proposition: Lemma ex_lim_inv (f : R -> R) (x : Rbar) : ex_lim f x -> Lim f x <> 0 -> ex_lim (fun y => / f y) x.
proof: Proof. move => /Lim_correct Hf Hlf. exists (Rbar_inv (Lim f x)). by apply is_lim_inv. Qed.
imports: Coq(Reals ssreflect) Rcomplements Rbar Hierarchy Compactness Lim_seq