some

mphantomSinheritance5

W3C sample	WIRIS
	$A A A A A A A + A A$

<math xmlns="http://www.w3.org/1998/Math/MathML">
  <mstyle mathbackground="Blue">
    <mi>A</mi>
    <mstyle scriptlevel="2">
      <mphantom>
        <mi>A</mi>
      </mphantom>
    </mstyle>
    <mi>A</mi>
    <mstyle fontweight="bold">
      <mphantom>
        <mi>A</mi>
        <mo>+</mo>
        <mi>A</mi>
      </mphantom>
      <mi>A</mi>
    </mstyle>
  </mstyle>
  <mi>A</mi>
  <mstyle scriptlevel="2">
    <mi>A</mi>
  </mstyle>
  <mi>A</mi>
  <mstyle fontweight="bold">
    <mi>A</mi>
    <mo>+</mo>
    <mi>A</mi>
    <mi>A</mi>
  </mstyle>
</math>

Author: Robert Miner and Jeff Schaefer, Geometry Technologies