proposition: Lemma NoDup_IndexedElement : forall (l1 : list IndexedElement), NoDup (map elementIndex l1) -> NoDup l1.
proof: Proof. induction l1; simpl; constructor; inversion H; subst; eauto using in_map. Qed.
imports: Fiat.Common.Coq__8_4__8_5__Compat Coq.Lists.List Coq.Strings.String Coq.ZArith.ZArith Coq.Logic.FunctionalExtensionality Coq.Sorting.Permutation Coq.Sets.Ensembles Fiat.Common.DecideableEnsembles Fiat.Common.List.PermutationFacts Fiat.Common.List.ListMorphisms Fiat.Common.List.ListFacts