rec-partialdiff5

W3C sample WIRIS
1 1 3 f 
<math xmlns="http://www.w3.org/1998/Math/MathML">
  <apply>
    <partialdiff/>
    <list>
      <cn>1</cn>
      <cn>1</cn>
      <cn>3</cn>
    </list>
    <ci type="fn">f</ci>
  </apply>
</math>

Author: MathML 2 Recommendation