fact: Definition add_vlabel2 (G: graph2) (x: G) a := point (add_vlabel G x a) input output.
imports: HB(structures) Coq(Setoid Morphisms) mathcomp(all_ssreflect) GraphTheory(edone finite_quotient preliminaries bij equiv) GraphTheory(setoid_bigop structures pttdom mgraph ptt)