proposition: Lemma le_lt_trans y x z: x <= y -> y < z -> x < z.
proof: Proof. by rewrite le_eqVlt => /orP [/eqP ->|/lt_trans t /t]. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat choice seq) mathcomp(path fintype tuple bigop finset div prime finfun) mathcomp(finset)