proposition: Lemma CV_shift : forall f k l, Un_cv (fun n => f (n + k)%nat) l -> Un_cv f l.
proof: Proof. intros f' k l cvfk eps ep; destruct (cvfk eps ep) as [N Pn]. exists (N + k)%nat; intros n nN; assert (tmp: (n = (n - k) + k)%nat). - rewrite Nat.sub_add;[ | apply Nat.le_trans with (N + k)%nat]; auto with arith. - rewrite tmp; apply Pn; apply Nat.le_add_le_sub_r; assumption. Qed.
imports: Rbase Rfunctions Compare