proposition: Lemma RFG_reachable_decicable: forall (g: PreGraph V E) {rfg: ReachableFiniteGraph g} x y, vvalid g x -> Decidable (reachable g x y).
proof: Proof. intros. pose proof finiteR x H. destruct X as [l [_ ?H]]. unfold Ensembles.In in H0. destruct (in_dec equiv_dec y l); [left | right]; rewrite <- H0; auto. Qed.
imports: CertiGraph.lib.Coqlib CertiGraph.lib.EnumEnsembles CertiGraph.lib.EquivDec_ext CertiGraph.lib.List_ext CertiGraph.lib.relation_list CertiGraph.lib.Equivalence_ext CertiGraph.graph.graph_model CertiGraph.graph.graph_gen CertiGraph.graph.path_lemmas