proposition: Lemma edgeless_GG_numV: forall v, 0 <= v -> numV edgeless_GG = size.
proof: Proof. unfold numV. intros. assert (Zlength (VList edgeless_GG) = Zlength (Zseq size)). apply Permutation_Zlength. apply edgeless_GG_Permutation. rewrite H0. rewrite Zseq_Zlength. auto. lia. Qed.
imports: VST.floyd.proofauto CertiGraph.lib.Coqlib CertiGraph.lib.EquivDec_ext CertiGraph.lib.List_ext CertiGraph.graph.graph_model CertiGraph.graph.graph_gen CertiGraph.graph.FiniteGraph CertiGraph.graph.undirected_graph