texmath-0.12.5: test/writer/mml/mid1.test

<<< native
[ ESymbol Rel "\8739" , EIdentifier "x" , ESymbol Rel "\8739" ]
>>> mml
<?xml version='1.0' ?>
<math display="block" xmlns="http://www.w3.org/1998/Math/MathML">
  <mrow>
    <mo>∣</mo>
    <mi>x</mi>
    <mo>∣</mo>
  </mrow>
</math>