On Tue, Dec 10, 2013 at 02:31:30PM -0800, Christopher Smith wrote:
>  > -    f = Function('f', nargs=1)
>    It would help if you give an example of what you mean by "it was working
>    before". Here's what I mean by saying it doesn't work:
>    >> from sympy import * >> f=Function('f', nargs=2)
>    # three issues: 1) f.nargs is not 2, it's None

Oh, I see.  I was wrong here.

Anyway, I think it should work this way for the second
reason (to be immutable).