proposition: Lemma pow2_abs : forall x, Rabs x^2 = x^2.
proof: Proof. intros x; destruct (Rle_lt_dec 0 x). - rewrite Rabs_pos_eq;[field | assumption]. - rewrite <- Rabs_Ropp, Rabs_pos_eq;[field | lra]. Qed.
imports: Lra Rbase PSeries_reg Rtrigo1 Rtrigo_facts Ranalysis_reg Rfunctions AltSeries Rseries SeqProp Ranalysis5 SeqSeries PartSum Lia