<!DOCTYPE html>
<html>
<head>
  <title>op-dict mo form</title>
</head>
<body>
  <math>
    <mrow>
      <mo form="prefix">+</mo>
      <!-- need a second child to avoid zeroing dictionary spacing -->
      <mn>1</mn>
    </mrow>
  </math>
</body>
</html>
