proposition: Lemma add_vlabel2_iso' F G (h: F ≃2 G) x a b (e: a ≡ b): F [tst x <- a] ≃2 G [tst h x <- b].
proof: Proof. by eapply add_vlabel2_iso''. Defined.
imports: HB(structures) Coq(Setoid Morphisms) mathcomp(all_ssreflect) GraphTheory(edone finite_quotient preliminaries bij equiv) GraphTheory(setoid_bigop structures pttdom mgraph ptt)