<refentry id="equation.element">
<?dbhtml filename="equation.html"?>
<refentryinfo>
<pubdate>$Date$</pubdate>
<releaseinfo>$Revision$</releaseinfo>
</refentryinfo>

<refmeta>
<indexterm><primary>elements</primary>
<secondary>equation</secondary></indexterm>
<refentrytitle>equation</refentrytitle>
<refmiscinfo>Element</refmiscinfo>
</refmeta>
<refnamediv>
<refname>equation</refname>
<refpurpose>&equation.purpose;</refpurpose>
</refnamediv>

&equation.synopsis.gen;
<refsect1 condition='ref.description'><title>Description</title>

<para>An <sgmltag>Equation</sgmltag> is a formal mathematical equation
(with an optional rather than required title).
</para>

<para>If the MathML Module is used, <sgmltag>Equation</sgmltag> can
also contain the <sgmltag>mml:math</sgmltag> element.</para>

<refsect2><title>Processing expectations</title>
<para>
&format.block; For an inline equation, use <sgmltag>InlineEquation</sgmltag>.
</para>

<para>Processing systems that number equations or build a table of
equations at the beginning of a document may have difficulty correctly
formatting documents that contain both <sgmltag>Equation</sgmltag>s
with <sgmltag>Title</sgmltag>s and <sgmltag>Equation</sgmltag>s
without <sgmltag>Title</sgmltag>s.  You are advised to use
<sgmltag>InformalEquation</sgmltag> for equations without titles.
</para>
</refsect2>

<refsect2 role='fu' revision="5.0"><title>&FutureChanges;</title>
<para><indexterm>
<primary>DocBook DTD</primary><secondary>Changes for
<acronym>V5.0</acronym></secondary>
</indexterm>In some future version of DocBook, probably
<acronym>V5.0</acronym>, even though the change has not yet been
announced, the <sgmltag>Title</sgmltag> on <sgmltag>Equation</sgmltag>
will be required.  For equations without titles, use
<sgmltag>InformalEquation</sgmltag>.
</para>
</refsect2>


&equation.parents.gen;
&equation.children.gen;
</refsect1>
<refsect1 condition='ref.elem.attrdesc'><title>Attributes</title>
<variablelist>
<varlistentry><term>label</term>
<listitem>
<para>
<sgmltag class='attribute'>Label</sgmltag> specifies an identifying string for presentation purposes.
</para>
<para>
Generally, an explicit <sgmltag class='attribute'>Label</sgmltag> attribute is
used only if the processing system is incapable of generating the label
automatically. If present, the <sgmltag class='attribute'>Label</sgmltag> 
is normative; it will used even
if the processing system is capable of automatic labelling.
</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1 condition='ref.elem.seealso'><title>See Also</title>
&equation.seealso.gen;
</refsect1>
<refsect1><title>Examples</title>

<informalexample role="example-source">
<programlisting>&equation.example.1.txt;</programlisting>
</informalexample>

<anchor id="ex.os.equation.1" role="HACK-ex.out.start"/>
&equation.example.1.gen;
<anchor id="ex.oe.equation.1" role="HACK-ex.out.end"/>

&equation.example.seealso.gen;
</refsect1>
</refentry>

