rec-piecewise1

W3C sample	WIRIS
	$\begin{cases}0 & \text{if $x< 0$}\\ x & \text{otherwise}\end{cases}$

<math xmlns="http://www.w3.org/1998/Math/MathML">
  <piecewise>
    <piece>
      <cn>0</cn>
      <apply>
        <lt/>
        <ci>x</ci>
        <cn>0</cn>
      </apply>
    </piece>
    <otherwise>
      <ci>x</ci>
    </otherwise>
  </piecewise>
</math>

Author: MathML 2 Recommendation