proposition: Lemma is_lim_plus (f g : R -> R) (x lf lg l : Rbar) : is_lim f x lf -> is_lim g x lg -> is_Rbar_plus lf lg l -> is_lim (fun y => f y + g y) x l.
proof: Proof. intros Cf Cg Hp. eapply filterlim_comp_2 ; try eassumption. by apply filterlim_Rbar_plus. Qed.
imports: Coq(Reals ssreflect) Rcomplements Rbar Hierarchy Compactness Lim_seq