proposition: Lemma path_ends_meet: forall (g: Gph) p1 p2 n1 n2 n3, path_ends g p1 n1 n2 -> path_ends g p2 n2 n3 -> paths_meet g p1 p2.
proof: Proof. unfold path_ends, paths_meet; intros. destruct H, H0. exists n2. split; 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