proposition: Lemma comparable_contraFlt b x y : x >=< y -> (y <= x -> b) -> (b = false -> x < y).
proof: Proof. by case: comparableP; case: b => // _ _ /implyP. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat choice seq) mathcomp(path fintype tuple bigop finset div prime finfun) mathcomp(finset)