texmath-0.13.1.2: test/writer/mml/msub-10.test

<<< native
[ ESub (EIdentifier "S") (ENumber "5")
, ESymbol Rel "="
, EUnder
    False
    (ESub (EIdentifier "S") (ENumber "5"))
    (EPhantom (EIdentifier "t"))
]
>>> mml
<?xml version='1.0' ?>
<math display="block" xmlns="http://www.w3.org/1998/Math/MathML">
  <mrow>
    <msub>
      <mi>S</mi>
      <mn>5</mn>
    </msub>
    <mo>=</mo>
    <munder>
      <msub>
        <mi>S</mi>
        <mn>5</mn>
      </msub>
      <mphantom>
        <mi>t</mi>
      </mphantom>
    </munder>
  </mrow>
</math>