proposition: Lemma CK4F_split_cpR : CK4F (igraph z output).
proof: Proof. apply: CK4F_igraph => //. rewrite cp_sym. exact: mem_cpl. Qed.
imports: Coq(RelationClasses Morphisms Setoid Lia) mathcomp(all_ssreflect) GraphTheory(edone finite_quotient preliminaries) GraphTheory(digraph sgraph minor checkpoint cp_minor) GraphTheory(setoid_bigop structures pttdom ptt) GraphTheory(mgraph mgraph2 skeleton bounded)