rec-set2

W3C sample	WIRIS
	$x x 5 x x$

<math xmlns="http://www.w3.org/1998/Math/MathML">
  <set>
    <bvar>
      <ci>x</ci>
    </bvar>
    <condition>
      <apply>
        <and/>
        <apply>
          <lt/>
          <ci>x</ci>
          <cn>5</cn>
        </apply>
        <apply>
          <in/>
          <ci>x</ci>
          <naturalnumbers/>
        </apply>
      </apply>
    </condition>
    <ci>x</ci>
  </set>
</math>

Author: MathML 2 Recommendation