informalequation — A displayed mathematical equation without a title.


informalequation ::=


Common attributes and common linking attributes.

Additional attributes:

  • floatstyle
  • pgwide (enumeration)
    • “0”
    • “1”
  • type

Additional Constraints

  • If this element is the root element, it must have a version attribute.


An informalequation is usually a mathematical equation or a group of related mathematical equations.

Processing expectations

Formatted as a displayed block.


Common attributes and common linking attributes.

any attribute

Any attribute in any other explicit namespace


Specifies style information to be used when rendering the float


Indicates if the element is rendered across the column or the page

Enumerated values:

The element should be rendered in the current text flow (with the flow column width).


The element should be rendered across the full text page.


Identifies the type of equation


These elements contain informalequation: abstract, acknowledgements, annotation, answer, appendix, article, bibliodiv, bibliography, bibliolist, blockquote, callout, calloutlist, caption (db.caption), caution, chapter, colophon, constraintdef, cover, danger, dedication, entry, example, figure, footnote, glossary, glossdef, glossdiv, glosslist, important, index, indexdiv, informalexample, informalfigure, itemizedlist, legalnotice, listitem, meta (db.meta.content), msgexplan, msgtext, note, orderedlist, para, partintro, preface, procedure, qandadiv, qandaset, question, refsect1, refsect2, refsect3, refsection, refsynopsisdiv, result, revdescription, sect1, sect2, sect3, sect4, sect5, section, setindex, sidebar, simplesect, step, taskprerequisites, taskrelated, tasksummary, td, textobject, th, tip, toc, tocdiv, topic, variablelist, warning.


The following elements occur in informalequation: alt, caption (db.caption), info (, mathphrase, mediaobject, mml:*.

See Also

Related elements: equation, example, figure, informalexample, informalfigure, informaltable, inlineequation, subscript, superscript, table.


 1 |<article xmlns=''>
   |<title>Example informalequation</title>
   |<para>The equation
 5 |<informalequation>
   |  <alt>e^(pi*i) + 1 = 0</alt>
   |  <mediaobject>
   |    <imageobject condition="print">
   |      <imagedata fileref="figs/print/db5d_refeqn02.pdf"/>
10 |    </imageobject>
   |    <imageobject condition="web">
   |      <imagedata fileref="figs/web/db5d_refeqn02.png"/>
   |    </imageobject>
   |  </mediaobject>
15 |</informalequation>
   |is delightful because it joins together five of the most
   |important mathematical constants.
20 |</article>

The equation

is delightful because it joins together five of the most important mathematical constants.