proposition: Lemma is_partial_graph_reachable: forall (g1 g2: PreGraph V E) (n: V) (n': V), is_partial_graph g1 g2 -> reachable g1 n n' -> reachable g2 n n'.
proof: Proof. intros. apply is_partial_graph_reachable_by with g1; auto. Qed.
imports: Coq.Arith.Arith Coq.Logic.ProofIrrelevance Coq.Logic.FunctionalExtensionality Coq.Classes.Morphisms Coq.Classes.Equivalence CertiGraph.lib.Coqlib CertiGraph.lib.Ensembles_ext CertiGraph.lib.relation_list CertiGraph.lib.List_ext CertiGraph.lib.Equivalence_ext CertiGraph.lib.EquivDec_ext VST.msl.Coqlib2 CertiGraph.graph.graph_model CertiGraph.graph.path_lemmas CertiGraph.graph.reachable_ind CertiGraph.graph.graph_gen CertiGraph.graph.graph_relation