<math xmlns="http://www.w3.org/1998/Math/MathML">
<apply>
<csymbol cd="set1">in</csymbol>
<ci>x</ci>
<semantics>
<ci>R</ci>
<annotation-xml cd="mathmltypes" name="type" encoding="MathML-Content">
<ci>set</ci>
</annotation-xml>
</semantics>
</apply>
</math>
Author: Design Science, Inc. (E. Cannon, E. Tabacman, R.Miner)