In 1964,Hayman,W.K.Predicated method of judging a functin family to be normal variety.This result was proved in 1985.Here.we give a method thawt judges a functi
This paper is devoted to the images and preimages of D0 spaces.First of all,we prove that the preimage X of a D0 space Y under a perfect mapping f is a D0 space
Finding all zeros of polynomial systems is very interesting and it is also useul for many applied science problems.In this paper,based on Wu's method,we giv