proposition: Lemma Qle_half (x : Q) : 0 <= x -> (1 # 2) * x <= x.
proof: Proof. intro H. rewrite <- (Qmult_1_l x) at 2. apply Qmult_le_compat_r; auto with qarith. Qed.
imports: Coq.QArith.QArith Coq.ZArith.ZArith Coq.NArith.NArith Coq.QArith.Qpower Coq.QArith.Qround Coq.QArith.Qround Coq.QArith.Qabs CoRN.stdlib_omissions.List