一个A（f）≠M（f）的紧致系统（X，f）

A Compact System(X,j)with A(f)≠M(f)

本文证明，存在紧致系统，其几乎周期点集闭包不等于其测度中心．藉此，我们否定地回答了两个未解决的问题．

In this paper, we prove that there is a compact system whose closure of the set ofalmost periodic points is contained genuinely in whose measure centre. Thereby,We concludethat a weakly almost periodic point not only could be not an almost periodic point but alsonot a limit point of almost periodic points and what the set of almost periodic points coincideswith the set of periodic points is only a necessary but not sufficient condition for that a compactsystem has no non-atomic ergodic measure.