Re(x+iy)
<math xmlns="http://www.w3.org/1998/Math/MathML"> <apply> <real/> <apply> <plus/> <ci>x</ci> <apply> <times/> <cn> ⅈ</cn> <ci>y</ci> </apply> </apply> </apply> </math>
Author: MathML 2 Recommendation