proposition: Corollary vvalid_dec: forall g {fg: FiniteGraph g} v, {vvalid g v} + {~ vvalid g v}.
proof: Proof. intros. destruct (in_dec EV v (VList g)). rewrite VList_vvalid in i; left; auto. rewrite VList_vvalid in n; right; 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