关于覆盖性质的逆保持性

On inversely preserving of covering properties

给出了亚Lindelf映射的定义,并证明亚Lindel f,δθ加细,弱δθ加细等覆盖性质在亚Lindelf映射下是逆象保持的.

We give the definition of meta-Lindeloef mapping. And we show that meta-Lindeloef, δθ-refinable and weakly δθ-refinable are inversely preserved under meta-Lindeloef mapping.