左非奇异左CS-环和左遗传左CS-环

本文首先证明了：环为左非奇异左CS-环当且仅当它为左余非奇异Baer环,然后给出左遗传左CS-环,正则左遗传左CS-环和左遗传左连续环的某些刻划.     

左C-wrpp 半群的左$\Delta$-积

We study another structure of so-called left C-wrpp semigroups. In particular, the concept of left △-product is extended and enriched. The aim of this paper is to give a construction of left C-wrpp semigroups by a left regular band and a strong semilattice of left-R cancellative monoids. Properties of left C-wrpp semigroups endowed with left △-products are particularly investigated.     

Left chain semigroups

The purpose of this note is to characterize the semigroups whose left congruences form a chain. Such semigroups are here called the left chain semigroups. It is clear that any semigroup with no more than two elements is a left chain one. Therefore we may consider only the semigroups which contain more than two elements. Our result is the following.     

Left Abundant Semigroups

Abstract

The aim of this paper is to study some special lpp-semigroups, namely, the left GC-lpp semigroups. After obtaining some properties and characterizations of such semigroups, we establish some structure theorems of this class of semigroups. In addition, we also consider some special cases. As an application, we describe the structure theorems of IC quasi-adequate semigroups whose idempotent band is a regular band.     

Left Cotorsion Rings

It is proved that if R is an associative ring that is cotorsionas a left module over itself, and J is the Jacobson radicalof R, then the quotient ring R/J is a left self-injective vonNeumann regular ring and idempotents lift modulo J. In particular,if R is indecomposable, then it is a local ring. 2000 MathematicsSubject Classification 16D50, 16D90, 16L30.