We investigate the existence and uniqueness of a fixed point of an operator via simultaneous functions in the setting of complete quasi-metric spaces. Our results generalize and improve several recent results in literature.
Alsulami, H. H., Karapinar, E., Khojasteh, F., & Roldán-López-De-Hierro, A. F. (2014). A proposal to the study of contractions in quasi-metric spaces. Discrete Dynamics in Nature and Society, 2014. https://doi.org/10.1155/2014/269286