Abstract
Let X be a Banach space and B a bounded subset of X. For each xX, define R(x) = sup{‖xy‖ : yB}. If C is a nonempty subset of X, we call the number R = inƒ{R(x) : xC} the Chebyshev radius of B in C and the set the Chebyshev center of B in C. It is well known that if C is weakly compact and convex, then and if, in addition, X is uniformly convex, then the Chebyshev center is unique; see e.g., [9].Let {Bα : α ∈ ∧} be a decreasing net of bounded subsets of X. For each x ∈ X and each α ∈ ∧, define

This publication has 0 references indexed in Scilit: