Mathematical equation, expression, or formula that is to be displayed inline. The mathematics itself can be expressed as ASCII characters, as a graphic, or using TeX, LaTeX, or MathML mathematics expressions.
Some print-oriented tag sets use a specific element to indicate “go into math mode or math font here”. While that was not the intended usage of this element, in nearly all cases the text inside such math-changes is a mathematical expression. It would not be incorrect to use this element to mark such material; however, some users may find this tagging undesirable.
<!ELEMENT inline-formula
%inline-formula-model; >(#PCDATA | bold | italic | monospace | overline | roman | sans-serif | sc | strike | underline | alternatives | inline-graphic | private-char | chem-struct | inline-formula | tex-math | mml:math | named-content | styled-content | sub | sup)*
Any combination of:
<addr-line>, <alt-title>, <article-title>, <attrib>, <award-id>, <bold>, <collab>, <comment>, <compound-kwd-part>, <compound-subject-part>, <conf-theme>, <def-head>, <disp-formula>, <element-citation>, <funding-source>, <inline-formula>, <italic>, <label>, <license-p>, <meta-value>, <mixed-citation>, <monospace>, <named-content>, <overline>, <p>, <product>, <roman>, <sans-serif>, <sc>, <strike>, <styled-content>, <sub>, <subject>, <subtitle>, <sup>, <supplement>, <td>, <term>, <term-head>, <th>, <title>, <trans-subtitle>, <trans-title>, <underline>, <verse-line>
... <p>... (e) For any neighboring cells, <italic>j</italic> and <italic>k</italic>, <inline-formula>σ<sub>je</sub>=σ<sub>ke</sub> </inline-formula>, <inline-formula>σ<sub>ji</sub>=σ<sub>ki</sub> </inline-formula> and <inline-formula>φ<sub>je</sub>=φ<sub>ke</sub> </inline-formula>, φ<sub>e</sub> is the potential in intercellular space. For convenience, we present the algorithm for the 2-D model here; the 3-D case is similar....</p> ...
JATS-math1.ent