Content model for the <disp-formula> element
<!ENTITY % disp-formula-model
"(#PCDATA %disp-formula-elements;)*" >(#PCDATA | alt-text | long-desc | email | ext-link | multi-link | uri | break | bold | italic | monospace | overline | overline-start | overline-end | roman | sans-serif | sc | strike | underline | underline-start | underline-end | inline-graphic | private-char | chem-struct | inline-formula | label | named-content | styled-content | tex-math | mml:math | alternatives | array | graphic | media | preformat | sub | sup)*
math3.ent