... easy to show that X, d is complete. Consider the mapping Φ : X → X defined by Φha1/4h2a, for all a ∈A. By the same reasoning as in the proof of Theorem 2.2, Φ isstrictly contractive on ... Modern Mathematics, chapter VI, John Wiley & Sons, New York, NY, USA,Science edition, 1940.2 D. H. Hyers, On the stability of the linear functional equation,” Proceedings of the National ... any approximatelysolution to the functional equation is near to a true solution of that functional equation, and issuper superstable if every approximately solution is an exact solution of...