^(<k)2上的无界闭集

Closed and Unbounded Sets on^(<k)2

本文引进了^(<k)2上的无界闭集(club集)和稳定集的概念,并研究了它们的基本性质,最后提出了几个开问题。

In this paper,we introduce concepts of closed unbounded sets and stationary sets,and investigate their poperties.at last,we prompt some open proplems.