ical" stretchy="true">⥜</mo>
      </mrow>
    </math>
  </p>
  <p>
    <math>
      <mrow>
        <mspace style="background: blue" width="1em" height=".75em"/>
        <mo style="font-size: 50%" id="smaller_op" stretchy="true">⥜</mo>
        <mspace style="background: blue" width="1em" height="1.5em"/>
        <mo style="font-size: 200%" id="bigger_op" stretchy="true">⥜</mo>
        <mspace style="background: blue" width="1em" height="1em"/>
      </mrow>
    </math>
  </p>
  <p>
    <math>
      <m