(** This file is an example of how to use power series. It defines and
gives properties of the Bessel functions. *)

Definition Bessel1_seq (n k : nat) :=
  (-1)^(k)/(INR (fact (k)) * INR (fact (n + (k)))).

Lemma ex_Bessel1 (n : nat) (x : R) : ex_pseries (Bessel1_seq n) x.