proposition: Lemma incomparable_ltF x y : (x >< y) -> (x < y) = false.
proof: Proof. by rewrite lt_neqAle => /incomparable_leF ->; rewrite andbF. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat choice seq) mathcomp(path fintype tuple bigop finset div prime finfun) mathcomp(finset)