<?xml version="1.0" encoding="UTF-8"?>
  <!DOCTYPE math PUBLIC "-//W3C//DTD MathML 2.0//EN"
           "http://www.w3.org/Math/DTD/mathml2/mathml2.dtd">
  <math xmlns="http://www.w3.org/1998/Math/MathML">
    <mrow>
      <mi>a</mi>
      <mo>&#x2062;<!-- &InvisibleTimes; --></mo>
      <msup>
        <mi>x</mi>
        <mn>2</mn>
      </msup>
      <mo>+</mo>
      <mi>b</mi>
      <mo>&#x2062;<!-- &InvisibleTimes; --></mo>
      <mi>x</mi>
      <mo>+</mo>
      <mi>c</mi>
    </mrow>
  </math>