<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>mfrac with three children</title>
</head>
<body>
  <p>This test passes if you see a single rectangle.</p>
  <math>
    <mrow style="padding-inline-start: 1px; padding-inline-end: 1px;">
      <mspace width="50px" height="200px" style="background: green"></mspace>
      <mspace width="50px" height="200px" style="background: green"></mspace>
      <mspace width="100px" height="200px" style="background: green"></mspace>
    </mrow>
  </math>
</body>
</html>
