add hash function for fofTypes

fofTypes.py

@@ -13,7 +13,7 @@ def __eq__(self,other):
         return repr(self) == repr(other)
 
     def __hash__(self):
-        return int(repr(self))
+        return hash(self.op) ^ hash(self.term)
 
 class BinaryOperand(object):
 
@@ -27,7 +27,7 @@ def __eq__(self,other):
         return repr(self) == repr(other)
 
     def __hash__(self):
-        return int(repr(self))
+        return hash(self.op) ^ hash(self.terms)
 
 class Identifier(object):
 
@@ -40,6 +40,9 @@ def __repr__(self):
     def __eq__(self,other):
         return repr(self) == repr(other)
 
+    def __hash__(self):
+        return hash(self.name)
+
 class Quantor(object):
 
     def __init__(self, string, variables, term):