Remarks about a P.K. Lin fixed-point free map

摘要

In 1987 P.K. Lin found a fixed-point free selfmapping ƒ of a closed convex subset of the unit ball of l_(2) . Here we point out some remarkable features of this mapping. In particular we will show that if |⋅| is any equivalent renorming of l_(2) , then ƒ is not nonexpansive with respect to |⋅|.