\input zb-basic
\input zb-matheduc
\iteman{ZMATH 2004f.04869}
\itemau{}
\itemti{A generalization of Brian Fisher's theorem.}
\itemso{Math. Educ. 38, No. 2, 92-94 (2004).}
\itemab
Suppose $S$ and $T$ are self-maps of a complete metric space $(X, d)$ satisfying the inequality:$d(Sx, TSy)\le{}c. max \{{}d(x, Sx), d(x, Sy), d(Sy, TSy), ((x, TSy)+d(Sx, Sy))/2\}${} for all $x, y\in{}X$, where $0\le{}c<1$. Brian Fisher has proved that if either $S$ or $T$ is continuous then $S$ and $T$ have a unique common fixed point. In this paper, we obtain a generalization of this result by relaxing the completeness of $X$ and dropping the condition of continuity. (Author's abstract)
\itemrv{~}
\itemcc{I95}
\itemut{self maps; associated sequences; metric spaces; common fixed points}
\itemli{}
\end