Following, a ring R is called right almost-perfect if every flat right R-module is projective
relative to R. In this article, we continue the study of these rings and will find some new …

A module M is skew-injective if each endomorphism of any submodule of M can be
extended to an endomorphism of M. A module M is called in~ egrally closed if all …

Erika Mares introduced the concepts of semi-perfectness and perfectness for projective
modules, generalised the structure theorems of H. Bass and obtained results on the …

Let X̲ be any class of R-modules containing O and closed under isomorphic images. With
any such X̲ we associate three classes ΓX̲ and ΔX̲. The study of some of the closure …

Alt the rings we consider will be associative with 1~ 0; all the ring homomorphisms will be
required to preserve the identity elements. All the modules we consider will be unitary …

Будем обозначать через J (R), ДМ) соответственно радикал Джекобсона кольца R, пра
вого Я-модуля М, через 5= Епс1д (М)-кольцо эндоморфизмов правого Д-модуля М,# …