Formatting of right hand side of equation should be identical to formatting of left hand side
<math xmlns="http://www.w3.org/1998/Math/MathML" display="block">
<msup>
<mi>x</mi>
<mn>3</mn>
</msup>
<mo>=</mo>
<msup>
<mrow>
<mi>x</mi>
</mrow>
<mrow>
<mn>3</mn>
</mrow>
</msup>
</math>
Author: George Chavchanidze, Opera Software ASA