test of differently sized table cells
<math xmlns="http://www.w3.org/1998/Math/MathML">
  <mtable>
    <mtr>
      <mtd>
        <mo>←</mo>
      </mtd>
      <mtd>
        <mn>1</mn>
      </mtd>
    </mtr>
    <mtr>
      <mtd>
        <mtext>a long cell</mtext>
      </mtd>
      <mtd>
        <mn>1</mn>
      </mtd>
    </mtr>
  </mtable>
</math>
Author: Design Science, Inc. (D. Doyle, E. Cannon, E. Tabacman, R.Miner)