<math xmlns="http://www.w3.org/1998/Math/MathML"> <apply> <int/> <bvar> <ci>x</ci> </bvar> <condition> <apply> <in/> <ci>x</ci> <ci>D</ci> </apply> </condition> <apply> <ci type="fn">f</ci> <ci>x</ci> </apply> </apply> </math>
Author: MathML 2 Recommendation