Comment #12 on issue 2014 by smichr: sympy.solvers.solvers.solve should
also allow frozenset to hold equations
http://code.google.com/p/sympy/issues/detail?id=2014
I'm +1/2 with comments below. I have often thought that listing all
iterable types was kind of a clunky way to test for iterabi
csousa wants someone to pull from csousa:sign_to_sage_method:
This implements the _sage_ method of sign function as proposed here:
http://code.google.com/p/sympy/issues/detail?id=345
I filled a parallel bug to Sage using their notebook form
(http://wiki.sagemath.org/support/ReportingBugs), since
