Test italic/upright text
<math xmlns="http://www.w3.org/1998/Math/MathML">
  <mover>
    <mi>xxx</mi>
    <mo>¯</mo>
  </mover>
  <mo>=</mo>
  <mover>
    <mi mathvariant="italic">xxx</mi>
    <mo>¯</mo>
  </mover>
</math>
Author: Design Science, Inc. (D. Doyle, R.Miner)