proposition: Lemma derive_Rball_opp: forall f c r x pr pr', derive_Rball c r (- f)%F pr x = - derive_Rball c r f pr' x.
proof: Proof. intros ; unfold derive_Rball ; destruct (in_Rball_dec c r x) as [x_in | x_nin] ; [apply derive_pt_Rball_opp ; assumption | rewrite Ropp_0 ; reflexivity]. Qed.
imports: Rbase Ranalysis Rinterval Rfunctions Rfunction_def Rfunction_facts Ranalysis_def Ranalysis_def_simpl Ranalysis_continuity MyRIneq MyR_dist Lra Tactics