texmath-0.12.5: test/writer/mml/msub-03.test

<<< native
[ ESub (EIdentifier "V") (ESymbol Bin "+")
, ESymbol Rel "="
, ESub
    (EIdentifier "V")
    (ESub (ESymbol Bin "+") (EPhantom (EIdentifier "fail")))
]
>>> mml
<?xml version='1.0' ?>
<math display="block" xmlns="http://www.w3.org/1998/Math/MathML">
  <mrow>
    <msub>
      <mi>V</mi>
      <mo>+</mo>
    </msub>
    <mo>=</mo>
    <msub>
      <mi>V</mi>
      <msub>
        <mo>+</mo>
        <mphantom>
          <mi>fail</mi>
        </mphantom>
      </msub>
    </msub>
  </mrow>
</math>