proposition: Lemma Dconst : forall (D:C -> Prop) (y x0:C), D_in (fun x:C => y) (fun x:C => C0) D x0.
proof: Proof. unfold D_in in |- *; intros; unfold limit1_in in |- *; unfold limit_in in |- *; unfold Cdiv in |- *; intros; simpl in |- *; split with eps; split; auto. intros; rewrite (Cminus_diag_eq y y (refl_equal y)) ; rewrite Cmult_0_l; unfold C_dist in |- *; rewrite (Cminus_diag_eq C0 C0 (refl_equal _)). rewrite Cnorm_C0 ; assumption. Qed.
imports: Ctacfield Cnorm Cprop_base Classical_Prop Classical_Pred_Type Cmet