by the ``Save as''	<p>Notice: if the translator is launched by the editor (by the ``Save as''
command), messages produced by the <tt>Write</tt> rule are not displayed.</p>	command), messages produced by the <tt>Write</tt> rule are not displayed.</p>

<blockquote class="example">	<blockquote class="example">
<p>	<p><strong>Example:</strong></p>
<strong>Example:</strong></p>
<p>	<p>To make the translator display the number of each section being
To make the translator display the number of each section being translated on	translated on the user's terminal, the following rule is specified for the
the user's terminal, the following rule is specified for the <tt>Section</tt>	<tt>Section</tt> element type:</p>
element type:</p>	<pre>Section : BEGIN
<pre>Section : BEGIN
Write VarSection;	Write VarSection;
...	...
END;</pre>	END;</pre>
<p>
(see <a href="#varsectexample">above</a> for the definition of the	<p>(see <a href="#varsectexample">above</a> for the definition of the
<tt>VarSection</tt> variable).</p>	<tt>VarSection</tt> variable).</p>
<p>
To display text on the terminal before issuing a read operation with the	<p>To display text on the terminal before issuing a read operation with the
<tt>Read</tt> rule, the following rule is used:</p>	<tt>Read</tt> rule, the following rule is used:</p>
<pre>BEGIN	<pre>BEGIN
Write 'Enter the name of the destination: ';	Write 'Enter the name of the destination: ';
...	...
END;</pre>	END;</pre>
Line 7844 END;</pre>	Line 7113 END;</pre>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc5212">The <tt>Read</tt> rule</a></h3>	<h3><a name="sectc5212">The <tt>Read</tt> rule</a></h3>
<p>
The <tt>Read</tt> rule reads text from the terminal during the translation of	<p>The <tt>Read</tt> rule reads text from the terminal during the translation
the document and saves the text read in one of the buffers declared in the	of the document and saves the text read in one of the buffers declared in the
<tt>BUFFERS</tt> section of the schema. The buffer to be used is indicated by	<tt>BUFFERS</tt> section of the schema. The buffer to be used is indicated by
its name, after the <tt>READ</tt> keyword. This name can be followed, as in	its name, after the <tt>READ</tt> keyword. This name can be followed, as in
the <tt>Create</tt> and <tt>Write</tt> rules, by a keyword indicating if the	the <tt>Create</tt> and <tt>Write</tt> rules, by a keyword indicating if the
Line 7858 operation is done beforehand. The text	Line 7126 operation is done beforehand. The text
there until a rule using the same buffer - possibly the same rule - is	there until a rule using the same buffer - possibly the same rule - is
applied.</p>	applied.</p>
<pre> 'Read' BufferID [ Position ] ';'</pre>	<pre> 'Read' BufferID [ Position ] ';'</pre>

<blockquote class="example">	<blockquote class="example">
<p>	<p><strong>Example:</strong></p>
<strong>Example:</strong></p>
<p>	<p>The following set of rules tells the user that the translator is waiting
The following set of rules tells the user that the translator is waiting for	for the entry of some text, reads this text into a buffer and copies the
the entry of some text, reads this text into a buffer and copies the text into	text into the translated document.</p>
the translated document.</p>	<pre>BEGIN
<pre>BEGIN
Write 'Enter the name of the destination: ';	Write 'Enter the name of the destination: ';
Read DestName;	Read DestName;
Create DestName;	Create DestName;
...	...
END;</pre>	END;</pre>
<p>
(see <a href="#destname">above</a> the definition of <tt>DestName</tt>).</p>	<p>(see <a href="#destname">above</a> the definition of
	<tt>DestName</tt>).</p>
</blockquote>	</blockquote>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc5213">The <tt>Include</tt> rule</a></h3>	<h3><a name="sectc5213">The <tt>Include</tt> rule</a></h3>
<p>
The <tt>Include</tt> rule, like the <tt>Create</tt> rule, is used to produce	<p>The <tt>Include</tt> rule, like the <tt>Create</tt> rule, is used to
text in the translated document. It inserts constant text which is not	produce text in the translated document. It inserts constant text which is
defined in the translation schema, but is instead taken from a file. The	not defined in the translation schema, but is instead taken from a file. The
file's name is specified after the <tt>Include</tt> keyword, either directly	file's name is specified after the <tt>Include</tt> keyword, either directly
as a character string between apostrophes or as the name of one of the buffers	as a character string between apostrophes or as the name of one of the buffers
declared in the <tt>BUFFERS</tt> section of the schema. In the latter case,	declared in the <tt>BUFFERS</tt> section of the schema. In the latter case,
Line 7890 the buffer is assumed to contain the fil	Line 7158 the buffer is assumed to contain the fil
included file's name is known only at the moment of translation. This only	included file's name is known only at the moment of translation. This only
requires that the <tt>Include</tt> rule is preceded by a <tt>Read</tt> rule	requires that the <tt>Include</tt> rule is preceded by a <tt>Read</tt> rule
which puts the name of the file desired by the user into the buffer.</p>	which puts the name of the file desired by the user into the buffer.</p>
<p>
Like the other rules, it is possible to specify whether the inclusion will	<p>Like the other rules, it is possible to specify whether the inclusion will
occur before or after the element's content, with the default being before.	occur before or after the element's content, with the default being before.
The file inclusion is only done at the moment of translation, not during the	The file inclusion is only done at the moment of translation, not during the
compilation of the translation schema. Thus, the file to be included need not	compilation of the translation schema. Thus, the file to be included need not
Line 7899 exist during the compilation, but it mus	Line 7167 exist during the compilation, but it mus
translation. Its contents can also be modified between two translations, thus	translation. Its contents can also be modified between two translations, thus
producing different results, even if neither the document or the translation	producing different results, even if neither the document or the translation
schema are modified.</p>	schema are modified.</p>
<p>
During translation, the file to be included is searched for along the schema	<p>During translation, the file to be included is searched for along the
directory path (indicated by the environment variable <tt>THOTSCH</tt>). The	schema directory path (indicated by the environment variable
file name is normally only composed of a simple name, without specification of	<tt>THOTSCH</tt>). The file name is normally only composed of a simple name,
a complete file path. However, if the filename starts with a '/', it is	without specification of a complete file path. However, if the filename
considered as an absolute path.</p>	starts with a '/', it is considered as an absolute path.</p>
<pre> 'Include' File [ Position ] ';'	<pre> 'Include' File [ Position ] ';'
File = FileName / BufferID .	File = FileName / BufferID .
FileName = STRING .</pre>	FileName = STRING .</pre>

<blockquote class="example">	<blockquote class="example">
<p>	<p><strong>Example:</strong></p>
<strong>Example:</strong></p>
<p>	<p>Suppose that it is desirable to print documents of the Article class with
Suppose that it is desirable to print documents of the Article class with a	a formatter which requires a number of declarations and definitions at the
formatter which requires a number of declarations and definitions at the	beginning of the file. The <tt>Include</tt>rule can be used to achieve
beginning of the file. The <tt>Include</tt>rule can be used to achieve this.	this. All the declarations and definitions a replaced in a file called
All the declarations and definitions a replaced in a file called	<tt>DeclarArt</tt> and then the <tt>Article</tt> element type is given the
<tt>DeclarArt</tt> and then the <tt>Article</tt> element type is given the	following rule:</p>
following rule:</p>	<pre>Article : BEGIN
<pre>Article : BEGIN
Include 'DeclarArt' Before;	Include 'DeclarArt' Before;
...	...
END;</pre>	END;</pre>
Line 7926 following rule:</p>	Line 7194 following rule:</p>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc5214">The <tt>Get</tt> rule</a></h3>	<h3><a name="sectc5214">The <tt>Get</tt> rule</a></h3>
<p>
The <tt>Get</tt> rule is used to change the order in which the elements appear	<p>The <tt>Get</tt> rule is used to change the order in which the elements
in the translated document. More precisely, it produces the translation of a	appear in the translated document. More precisely, it produces the
specified element before or after the translation of the content of the	translation of a specified element before or after the translation of the
element to which the rule applies. The <tt>Before</tt> and <tt>After</tt>	content of the element to which the rule applies. The <tt>Before</tt> and
keywords are placed at the end of the rule to specify whether the operation	<tt>After</tt> keywords are placed at the end of the rule to specify whether
should be performed before or after translation of the rule's element (the	the operation should be performed before or after translation of the rule's
default is before). The type of the element to be moved must be specified	element (the default is before). The type of the element to be moved must be
after the <tt>Get</tt> keyword, optionally preceded by a keyword indicating	specified after the <tt>Get</tt> keyword, optionally preceded by a keyword
where the element will be found in the logical structure of the document:</p>	indicating where the element will be found in the logical structure of the
	document:</p>
<dl>	<dl>
<dt><tt>Included</tt></dt>	<dt><tt>Included</tt></dt>
<dd>	<dd>The element to be moved is the first element of the indicated type
The element to be moved is the first element of the indicated type which is	which is found inside the element to which the rule applies.</dd>
found inside the element to which the rule applies.	<dt><tt>Referred</tt></dt>
</dd>	<dd>This keyword can only be used if the rule applies to a reference
<dt><tt>Referred</tt></dt>	element. The element to be moved is either the element designated by the
<dd>	reference (if that element is of the specified type), or the first
This keyword can only be used if the rule applies to a reference element. The	element of the desired type contained within the element designated by
element to be moved is either the element designated by the reference (if that	the reference.</dd>
element is of the specified type), or the first element of the desired type	<dt>no keyword</dt>
contained within the element designated by the reference.	<dd>If the element to be moved is an associated element, defined in the <a
</dd>	href="#sectc314"><tt>ASSOC</tt> section</a> of the structure schema, all
<dt>no keyword</dt>	associated elements of this type which have not been translated yet are
<dd>	then translated. Certain elements may in fact have already been
If the element to be moved is an associated element, defined in the <a	translated by a <tt>Get Referred</tt> rule.
href="#sectc314"><tt>ASSOC</tt> section</a> of the structure schema, all	<p>If the element to be moved is not an associated element, the
associated elements of this type which have not been translated yet are then	translator takes the first element of the indicated type from among the
translated. Certain elements may in fact have already been translated by a	siblings of the rule's element. This is primarily used to change the
<tt>Get Referred</tt> rule.	order of the components of an aggregate.</p>
<p>	</dd>
If the element to be moved is not an associated element, the translator takes
the first element of the indicated type from among the siblings of the rule's
element. This is primarily used to change the order of the components of an
aggregate.</p>
</dd>
</dl>	</dl>
<p>
If the element to be moved is defined in a structure schema which is not the	<p>If the element to be moved is defined in a structure schema which is not
one which corresponds to the translation schema (in the case of an included	the one which corresponds to the translation schema (in the case of an
object with a different schema), the type name of this element must be	included object with a different schema), the type name of this element must
followed, between parentheses, by the name of the structure schema which	be followed, between parentheses, by the name of the structure schema which
defines it.</p>	defines it.</p>
<pre> 'Get' [ RelPosition ] ElemID	<pre> 'Get' [ RelPosition ] ElemID
[ ExtStruct ]	[ ExtStruct ]
[ Position ] ';' /	[ Position ] ';' /
RelPosition = 'Included' / 'Referred' .	RelPosition = 'Included' / 'Referred' .
ExtStruct = '(' ElemID ')' .</pre>	ExtStruct = '(' ElemID ')' .</pre>
<p>
The <tt>Get</tt> rule has no effect if the element which it is supposed to	<p>The <tt>Get</tt> rule has no effect if the element which it is supposed to
move has already been translated. Thus, the element will not be duplicated.	move has already been translated. Thus, the element will not be duplicated.
It is generally best to associate the rule with the first element which will	It is generally best to associate the rule with the first element which will
be encountered by the translator in its traversal of the document. Suppose an	be encountered by the translator in its traversal of the document. Suppose an
Line 7989 After</tt>, even though syntactically co	Line 7252 After</tt>, even though syntactically co
time it will be applied, after the translation of the contents of the element	time it will be applied, after the translation of the contents of the element
to which it is attached, the <tt>X</tt> element will already have been	to which it is attached, the <tt>X</tt> element will already have been
translated.</p>	translated.</p>
<p>
The <tt>Get</tt> rule is the only way to obtain the translation of the	<p>The <tt>Get</tt> rule is the only way to obtain the translation of the
associated elements. In fact, the translator only traverses the primary tree	associated elements. In fact, the translator only traverses the primary tree
of the document and thus does not translate the associated elements, except	of the document and thus does not translate the associated elements, except
when the translation is explicitly required by a <tt>Get Referred Type</tt> or	when the translation is explicitly required by a <tt>Get Referred Type</tt> or
<tt>Get Type</tt> rule where <tt>Type</tt> is an associated element type.</p>	<tt>Get Type</tt> rule where <tt>Type</tt> is an associated element type.</p>

<blockquote class="example">	<blockquote class="example">
<p>	<p><strong>Example:</strong></p>
<strong>Example:</strong></p>
<p>	<p>The structure schema defined figures as associated element which are
The structure schema defined figures as associated element which are composed	composed of some content and a caption. Moreover, it is possible to make
of some content and a caption. Moreover, it is possible to make references to	references to figures, using elements of the <tt>RefFigure</tt> type:</p>
figures, using elements of the <tt>RefFigure</tt> type:</p>	<pre> ...
<pre> ...
RefFigure = REFERENCE(Figure);	RefFigure = REFERENCE(Figure);
ASSOC	ASSOC
Figure = BEGIN	Figure = BEGIN
Line 8010 ASSOC	Line 7273 ASSOC
Caption = Text;	Caption = Text;
END;	END;
...</pre>	...</pre>
<p>
Suppose it would be useful to make a figure appear in the translated document	<p>Suppose it would be useful to make a figure appear in the translated
at the place in the text where the first reference to the figure is made. If	document at the place in the text where the first reference to the figure is
some figures are not referenced, then they would appear at the end of the	made. If some figures are not referenced, then they would appear at the end
document. Also, each figure's caption should appear before the content. The	of the document. Also, each figure's caption should appear before the
following rules in the translation schema will produce this result:</p>	content. The following rules in the translation schema will produce this
<pre>Article : BEGIN	result:</p>
	<pre>Article : BEGIN
...	...
Get Figures After;	Get Figures After;
END;	END;
Line 8032 Content : BEGIN	Line 7296 Content : BEGIN
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc5215">The <tt>Copy</tt> rule</a></h3>	<h3><a name="sectc5215">The <tt>Copy</tt> rule</a></h3>
<p>
Like the <tt>Get</tt> rule, the <tt>Copy</tt> rule generates the translation	<p>Like the <tt>Get</tt> rule, the <tt>Copy</tt> rule generates the
of a specified element, but it acts even if the element has already been	translation of a specified element, but it acts even if the element has
translated and it allows to copy it or to translate it later. Both rules have	already been translated and it allows to copy it or to translate it later.
the same syntax.</p>	Both rules have the same syntax.</p>
<pre> 'Copy' [ RelPosition ] ElemID	<pre> 'Copy' [ RelPosition ] ElemID
[ ExtStruct ] [ Position ] ';'</pre>	[ ExtStruct ] [ Position ] ';'</pre>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc5216">The <tt>Use</tt> rule</a></h3>	<h3><a name="sectc5216">The <tt>Use</tt> rule</a></h3>
<p>
The <tt>Use</tt> rule specifies the translation schema to be applied to	<p>The <tt>Use</tt> rule specifies the translation schema to be applied to
objects of a certain class that are part of the document. This rule only	objects of a certain class that are part of the document. This rule only
appears in the rules for the root element of the document (the first type	appears in the rules for the root element of the document (the first type
defined after the <tt>STRUCT</tt> keyword in the structure schema) or the	defined after the <tt>STRUCT</tt> keyword in the structure schema) or the
rules of an element defined by an external structure (by another structure	rules of an element defined by an external structure (by another structure
schema). Also, the <tt>Use</tt> rule cannot be conditional.</p>	schema). Also, the <tt>Use</tt> rule cannot be conditional.</p>
<p>
If the rule is applied to an element defined by an external structure, the	<p>If the rule is applied to an element defined by an external structure, the
<tt>Use</tt> keyword is simply followed by the name of the translation schema	<tt>Use</tt> keyword is simply followed by the name of the translation schema
to be used for element constructed according to that external structure. If	to be used for element constructed according to that external structure. If
the rule is applied to the document's root element, it is formed by the	the rule is applied to the document's root element, it is formed by the
Line 8063 the rule is applied to the document's ro	Line 7325 the rule is applied to the document's ro
indicated translation schema should be applied.</p>	indicated translation schema should be applied.</p>
<pre> 'Use' TrSchema [ 'For' ElemID ] ';'	<pre> 'Use' TrSchema [ 'For' ElemID ] ';'
TrSchema = NAME .</pre>	TrSchema = NAME .</pre>
<p>
If no <tt>Use</tt> rule defines the translation schema to be used for an	<p>If no <tt>Use</tt> rule defines the translation schema to be used for an
external structure which appears in a document, the translator asks the user,	external structure which appears in a document, the translator asks the user,
during the translation process, which schema should be used. Thus, it is not	during the translation process, which schema should be used. Thus, it is not
necessary to give the translation schema a <tt>Use</tt> rule for every	necessary to give the translation schema a <tt>Use</tt> rule for every
external structure used, especially when the choice of translation schemas is	external structure used, especially when the choice of translation schemas is
to be left to the user.</p>	to be left to the user.</p>
<p>
Notice: if the translator is launched by the editor (by the ``Save as''	<p>Notice: if the translator is launched by the editor (by the ``Save as''
command), prompts are not displayed.</p>	command), prompts are not displayed.</p>

<blockquote class="example">	<blockquote class="example">
<p>	<p><strong>Example:</strong></p>
<strong>Example:</strong></p>
<p>	<p>The <tt>Article</tt> structure schema uses the <tt>Formula</tt> external
The <tt>Article</tt> structure schema uses the <tt>Formula</tt> external	structure, defined by another structure schema, for mathematical
structure, defined by another structure schema, for mathematical formulas:</p>	formulas:</p>
<pre>STRUCTURE Article;	<pre>STRUCTURE Article;
...	...
STRUCT	STRUCT
Article = ...	Article = ...
Line 8088 STRUCT	Line 7351 STRUCT
Isolated_formula = Formula;	Isolated_formula = Formula;
...	...
END</pre>	END</pre>
<p>
Suppose that it would be useful to use the <tt>FormulaT</tt> translation	<p>Suppose that it would be useful to use the <tt>FormulaT</tt> translation
schema for the formulas of an article. This can be expressed in two different	schema for the formulas of an article. This can be expressed in two
ways in the <tt>Article</tt> class translation schema, using the rules:</p>	different ways in the <tt>Article</tt> class translation schema, using the
<pre>RULES	rules:</p>
	<pre>RULES
Article :	Article :
Use FormulaT for Formula;</pre>	Use FormulaT for Formula;</pre>
<p>
or:</p>	<p>or:</p>
<pre>RULES	<pre>RULES
...	...
Formula :	Formula :
Use FormulaT;</pre>	Use FormulaT;</pre>
Line 8105 or:</p>	Line 7369 or:</p>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc5217">The <tt>Remove</tt> rule</a></h3>	<h3><a name="sectc5217">The <tt>Remove</tt> rule</a></h3>
<p>
The <tt>Remove</tt> rule indicates that nothing should be generated, in the	<p>The <tt>Remove</tt> rule indicates that nothing should be generated, in the
translated document, for the content of the element to which the rule applies.	translated document, for the content of the element to which the rule applies.
The content of that element is simply ignored by the translator. This does	The content of that element is simply ignored by the translator. This does
not prevent the generation of text for the element itself, using the	not prevent the generation of text for the element itself, using the
<tt>Create</tt> or <tt>Include</tt> rules, for example.</p>	<tt>Create</tt> or <tt>Include</tt> rules, for example.</p>
<p>
The <tt>Remove</tt> rule is simply written with the <tt>Remove</tt> keyword.	<p>The <tt>Remove</tt> rule is simply written with the <tt>Remove</tt>
It is terminated, like all rules, by a semicolon.</p>	keyword. It is terminated, like all rules, by a semicolon.</p>
<pre> 'Remove' ';'</pre>	<pre> 'Remove' ';'</pre>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc5218">The <tt>NoTranslation</tt> rule</a></h3>	<h3><a name="sectc5218">The <tt>NoTranslation</tt> rule</a></h3>
<p>
The <tt>NoTranslation</tt> rule indicates to the translator that it must not	<p>The <tt>NoTranslation</tt> rule indicates to the translator that it must
translate the content of the leaves of the element to which it applies. In	not translate the content of the leaves of the element to which it applies. In
contrast to the <tt>Remove</tt> rule, it does not suppress the content of the	contrast to the <tt>Remove</tt> rule, it does not suppress the content of the
element, but it inhibits the translation of character strings, symbols, and	element, but it inhibits the translation of character strings, symbols, and
graphical elements contained in the element. These are retrieved so that	graphical elements contained in the element. These are retrieved so that
after the translation of the document, the rules of the <a	after the translation of the document, the rules of the <a
href="#sectc5225"><tt>TEXTTRANSLATE</tt>, <tt>SYMBTRANSLATE</tt> and	href="#sectc5225"><tt>TEXTTRANSLATE</tt>, <tt>SYMBTRANSLATE</tt> and
<tt>GRAPHTRANSLATE</tt> sections</a> will not be applied to them.</p>	<tt>GRAPHTRANSLATE</tt> sections</a> will not be applied to them.</p>
<p>
The <tt>NoTranslation</tt> rule is written with the <tt>NoTranslation</tt>	<p>The <tt>NoTranslation</tt> rule is written with the <tt>NoTranslation</tt>
keyword followed by a semicolon.</p>	keyword followed by a semicolon.</p>
<pre> 'NoTranslation' ';'</pre>	<pre> 'NoTranslation' ';'</pre>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc5219">The <tt>NoLineBreak</tt> rule</a></h3>	<h3><a name="sectc5219">The <tt>NoLineBreak</tt> rule</a></h3>
<p>
The <tt>NoLineBreak</tt> rule indicates to the translator that it must not	<p>The <tt>NoLineBreak</tt> rule indicates to the translator that it must not
generate additional line breaks in the output produced for the element to	generate additional line breaks in the output produced for the element to
which it applies. This is as if it was an <a href="#sectc522">instruction	which it applies. This is as if it was an <a href="#sectc522">instruction
<tt>LINELENGTH 0;</tt></a> at the beginning of the translation schema, but	<tt>LINELENGTH 0;</tt></a> at the beginning of the translation schema, but
only for the current element.</p>	only for the current element.</p>
<p>
The <tt>NoLineBreak</tt> rule is written with the <tt>NoLineBreak</tt> keyword	<p>The <tt>NoLineBreak</tt> rule is written with the <tt>NoLineBreak</tt>
followed by a semicolon.</p>	keyword followed by a semicolon.</p>
<pre> 'NoLineBreak' ';'</pre>	<pre> 'NoLineBreak' ';'</pre>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc5220">The <tt>ChangeMainFile</tt> rule</a></h3>	<h3><a name="sectc5220">The <tt>ChangeMainFile</tt> rule</a></h3>
<p>
When the translation program starts, it opens a main output file, whose name	<p>When the translation program starts, it opens a main output file, whose
is given as a parameter of the translator. All <a	name is given as a parameter of the translator. All <a
href="#sectc5210"><tt>Create</tt> rules</a> without explicit indication of the	href="#sectc5210"><tt>Create</tt> rules</a> without explicit indication of the
output file write sequentially in this file. When a <tt>ChangeMainFile</tt>	output file write sequentially in this file. When a <tt>ChangeMainFile</tt>
rule is executed, the main output file is closed and it is replaced by a new	rule is executed, the main output file is closed and it is replaced by a new
Line 8166 one, whose name is specified in the <tt>	Line 7426 one, whose name is specified in the <tt>
executed write in this new file. Several <tt>ChangeMainFile</tt> rules can be	executed write in this new file. Several <tt>ChangeMainFile</tt> rules can be
executed during the same translation, for dividing the main output into	executed during the same translation, for dividing the main output into
several files.</p>	several files.</p>
<p>
This rule is written with the <tt>ChangeMainFile</tt> keyword followed by the	<p>This rule is written with the <tt>ChangeMainFile</tt> keyword followed by
name of a variable that specifies the name of the new main file. The keyword	the name of a variable that specifies the name of the new main file. The
<tt>Before</tt> or <tt>After</tt> can be placed at the end of the rule to	keyword <tt>Before</tt> or <tt>After</tt> can be placed at the end of the rule
specify whether the operation should be performed before or after translation	to specify whether the operation should be performed before or after
of the rule's element (the default is before). This rule, like all translation	translation of the rule's element (the default is before). This rule, like all
rules, is terminated by a semicolon.</p>	translation rules, is terminated by a semicolon.</p>
<pre> 'ChangeMainFile' VarID [ Position ] ';'</pre>	<pre> 'ChangeMainFile' VarID [ Position ] ';'</pre>

<blockquote class="example">	<blockquote class="example">
<p>	<p><strong>Example:</strong></p>
<strong>Example:</strong></p>
<p>	<p>To generate the translation of each section in a different file, the
To generate the translation of each section in a different file, the following	following rule can be associated with type <tt>Section</tt>. That rule uses
rule can be associated with type <tt>Section</tt>. That rule uses the <a	the <a href="#varoutputfile"><tt>VarOutpuFile</tt> variable</a> defined
href="#varoutputfile"><tt>VarOutpuFile</tt> variable</a> defined above.</p>	above.</p>
<pre> Section:	<pre> Section:
ChangeMainFile VarOutpuFile Before;</pre>	ChangeMainFile VarOutpuFile Before;</pre>
<p>
If <tt>output.txt</tt> is the name of the output file specified when starting	<p>If <tt>output.txt</tt> is the name of the output file specified when
the translation program, translated sections are written in files	starting the translation program, translated sections are written in files
<tt>output1.txt</tt>, <tt>output2.txt</tt>, etc.</p>	<tt>output1.txt</tt>, <tt>output2.txt</tt>, etc.</p>
</blockquote>	</blockquote>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc5220a">The <tt>RemoveFile</tt> rule</a></h3>	<h3><a name="sectc5220a">The <tt>RemoveFile</tt> rule</a></h3>
<p>
Files may be used for storing temporary data that are no longer needed when	<p>Files may be used for storing temporary data that are no longer needed when
the translation of a document is complete. These files may be removed by the	the translation of a document is complete. These files may be removed by the
<tt>RemoveFile</tt> rule.</p>	<tt>RemoveFile</tt> rule.</p>
<p>
This rule is written with the <tt>RemoveFile</tt> keyword followed by the name	<p>This rule is written with the <tt>RemoveFile</tt> keyword followed by the
of a variable that specifies the name of the file to be removed. The keyword	name of a variable that specifies the name of the file to be removed. The
<tt>Before</tt> or <tt>After</tt> can be placed at the end of the rule to	keyword <tt>Before</tt> or <tt>After</tt> can be placed at the end of the rule
specify whether the operation should be performed before or after translation	to specify whether the operation should be performed before or after
of the rule's element (the default is before). This rule, like all	translation of the rule's element (the default is before). This rule, like
translation rules, is terminated by a semicolon.</p>	all translation rules, is terminated by a semicolon.</p>
<pre> 'RemoveFile' VarID [ Position ] ';'</pre>	<pre> 'RemoveFile' VarID [ Position ] ';'</pre>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc5221">The <tt>Set</tt> and <tt>Add</tt> rules</a></h3>	<h3><a name="sectc5221">The <tt>Set</tt> and <tt>Add</tt> rules</a></h3>
<p>
The <tt>Set</tt> and <tt>Add</tt> rules are used for modifying the value of	<p>The <tt>Set</tt> and <tt>Add</tt> rules are used for modifying the value of
counters that have no <a href="#sectc524">counting function</a>. Only this	counters that have no <a href="#sectc524">counting function</a>. Only this
type of counter can be used in the <tt>Set</tt> and <tt>Add</tt> rules.</p>	type of counter can be used in the <tt>Set</tt> and <tt>Add</tt> rules.</p>
<p>
Both rules have the same syntax: after the keyword <tt>Set</tt> or	<p>Both rules have the same syntax: after the keyword <tt>Set</tt> or
<tt>Add</tt> appear the counter name and the value to assign to the counter	<tt>Add</tt> appear the counter name and the value to assign to the counter
(<tt>Set</tt> rule) or the value to be added to the counter (<tt>Add</tt>	(<tt>Set</tt> rule) or the value to be added to the counter (<tt>Add</tt>
rule). The keyword <tt>Before</tt> or <tt>After</tt> can follow that value to	rule). The keyword <tt>Before</tt> or <tt>After</tt> can follow that value to
Line 8227 the rule.</p>	Line 7486 the rule.</p>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc5221a">The <tt>Indent</tt> rule</a></h3>	<h3><a name="sectc5221a">The <tt>Indent</tt> rule</a></h3>
<p>
The <tt>Indent</tt> rule is used to modify the value of text indentation in	<p>The <tt>Indent</tt> rule is used to modify the value of text indentation in
the output files.</p>	the output files.</p>
<p>
Each time the translator creates a new line in an output file, it generates a	<p>Each time the translator creates a new line in an output file, it generates
variable number of space characters at the beginning of the new line. By	a variable number of space characters at the beginning of the new line. By
default, the number of these characters (the indentation value) is 0. It can	default, the number of these characters (the indentation value) is 0. It can
be changed with the <tt>Indent</tt> rule.</p>	be changed with the <tt>Indent</tt> rule.</p>
<p>
In its simple form, the rule begins with the <tt>Indent</tt> keyword,	<p>In its simple form, the rule begins with the <tt>Indent</tt> keyword,
followed by the indentation sign (optional) and value and a keyword	followed by the indentation sign (optional) and value and a keyword
<tt>Before</tt> or <tt>After</tt> indicating that the indentation should	<tt>Before</tt> or <tt>After</tt> indicating that the indentation should be
be changed <a href="#sectc5222">before or after</a> the element's content	changed <a href="#sectc5222">before or after</a> the element's content is
is generated. If the position is not indicated, the indentation is changed	generated. If the position is not indicated, the indentation is changed
before the element's content is generated. This rule, like all translation	before the element's content is generated. This rule, like all translation
rules, is terminated by a semicolon.</p>	rules, is terminated by a semicolon.</p>
<p>
The indentation value is indicated by an integer, which is the number of space	<p>The indentation value is indicated by an integer, which is the number of
characters to be generated at the beginning of each new line. A sign	space characters to be generated at the beginning of each new line. A sign
(<tt>+</tt> or <tt>-</tt>) can appear before the integer to indicate that the	(<tt>+</tt> or <tt>-</tt>) can appear before the integer to indicate that the
value is relative: the current value of indentation is incremented (if sign is	value is relative: the current value of indentation is incremented (if sign is
<tt>+</tt>) or decremented (if sign is <tt>-</tt>) by the specified value.</p>	<tt>+</tt>) or decremented (if sign is <tt>-</tt>) by the specified value.</p>
<p>
Keyword <tt>Suspend</tt> or <tt>Resume</tt> can appear instead of the	<p>Keyword <tt>Suspend</tt> or <tt>Resume</tt> can appear instead of the
(possibly signed) identation value. <tt>Suspend</tt> means that the new	(possibly signed) identation value. <tt>Suspend</tt> means that the new
indentation value to be used is zero until another <tt>Indent</tt> rule	indentation value to be used is zero until another <tt>Indent</tt> rule is
is executed and changes the indentation value. <tt>Resume</tt> means that	executed and changes the indentation value. <tt>Resume</tt> means that the
the indentation value that was used before the last <tt>Indent Suspend</tt>	indentation value that was used before the last <tt>Indent Suspend</tt> was
was executed becomes the new value. Only one <tt>Suspend</tt> can be used	executed becomes the new value. Only one <tt>Suspend</tt> can be used before
before a <tt>Resume</tt>; <tt>Supend</tt>-<tt>Resume</tt> pairs can not be	a <tt>Resume</tt>; <tt>Supend</tt>-<tt>Resume</tt> pairs can not be
nested.	nested.</p>
<p>
Like the <a href="#sectc5210"><tt>Create</tt> rule</a>, the <tt>Indent</tt>	<p>Like the <a href="#sectc5210"><tt>Create</tt> rule</a>, the <tt>Indent</tt>
keyword can be followed by the <tt>IN</tt> keyword and by the name of a <a	keyword can be followed by the <tt>IN</tt> keyword and by the name of a <a
href="#sectc526">variable</a>. This means that the rule must not change	href="#sectc526">variable</a>. This means that the rule must not change
indentation in the main output file, but in the file whose name is specified	indentation in the main output file, but in the file whose name is specified
Line 8275 IndentValue = NUMBER .</pre>	Line 7533 IndentValue = NUMBER .</pre>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc5222">Rule application order</a></h3>	<h3><a name="sectc5222">Rule application order</a></h3>
<p>
The translator translates the elements which comprise the document in the	<p>The translator translates the elements which comprise the document in the
order induced by the tree structure, except when the <tt>Get</tt> rule is used	order induced by the tree structure, except when the <tt>Get</tt> rule is used
to change the order of translation. For each element, the translator first	to change the order of translation. For each element, the translator first
applies the rules specified for the element's type that must be applied before	applies the rules specified for the element's type that must be applied before
Line 8286 translation of the element's content (ru	Line 7543 translation of the element's content (ru
keyword or which have no position keyword). If several rules meet these	keyword or which have no position keyword). If several rules meet these
criteria, the translator applies them in the order in where they appear in the	criteria, the translator applies them in the order in where they appear in the
translation schema.</p>	translation schema.</p>
<p>
It then applies all <a href="#sectc5223">rules for the attributes</a> which	<p>It then applies all <a href="#sectc5223">rules for the attributes</a> which
the element has and which must be applied before the translation of the	the element has and which must be applied before the translation of the
element's content (rules ending with the <tt>Before</tt> keyword or which have	element's content (rules ending with the <tt>Before</tt> keyword or which have
no position keyword). For one attribute value, the translator applies the	no position keyword). For one attribute value, the translator applies the
rules in the order in which they are defined in the translation schema.</p>	rules in the order in which they are defined in the translation schema.</p>
<p>
The same procedure is followed with translation rules for specific	<p>The same procedure is followed with translation rules for specific
presentations.</p>	presentations.</p>
<p>
Next, the element's content is translated, as long as a <tt>Remove</tt> rule	<p>Next, the element's content is translated, as long as a <tt>Remove</tt>
does not apply.</p>	rule does not apply.</p>
<p>
In the next step, the translator applies rules for the specific presentation	<p>In the next step, the translator applies rules for the specific
of the element that are to be applied after translation of the content (rules	presentation of the element that are to be applied after translation of the
which end with the <tt>After</tt> keyword). The rules for each type of	content (rules which end with the <tt>After</tt> keyword). The rules for each
presentation rule or each value are applied in the order in which the	type of presentation rule or each value are applied in the order in which the
translation appear in the schema.</p>	translation appear in the schema.</p>
<p>
Then, the same procedure is followed for translation rules for attributes of	<p>Then, the same procedure is followed for translation rules for attributes
the element.</p>	of the element.</p>
<p>
Finally, the translator applies rules for the element which must be applied	<p>Finally, the translator applies rules for the element which must be applied
after translation of the element's content. These rules are applied in the	after translation of the element's content. These rules are applied in the
order that they appear in the translation schema. When the translation of an	order that they appear in the translation schema. When the translation of an
element is done, the translator procedes to translate the following	element is done, the translator procedes to translate the following
element.</p>	element.</p>
<p>
This order can be changed with the <tt>Attributes</tt> and	<p>This order can be changed with the <tt>Attributes</tt> and
<tt>Presentation</tt> options of the <a href="#sectc5210"><tt>Create</tt>	<tt>Presentation</tt> options of the <a href="#sectc5210"><tt>Create</tt>
rule</a>.</p>	rule</a>.</p>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc5223">Translation of logical attributes</a></h3>	<h3><a name="sectc5223">Translation of logical attributes</a></h3>
<p>
After the rules for the element types, the translation schema defines rules	<p>After the rules for the element types, the translation schema defines rules
for attribute values. This section begins with the <tt>ATTRIBUTES</tt>	for attribute values. This section begins with the <tt>ATTRIBUTES</tt>
keyword and is composed of a sequence of rule blocks each preceded by an	keyword and is composed of a sequence of rule blocks each preceded by an
attribute name and an optional value or value range.</p>	attribute name and an optional value or value range.</p>
<p>
If the attribute's name appears alone before the rule block, the rule are	<p>If the attribute's name appears alone before the rule block, the rule are
applied to all element which have the attribute, no matter what value the	applied to all element which have the attribute, no matter what value the
attribute has. In this case, the attribute name is followed by a colon before	attribute has. In this case, the attribute name is followed by a colon before
the beginning of the rule block.</p>	the beginning of the rule block.</p>
<p>
The attribute's name can be followed by the name of an element type between	<p>The attribute's name can be followed by the name of an element type between
parentheses. This says, as in presentation schemas, that the rule block which	parentheses. This says, as in presentation schemas, that the rule block which
follows applies not to the element which has the attribute, but to its	follows applies not to the element which has the attribute, but to its
descendants of the type indicated between the parentheses.</p>	descendants of the type indicated between the parentheses.</p>
<p>
If values are given after the attribute name (or after the name of the element	<p>If values are given after the attribute name (or after the name of the
type), the rules are applied only when the attribute has the indicated values.	element type), the rules are applied only when the attribute has the indicated
The same attribute can appear several times, with different values and	values. The same attribute can appear several times, with different values and
different translation rules. Attribute values are indicated in the same way	different translation rules. Attribute values are indicated in the same way
as in <a href="#sectc528">conditions</a> and are followed by a colon before	as in <a href="#sectc528">conditions</a> and are followed by a colon before
the block of rules.</p>	the block of rules.</p>
<p>
The rule block associated with an attribute is either a simple rule or a	<p>The rule block associated with an attribute is either a simple rule or a
sequence of rules delimited by the <tt>BEGIN</tt> and <tt>END</tt> keywords.	sequence of rules delimited by the <tt>BEGIN</tt> and <tt>END</tt> keywords.
Note that rules associated with attribute values cannot be conditional.</p>	Note that rules associated with attribute values cannot be conditional.</p>
<p>
Translation rules are not required for all attributes (or their values)	<p>Translation rules are not required for all attributes (or their values)
defined in a structure schema. Only those attributes for which a particular	defined in a structure schema. Only those attributes for which a particular
action must be performed by the translator must have such rules. The rules	action must be performed by the translator must have such rules. The rules
that can be used are those described above, from <a	that can be used are those described above, from <a
href="#sectc5210"><tt>Create</tt></a> to <a	href="#sectc5210"><tt>Create</tt></a> to <a
href="#sectc5218"><tt>NoTranslation</tt></a>.</p>	href="#sectc5218"><tt>NoTranslation</tt></a>.</p>
<pre> AttrSeq = TransAttr < TransAttr > .	<pre> AttrSeq = TransAttr < TransAttr > .
TransAttr = AttrID [ '(' ElemID ')' ]	TransAttr = AttrID [ '(' ElemID ')' ]
[ RelatAttr ] ':' RuleSeq .	[ RelatAttr ] ':' RuleSeq .
AttrID = NAME .	AttrID = NAME .
ElemID = NAME .</pre>	ElemID = NAME .</pre>

<blockquote class="example">	<blockquote class="example">
<p>	<p><strong>Example:</strong></p>
<strong>Example:</strong></p>
<p>	<p>The structure defined the ``Language'' attribute which can take the
The structure defined the ``Language'' attribute which can take the values	values ``French'' and ``English''. To have the French parts of the original
``French'' and ``English''. To have the French parts of the original document	document removed and prevent the translation of the leaves of the English
removed and prevent the translation of the leaves of the English parts, the	parts, the following rules would be used:</p>
following rules would be used:</p>	<pre>ATTRIBUTES
<pre>ATTRIBUTES
Language=French :	Language=French :
Remove;	Remove;
Language=English :	Language=English :
Line 8377 following rules would be used:</p>	Line 7633 following rules would be used:</p>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc5224">Translation of specific presentations</a></h3>	<h3><a name="sectc5224">Translation of specific presentations</a></h3>
<p>
After the rules for attributes, the translation schema defines rules for the	<p>After the rules for attributes, the translation schema defines rules for
specific presentation. This section begins with the <tt>PRESENTATION</tt>	the specific presentation. This section begins with the <tt>PRESENTATION</tt>
keyword and is composed of a sequence of translation rule blocks each preceded	keyword and is composed of a sequence of translation rule blocks each preceded
by a presentation rule name, optionally accompanied by a part which depends on	by a presentation rule name, optionally accompanied by a part which depends on
the particular presentation rule.</p>	the particular presentation rule.</p>
<p>
Each of these translation rule blocks is applied when the translator operates	<p>Each of these translation rule blocks is applied when the translator
on an element which has a specific presentation rule of the type indicated at	operates on an element which has a specific presentation rule of the type
the head of the block. Depending on the type of the specific presentation	indicated at the head of the block. Depending on the type of the specific
rule, it is possible to specify values of the presentation rule for which the	presentation rule, it is possible to specify values of the presentation rule
translation rule block should be applied.</p>	for which the translation rule block should be applied.</p>
<p>
There are three categories of the presentation rules:</p>	<p>There are three categories of the presentation rules:</p>
<ul>	<ul>
<li>	<li>rules taking numeric values: <tt>Size</tt>, <tt>Indent</tt>,
rules taking numeric values: <tt>Size</tt>, <tt>Indent</tt>,	<tt>LineSpacing</tt>, <tt>LineWeight</tt>,</li>
<tt>LineSpacing</tt>, <tt>LineWeight</tt>,	<li>rules whose values are taken from a predefined list (i.e. whose type is
</li>	an enumeration): <tt>Adjust</tt>, <tt>Justify</tt>, <tt>Hyphenate,/TT>,
<li>	<tt>Style</tt>, <tt>Weight</tt>, <tt>Font</tt>, <tt>UnderLine</tt>,
rules whose values are taken from a predefined list (i.e. whose type is an	<tt>Thickness</tt>, <tt>LineStyle</tt>,</tt></li>
enumeration): <tt>Adjust</tt>, <tt>Justify</tt>, <tt>Hyphenate,/TT>,	<li>rules whose value is a name: <tt>FillPattern</tt>, <tt>Background</tt>,
<tt>Style</tt>, <tt>Weight</tt>, <tt>Font</tt>, <tt>UnderLine</tt>,	<tt>Foreground</tt>.</li>
<tt>Thickness</tt>, <tt>LineStyle</tt>,</tt>
</li>
<li>
rules whose value is a name: <tt>FillPattern</tt>, <tt>Background</tt>,
<tt>Foreground</tt>.
</li>
</ul>	</ul>
<p>
For presentation rules of the first category, the values which provoke	<p>For presentation rules of the first category, the values which provoke
application of the translation rules are indicated in the same manner as for	application of the translation rules are indicated in the same manner as for
<a href="#relattr">numeric attributes</a>. This can be either a unique value	<a href="#relattr">numeric attributes</a>. This can be either a unique value
or range of values. For a unique value, the value (an integer) is simply	or range of values. For a unique value, the value (an integer) is simply
preceded by an equals sign. Value ranges can be specified in one of three	preceded by an equals sign. Value ranges can be specified in one of three
ways:</p>	ways:</p>
<ul>	<ul>
<li>	<li>all values less than a given value (this value is preceded by a ``less
all values less than a given value (this value is preceded by a ``less than''	than'' sign '<tt><</tt>'),</li>
sign '<tt><</tt>'),	<li>all values greater than a given value (this value is preceded by a`
</li>	`greater than'' sign '<tt>></tt>'),</li>
<li>	<li>all values falling in an interval, bounds included. The range of values
all values greater than a given value (this value is preceded by a` `greater	is then specified <tt>IN [</tt>Minimum<tt>..</tt>Maximum<tt>]</tt>, where
than'' sign '<tt>></tt>'),	Minimum and Maximum are integers.</li>
</li>
<li>
all values falling in an interval, bounds included. The range of values is
then specified <tt>IN [</tt>Minimum<tt>..</tt>Maximum<tt>]</tt>, where Minimum
and Maximum are integers.
</li>
</ul>	</ul>
<p>
All numeric values can be negative, in which case the integer is preceded by a	<p>All numeric values can be negative, in which case the integer is preceded
minus sign. All values must be given in typographers points.</p>	by a minus sign. All values must be given in typographers points.</p>
<p>
For presentation rules whose values are taken from a predefined list, the	<p>For presentation rules whose values are taken from a predefined list, the
value which provokes application of the translation rules is simply indicated	value which provokes application of the translation rules is simply indicated
by the equals sign followed by the name of the value.</p>	by the equals sign followed by the name of the value.</p>
<p>
For presentation rules whose values are names, the value which provokes the	<p>For presentation rules whose values are names, the value which provokes the
application of translation rules is simply indicated by the equals sign	application of translation rules is simply indicated by the equals sign
followed by the name of the value. The names of the fill patterns (the	followed by the name of the value. The names of the fill patterns (the
<tt>FillPattern</tt> rule) and of the colors (the <tt>Foreground</tt> and	<tt>FillPattern</tt> rule) and of the colors (the <tt>Foreground</tt> and
<tt>Background</tt> rules) used in Thot are the same as in the P language.</p>	<tt>Background</tt> rules) used in Thot are the same as in the P language.</p>
<pre> PresSeq = PresTrans < PresTrans > .	<pre> PresSeq = PresTrans < PresTrans > .
PresTrans = PresRule ':' RuleSeq .	PresTrans = PresRule ':' RuleSeq .
PresRule = 'Size' [ PresRelation ] /	PresRule = 'Size' [ PresRelation ] /
'Indent' [ PresRelation ] /	'Indent' [ PresRelation ] /
Line 8464 followed by the name of the value. The	Line 7707 followed by the name of the value. The
'Foreground' [ '=' Color ] .	'Foreground' [ '=' Color ] .

PresRelation = '=' PresValue /	PresRelation = '=' PresValue /
'>' [ '-' ] PresMinimum /	'>' [ '-' ] PresMinimum /
'<' [ '-' ] PresMaximum /	'<' [ '-' ] PresMaximum /
'IN' '[' [ '-' ] PresIntervalMin '..'	'IN' '[' [ '-' ] PresIntervalMin '..'
[ '-' ] PresIntervalMax ']' .	[ '-' ] PresIntervalMax ']' .
Line 8486 followed by the name of the value. The	Line 7729 followed by the name of the value. The
PresIntervalMax= NUMBER .	PresIntervalMax= NUMBER .
PresValue = [ '-' ] PresVal .	PresValue = [ '-' ] PresVal .
PresVal = NUMBER .</pre>	PresVal = NUMBER .</pre>
<p>
The <a name="prestransl">translation rules associated with specific	<p>The <a name="prestransl">translation rules associated with specific
presentation rules</a> can use the value of the specific presentation rule	presentation rules</a> can use the value of the specific presentation rule
that causes them to be applied. This behavior is designated by the keyword	that causes them to be applied. This behavior is designated by the keyword
<tt>Value</tt>. For numerically-valued presentation rules, the numeric value	<tt>Value</tt>. For numerically-valued presentation rules, the numeric value
is produced. For other presentation rules, the name of the value is	is produced. For other presentation rules, the name of the value is
produced.</p>	produced.</p>
<p>
It should be noted that modifications to the layout of the document's elements	<p>It should be noted that modifications to the layout of the document's
that are made using the combination of the control key and a mouse button will	elements that are made using the combination of the control key and a mouse
have no effect on the translation of the document.</p>	button will have no effect on the translation of the document.</p>
<blockquote class="example">
<p>	<blockquote class="example">
<strong>Example:</strong></p>	<p><strong>Example:</strong></p>
<p>
Suppose that it is desirable to use the same font sizes as in the specific	<p>Suppose that it is desirable to use the same font sizes as in the
presentation, but the font size must be between 10 and 18 typographer's	specific presentation, but the font size must be between 10 and 18
points. If font size is set in the translated document by the string	typographer's points. If font size is set in the translated document by the
<tt>pointsize=n</tt> where <tt>n</tt> is the font size in typographer's points	string <tt>pointsize=n</tt> where <tt>n</tt> is the font size in
then the following rules will suffice:</p>	typographer's points then the following rules will suffice:</p>
<pre>PRESENTATION	<pre>PRESENTATION
Size < 10 :	Size < 10 :
Create 'pointsize=10';	Create 'pointsize=10';
Size in [10..18] :	Size in [10..18] :
Line 8514 then the following rules will suffice:</	Line 7757 then the following rules will suffice:</
Create 'pointsize=';	Create 'pointsize=';
Create Value;	Create Value;
END;	END;
Size > 18 :	Size > 18 :
Create 'pointsize=18';</pre>	Create 'pointsize=18';</pre>
</blockquote>	</blockquote>
</div>	</div>

<div class="subsection">	<div class="subsection">

<h3><a name="sectc5225">Recoding of characters, symbols and graphics</a></h3>	<h3><a name="sectc5225">Recoding of characters, symbols and graphics</a></h3>
<p>
The coding of characters, graphical elements and symbols as defined in Thot	<p>The coding of characters, graphical elements and symbols as defined in Thot
does not necessarily correspond to what is required by an application to which	does not necessarily correspond to what is required by an application to which
a Thot document must be exported. Because of this the translator can recode	a Thot document must be exported. Because of this the translator can recode
these terminal elements of the documents structure. The last sections of a	these terminal elements of the documents structure. The last sections of a
translation schema are intended for this purpose, each specifying the recoding	translation schema are intended for this purpose, each specifying the recoding
rules for one type of terminal element.</p>	rules for one type of terminal element.</p>
<p>
The recoding rules for character strings are grouped by alphabets. There is a	<p>The recoding rules for character strings are grouped by alphabets. There is
group of rules for each alphabet of the Thot document that must be translated.	a group of rules for each alphabet of the Thot document that must be
Each such group of rules begins with the <tt>TEXTTRANSLATE</tt> keyword,	translated. Each such group of rules begins with the <tt>TEXTTRANSLATE</tt>
followed by the specification of the alphabet to translate and the recoding	keyword, followed by the specification of the alphabet to translate and the
rules, between the <tt>BEGIN</tt> and <tt>END</tt> keywords unless there is	recoding rules, between the <tt>BEGIN</tt> and <tt>END</tt> keywords unless
only one recoding rule for the alphabet. The specification of the alphabet is	there is only one recoding rule for the alphabet. The specification of the
not required: by default it is assumed to the Latin alphabet (the ISO Latin-1	alphabet is not required: by default it is assumed to the Latin alphabet (the
character set).</p>	ISO Latin-1 character set).</p>
<p>
Each recoding rule is formed by a source string between apostrophes and a	<p>Each recoding rule is formed by a source string between apostrophes and a
target string, also between apostrophes, the two strings being separated by	target string, also between apostrophes, the two strings being separated by
the arrow symbol (<tt>-></tt>), formed by the ``minus'' and ``greater than''	the arrow symbol (<tt>-></tt>), formed by the ``minus'' and ``greater
characters. The rule is terminated by a semi-colon.</p>	than'' characters. The rule is terminated by a semi-colon.</p>
<pre> TextTransSeq = [ Alphabet ] TransSeq .	<pre> TextTransSeq = [ Alphabet ] TransSeq .
Alphabet = NAME .	Alphabet = NAME .
TransSeq ='BEGIN' < Translation > 'END' ';' /	TransSeq ='BEGIN' < Translation > 'END' ';' /
Translation .	Translation .
Translation = Source [ '->' Target ] ';' .	Translation = Source [ '->' Target ] ';' .
Source = STRING .	Source = STRING .
Target = STRING .</pre>	Target = STRING .</pre>
<p>
One such rule signifies that when the source string appears in a text leaf of	<p>One such rule signifies that when the source string appears in a text leaf
the document being translated, the translator must replace it, in the	of the document being translated, the translator must replace it, in the
translated document, with the target string. The source string and the target	translated document, with the target string. The source string and the target
string can have different lengths and the target string can be empty. In this	string can have different lengths and the target string can be empty. In this
last case, the translator simply suppresses every occurrence of the source	last case, the translator simply suppresses every occurrence of the source
string in the translated document.</p>	string in the translated document.</p>
<p>
For a given alphabet, the order of the rules is not important and has no	<p>For a given alphabet, the order of the rules is not important and has no
significance because the T language compiler reorders the rules in ways that	significance because the T language compiler reorders the rules in ways that
speed up the translator's work. The total number of recoding rules is limited	speed up the translator's work. The total number of recoding rules is limited
by the compiler as is the maximum length of the source and target strings.</p>	by the compiler as is the maximum length of the source and target strings.</p>
<p>
The recoding rules for symbols and graphical elements are written in the same	<p>The recoding rules for symbols and graphical elements are written in the
manner as the recoding rules for character strings. They are preceded,	same manner as the recoding rules for character strings. They are preceded,
respectively, by the <tt>SYMBTRANSLATE</tt> and <tt>GRAPHTRANSLATE</tt> and so	respectively, by the <tt>SYMBTRANSLATE</tt> and <tt>GRAPHTRANSLATE</tt> and so
not require a specification of the alphabet. Their source string is limited to	not require a specification of the alphabet. Their source string is limited to
one character, since, in Thot, each symbol and each graphical element is	one character, since, in Thot, each symbol and each graphical element is
represented by a single character. The symbol and graphical element codes are	represented by a single character. The symbol and graphical element codes are
defined along with the <a href="#sect7">non-standard character codes</a>.</p>	defined along with the <a href="#sect7">non-standard character codes</a>.</p>

<blockquote class="example">	<blockquote class="example">
<p>	<p><strong>Example:</strong></p>
<strong>Example:</strong></p>
<p>	<p>In a translation schema producing documents destined for use with the
In a translation schema producing documents destined for use with the	L<sup>A</sup>T<sub><big>E</big></sub>X formatter, the Latin characters``é''
L<sup>A</sup>T<sub><big>E</big></sub>X formatter, the Latin	(octal code 351 in Thot) and ``è'' (octal code 350 in Thot) must be
characters``é'' (octal code 351 in Thot) and ``è'' (octal code	converted to their representation in
350 in Thot) must be converted to their representation in	L<sup>A</sup>T<sub><big>E</big></sub>X:</p>
L<sup>A</sup>T<sub><big>E</big></sub>X:</p>	<pre>TEXTTRANSLATE Latin
<pre>TEXTTRANSLATE Latin
BEGIN	BEGIN
'\350' -> '\`{e}'; { e grave }	'\350' -> '\`{e}'; { e grave }
'\351' -> '\''{e}'; { e acute }	'\351' -> '\''{e}'; { e acute }
END;</pre>	END;</pre>
</blockquote>	</blockquote>
</div>	</div>
</div>	</div>
<hr>	<hr>

</div>	</div>

<div class="chapter">	<div class="chapter">

<h1><a name="sect6">Language grammars</a></h1>	<h1><a name="sect6">Language grammars</a></h1>
<p>
This chapter gives the complete grammars of the languages of Thot. The	<p>This chapter gives the complete grammars of the languages of Thot. The
grammars were presented and described in the preceding chapters, which also	grammars were presented and described in the preceding chapters, which also
specify the semantics of the languages. This section gives only the	specify the semantics of the languages. This section gives only the
syntax.</p>	syntax.</p>

<div class="section">	<div class="section">

<h2><a name="sectb61">The M meta-language</a></h2>	<h2><a name="sectb61">The M meta-language</a></h2>
<p>
The language grammars are all expressed in the same formalism, the M	<p>The language grammars are all expressed in the same formalism, the M
meta-language, which is defined in this section.</p>	meta-language, which is defined in this section.</p>
<pre>{ Any text between braces is a comment. }	<pre>{ Any text between braces is a comment. }
Grammar = Rule < Rule > 'END' .	Grammar = Rule < Rule > 'END' .
{ The < and > signs indicate zero }	{ The < and > signs indicate zero }
{ or more repetitions. }	{ or more repetitions. }
{ END marks the end of the grammar. }	{ END marks the end of the grammar. }
Rule = Ident '=' RightPart '.' .	Rule = Ident '=' RightPart '.' .
Line 8617 RightPart = RtTerminal / RtIntermed .	Line 7856 RightPart = RtTerminal / RtIntermed .
{ The slash indicates a choice }	{ The slash indicates a choice }
RtTerminal ='NAME' / 'STRING' / 'NUMBER' .	RtTerminal ='NAME' / 'STRING' / 'NUMBER' .
{ Right part of a terminal rule }	{ Right part of a terminal rule }
RtIntermed = Possibility < '/' Possibility > .	RtIntermed = Possibility < '/' Possibility > .
{ Right part of an intermediate rule }	{ Right part of an intermediate rule }
Possibility = ElemOpt < ElemOpt > .	Possibility = ElemOpt < ElemOpt > .
ElemOpt = Element / '[' Element < Element > ']' /	ElemOpt = Element / '[' Element < Element > ']' /
'<' Element < Element > '>' .	'<' Element < Element > '>' .
{ Brackets delimit optional parts }	{ Brackets delimit optional parts }
Element = Ident / KeyWord .	Element = Ident / KeyWord .
Ident = NAME .	Ident = NAME .
Line 8632 END</pre>	Line 7871 END</pre>
</div>	</div>

<div class="section">	<div class="section">

<h2><a name="sectb62">The S language</a></h2>	<h2><a name="sectb62">The S language</a></h2>
<p>
The S language is used to write structure schemas, which contain the generic	<p>The S language is used to write structure schemas, which contain the
logical structures of document and object classes. It is described here in	generic logical structures of document and object classes. It is described
the M meta-language.</p>	here in the M meta-language.</p>
<pre>StructSchema = 'STRUCTURE' [ 'EXTENSION' ] ElemID ';'	<pre>StructSchema = 'STRUCTURE' [ 'EXTENSION' ] ElemID ';'
'DEFPRES' PresID ';'	'DEFPRES' PresID ';'
[ 'ATTR' AttrSeq ]	[ 'ATTR' AttrSeq ]
Line 8653 the M meta-language.</p>	Line 7891 the M meta-language.</p>
ElemID = NAME .	ElemID = NAME .
PresID = NAME .	PresID = NAME .

AttrSeq = Attribute < Attribute > .	AttrSeq = Attribute < Attribute > .
Attribute = AttrID '=' AttrType ';' .	Attribute = AttrID '=' AttrType ';' .
AttrType = 'INTEGER' / 'TEXT' /	AttrType = 'INTEGER' / 'TEXT' /
'REFERENCE' '(' RefType ')' /	'REFERENCE' '(' RefType ')' /
ValueSeq .	ValueSeq .
RefType = 'ANY' /	RefType = 'ANY' /
[ FirstSec ] ElemID [ ExtStruct ] .	[ FirstSec ] ElemID [ ExtStruct ] .
ValueSeq = AttrVal < ',' AttrVal > .	ValueSeq = AttrVal < ',' AttrVal > .
AttrID = NAME .	AttrID = NAME .
FirstSec = 'First' / 'Second' .	FirstSec = 'First' / 'Second' .
ExtStruct = '(' ElemID ')' .	ExtStruct = '(' ElemID ')' .
AttrVal = NAME .	AttrVal = NAME .

RulesSeq = Rule < Rule > .	RulesSeq = Rule < Rule > .
Rule = ElemID [ LocAttrSeq ] '='	Rule = ElemID [ LocAttrSeq ] '='
DefWithAttr ';' .	DefWithAttr ';' .
LocAttrSeq = '(' 'ATTR' LocalAttr	LocAttrSeq = '(' 'ATTR' LocalAttr
< ';' LocalAttr > ')' .	< ';' LocalAttr > ')' .
LocalAttr = [ '!' ] AttrID [ '=' AttrType ] .	LocalAttr = [ '!' ] AttrID [ '=' AttrType ] .
DefWithAttr = Definition	DefWithAttr = Definition
[ '+' '(' ExtensionSeq ')' ]	[ '+' '(' ExtensionSeq ')' ]
[ '-' '(' RestrictSeq ')' ]	[ '-' '(' RestrictSeq ')' ]
[ 'WITH' FixedAttrSeq ] .	[ 'WITH' FixedAttrSeq ] .
ExtensionSeq = ExtensionElem < ',' ExtensionElem > .	ExtensionSeq = ExtensionElem < ',' ExtensionElem > .
ExtensionElem = ElemID / 'TEXT' / 'GRAPHICS' /	ExtensionElem = ElemID / 'TEXT' / 'GRAPHICS' /
'SYMBOL' / 'PICTURE' .	'SYMBOL' / 'PICTURE' .
RestrictSeq = RestrictElem < ',' RestrictElem > .	RestrictSeq = RestrictElem < ',' RestrictElem > .
RestrictElem = ElemID / 'TEXT' / 'GRAPHICS' /	RestrictElem = ElemID / 'TEXT' / 'GRAPHICS' /
'SYMBOL' / 'PICTURE' .	'SYMBOL' / 'PICTURE' .
FixedAttrSeq = FixedAttr < ',' FixedAttr > .	FixedAttrSeq = FixedAttr < ',' FixedAttr > .
FixedAttr = AttrID [ FixedOrModifVal ] .	FixedAttr = AttrID [ FixedOrModifVal ] .
FixedOrModifVal= [ '?' ] '=' FixedValue .	FixedOrModifVal= [ '?' ] '=' FixedValue .
FixedValue = [ '-' ] NumValue / TextValue / AttrVal .	FixedValue = [ '-' ] NumValue / TextValue / AttrVal .
Line 8709 min = Integer / '*' .	Line 7947 min = Integer / '*' .
max = Integer / '*' .	max = Integer / '*' .
Integer = NUMBER .	Integer = NUMBER .

DefOptSeq = DefOpt ';' < DefOpt ';' > .	DefOptSeq = DefOpt ';' < DefOpt ';' > .
DefOpt = [ '?' ] DefWithAttr .	DefOpt = [ '?' ] DefWithAttr .

DefSeq = DefWithAttr ';' < DefWithAttr ';' > .	DefSeq = DefWithAttr ';' < DefWithAttr ';' > .

SkeletonSeq = SkeletonElem < ',' SkeletonElem > ';' .	SkeletonSeq = SkeletonElem < ',' SkeletonElem > ';' .
SkeletonElem = ElemID [ 'WITH' Contents ] .	SkeletonElem = ElemID [ 'WITH' Contents ] .
Contents = 'Nothing' / ElemID [ ExtStruct ] .	Contents = 'Nothing' / ElemID [ ExtStruct ] .

ExceptSeq = Except ';' < Except ';' > .	ExceptSeq = Except ';' < Except ';' > .
Except = [ 'EXTERN' ] [ FirstSec ] ExcTypeOrAttr ':'	Except = [ 'EXTERN' ] [ FirstSec ] ExcTypeOrAttr ':'
ExcValSeq .	ExcValSeq .
ExcTypeOrAttr = ElemID / AttrID .	ExcTypeOrAttr = ElemID / AttrID .
ExcValSeq = ExcValue < ',' ExcValue > .	ExcValSeq = ExcValue < ',' ExcValue > .
ExcValue = 'NoCut' / 'NoCreate' /	ExcValue = 'NoCut' / 'NoCreate' /
'NoHMove' / 'NoVMove' / 'NoMove' /	'NoHMove' / 'NoVMove' / 'NoMove' /
'NoHResize' / 'NoVResize' / 'NoResize' /	'NoHResize' / 'NoVResize' / 'NoResize' /
Line 8736 ExcValue = 'NoCut' / 'NoCreate' /	Line 7974 ExcValue = 'NoCut' / 'NoCreate' /
'HighlightChildren' / 'ExtendedSelection' /	'HighlightChildren' / 'ExtendedSelection' /
'ReturnCreateNL' / 'ReturnCreateWithin' .	'ReturnCreateNL' / 'ReturnCreateWithin' .

ExtensRuleSeq = ExtensRule ';' < ExtensRule ';' > .	ExtensRuleSeq = ExtensRule ';' < ExtensRule ';' > .
ExtensRule = RootOrElem [ LocAttrSeq ]	ExtensRule = RootOrElem [ LocAttrSeq ]
[ '+' '(' ExtensionSeq ')' ]	[ '+' '(' ExtensionSeq ')' ]
[ '-' '(' RestrictSeq ')' ]	[ '-' '(' RestrictSeq ')' ]
Line 8747 END</pre>	Line 7985 END</pre>
</div>	</div>

<div class="section">	<div class="section">

<h2><a name="sectb63">The P language</a></h2>	<h2><a name="sectb63">The P language</a></h2>
<p>
The P language is used to write presentation schemas, which define the	<p>The P language is used to write presentation schemas, which define the
graphical presentation rules to be applied to different classes of documents	graphical presentation rules to be applied to different classes of documents
and objects. It is described here in the M meta-language.</p>	and objects. It is described here in the M meta-language.</p>
<pre>PresSchema = 'PRESENTATION' ElemID ';'	<pre>PresSchema = 'PRESENTATION' ElemID ';'
Line 8769 and objects. It is described here in th	Line 8006 and objects. It is described here in th
ElemID = NAME .	ElemID = NAME .

ViewSeq = ViewDeclaration	ViewSeq = ViewDeclaration
< ',' ViewDeclaration > ';' .	< ',' ViewDeclaration > ';' .
ViewDeclaration = ViewID [ 'EXPORT' ] .	ViewDeclaration = ViewID [ 'EXPORT' ] .
ViewID = NAME .	ViewID = NAME .

PrintViewSeq = PrintView < ',' PrintView > ';' .	PrintViewSeq = PrintView < ',' PrintView > ';' .
PrintView = ViewID / ElemID .	PrintView = ViewID / ElemID .

CounterSeq = Counter < Counter > .	CounterSeq = Counter < Counter > .
Counter = CounterID ':' CounterFunc ';' .	Counter = CounterID ':' CounterFunc ';' .
CounterID = NAME .	CounterID = NAME .
CounterFunc = 'RANK' 'OF' TypeOrPage [ SLevelAsc ]	CounterFunc = 'RANK' 'OF' TypeOrPage [ SLevelAsc ]
[ 'INIT' AttrID ] [ 'REINIT' AttrID ] /	[ 'INIT' AttrID ] [ 'REINIT' AttrID ] /
SetFunction < SetFunction >	SetFunction < SetFunction >
AddFunction < AddFunction >	AddFunction < AddFunction >
[ 'INIT' AttrID ] /	[ 'INIT' AttrID ] /
'RLEVEL' 'OF' ElemID .	'RLEVEL' 'OF' ElemID .
SLevelAsc = [ '-' ] LevelAsc .	SLevelAsc = [ '-' ] LevelAsc .
Line 8793 TypeOrPage = 'Page' [ '(' ViewID ')	Line 8030 TypeOrPage = 'Page' [ '(' ViewID ')
[ '*' ] ElemID .	[ '*' ] ElemID .
CounterValue = NUMBER .	CounterValue = NUMBER .

ConstSeq = Const < Const > .	ConstSeq = Const < Const > .
Const = ConstID '=' ConstType ConstValue ';' .	Const = ConstID '=' ConstType ConstValue ';' .
ConstID = NAME .	ConstID = NAME .
ConstType = 'Text' [ Alphabet ] / 'Symbol' /	ConstType = 'Text' [ Alphabet ] / 'Symbol' /
Line 8801 ConstType = 'Text' [ Alphabet ] /	Line 8038 ConstType = 'Text' [ Alphabet ] /
ConstValue = STRING .	ConstValue = STRING .
Alphabet = NAME .	Alphabet = NAME .

VarSeq = Variable < Variable > .	VarSeq = Variable < Variable > .
Variable = VarID ':' FunctionSeq ';' .	Variable = VarID ':' FunctionSeq ';' .
VarID = NAME .	VarID = NAME .
FunctionSeq = Function < Function > .	FunctionSeq = Function < Function > .
Function = 'DATE' / 'FDATE' /	Function = 'DATE' / 'FDATE' /
'DocName' / 'DirName' /	'DocName' / 'DirName' /
'ElemName' / 'AttributeName' /	'ElemName' / 'AttributeName' /
Line 8818 CounterStyle = 'Arabic' / 'LRoman' /	Line 8055 CounterStyle = 'Arabic' / 'LRoman' /
'Uppercase' / 'Lowercase' .	'Uppercase' / 'Lowercase' .
MinMax = 'MaxRangeVal' / 'MinRangeVal' .	MinMax = 'MaxRangeVal' / 'MinRangeVal' .

BoxSeq = Box < Box > .	BoxSeq = Box < Box > .
Box = 'FORWARD' BoxID ';' /	Box = 'FORWARD' BoxID ';' /
BoxID ':' ViewRuleSeq .	BoxID ':' ViewRuleSeq .
BoxID = NAME .	BoxID = NAME .

PresentSeq = Present < Present > .	PresentSeq = Present < Present > .
Present = [ '*' ] [ FirstSec ] ElemID ':'	Present = [ '*' ] [ FirstSec ] ElemID ':'
ViewRuleSeq .	ViewRuleSeq .
FirstSec = 'First' / 'Second' .	FirstSec = 'First' / 'Second' .

PresAttrSeq = PresAttr < PresAttr > .	PresAttrSeq = PresAttr < PresAttr > .
PresAttr = AttrID [ '(' [ FirstSec ] ElemID ')' ]	PresAttr = AttrID [ '(' [ FirstSec ] ElemID ')' ]
[ AttrRelation ] ':' ViewRuleSeq .	[ AttrRelation ] ':' ViewRuleSeq .
AttrID = NAME .	AttrID = NAME .
AttrRelation = '=' AttrVal /	AttrRelation = '=' AttrVal /
'>' [ '-' ] MinValue /	'>' [ '-' ] MinValue /
'<' [ '-' ] MaxValue /	'<' [ '-' ] MaxValue /
'IN' '[' [ '-' ] LowerBound '..'	'IN' '[' [ '-' ] LowerBound '..'
[ '-' ] UpperBound ']' /	[ '-' ] UpperBound ']' /
Line 8849 EqualNum = NUMBER .	Line 8086 EqualNum = NUMBER .
EqualText = STRING .	EqualText = STRING .
AttrValue = NAME .	AttrValue = NAME .

ViewRuleSeq = 'BEGIN' < RulesAndCond > < ViewRules >	ViewRuleSeq = 'BEGIN' < RulesAndCond > < ViewRules >
'END' ';' /	'END' ';' /
ViewRules / CondRules / Rule .	ViewRules / CondRules / Rule .
RulesAndCond = CondRules / Rule .	RulesAndCond = CondRules / Rule .
ViewRules = 'IN' ViewID CondRuleSeq .	ViewRules = 'IN' ViewID CondRuleSeq .
CondRuleSeq = 'BEGIN' < RulesAndCond > 'END' ';' /	CondRuleSeq = 'BEGIN' < RulesAndCond > 'END' ';' /
CondRules / Rule .	CondRules / Rule .
CondRules = CondRule < CondRule >	CondRules = CondRule < CondRule >
[ 'Otherwise' RuleSeq ] .	[ 'Otherwise' RuleSeq ] .
CondRule = 'IF' ConditionSeq RuleSeq .	CondRule = 'IF' ConditionSeq RuleSeq .
RulesSeq = 'BEGIN' Rule < Rule > 'END' ';' / Rule .	RulesSeq = 'BEGIN' Rule < Rule > 'END' ';' / Rule .

ConditionSeq = Condition < 'AND' Condition > .	ConditionSeq = Condition < 'AND' Condition > .
Condition = [ 'NOT' ] [ 'Target' ] ConditionElem .	Condition = [ 'NOT' ] [ 'Target' ] ConditionElem .
ConditionElem = 'First' / 'Last' /	ConditionElem = 'First' / 'Last' /
[ 'Immediately' ] 'Within' [ NumParent ]	[ 'Immediately' ] 'Within' [ NumParent ]
Line 8875 ConditionElem = 'First' / 'Last' /	Line 8112 ConditionElem = 'First' / 'Last' /
'(' [ MinMax ] CounterName CounterCond ')' /	'(' [ MinMax ] CounterName CounterCond ')' /
CondPage '(' CounterID ')' .	CondPage '(' CounterID ')' .
NumParent = [ GreaterLess ] NParent .	NumParent = [ GreaterLess ] NParent .
GreaterLess = '>' / '<' .	GreaterLess = '>' / '<' .
NParent = NUMBER.	NParent = NUMBER.
CounterCond = '<' MaxCtrVal / '>' MinCtrVal /	CounterCond = '<' MaxCtrVal / '>' MinCtrVal /
'=' EqCtrVal /	'=' EqCtrVal /
'IN' '[' ['-'] MinCtrBound '..'	'IN' '[' ['-'] MinCtrBound '..'
['-'] MaxCtrBound ']' .	['-'] MaxCtrBound ']' .
Line 8939 PresParam = 'VertRef' ':' HorizPos	Line 8176 PresParam = 'VertRef' ':' HorizPos
'LineStyle' ':' LineStyleInherit /	'LineStyle' ':' LineStyleInherit /
'LineWeight' ':' DistOrInherit /	'LineWeight' ':' DistOrInherit /
'FillPattern' ':' NameInherit /	'FillPattern' ':' NameInherit /
'Background' ':' NameInherit /	'Background' ':' Color /
'Foreground' ':' NameInherit /	'Foreground' ':' Color /
'Content' ':' VarConst .	'Content' ':' VarConst .
PresFunc = Creation '(' BoxID ')' /	PresFunc = Creation '(' BoxID ')' /
'Line' /	'Line' /
Line 9058 PercentSize = NUMBER .	Line 8295 PercentSize = NUMBER .

NameInherit = Kinship '=' / FontName .	NameInherit = Kinship '=' / FontName .
FontName = NAME .	FontName = NAME .
	Color = 'Transparent' / Kinship '=' / FontName .
StyleInherit = Kinship '=' /	StyleInherit = Kinship '=' /
'Roman' / 'Italics' / 'Oblique' .	'Roman' / 'Italics' / 'Oblique' .
WeightInherit = Kinship '=' /	WeightInherit = Kinship '=' /
Line 9080 Create = 'CreateFirst' / 'Creat	Line 8318 Create = 'CreateFirst' / 'Creat
'CreateBefore' / 'CreateAfter' /	'CreateBefore' / 'CreateAfter' /
'CreateEnclosing' .	'CreateEnclosing' .

TransmitSeq = Transmit < Transmit > .	TransmitSeq = Transmit < Transmit > .
Transmit = TypeOrCounter 'To' ExternAttr	Transmit = TypeOrCounter 'To' ExternAttr
'(' ElemID ')' ';' .	'(' ElemID ')' ';' .
TypeOrCounter = CounterID / ElemID .	TypeOrCounter = CounterID / ElemID .
Line 9090 END</pre>	Line 8328 END</pre>
</div>	</div>

<div class="section">	<div class="section">

<h2><a name="sectb64">The T language</a></h2>	<h2><a name="sectb64">The T language</a></h2>
<pre>TransSchema = 'TRANSLATION' ElemID ';'	<pre>TransSchema = 'TRANSLATION' ElemID ';'
[ 'LINELENGTH' LineLength ';' ]	[ 'LINELENGTH' LineLength ';' ]
Line 9103 END</pre>	Line 8340 END</pre>
'RULES' ElemSeq	'RULES' ElemSeq
[ 'ATTRIBUTES' AttrSeq ]	[ 'ATTRIBUTES' AttrSeq ]
[ 'PRESENTATION' PresSeq ]	[ 'PRESENTATION' PresSeq ]
< 'TEXTTRANSLATE' TextTransSeq >	< 'TEXTTRANSLATE' TextTransSeq >
[ 'SYMBTRANSLATE' TransSeq ]	[ 'SYMBTRANSLATE' TransSeq ]
[ 'GRAPHTRANSLATE' TransSeq ]	[ 'GRAPHTRANSLATE' TransSeq ]
'END' .	'END' .

LineLength = NUMBER .	LineLength = NUMBER .

BufferSeq = Buffer < Buffer > .	BufferSeq = Buffer < Buffer > .
Buffer = BufferID [ '(' 'Picture' ')' ] ';' .	Buffer = BufferID [ '(' 'Picture' ')' ] ';' .
BufferID = NAME .	BufferID = NAME .

CounterSeq = Counter < Counter > .	CounterSeq = Counter < Counter > .
Counter = CounterID [ ':' CounterFunc ] ';' .	Counter = CounterID [ ':' CounterFunc ] ';' .
CounterID = NAME .	CounterID = NAME .
CounterFunc = 'Rank' 'of' ElemID [ SLevelAsc ]	CounterFunc = 'Rank' 'of' ElemID [ SLevelAsc ]
Line 9130 Increment = NUMBER .	Line 8367 Increment = NUMBER .
ElemID = NAME .	ElemID = NAME .
AttrID = NAME .	AttrID = NAME .

ConstSeq = Const < Const > .	ConstSeq = Const < Const > .
Const = ConstID '=' ConstValue ';' .	Const = ConstID '=' ConstValue ';' .
ConstID = NAME .	ConstID = NAME .
ConstValue = STRING .	ConstValue = STRING .

VariableSeq = Variable < Variable > .	VariableSeq = Variable < Variable > .
Variable = VarID ':' Function < Function > ';' .	Variable = VarID ':' Function < Function > ';' .
VarID = NAME .	VarID = NAME .
Function = 'Value' '(' CounterID [ ':' Length ]	Function = 'Value' '(' CounterID [ ':' Length ]
[ ',' CounterStyle ] ')' /	[ ',' CounterStyle ] ')' /
Line 9149 CounterStyle= 'Arabic' / 'LRoman' / 'U	Line 8386 CounterStyle= 'Arabic' / 'LRoman' / 'U
'Uppercase' / 'Lowercase' .	'Uppercase' / 'Lowercase' .
CharString = STRING .	CharString = STRING .

ElemSeq = TransType < TransType > .	ElemSeq = TransType < TransType > .
TransType = [ FirstSec ] ElemID ':' RuleSeq .	TransType = [ FirstSec ] ElemID ':' RuleSeq .
FirstSec = 'First' / 'Second' .	FirstSec = 'First' / 'Second' .
RuleSeq = Rule / 'BEGIN' < Rule > 'END' ';' .	RuleSeq = Rule / 'BEGIN' < Rule > 'END' ';' .
Rule = SimpleRule / ConditionBlock .	Rule = SimpleRule / ConditionBlock .
ConditionBlock= 'IF' ConditionSeq SimpleRuleSeq .	ConditionBlock= 'IF' ConditionSeq SimpleRuleSeq .
SimpleRuleSeq = 'BEGIN' < SimpleRule > 'END' ';' /	SimpleRuleSeq = 'BEGIN' < SimpleRule > 'END' ';' /
SimpleRule .	SimpleRule .

ConditionSeq = Condition [ 'AND' Condition ] .	ConditionSeq = Condition [ 'AND' Condition ] .
Line 9184 CondOnAscend = 'First' / 'Last' /	Line 8421 CondOnAscend = 'First' / 'Last' /
PresRule /	PresRule /
'Comment' .	'Comment' .
NumParent = [ GreaterLess ] NParent .	NumParent = [ GreaterLess ] NParent .
GreaterLess = '>' / '<' .	GreaterLess = '>' / '<' .
NParent = NUMBER.	NParent = NUMBER.
Alphabet = NAME .	Alphabet = NAME .
RelatAttr = '=' Value /	RelatAttr = '=' Value /
'>' [ '-' ] Minimum /	'>' [ '-' ] Minimum /
'<' [ '-' ] Maximum /	'<' [ '-' ] Maximum /
'IN' '[' [ '-' ] MinInterval '..'	'IN' '[' [ '-' ] MinInterval '..'
[ '-' ] MaxInterval ']' .	[ '-' ] MaxInterval ']' .
Line 9229 IndentValue = NUMBER .	Line 8466 IndentValue = NUMBER .
Object = ConstID / CharString /	Object = ConstID / CharString /
BufferID /	BufferID /
VarID /	VarID /
'(' Function < Function > ')' /	'(' Function < Function > ')' /
[ 'Translated' ] AttrID /	[ 'Translated' ] AttrID /
'Value' /	'Value' /
'Content' /	'Content' /
Line 9256 ExtStruct = '(' ElemID ')' .	Line 8493 ExtStruct = '(' ElemID ')' .

TrSchema = NAME .	TrSchema = NAME .

AttrSeq = TransAttr < TransAttr > .	AttrSeq = TransAttr < TransAttr > .
TransAttr = AttrID [ '(' ElemID ')' ]	TransAttr = AttrID [ '(' ElemID ')' ]
[ RelatAttr ] ':' RuleSeq .	[ RelatAttr ] ':' RuleSeq .

PresSeq = PresTrans < PresTrans > .	PresSeq = PresTrans < PresTrans > .
PresTrans = PresRule ':' RuleSeq .	PresTrans = PresRule ':' RuleSeq .
PresRule = 'Size' [ PresRelation ] /	PresRule = 'Size' [ PresRelation ] /
'Indent' [ PresRelation ] /	'Indent' [ PresRelation ] /
Line 9280 PresRule = 'Size' [ PresRelation ]	Line 8517 PresRule = 'Size' [ PresRelation ]
'Foreground' [ '=' Color ] .	'Foreground' [ '=' Color ] .

PresRelation = '=' PresValue /	PresRelation = '=' PresValue /
'>' [ '-' ] PresMinimum /	'>' [ '-' ] PresMinimum /
'<' [ '-' ] PresMaximum /	'<' [ '-' ] PresMaximum /
'IN' '[' [ '-' ] PresIntervalMin '..'	'IN' '[' [ '-' ] PresIntervalMin '..'
[ '-' ] PresIntervalMax ']' .	[ '-' ] PresIntervalMax ']' .
Line 9305 PresVal = NUMBER .	Line 8542 PresVal = NUMBER .

TextTransSeq = [ Alphabet ] TransSeq .	TextTransSeq = [ Alphabet ] TransSeq .
Alphabet = NAME .	Alphabet = NAME .
TransSeq = 'BEGIN' < Translation > 'END' ';' /	TransSeq = 'BEGIN' < Translation > 'END' ';' /
Translation .	Translation .
Translation = Source [ '->' Target ] ';' .	Translation = Source [ '->' Target ] ';' .
Source = STRING .	Source = STRING .
Target = STRING .</pre>	Target = STRING .</pre>
</div>	</div>
<hr>	<hr>

</div>	</div>

<div class="chapter">	<div class="chapter">

<h1><a name="sect7">Character coding</a></h1>	<h1><a name="sect7">Character coding</a></h1>

<div class="section">	<div class="section">

<h2><a name="sectb71">Characters</a></h2>	<h2><a name="sectb71">Characters</a></h2>
<p>
The characters of the Latin alphabet follow the encoding defined in the ISO	<p>The characters of the Latin alphabet follow the encoding defined in the ISO
8859-1 (ISO Latin-1) standard. The characters of the Greek alphabet follow	8859-1 (ISO Latin-1) standard. The characters of the Greek alphabet follow
the encoding defined by Adobe for its Symbol font (Adobe FontSpecific).</p>	the encoding defined by Adobe for its Symbol font (Adobe FontSpecific).</p>
<p>
Characters whose octal code is greater than 0200 are written in the form of	<p>Characters whose octal code is greater than 0200 are written in the form of
their octal code preceded by a backslash character (``\''). For example, the	their octal code preceded by a backslash character (``\''). For example, the
French word 'Résumé' is written <tt>R\351sum\351</tt>.</p>	French word 'Résumé' is written <tt>R\351sum\351</tt>.</p>
<p>
To the ISO 8859-1 encoding four characters with the following codes have been	<p>To the ISO 8859-1 encoding four characters with the following codes have
added:<br>	been added:<br>
<tt>212</tt>: line break<br>	<tt>212</tt>: line break<br>
<tt>240</tt>: sticky space<br>	<tt>240</tt>: sticky space<br>
<tt>201</tt>: thin space<br>	<tt>201</tt>: thin space<br>
<tt>202</tt>: en space</p>	<tt>202</tt>: en space</p>
<p>
The <tt>212</tt> character is a ``line break'' character which forces a line	<p>The <tt>212</tt> character is a ``line break'' character which forces a
break. The <tt>240</tt> character is a ``sticky space'', which cannot be	line break. The <tt>240</tt> character is a ``sticky space'', which cannot be
replaced by a line break.</p>	replaced by a line break.</p>
</div>	</div>

<div class="section">	<div class="section">

<h2><a name="sectb72">Symbols</a></h2>	<h2><a name="sectb72">Symbols</a></h2>
<p>
The table below gives the codes for the symbols of Thot. Symbols can be used	<p>The table below gives the codes for the symbols of Thot. Symbols can be
in presentation schemas constants and in transcoding rules of translation	used in presentation schemas constants and in transcoding rules of translation
schemas. Each symbol is represented by a single character.</p>	schemas. Each symbol is represented by a single character.</p>
<ul>	<ul>
<li>	<li><tt>r</tt>: a radical</li>
<tt>r</tt>: a radical	<li><tt>i</tt>: a simple integral</li>
</li>	<li><tt>c</tt>: a curvilinear integral</li>
<li>	<li><tt>d</tt>: a double integral</li>
<tt>i</tt>: a simple integral	<li><tt>t</tt>: a triple integral</li>
</li>	<li><tt>S</tt>: the summation symbol</li>
<li>	<li><tt>P</tt>: the product symbol</li>
<tt>c</tt>: a curvilinear integral	<li><tt>U</tt>: the union symbol</li>
</li>	<li><tt>I</tt>: the intersection symbol</li>
<li>	<li><tt>></tt>: a right arrow</li>
<tt>d</tt>: a double integral	<li><tt><</tt>: a left arrow</li>
</li>	<li><tt>^</tt>: an up arrow</li>
<li>	<li><tt>V</tt>: a down arrow</li>
<tt>t</tt>: a triple integral	<li><tt>(</tt>: an opening parenthesis</li>
</li>	<li><tt>)</tt>: a closing parenthesis</li>
<li>	<li><tt>{</tt>: an opening brace</li>
<tt>S</tt>: the summation symbol	<li><tt>}</tt>: a closing brace</li>
</li>	<li><tt>[</tt>: an opening bracket</li>
<li>	<li><tt>]</tt>: a closing bracket</li>
<tt>P</tt>: the product symbol
</li>
<li>
<tt>U</tt>: the union symbol
</li>
<li>
<tt>I</tt>: the intersection symbol
</li>
<li>
<tt>></tt>: a right arrow
</li>
<li>
<tt><</tt>: a left arrow
</li>
<li>
<tt>^</tt>: an up arrow
</li>
<li>
<tt>V</tt>: a down arrow
</li>
<li>
<tt>(</tt>: an opening parenthesis
</li>
<li>
<tt>)</tt>: a closing parenthesis
</li>
<li>
<tt>{</tt>: an opening brace
</li>
<li>
<tt>}</tt>: a closing brace
</li>
<li>
<tt>[</tt>: an opening bracket
</li>
<li>
<tt>]</tt>: a closing bracket
</li>
</ul>	</ul>
</div>	</div>

<div class="section">	<div class="section">

<h2><a name="sectb73">Graphical elements</a></h2>	<h2><a name="sectb73">Graphical elements</a></h2>
<p>
The table below gives the codes for the graphical elements of Thot. These	<p>The table below gives the codes for the graphical elements of Thot. These
elements can be used in presentation schemas constants and in transcoding	elements can be used in presentation schemas constants and in transcoding
rules of translation schemas. Each graphical element is represented by a	rules of translation schemas. Each graphical element is represented by a
single character.</p>	single character.</p>
<ul>	<ul>
<li>	<li>a: a circle</li>
a: a circle	<li><p><tt>A</tt>: an open curve with an arrow head at the end</p>
</li>	</li>
<li><p>	<li><tt>b</tt>: a horizontal line along the lower side of the box</li>
<tt>A</tt>: an open curve with an arrow head at the end</p>	<li><tt>B</tt>: an open curve</li>
</li>	<li><tt>c</tt>: an ellipse inscribed in the box</li>
<li>	<li><tt>C</tt>: a rectangle with rounded corners</li>
<tt>b</tt>: a horizontal line along the lower side of the box	<li><tt>D</tt>: an open curve with two arrow heads</li>
</li>	<li><tt>e</tt>: The northwest/southeast diagonal of the box with an
<li>	arrowhead at the bottom</li>
<tt>B</tt>: an open curve	<li><tt>E</tt>: The southwest/northeast diagonal of the box with an
</li>	arrowhead at the top</li>
<li>	<li><tt>F</tt>: an open curve with an arrow head at start</li>
<tt>c</tt>: an ellipse inscribed in the box	<li><tt>g</tt>: a line from the origin of the box to its opposite
</li>	corner</li>
<li>	<li><tt>h</tt>: a horizontal line as wide as the box and placed in its
<tt>C</tt>: a rectangle with rounded corners	middle</li>
</li>	<li><tt>l</tt>: a vertical line on the left side of the box</li>
<li>	<li><tt>L</tt>: a lozenge</li>
<tt>D</tt>: an open curve with two arrow heads	<li><tt>M</tt>: an open broken line with two arrow heads</li>
</li>	<li><tt>N</tt>: an open broken line with an arrow head at start</li>
<li>	<li><tt>o</tt>: The southwest/northeast diagonal of the box with an
<tt>e</tt>: The northwest/southeast diagonal of the box with an arrowhead at	arrowhead at the bottom</li>
the bottom	<li><tt>O</tt>: The northwest/southeast diagonal of the box with an
</li>	arrowhead at the top</li>
<li>	<li><tt>p</tt>: a polygon</li>
<tt>E</tt>: The southwest/northeast diagonal of the box with an arrowhead at	<li><tt>P</tt>: a rectangle with round corners and a horizontal bar at the
the top	top</li>
</li>	<li><tt>Q</tt>: an ellipse with a horizontal bar at the top</li>
<li>	<li><tt>r</tt>: a vertical line on the right side of the box</li>
<tt>F</tt>: an open curve with an arrow head at start	<li><tt>R</tt>: a rectangle which is the shape of the box</li>
</li>	<li><tt>s</tt>: a closed curve</li>
<li>	<li><tt>S</tt>: an open broken line</li>
<tt>g</tt>: a line from the origin of the box to its opposite corner	<li><tt>t</tt>: a horizontal line along the upper side of the box</li>
</li>	<li><tt>U</tt>: an open broken line with an arrow head at the end</li>
<li>	<li><tt>v</tt>: a vertical line as tall as the box and placed in its
<tt>h</tt>: a horizontal line as wide as the box and placed in its middle	middle</li>
</li>	<li><tt>V</tt>: a down arrow as tall as the box and in its middle</li>
<li>	<li>w: a segment (2 points)</li>
<tt>l</tt>: a vertical line on the left side of the box	<li><tt>W</tt>: the upper right corner</li>
</li>	<li>x: a segment (2 points) with an arrow head at the end</li>
<li>	<li><tt>X</tt>: the lower right corner</li>
<tt>L</tt>: a lozenge	<li>y: a segment (2 points) with an arrow head at the end</li>
</li>	<li><tt>Y</tt>: the lower left corner</li>
<li>	<li>z: a segment (2 points) with an arrow head at the end</li>
<tt>M</tt>: an open broken line with two arrow heads	<li><tt>Z</tt>: the upper left corner</li>
</li>	<li><tt>space</tt>: a transparent element</li>
<li>	<li><tt>^</tt>: an up arrow as tall as the box and in its middle</li>
<tt>N</tt>: an open broken line with an arrow head at start	<li><tt>></tt>: a right arrow as long as the box's width and in its
</li>	middle</li>
<li>	<li><tt>></tt>: a left arrow as long as the box's width and in its
<tt>o</tt>: The southwest/northeast diagonal of the box with an arrowhead at	middle</li>
the bottom	<li><tt>/</tt>: The southwest/northeast diagonal of the box</li>
</li>	<li><tt>\</tt>: the northwest/southeast diagonal of the box</li>
<li>
<tt>O</tt>: The northwest/southeast diagonal of the box with an arrowhead at
the top
</li>
<li>
<tt>p</tt>: a polygon
</li>
<li>
<tt>P</tt>: a rectangle with round corners and a horizontal bar at the top
</li>
<li>
<tt>Q</tt>: an ellipse with a horizontal bar at the top
</li>
<li>
<tt>r</tt>: a vertical line on the right side of the box
</li>
<li>
<tt>R</tt>: a rectangle which is the shape of the box
</li>
<li>
<tt>s</tt>: a closed curve
</li>
<li>
<tt>S</tt>: an open broken line
</li>
<li>
<tt>t</tt>: a horizontal line along the upper side of the box
</li>
<li>
<tt>U</tt>: an open broken line with an arrow head at the end
</li>
<li>
<tt>v</tt>: a vertical line as tall as the box and placed in its middle
</li>
<li>
<tt>V</tt>: a down arrow as tall as the box and in its middle
</li>
<li>
w: a segment (2 points)
</li>
<li>
<tt>W</tt>: the upper right corner
</li>
<li>
x: a segment (2 points) with an arrow head at the end
</li>
<li>
<tt>X</tt>: the lower right corner
</li>
<li>
y: a segment (2 points) with an arrow head at the end
</li>
<li>
<tt>Y</tt>: the lower left corner
</li>
<li>
z: a segment (2 points) with an arrow head at the end
</li>
<li>
<tt>Z</tt>: the upper left corner
</li>
<li>
<tt>space</tt>: a transparent element
</li>
<li>
<tt>^</tt>: an up arrow as tall as the box and in its middle
</li>
<li>
<tt>></tt>: a right arrow as long as the box's width and in its middle
</li>
<li>
<tt>></tt>: a left arrow as long as the box's width and in its middle
</li>
<li>
<tt>/</tt>: The southwest/northeast diagonal of the box
</li>
<li>
<tt>\</tt>: the northwest/southeast diagonal of the box
</li>
</ul>	</ul>
<hr>	<hr>

</div>	</div>
</div>	</div>
</body>	</body>

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