proposition: Lemma add_vlabel2_iso F G (h: F ≃2 G) x a: F [tst x <- a] ≃2 G [tst h x <- a].
proof: Proof. by apply 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)