proposition: Lemma embdd_inj : injective embdd.
proof: Proof. by move=> u v /(embed_inj (valP u) (valP v))/embd_inj. Qed.
imports: mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(fintype path fingraph) fourcolor(hypermap geometry color chromogram coloring patch) fourcolor(snip revsnip kempe birkhoff contract)