
<!DOCTYPE math
  PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<math xmlns="http://www.w3.org/1998/Math/MathML">
<condition>
  <apply><in/><ci> x </ci><ci type="set"> R </ci></apply>
</condition>
</math>
