In hyperconvex metric spaces, we introduce Knaster-KuratowskiMazurkiewicz mappings (in short KKM-maps). Then we prove an analogue to Ky Fan fixed point theorem in hyperconvex metric spaces.

is said to be consistent, if an element xEK satisfying all m inequalities (i.e. a solution of (1)) does exist. Otherwise (1) is said to be inconsistent. A system (1) is said to be irreduciblyâ€¦ (More)

In the first section of this note we prove an approximate selection theorem for upper semicontinuous mappings defined on paracompact subsets of a Hausdorff topological vector space. In Section 2 weâ€¦ (More)