sympy/sympy — pull request #2658 by smichr (2013-12-07 22:38:11+00:00)
Title: Nan compares with Rational and Add.flatten doesn't evaluate powers

https://code.google.com/p/sympy/issues/detail?id=4123

The evaluation of powers is not an open issue, but is something that came up in discussing the oo + I*oo in #2652.