Give up on depends().

theano/gof/sched.py

@@ -36,8 +36,9 @@ def memodict(f):
 
 def make_depends():
     @memodict
-    def depends(a, b):
+    def depends(pair):
         """ Returns True if a depends on b """
+        a, b = pair
         return (any(bout in a.inputs for bout in b.outputs)
                 or any(depends((ainp.owner, b)) for ainp in a.inputs
                        if ainp.owner))
@@ -56,9 +57,9 @@ def make_dependence_cmp():
         Returns negative number if b depends on a
         Returns 0 otherwise
         """
-        if depends(a, b):
+        if depends((a, b)):
             return 1
-        if depends(b, a):
+        if depends((b, a)):
             return -1
         return 0