proposition: Lemma Lim_seq_inv (u : nat -> R) : ex_lim_seq u -> (Lim_seq u <> 0) -> Lim_seq (fun n => / u n) = Rbar_inv (Lim_seq u).
proof: Proof. move => Hl Hu. apply is_lim_seq_unique. apply is_lim_seq_inv. by apply Lim_seq_correct. by apply Hu. Qed.
imports: Coq(Reals Psatz ssreflect) Rcomplements Rbar Lub Markov Hierarchy