rec-notanumber1

NaN

W3C sample	WIRIS
	$\frac{0}{0}=NaN$

<math xmlns="http://www.w3.org/1998/Math/MathML">
  <apply>
    <eq/>
    <apply>
      <divide/>
      <cn>0</cn>
      <cn>0</cn>
    </apply>
    <notanumber/>
  </apply>
</math>

Author: MathML 2 Recommendation