proposition: Lemma reachable_by_through_foot: forall g P n l l0, reachable_by g l0 P n -> reachable_by_through_set g (l ++ l0 :: nil) P n.
proof: Proof. intros. rewrite reachable_by_through_app, reachable_by_through_singleton; 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