proposition: Lemma Lim_seq_abs (u : nat -> R) : ex_lim_seq u -> Lim_seq (fun n => Rabs (u n)) = Rbar_abs (Lim_seq u).
proof: Proof. intros. apply is_lim_seq_unique. apply is_lim_seq_abs. by apply Lim_seq_correct. Qed.
imports: Coq(Reals Psatz ssreflect) Rcomplements Rbar Lub Markov Hierarchy