in the Hilbert space l2 with the following two properties: (i) C has the approximate fixed-point property for nonexpansive mappings, (ii) C is not contained in a block for every orthogonal basis in l2.">
我们举个例子一个无界的,凸和闭集 C 在希尔伯特空间 l 2 以下两个属性:(i) C 有近似的定点财产扩张映射,(2) C 不包含在一个块中的每个正交基 l 2 。