proposition: Lemma Σ_sub f g n: Σ n f - Σ n g == Σ n (fun x => f x - g x).
proof: Proof. unfold Σ. induction n. reflexivity. simpl. rewrite <- IHn. ring. Qed.
imports: CoRN.stdlib_omissions.List Coq.QArith.QArith Coq.QArith.Qabs CoRN.model.totalorder.QposMinMax CoRN.model.metric2.Qmetric Coq.Program.Program CoRN.stdlib_omissions.N CoRN.stdlib_omissions.Z CoRN.stdlib_omissions.Q