How does one define a generic real valued function in Mathematica? In particular, I would like to utilize Mathematica to perform algebraic reductions that involve combinations of zj(q) = xj(q) + i yj(q) and D[zj(q),{q,n}] where xj(q), yj(q) and q are all generic real valued functions, and where j and n are integers; i is used here to represent the square root of -1. For example, by default Mathematica assumes these are complex valued functions, which, in turn, significantly effects the output of Simplify[] and and FullSimplify[]. Thanks in advance!
