Let X be a partialiy ordered set (T0A-space). S(X) denote the semigroup of isotone se lfmaps ( continuous selfmaps) on parti-ally orde red se t ( T0 A - space ) X.

• 设X为偏序集(T_0A-空间)；S(X)表示X上保序(连续)自映射作成的半群.