sympy/sympy — pull request #948 by goodok (2012-01-10 04:34:24+00:00)
Title: issue 2975: Simplification of hypebolic identity.

For hyperbolic functions added simplification rules, similar like for trigonometric ones.

That is:
>>> (cosh(x)**2 - sinh(x)**2).simplify()
1
>>> (sinh(x)**2 + 1).simplify()
cosh(x)**2

Remarks:
The new analog of 'trigsim' is 'hyperbolic_simp'. This name-token is not fine.
But there is the 'hypersimp' which is present already and deal with combinatorics.

See [Issue 2975](http://code.google.com/p/sympy/issues/detail?id=2975)