we obtain a sucint and nesessery theoreoms simple for compactness andweakly compactness of the best approximate sets by closed unit balls. also weconsider relations kadec-klee property and shur property with this objects.these theorems are extend of papers mohebi and narayana.

The present work is concerned with the uniqueness problem of best simultaneous approximation. An n-dimensional l1or l∞-simultaneous unicity space is characterized in terms of Property A. c © 2007 Elsevier Ltd. All rights reserved.

In this paper, we prove some results concerning the existence of invariant best approximation in Banach spaces. Our main result improves the corresponding results of Jungck and Hussain, Hussain et.al. In the sequel, we discuss some results on best simultaneous approximation in ordered semi-convex structure.

We obtain a sucint and nesessery theoreoms simple for compactness andweakly compactness of the best approximate sets by closed unit balls. Also weconsider relations Kadec-Klee property and shur property with this objects.These theorems are extend of papers mohebi and Narayana.

This is an experimental computational account of projection algorithms for the linear best approximation problem. We focus on the sequential and simultaneous versions of Dykstra’s algorithm and the Halpern-Lions-Wittmann-Bauschke algorithm for the best approximation problem from a point to the intersection of closed convex sets in the Euclidean space. These algorithms employ different iterative...