[lib] CLUnfolder: __backward_code() fix typos

library/cadbiom/models/clause_constraints/mcl/CLUnfolder.py

@@ -483,15 +483,19 @@ class CLUnfolder(object):
         @return: the DIMACS coding of the backward shifted clause
         """
         num_clause = []
-        for lit in clause.list_of_literals:
-            if not lit.name[-1] == '`': # t variable
-                num_clause.append(-(self.__var_code_table[lit.name] + self.__shift_step) \
-                if not lit.sign \
-                else (self.__var_code_table[lit.name] + self.__shift_step))
-            else:  # t+1 variable
-                num_clause.append(-self.__var_code_table[lit.name[:-1]] \
-                if not lit.sign \
-                else self.__var_code_table[lit.name[:-1]])
+        for lit in clause.literals:
+            if lit.name[-1] == '`': # t+1 variable
+                num_clause.append(
+                    -self.__var_code_table[lit.name[:-1]] \
+                    if not lit.sign \
+                    else self.__var_code_table[lit.name[:-1]]
+                )
+            else: # t variable, base variable
+                num_clause.append(
+                    -(self.__var_code_table[lit.name] + self.__shift_step) \
+                    if not lit.sign \
+                    else (self.__var_code_table[lit.name] + self.__shift_step)
+                )
         return num_clause
 
     def __code_clause(self, clause):