proposition: Lemma ufroot_vvalid_rt: forall rt v, uf_root g v rt -> vvalid g rt.
proof: Proof. intros. destruct H as [? _]. apply (reachable_foot_valid _ _ _ H). Qed.
imports: CertiGraph.lib.Coqlib CertiGraph.lib.EquivDec_ext CertiGraph.lib.List_ext CertiGraph.lib.Ensembles_ext CertiGraph.lib.EnumEnsembles CertiGraph.graph.graph_model CertiGraph.graph.path_lemmas CertiGraph.graph.graph_gen CertiGraph.graph.MathGraph CertiGraph.graph.LstGraph CertiGraph.graph.FiniteGraph CertiGraph.graph.reachable_computable