proposition: Lemma floorN : {in int_num, {morph floor : x / - x}}.
proof: Proof. by move=> _ /intrP[m ->]; rewrite -rmorphN !intrKfloor. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(fintype bigop order ssralg poly ssrnum ssrint)