proposition: Lemma denq_lt0 x : (denq x < 0) = false.
proof: Proof. by rewrite lt_gtF. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(fintype bigop order ssralg countalg div ssrnum) mathcomp(ssrint prime archimedean)