Best Co-approximation and Worst Approximation by Closed Unit Balls

محورهای موضوعی : Mathematical Analysis

Hamid Tehrani ¹ (Department of Mathematics, Yazd University, Yazd, Iran)

تاریخ دریافت : 1401/08/19 تاریخ پذیرش : 1401/09/23 تاریخ انتشار : 1401/07/09

کلید واژه: ‎Copoximinal‎, ‎Closed Unit Balls, ‎Qcoproximinal‎, ‎ ‎Uniquely remotal‎, ‎Cochebyshevl‎,

چکیده مقاله :

‎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.