proposition: Lemma omorph_inj : injective f.
proof: Proof. by move=> x y fxfy; apply: le_anti; rewrite -!omorph_le fxfy lexx. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat choice seq) mathcomp(path fintype tuple bigop finset div prime finfun) mathcomp(finset)