proposition: Lemma C_derive : forall n f (pr : derivable f), C (S n) f -> C n (derive f pr).
proof: Proof. intros n f pr Cnf ; inversion_clear Cnf ; eapply C_ext ; [| eassumption] ; intro ; eapply pr_nu. Qed.
imports: Rbase Ranalysis Lia Lra Rfunctions Rfunction_facts Rextensionality Rinterval Ranalysis_def Ranalysis_def_simpl Ranalysis_facts Ranalysis_continuity Ranalysis_derivability Ranalysis_monotonicity Rfunction_classes_def MyR_dist Reals.Tactics