proposition: Lemma plusNonnegativeReals_lecompat : ∏ x y x' y' : NonnegativeReals, x <= y -> x' <= y' -> x + x' <= y + y'.
proof: Proof. intros x y x' y' H H'. refine (istrans_leNonnegativeReals _ _ _ _ _). - apply plusNonnegativeReals_lecompat_l. apply H. - apply plusNonnegativeReals_lecompat_r. exact H'. Qed.
imports: UniMath.MoreFoundations.Orders UniMath.MoreFoundations.Tactics UniMath.MoreFoundations.Notations UniMath.RealNumbers.Sets UniMath.Algebra.ConstructiveStructures UniMath.OrderTheory.Lattice.Lattice UniMath.RealNumbers.Prelim UniMath.RealNumbers.NonnegativeRationals