proposition: Lemma IR_minus_as_CR : forall x y, (IRasCR (x[-]y)== IRasCR x - IRasCR y)%CR.
proof: Proof. unfold cg_minus. intros x y. rewrite -> IR_plus_as_CR. rewrite -> IR_opp_as_CR. reflexivity. Qed.
imports: CoRN.algebra.RSetoid CoRN.metric2.Metric CoRN.metric2.UniformContinuity CoRN.reals.CauchySeq CoRN.reals.iso_CReals CoRN.reals.R_morphism CoRN.reals.fast.CRArith CoRN.model.reals.CRreal CoRN.tactics.CornTac