sympy/sympy — pull request #1492 by hector1618 (2012-08-16 10:38:34+00:00)
Title: Modified gcd function (Issue 2463)

gcd takes two Integer arguments. For any other input it raises the TypeError.

Modified gcd created a problem in simplifying exponential powers. Instead of returning gcd of Rational and Integers, now it returns the gcd of nominator of Rational and Integers, wherever applicable.