i2 : mathML matrix {{x,y},{x^2+2,0}}
o2 = <matrix>
<matrixrow><ci>x</ci><ci>y</ci></matrixrow>
<matrixrow><apply><plus/><apply><power/><ci>x</ci><cn type='integer'>2</cn></apply>
<cn type='integer'>2</cn></apply>
<ci>0</ci></matrixrow>
</matrix>
o2 : String |