<!doctype html>
<body>
  <math>
    <mmultiscripts>
      <mo>A</mo>
      <mprescripts/>
      <mmultiscripts>
        <mo>A</mo>
        <mprescripts/>
        <mo>A</mo>
        <mo>A</mo>
      </mmultiscripts>
      <mmultiscripts>
        <mo>A</mo>
        <mprescripts/>
        <mo>A</mo>
        <mo>A</mo>
      </mmultiscripts>
    </mmultiscripts>
  </math>
</body>
