A Generalization of VNL-Rings and $PP$-Rings

Abstract:

      Let $R$ be a ring. An element $a$ of $R$ is called a left $PP$-element if $Ra$ is projective. The ring $R$ is said to be a left almost $PP$-ring provided that for any element $a$ of $R$, either $a$ or $1-a$ is left $PP$. We develop, in this paper, left almost $PP$-rings as a generalization of von Neumann local (VNL) rings and left $PP$-rings. Some properties of left almost $PP$-rings are studied and some examples are also constructed.