rec-bvar2

<math xmlns="http://www.w3.org/1998/Math/MathML">
  <apply>
    <csymbol cd="calculus1">defint</csymbol>
    <apply>
      <csymbol cd="set1">suchthat</csymbol>
      <ci>R</ci>
      <bind>
        <csymbol cd="fns1">lambda</csymbol>
        <bvar>
          <ci>x</ci>
        </bvar>
        <apply>
          <csymbol cd="set1">in</csymbol>
          <ci>x</ci>
          <ci>D</ci>
        </apply>
      </bind>
    </apply>
    <bind>
      <csymbol cd="fns1">lambda</csymbol>
      <bvar>
        <ci>x</ci>
      </bvar>
      <apply>
        <semantics>
          <ci>f</ci>
          <annotation-xml cd="mathmltypes" name="type" encoding="MathML-Content">
            <ci>fn</ci>
          </annotation-xml>
        </semantics>
        <ci>x</ci>
      </apply>
    </bind>
  </apply>
</math>

Author: MathML 2 Recommendation