ElementaryMathExamples-mstack02

test for : mstack stackalign="center"

W3C sample	WIRIS
	$111111111$

<math xmlns="http://www.w3.org/1998/Math/MathML">
  <mstack stackalign="center">
    <mn>1</mn>
    <mn>111</mn>
    <mn>11111</mn>
  </mstack>
</math>

Author: Yecheng Gu