id1.test

<<< mml
<?xml version="1.0" encoding="UTF-8"?>

<math xmlns="http://www.w3.org/1998/Math/MathML">
  <mn id="number">2</mn> 
  <mo id="operator">+</mo> 
  <mi id="identifier">x</mi> </math>
>>> native
[ ENumber "2" , ESymbol Bin "+" , EIdentifier "x" ]