boost_1_45_0/libs/math/doc/sf_and_dist/equations/igamma5.mml

<math xmlns="http://www.w3.org/1998/Math/MathML" display="block">
  <mrow>
    <mi>Q</mi>
    <mfenced>
      <mrow>
        <mi>a</mi>
        <mo>,</mo>
        <mi>x</mi>
      </mrow>
    </mfenced>
    <mo>+</mo>
    <mi>P</mi>
    <mfenced>
      <mrow>
        <mi>a</mi>
        <mo>,</mo>
        <mi>x</mi>
      </mrow>
    </mfenced>
    <mspace width="1em"/>
    <mo>=</mo>
    <mspace width="1em"/>
    <mn>1</mn>
  </mrow>
</math>