proposition: Lemma reachable_list_permutation: forall (g: Gph) x l1 l2, reachable_list g x l1 -> reachable_list g x l2 -> NoDup l1 -> NoDup l2 -> Permutation l1 l2.
proof: Proof. intros. apply NoDup_Permutation; auto. intro y. rewrite (H y), (H0 y). tauto. Qed.
imports: Coq.Logic.ProofIrrelevance Coq.micromega.Lia CertiGraph.lib.Coqlib CertiGraph.lib.EnumEnsembles CertiGraph.lib.List_ext CertiGraph.lib.EquivDec_ext CertiGraph.graph.graph_model Coq.Lists.List Coq.Lists.ListDec