准H－闭骨架

ALMOST H-CLOSED FRAMES

给出了准Ｈ－闭骨架的定义，并证明了：任何一个准Ｈ－闭骨架都是Ｈ－闭和局部Ｈ－闭的；一个非Ｈ－闭的骨架的Ｋａｔｅｔｏｖ扩张同构于该骨架的一个单点Ｈ－闭扩张的充分必要条件是该骨架为准Ｈ－闭骨架．最后，给出了一个非Ｈ－闭的准Ｈ－闭骨架的例子．

This paper studies almost H-closed frames.After introducing the concept of an almost H-closed frame,it shows that an almost H-closed frame is H-closed and locally H-closed.Moreover,the necessary and sufficient condition for the Katetov extension of a non-H-closed frame to be isomorphic to a one-point H-closed extension of the frame is discussed.Finally,an example of an almost H-closed but not H-colsed frame is presented.