<formula>

<formula> 包含數學或其他方程式。 [14.2 Formulæ and Mathematical Expressions]
組件figures — Tables, Formulæ, Graphics and Notated Music
屬性att.global (@xml:id, @n, @xml:lang, @xml:base, @xml:space) (att.global.rendition (@rend, @style, @rendition)) (att.global.linking (@corresp, @synch, @sameAs, @copyOf, @next, @prev, @exclude, @select)) (att.global.analytic (@ana)) (att.global.facs (@facs)) (att.global.change (@change)) (att.global.responsibility (@cert, @resp))
notation提供先前已定義過、適用於該元素內容的記號名稱。
狀態 非必備的
資料類型 

<rng:ref name="data.enumerated"/>
data.enumerated
俱乐部会员
model.graphicLike
可包含在於
analysis: cl phr s
core: abbr add addrLine author biblScope citedRange corr date del distinct editor email emph expan foreign gloss head headItem headLabel hi item l label measure mentioned name note num orig p pubPlace publisher q quote ref reg rs said sic soCalled speaker stage street term textLang time title unclear
dictionaries: case colloc def dictScrap entryFree etym form gen gram gramGrp hyph iType lang lbl mood number orth per pos pron re sense stress subc syll tns usg xr
drama: actor camera caption castItem role roleDesc sound tech view
figures: cell figure formula table
gaiji: char glyph
header: change distributor edition extent geoDecl handNote licence scriptNote typeNote
linking: ab seg
msdescription: accMat acquisition additions catchwords collation colophon condition custEvent decoNote explicit filiation finalRubric foliation heraldry incipit layout material musicNotation objectType origDate origPlace origin provenance rubric secFol signatures source stamp summary support surrogates watermark
namesdates: addName affiliation birth bloc country death district education faith floruit forename genName geogFeat geogName nameLink nationality occupation offset orgName persName placeName region residence roleName settlement sex socecStatus surname
spoken: u writing
tagdocs: eg
textcrit: lem rdg wit witDetail
textstructure: byline closer dateline docAuthor docDate docEdition docImprint imprimatur opener salute signed titlePart trailer
transcr: damage facsimile fw metamark mod restore retrace secl sourceDoc supplied surface surplus zone
verse: rhyme
可包含
core: binaryObject graphic hi media
figures: formula
宣告

<rng:element name="formula">
 <rng:ref name="att.global.attributes"/>
 <rng:ref name="att.global.rendition.attributes"/>
 <rng:ref name="att.global.linking.attributes"/>
 <rng:ref name="att.global.analytic.attributes"/>
 <rng:ref name="att.global.facs.attributes"/>
 <rng:ref name="att.global.change.attributes"/>
 <rng:ref name="att.global.responsibility.attributes"/>
 <rng:optional>
  <rng:attribute name="notation">
   <rng:ref name="data.enumerated"/>
  </rng:attribute>
 </rng:optional>
 <rng:zeroOrMore>
  <rng:choice>
   <rng:text/>
   <rng:ref name="model.graphicLike"/>
   <rng:ref name="model.hiLike"/>
  </rng:choice>
 </rng:zeroOrMore>
</rng:element>
element formula
{
   att.global.attributes,
   att.global.rendition.attributes,
   att.global.linking.attributes,
   att.global.analytic.attributes,
   att.global.facs.attributes,
   att.global.change.attributes,
   att.global.responsibility.attributes,
   attribute notation { data.enumerated }?,
   ( text | model.graphicLike | model.hiLike )*
}
例子
<formula notation="tex">$E=mc^2$</formula>
例子
<formula notation="none">E=mc<hi rend="sup">2</hi>
</formula>
例子
<formula notation="mathml">
 <m:math>
  <m:mi>E</m:mi>
  <m:mo>=</m:mo>
  <m:mi>m</m:mi>
  <m:msup>
   <m:mrow>
    <m:mi>c</m:mi>
   </m:mrow>
   <m:mrow>
    <m:mn>2</m:mn>
   </m:mrow>
  </m:msup>
 </m:math>
</formula>