supported by National Natural Science Foundation of China(Grant No.11371296);supported by National Natural Science Foundation of China(Grant No.11201160);supported by National Natural Science Foundation of China(Grant No.11471270);Ph.D Programs Foundation of MEC(Grant No.20130121110032);Natural Science Foundation of Fujian Province(Grant No.2012J05006);Natural Science Foundation of Fujian Province(Grant No.2015J01022);supported by NSF(Grant No.DMS-1200370)
Abstract In this paper, we show that a closed convex subset C of a Banach space is strongly proximinal (proximinal, resp.) in every Banach space isometrically containing it if and only if C is locally (weakly, resp...