Merge pull request #1437 from Krastanov/subs_hashable_content

Correct the _hashable_content of Subs.
sympy · Jul 21, 2012 · c84e5df · c84e5df
2 parents 1cc8817 + 9644d2f
commit c84e5df
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/sympy/core/function.py b/sympy/core/function.py
@@ -1445,7 +1445,7 @@ def __hash__(self):
         return super(Subs, self).__hash__()
 
     def _hashable_content(self):
-        return self._expr
+        return (self._expr, )
 
     def _eval_subs(self, old, new):
         if old in self.variables: