proposition: Lemma gen_dst_preserve_bin: forall (g: PreGraph V E) e t, BinGraph g left_out_edge right_out_edge -> BinGraph (pregraph_gen_dst g e t) left_out_edge right_out_edge.
proof: Proof. intros. apply Build_BinGraph; intros. + apply bin_consist; auto. + simpl. apply (only_two_edges); auto. Qed.
imports: CertiGraph.lib.Coqlib CertiGraph.lib.Ensembles_ext 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.MathGraph