fin de constant propag sans raffinement

tp2/Pystan/config/constant_propagation.py

@@ -121,7 +121,7 @@ class Constant_propagation(Transfer[state]):
             return False
         else:
             for var in s1:
-                included = included and ((s1[var]==s2[var]) | (s1[var] == None))
+                included = included and ((s1[var]==s2[var]) | (s1[var] == abstract_value(None)))
             return included
 
     def tr_skip(self,s: state) -> state: