sizeunits3

W3C sample	WIRIS
	$x+M+x+x+x+x+x+x+x+x+x$

<math xmlns="http://www.w3.org/1998/Math/MathML">
  <mrow>
    <mi>x</mi>
    <mo>+</mo>
    <mi>M</mi>
    <mo>+</mo>
    <mi mathsize="2em">x</mi>
    <mo>+</mo>
    <mi mathsize="2ex">x</mi>
    <mo>+</mo>
    <mi mathsize=".1in">x</mi>
    <mo>+</mo>
    <mi mathsize=".5cm">x</mi>
    <mo>+</mo>
    <mi mathsize="8mm">x</mi>
    <mo>+</mo>
    <mi mathsize="24pt">x</mi>
    <mo>+</mo>
    <mi mathsize="2pc">x</mi>
    <mo>+</mo>
    <mi mathsize="75%">x</mi>
    <mo>+</mo>
    <mi mathsize="36pt">x</mi>
  </mrow>
</math>

Author: Robert Miner and Jeff Schaefer, Geometry Technologies