Display:

$\frac{\partial^{n+m}\sin (xy)}{\partial x^n\partial y^m}$

Source:

<apply>
     <partialdiff/>
     <bvar>
          <ci> x </ci>
          <degree>
               <ci> n </ci>
          </degree>
     </bvar>
     <bvar>
          <ci> y </ci>
          <degree>
               <ci> m </ci>
          </degree>
     </bvar>
     <apply>
          <sin/>
          <apply>
               <times/>
               <ci> x </ci>
               <ci> y </ci>
          </apply>
     </apply>
</apply>