sympy/sympy — pull request #1629 by rlamy (2012-10-31 02:55:22+00:00)
Title: Make AssocOp inherit directly from Basic, not Expr.

This change allows AssocOp to be used as base class for any kind
of object, not just Expr subclasses. Additionally, it avoids
the nonsensical inheritance of Expr by And and Or.

* Fix relevant bases declarations and imports.
* Remove the one test allowing multiplication of Or objects.
* count_ops() now treats And the same as Eq.