texmath-0.12.5: test/writer/mml/msubsup-02.test

<<< native
[ ESubsup
    (EGrouped [ EPhantom (EIdentifier "z") , EIdentifier "S" ])
    (EIdentifier "t")
    (ENumber "7")
, ESymbol Rel "="
, ESubsup (EIdentifier "S") (EIdentifier "t") (ENumber "7")
]
>>> mml
<?xml version='1.0' ?>
<math display="block" xmlns="http://www.w3.org/1998/Math/MathML">
  <mrow>
    <msubsup>
      <mrow>
        <mphantom>
          <mi>z</mi>
        </mphantom>
        <mi>S</mi>
      </mrow>
      <mi>t</mi>
      <mn>7</mn>
    </msubsup>
    <mo>=</mo>
    <msubsup>
      <mi>S</mi>
      <mi>t</mi>
      <mn>7</mn>
    </msubsup>
  </mrow>
</math>