boost_1_45_0/libs/math/doc/sf_and_dist/equations/beta5.mml

<math xmlns="http://www.w3.org/1998/Math/MathML" display="block">
  <mrow>
    <mtext>beta</mtext>
    <mfenced>
      <mrow>
        <mi>a</mi>
        <mo>,</mo>
        <mi>b</mi>
      </mrow>
    </mfenced>
    <mo>=</mo>
    <mfrac>
      <mrow>
        <mfenced>
          <mrow>
            <mi>a</mi>
            <mo>+</mo>
            <mi>b</mi>
          </mrow>
        </mfenced>
        <mfenced>
          <mrow>
            <mi>a</mi>
            <mo>+</mo>
            <mi>b</mi>
            <mo>+</mo>
            <mn>1</mn>
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        </mfenced>
      </mrow>
      <mrow>
        <mi>a</mi>
        <mi>b</mi>
      </mrow>
    </mfrac>
    <mtext>beta</mtext>
    <mfenced>
      <mrow>
        <mi>a</mi>
        <mo>+</mo>
        <mn>1,</mn>
        <mi>b</mi>
        <mo>+</mo>
        <mn>1</mn>
      </mrow>
    </mfenced>
  </mrow>
</math>