fissility

In this paper, the concepts of weakly short splitting exact sequences which are generalized from splits are introduced.

把短正合列的可裂推广到短正合列的弱可裂,并对弱可裂进行了等价刻画,最后还运用左弱可列证明了平坦模的一个充要条件。

in this paper, the writer proves that the fragmentable spaces belong to theclass Z and he also gives an example in which some spaces belong to the class X, butit is not fragmented.

本文证明了可裂空间必属子￡类，同时我们给出了一个例子，某空间属于￡类，但它不是可裂的。