proposition: Lemma epath_to_vpath_cons_eq: forall g v e p, v = src g e -> epath_to_vpath g (v, e :: p) = v :: epath_to_vpath g (dst g e, p).
proof: Proof. intros. remember (epath_to_vpath g (v, e :: p)) as l. destruct l. 1: simpl in Heql; destruct p; inversion Heql. symmetry in Heql. rewrite (epath_to_vpath_cons _ _ _ _ _ _ Heql). f_equal. subst. simpl in Heql. destruct p; inversion Heql; auto. 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