left quasi inverse

we will give some characterization of the quasi-invertibility and the relation "≤" in R~r,and describe the relation between Von Neumann regular elements and quasi-invertible elements in R.

我们给出了拟可逆性以及R~r上的关系“≤”的一系列特征刻画,并对R中Von Neumann正则元与拟可逆元之间的关系做了相关描述。