passed

mphantomB1

Basic test of <mphantom> element.

W3C sample	WIRIS
	$A A + \frac{1 + 2 + 3}{1 + 3}$

<math xmlns="http://www.w3.org/1998/Math/MathML">
  <mrow>
    <mi>A</mi>
    <mphantom>
      <mi>A</mi>
    </mphantom>
    <mi>A</mi>
    <mo>+</mo>
    <mfrac>
      <mrow>
        <mn>1</mn>
        <mo>+</mo>
        <mn>2</mn>
        <mo>+</mo>
        <mn>3</mn>
      </mrow>
      <mrow>
        <mn>1</mn>
        <mo>+</mo>
        <mphantom>
          <mn>2</mn>
          <mo form="infix">+</mo>
        </mphantom>
        <mn>3</mn>
      </mrow>
    </mfrac>
  </mrow>
</math>

Author: Robert Miner and Jeff Schaefer, Geometry Technologies