proposition: Lemma inj_v_fresh (x : G) (z : VT) : z \notin vset open -> inj_v x != z.
proof: Proof. apply: contraNneq => <-. exact: inj_v_open. 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)