SymPy exports module Q

[olof3]

This is a bit annoying since Q is quite nice letter for various matrices and other objects.

julia> using SymPy
julia> Q = [2 1; 1 3]
ERROR: cannot assign a value to variable SymPy.Q from module Main

Would it be reasonable to just avoid exporting Q? With or without deprecating it first.

I couldn't immediately find any other instances that are as problematic as this one, but I guess it could be worthwhile to have a second look.

[jverzani]

I would think we could deprecate Q from being exported. N is a different matter, as it has a pretty common usage. I would think offering a unicode alternative and SymPy.Q. What is somewhat cumbersome, is sympy.Q doesn't offer an alternative. Do you want to put together a PR? If not, I'll get to it at some point in the near term.

[olof3]

I think you have a better vision of how to fix this. No hurry on my part.