type check
<math xmlns="http://www.w3.org/1998/Math/MathML"> <apply> <plus/> <ci type="real">x</ci> <ci type="integer">x</ci> <ci type="rational">x</ci> <ci type="complex-cartesian">y</ci> <ci type="complex-polar"> θ</ci> <ci type="vector">v</ci> <ci type="constant"> π</ci> <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)