ci4

type check

<math xmlns="http://www.w3.org/1998/Math/MathML">
  <apply>
    <csymbol cd="arith1">plus</csymbol>
    <semantics>
      <ci>x</ci>
      <annotation-xml cd="mathmltypes" name="type" encoding="MathML-Content">
        <ci>real</ci>
      </annotation-xml>
    </semantics>
    <semantics>
      <ci>x</ci>
      <annotation-xml cd="mathmltypes" name="type" encoding="MathML-Content">
        <ci>integer</ci>
      </annotation-xml>
    </semantics>
    <semantics>
      <ci>x</ci>
      <annotation-xml cd="mathmltypes" name="type" encoding="MathML-Content">
        <ci>rational</ci>
      </annotation-xml>
    </semantics>
    <semantics>
      <ci>y</ci>
      <annotation-xml cd="mathmltypes" name="type" encoding="MathML-Content">
        <ci>complex-cartesian</ci>
      </annotation-xml>
    </semantics>
    <semantics>
      <ci>θ</ci>
      <annotation-xml cd="mathmltypes" name="type" encoding="MathML-Content">
        <ci>complex-polar</ci>
      </annotation-xml>
    </semantics>
    <semantics>
      <ci>v</ci>
      <annotation-xml cd="mathmltypes" name="type" encoding="MathML-Content">
        <ci>vector</ci>
      </annotation-xml>
    </semantics>
    <semantics>
      <ci>π</ci>
      <annotation-xml cd="mathmltypes" name="type" encoding="MathML-Content">
        <ci>constant</ci>
      </annotation-xml>
    </semantics>
    <ci>ⅇ</ci>
    <ci>ⅇ</ci>
    <ci>ⅈ</ci>
    <ci>ⅈ</ci>
    <ci>γ</ci>
    <ci>∞</ci>
  </apply>
</math>

Author: Design Science, Inc. (E. Cannon, E. Tabacman, R.Miner)