<!DOCTYPE html>
<html>
<head>
  <title>op-dict lspace and rspace</title>
</head>
<body>
  <math>
    <mrow>
      <!-- This spacing was specified in older MathML specification, see
          https://www.w3.org/TR/MathML3/appendixc.html -->
      <mi>x</mi><mo form="prefix" lspace="0.1111111111111111em" rspace="0.05555555555555555em">&#x2202;</mo><mi>y</mi>
    </mrow>
  </math>
</body>
</html>
