<!doctype html>
<html>
  <head>
    <title>mo whitespaces</title>
    <meta charset="utf-8"/>
  </head>
  <body>

    <!-- FIXME: Currently whitespace are only collapsed for operators with special painting -->
    <math><mo>(</mo><mi>x</mi><mo>&#x20;&#x9;&#xA;&#xD;+&#x20;&#x9;&#xA;&#xD;</mo><mi>y</mi><mo>)</mo></math>

  </body>
</html>