摘要
Given a positive integer n≥2. Let W;∞n（R） be the set of differentiable functions defined on R where for each f∈W∞n（R） f（n-1） is absolutely continuous on any interval bounded on R and ‖fn‖∞（?） ess sup |f（x）|;≤1. Denote K=W∞n（R）∩L∞（R）.
基金
Project supported by the Science Fund of Academia Sinica
