sympy/sympy — pull request #1246 by smichr (2012-04-17 09:47:06+00:00)
Title: WIP Integral.transform changes

There is no inverse option any more: you either pass something like `transform(x**2 - 1, u)` or `transform(x, 2*u)` to change x -> u in the integral using the relationships given. u (or f(u)) can be written in terms of x if you don't want a new variable -- a temporary u is used internally to make this work.

This should feel a lot more natural in terms of thought process (IMHO). If you have any transforms that you think should work that don't work here, please make a note.

This is an alternative to https://github.com/sympy/sympy/pull/1232 .