proposition: Lemma reachable_through_set_single': forall (g: Gph) x, Same_set (reachable_through_set g (x :: nil)) (reachable g x).
proof: Proof. intros. rewrite Same_set_spec; intros y. apply reachable_through_set_single. Qed.
imports: Coq.Logic.ProofIrrelevance Coq.micromega.Lia CertiGraph.lib.Coqlib CertiGraph.lib.EnumEnsembles CertiGraph.lib.List_ext CertiGraph.lib.EquivDec_ext CertiGraph.graph.graph_model Coq.Lists.List Coq.Lists.ListDec