Remarks on Some Generalizations of ?-Contraction

Abstract

The concept of 0-contraction was modified and generalized in several ways during the last decade. Some assumptions concerning the class T are shown to be superfluous in order to obtain a unique fixed point for a ?-type contraction, ?-Suzuki type and, consequently, ?-contraction. Improvement of several previously published results are derived with a modified contractive condition and we have presented an example of possible application. The same approach was used for the F-Suzuki contraction and numerous generalizations are made.