Display:

$\begin{pmatrix}1 & 2\\ 3 & 4\end{pmatrix}_{1}1 & 2\\ A_{3, 2}V_1$

Source:

<apply>
     <selector/>
     <matrix>
          <matrixrow>
               <cn> 1 </cn>
               <cn> 2 </cn>
          </matrixrow>
          <matrixrow>
               <cn> 3 </cn>
               <cn> 4 </cn>
          </matrixrow>
     </matrix>
     <cn> 1 </cn>
</apply>
<matrixrow>
     <cn> 1 </cn>
     <cn> 2 </cn>
</matrixrow>
<apply>
     <selector/>
     <ci type="matrix"> A </ci>
     <cn> 3 </cn>
     <cn> 2 </cn>
</apply>
<apply>
     <selector/>
     <ci type="vector">V</ci>
     <cn> 1 </cn>
</apply>