Author/Authors :
MUSTAFA, ZEAD Qatar University - Department of Mathematics, Statistics and Physics, Qatar , HUANG, HUAPING Hubei Normal University - School of Mathematics and Statistics, China , RADENOVIC, STOJAN Dong Thap University - Faculty of Mathematics and Information Technology, Vietnam
Abstract :
In this short paper we show that the results obtained by using the axiom of choice in [R.H. Haghi, Sh. Rezapour and S. Naseer: Some fixed point generalizations are not real generalizations, Nonlinear Anal., 77(2011), 1799-1803], [N. Hussain, A. Latif andM.H. Shah: Coupled and tripled coincidence point results without compatibility, Fixed Point Theory Appl., 2012, 2012:77] and [B.K. Bisht, M. Jain and S. Kumar: Erratum to: Common fixed point theorems for expansion mappings in various spaces, ActaMath. Hungar., 146(2015), No. 1, 261-264] are weaker than the ones obtained without axiomof choice. Furthermore, we claim that all known results with two self-maps f, g : X → X satisfying f(X) ⊆ g(X) do be genuine generalizations of the results with one self-map f : X → X.
