fact: Parameter remove_garbage_subst : forall sigma : substitution , {sigma' : substitution | (forall x, find eq_var_bool x sigma = find eq_var_bool x sigma') /\ (forall x val, In (x,val) sigma' -> find eq_var_bool x sigma' = Some val) /\ (forall x y val val' (tau tau' tau'' : substitution), sigma' = tau ++ (x,val) :: tau' ++ (y,val') :: tau'' -> x <> y)}.
imports: Coq(Recdef List Arith Setoid) CoLoR(closure more_list list_permut list_set decidable_set)