proposition: Lemma CV_radius_inside (a : nat -> R) (x : R) : Rbar_lt (Finite (Rabs x)) (CV_radius a) -> ex_pseries a x.
proof: Proof. move => Ha. by apply CV_disk_correct, CV_disk_inside. Qed.
imports: Coq(Reals Psatz ssreflect) Rcomplements Rbar Lim_seq Lub Hierarchy Continuity Derive Seq_fct Series