proposition: Corollary connected_exists_list_edges': forall g p u v, (forall v, In v p -> vvalid g v) -> (exists l, fits_upath g l p) -> hd_error p = Some u -> last_error p = Some v -> connected_by_path g p u v.
proof: Proof. intros. split. apply valid_upath_exists_list_edges'; auto. split; auto. Qed.
imports: Coq.Logic.Classical CertiGraph.lib.List_ext CertiGraph.lib.EquivDec_ext CertiGraph.graph.graph_model CertiGraph.graph.graph_relation CertiGraph.graph.path_lemmas CertiGraph.graph.graph_gen CertiGraph.graph.FiniteGraph