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Glossary

What is MathML?

Updated:

MathML is the XML language for mathematical notation, allowed inside EPUB 3 content documents so equations stay text instead of images. Support in reading apps varies.

Why it matters when you convert a PDF to EPUB

A PDF draws an equation as positioned glyphs and lines, with no record of its structure. Rebuilding MathML from that is hard; a converter that cannot do it reliably should keep the equation's text in order rather than produce wrong mathematics. EPUBCheck asks MathML to carry alternative text (ACC-009).

How EpubCC handles it: the engine does not build MathML. An equation in a PDF comes out as the text characters the PDF contains, which keeps simple formulas readable but loses fraction bars, roots and layout in complex ones; the calculus textbook case shows what that looks like on a real book. A document full of equations is usually better kept as a PDF.

Related terms

EPUBCheck messages about this

  • ACC-009 MathML should either have an "alttext" attribute or "annotation-xml" child element.
  • OPF-014 The property "…" should be declared in the OPF file.

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FAQ

What is MathML?

MathML is the XML language for mathematical notation, allowed inside EPUB 3 content documents so equations stay text instead of images. Support in reading apps varies.