proposition: Lemma derivable_derivable_in : forall f D, derivable f -> derivable_in D f.
proof: Proof. intros f D Hf x Dx ; apply derivable_pt_derivable_pt_in, Hf. Qed.
imports: Rbase Ranalysis Rinterval Rfunctions Rfunction_def Rfunction_facts Ranalysis_def Ranalysis_def_simpl Ranalysis_continuity MyRIneq MyR_dist Lra Tactics