proposition: Lemma Invariance2: invariant input_nodup.
proof: Proof. unfold input_nodup. intros; intros len g l r; simpl; intros. split. + constructor; [| tauto]. destruct H0 as [_ ?]. specialize (H0 g). spec H0; [left; auto |]. exact H0. + intros. rewrite in_new_working_list in H1. simpl in H1. tauto. Qed.
imports: Coq.Sets.Finite_sets Coq.Arith.Arith Coq.Logic.ProofIrrelevance Coq.Logic.FunctionalExtensionality Coq.Sorting.Permutation Coq.micromega.Lia CertiGraph.lib.Coqlib CertiGraph.lib.List_ext CertiGraph.lib.EquivDec_ext CertiGraph.lib.EnumEnsembles Coq.Lists.List VST.msl.Coqlib2 CertiGraph.graph.graph_model CertiGraph.graph.path_lemmas CertiGraph.graph.reachable_ind CertiGraph.graph.subgraph2 CertiGraph.graph.graph_gen CertiGraph.graph.MathGraph CertiGraph.graph.FiniteGraph