Korovkin Type Approximation Theorem via $A^I_2$-Summability Methods

Sudipta Dutta, Sevda Akdağ, Pratulananda Das

In this paper we consider the notion of $A^I_2$-summability for real double sequences which is an extension of the notion of $A^I$-summability for real single sequences introduced by Savas, Das and Dutta. We primarily apply this new notion to prove a Korovkin type approximation theorem. In the last section, we study the rate of $A^I_2$-summability.