mover1

W3C sample WIRIS
x ^  vs   x ^ 
<math xmlns="http://www.w3.org/1998/Math/MathML">
  <mrow>
    <mover accent="true">
      <mi>x</mi>
      <mo> &#x005E;</mo>
    </mover>
    <mtext> &#x2003;vs &#x2003;</mtext>
    <mover accent="false">
      <mi>x</mi>
      <mo> &#x005E;</mo>
    </mover>
  </mrow>
</math>

Author: Wolfram Research