Fixed points on two generalized metric spaces (Q2901487)

\textit{A. Branciari} [Publ. Math. 57, No. 1--2, 31--37 (2000; Zbl 0963.54031)] introduced the concept of generalized metric space as follows. Let \(X\) be a nonempty set and \(d: X^2\to\mathbb{R}_+\) a mapping such that:NEWLINENEWLINE (1) \(d(x,y)= 0\) if and only if \(x= y\),NEWLINENEWLINE (2) \(d(x,y)= d(y,x)\),NEWLINENEWLINE (3) \(d(x,y)\leq d(x,z)+ d(z, w)+ d(w,y)\) for all \(x,y,z,w\in X\).NEWLINENEWLINE Then \(d\) is called a generalized metric on \(X\) and \((X,d)\) in a generalized metric space.NEWLINENEWLINE \textit{B. Fisher} [Glas. Mat., III. Ser. 16(36), 333--337 (1981; Zbl 0472.54031)] initiated the study of fixed points on two metric spaces. Other results on this topic were obtained by the reviewer [\textit{V. Popa}, Zb. Rad., Prir.-Mat. Fak., Univ. Novom Sadu, Ser. Mat. 21, No. 1, 83--93 (1991; Zbl 0783.54040)].NEWLINENEWLINE In the present paper, a general fixed point theorem which extends the results of Fisher and the reviewer is proved for two generalized metric spaces.