        font-family: operators;
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    <math display=block>
     <mrow>
     <mspace depth="5em"/>
      <mrow>
        <mover>
          <mo stretchy="true">&#x2191;</mo>
          <mn>B</mn>
        </mover>
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      <mspace depth="5em"/>
     </mrow>
    </math>
  </body>
</html>
