proposition: Lemma C_minus : forall n f g, C n f -> C n g -> C n (f - g)%F.
proof: Proof. intros ; unfold minus_fct, Rminus ; apply C_plus ; [| apply C_opp] ; assumption. 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