proposition: Lemma list_composed_by_edges_nil: list_composed_by_edges nil.
proof: Proof. repeat intro. assert (@length Vertex nil = length (l1 ++ s :: d :: l2)) by (rewrite H; tauto). rewrite app_length in H0; simpl in H0. intuition. Qed.
imports: Coq.Arith.Arith CertiGraph.lib.Coqlib CertiGraph.lib.EnumEnsembles CertiGraph.lib.EquivDec_ext CertiGraph.lib.List_ext CertiGraph.graph.graph_model CertiGraph.graph.path_lemmas CertiGraph.graph.subgraph2 CertiGraph.graph.MathGraph CertiGraph.graph.FiniteGraph CertiGraph.graph.reachable_computable Coq.Lists.List