Abstract

Let S be a subset of a metric space X and let B(X) be the class of all nonempty bounded subsets of X with the Hausdorff pseudometric H. A mapping F:SB(X) is a directional contraction iff there exists a real α[0,1) such that for each xS and yF(x), H(F(x),F(z))αd(x,z) for each z[x,y]S, where [x,y]={zX:d(x,z)+d(z,y)=d(x,y)}. In this paper, sufficient conditions are given under which such mappings have a fixed point.