4.8.15 MathML

The math element from the MathML namespace falls into the embedded content, phrasing content, and flow content categories for the purposes of the content models in this specification.

User agents must handle text other than inter-element whitespace found in MathML elements whose content models do not allow straight text by pretending for the purposes of MathML content models, layout, and rendering that that text is actually wrapped in an mtext element in the MathML namespace. (Such text is not, however, conforming.)

User agents must act as if any MathML element whose contents does not match the element's content model was replaced, for the purposes of MathML layout and rendering, by an merror element in the MathML namespace containing some appropriate error message.

To enable authors to use MathML tools that only accept MathML in its XML form, interactive HTML user agents are encouraged to provide a way to export any MathML fragment as an XML namespace-well-formed XML fragment.

The semantics of MathML elements are defined by the MathML specification and other applicable specifications. [MATHML]

Here is an example of the use of MathML in an HTML document:

<!DOCTYPE html>
  <title>The quadratic formula</title>
  <h1>The quadratic formula</h1>
      <mo form="prefix">−</mo> <mi>b</mi>
       <msup> <mi>b</mi> <mn>2</mn> </msup>
       <mn>4</mn> <mo>⁢</mo> <mi>a</mi> <mo>⁢</mo> <mi>c</mi>
      <mn>2</mn> <mo>⁢</mo> <mi>a</mi>