Formula, Display

Mathematical equation, expression, or formula that is to be displayed as a block (callout) within the narrative flow.


A <disp-formula> need not be a “formula” in the strict mathematical sense, but can be used for any mathematical expression or equation.
This element may contain the actual characters that make up an equation or formula or a graphic that contains the formula. Thus, the mathematics can be expressed as ASCII characters; MathML, TeX, or LaTeX expressions; or as a graphic or series of graphics.
A display equation may numbered, using automatic numbering or by storing the number in a <label> element.

Related Elements

For a mathematical equation, expression, or formula which is to be displayed inline with the text, use the <inline-formula> element.


Content Model

<!ELEMENT  disp-formula %disp-formula-model;                         >

Expanded Content Model

(#PCDATA | email | ext-link | uri | inline-supplementary-material | related-article | related-object | hr | bold | fixed-case | italic | monospace | overline | overline-start | overline-end | roman | sans-serif | sc | serif | strike | underline | underline-start | underline-end | ruby | alternatives | inline-graphic | private-char | chem-struct | inline-formula | tex-math | mml:math | abbrev | index-term | index-term-range-end | milestone-end | milestone-start | named-content | styled-content | fn | target | xref | sub | sup | x | abstract | alt-text | long-desc | break | attrib | permissions | kwd-group | label | array | code | graphic | media | preformat)*


Any combination of:

This element may be contained in:

Example 1

Display formula with TeX math inside:
<p>... PCR products were separated on gel, blotted, and probed 
with a probe designed to react only with the <italic>ter1-Acc</italic>
template sequence and not with the wild-type sequence. Acc-35: 
(GG1935 <italic>ter1-Acc</italic>). Selected as described for Acc-29
<tex-math id="M1"><![CDATA[\documentclass[12pt]{minimal}
\DeclareFontShape{T1}{linotext}{m}{n} { &#x003C;-&#x003E; linotext }{}
</disp-formula> TER1/ter1-Acc: Acc-29 crossed with GG1935 Bsi-29:
(GG1929 <italic>ter1-Bsi</italic>). Constructed by integration of 
pTER1-Bsi into GG1929 and screening for cells that retained ...</p>

Example 2

Display formula with alternatives to an equation, including a textual form, a graphic, and tagged MathML:
<p>... This can be seen in the following:
<textual-form>(a + 3)<sup>2</sup> - (10 - b) = 24</textual-form>
<graphic xmlns:xlink="http://www.w3.org/1999/xlink"
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML">