Best Co-approximation and Worst Approximation by Closed Unit Balls
الموضوعات :
Hamid Tehrani
1
(
Department of Mathematics, Yazd University, Yazd, Iran
)
الکلمات المفتاحية: Copoximinal, Closed Unit Balls, Qcoproximinal, Uniquely remotal, Cochebyshevl,
ملخص المقالة :
A kind of approximation, called best coapproximation was introduced and discussed in normed linear spaces by C. Franchetti and M. Furi in 1972. Subsequently, this study was taken up by several researchers in different abstract spaces. In this paper, we consider best coapproximation by closed unit balls. We define qcoproximinal and coremotal, and find some theorems.