Common fixed-point theorems of Caristi-type mappings by using its absolute derivative

In this article, we introduce common fixed-point theorems of Caristi-type mappings by using the absolute derivative of the mapping as a generator of its Caristi-type maps. The common fixed-point theorem that we obtain covers the single-valued and set-valued mappings. Some of the examples are given to support usability of our result. © 2019 NSP Natural Sciences Publishing Cor.