proposition: Lemma floor_lt0 x : x < 0 -> floor x < 0.
proof: Proof. by move=> ?; rewrite -(@ltrz0 R) RtointK ?isint_Rfloor// Rfloor_lt0. Qed.
imports: HB(structures) mathcomp(all_ssreflect all_algebra) mathcomp(mathcomp_extra boolp classical_sets set_interval) Setoid