proposition: Lemma cface_icpK : {mono icpK : x y / cface x y}.
proof: Proof. exact: (cface_icpN ecpR'). Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(fintype path fingraph) fourcolor(hypermap geometry color)