rec-int4

W3C sample	WIRIS
	$x a b x$

<math xmlns="http://www.w3.org/1998/Math/MathML">
  <apply>
    <int/>
    <bvar>
      <ci>x</ci>
    </bvar>
    <interval>
      <ci>a</ci>
      <ci>b</ci>
    </interval>
    <apply>
      <cos/>
      <ci>x</ci>
    </apply>
  </apply>
</math>

Author: MathML 2 Recommendation