texmath-0.12.5: test/writer/mml/msubsup-10.test

<<< native
[ ESubsup (EIdentifier "p") (EIdentifier "x") (ENumber "3")
, ESymbol Rel "="
, EUnder
    False
    (ESubsup (EIdentifier "p") (EIdentifier "x") (ENumber "3"))
    (EPhantom (EText TextNormal "l"))
]
>>> mml
<?xml version='1.0' ?>
<math display="block" xmlns="http://www.w3.org/1998/Math/MathML">
  <mrow>
    <msubsup>
      <mi>p</mi>
      <mi>x</mi>
      <mn>3</mn>
    </msubsup>
    <mo>=</mo>
    <munder>
      <msubsup>
        <mi>p</mi>
        <mi>x</mi>
        <mn>3</mn>
      </msubsup>
      <mphantom>
        <mtext mathvariant="normal">l</mtext>
      </mphantom>
    </munder>
  </mrow>
</math>