texmath-0.12.5: test/writer/mml/attribQuote1.test

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