proposition: Lemma arctan_sum_1_PI4 : arctan_sum 1 = PI / 4.
proof: Proof. unfold arctan_sum ; destruct (MyRIneq.Req_dec 1 1) as [Heq | Hf] ; [| destruct Hf] ; reflexivity. Qed.
imports: MyReals MyINR MyNNR Rsequence_def Rsequence_facts Rsequence_cv_facts Rsequence_sums_facts Rsequence_base_facts Rsequence_rewrite_facts Rsequence_usual_facts Rsequence_subsequence PeanoNat Lra Rpser_def Rpser_def_simpl Rpser_base_facts Rpser_cv_facts Rpser_radius_facts Rpser_sums Rpser_derivative Rpser_derivative_facts Rfunction_def Functions Rextensionality Rpow_facts Rinterval Ranalysis_def Ranalysis_def_simpl Ranalysis_continuity Ranalysis_derivability Ranalysis_monotonicity Rpser_sums_facts