proposition: Lemma omorph_lt : {mono f : x y / x < y}.
proof: Proof. move=> x y; rewrite !lt_def omorph_le inj_eq//; exact: omorph_inj. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat choice seq) mathcomp(path fintype tuple bigop finset div prime finfun) mathcomp(finset)