<?xml version="1.0" encoding="UTF-8" ?>
<math xmlns="http://www.w3.org/1998/Math/MathML">
  <msup>
    <mfenced>
      <mrow>
        <mi>a</mi>
        <mo>+</mo>
        <mi>b</mi>
      </mrow>
    </mfenced>
    <mn>2</mn>
  </msup>
</math>
