sympy/sympy — pull request #8389 by cbm755 (2014-11-06 00:08:45+00:00)
Title: Infinity/NegativeInfinity: simplify relational code

> If we call `Expr.__lt__` then we do not need as much error checking
> here. In particular, can drop the "compare to nonreal" error.

This is also makes #7834 bit nicer, but seems reasonable change on its own too.