texmath-0.13.1.2: test/writer/mml/msup-02.test

<<< native
[ ESuper
    (EGrouped [ EPhantom (EIdentifier "fail") , EIdentifier "k" ])
    (ENumber "2")
, ESymbol Rel "="
, ESuper (EIdentifier "k") (ENumber "2")
]
>>> mml
<?xml version='1.0' ?>
<math display="block" xmlns="http://www.w3.org/1998/Math/MathML">
  <mrow>
    <msup>
      <mrow>
        <mphantom>
          <mi>fail</mi>
        </mphantom>
        <mi>k</mi>
      </mrow>
      <mn>2</mn>
    </msup>
    <mo>=</mo>
    <msup>
      <mi>k</mi>
      <mn>2</mn>
    </msup>
  </mrow>
</math>