proposition: Lemma pack_vE z (Vz : z \in vset G) : pack_v z = Sub z Vz.
proof: Proof. rewrite /pack_v. case: {-}_ / idP => [p|]; [exact: val_inj|by rewrite Vz]. Qed.
imports: Coq(Relation_Definitions Morphisms RelationClasses) mathcomp(all_ssreflect) GraphTheory(edone finite_quotient preliminaries bij equiv) GraphTheory(setoid_bigop structures pttdom mgraph mgraph2) GraphTheory(rewriting open_confluence finmap_plus)