sympy/sympy — pull request #1637 by mrocklin (2012-11-02 13:01:23+00:00)
Title: Assumptions on non-atomic args in predictates

Removed the following lines from ask.py

```
if not expr.is_Atom:
return None
```

This stopped things like the following from working

ask(Q.real(Trace(X)), Q.positive(Trace(X)))

Because it would return None if all it had were non-atomic arguments in applied predicates.

This fixes an error with #1633 so I'd like to get it in quickly. I put it here because I don't know much about assumptions and I felt that this was easier to review.