<<< native
[ ENumber "1" , ESpace (1 % 6) , ENumber "2" ]
>>> mml
<?xml version='1.0' ?>
<math display="block" xmlns="http://www.w3.org/1998/Math/MathML">
  <mrow>
    <mn>1</mn>
    <mspace width="0.167em" />
    <mn>2</mn>
  </mrow>
</math>