富足半群上的fuzzy-t同余

引入富足半群上fuzzy-t同余的概念,给出富足半群上fuzzy-t同余的性质和特征。在此基础上,给出满足正则性条件的富足半群上fuzzy-t同余的性质。最后,就若干特例作讨论,得到一些结果。     

关于左型A半群上的fuzzy同余

引入了左富足半群上fuzzy右好同余和fuzzy右消去同余的概念,给出了左富足半群上fuzzy右好同余的性质和特征.在此基础上,给出了左型A半群上fuzzy右好同余和fuzzy右消去同余的性质.得到了左型A半群上的fuzzy右好同余为fuzzy右消去同余的充要条件.     

关于Clifford半群上的fuzzy同余

利用半群fuzzy同余的概念,讨论一类特殊的完全正则半群,即Clifford半群上的fuzzy同余.研究该类半群上fuzzy同余的性质.在此基础上,给出Clifford半群上fuzzy同余的性质和特征,得到Cllifford半群上fuzzy同余为fuzzy消去同余的充要条件.     

半群的子半群上的同余扩张

设ρ是半群Ｓ上的一个同余,如果Ｓ／ρ是矩形带,则称ρ是矩形同余,本文刻画了半群上的最小矩形带同余,设Ｔ是半群Ｓ的子半群,本文给出了Ｔ上每个矩形带同余能扩张成Ｓ上矩形带同余的充分必要条件。     

含有中间幂等元满足同余条件的◇-富足半群

本文引入了--格林关系和--富足半群,研究了满足同余条件含有中间幂等元的--富足半群.利用具有中间幂等元的由幂等元生成的正则半群和◇-拟恰当半群建立了满足同余条件含有中间幂等元的◇-富足半群的结构.     

D—正则半群上的同余

刻划Ｄ－正则半群上的如下同余：包括在Ｄ［Ｒ］中的最大同余、最大幂等元分离同余、（最小）基本强Ｄ－同余和群同余。     

左富足半群上的同余（英文）

本文研究了一类特殊的左富足半群,即左GC-lpp-半群上的R^*-同余.我们利用类似正则半群上同余的核迹方法分别刻画了这类半群上具有相同核和迹的最大和最小同余.同时,我们也得到了左GC-lpp-半群上的幂等元R*-同余的一些性质,并建立了这种同余的结构.     

强双单严格纯正半群上同余的刻划

本文利用正则半群同余的概念，找到了任一强双单严格纯正半群Ｓ的一个正规子半群ＮＫ和Ｅ上的一个正规同余ГＰ，证明了Ｓ的任何一同余可由余偶确定，从而给出了Ｓ上任一同余的一个具体刻划。     

亚纯正半群上的同余

本文讨论了亚纯正半群S上特殊同余间的关系.利用超迹和核给出了S上任一同余与特殊同余的关系及与群同余并的等式.用核正规系刻画了S上的极大幂等分离同余,得到了S/μ同构于E的几个等价条件.     

正规纯正左消幺半群并半群上的(*,~)-好同余(英文)

本文利用(*,~)-好同余对刻画了正规纯正左消幺半群并半群上的(*,~)-好同余.此结果将正则半群中有关正规纯正群并半群上同余的相关结论推广到了r-wide半群中.     

Fuzzy Good Congruences on Left Semiperfect Abundant Semigroups

Motivated by studying fuzzy congruences in groups, semigroups, and ordered semigroups, and as a continuation of N. Kuroki and Y. Tan's works in regular semigroups in terms of fuzzy subsets, in this article we introduce the notions of a fuzzy good congruence relation, a fuzzy cancellative congruence relation on abundant semigroups, and give some properties, and characterizations of fuzzy good congruences on such semigroups. Furthermore, we characterize fuzzy good congruences of left semiperfect abundant semigroups, and get sufficient and necessary conditions for an abundant semigroup to be left semiperfect.     

半群的模糊同余扩张

本文引入半群的模糊同余扩张的概念,给出了模糊同余扩张的同态性质,同时,本文研究了带有模糊同余扩张性质的半群类,证明了一个半群S有模糊同余扩张性质当且仅当S有同余扩张性质,最后进一步给出 有模糊同余张张性质的半群类的特征。     

完全零单半群的模糊同余

介绍完全零单半群上的真模糊同余和连接模糊三元组的概念,由此得到完全零单半群上的真模糊同余集和连接模糊三元组集之间的双射。     

带逆断面的正则半群上的强模糊同余

带逆断面的正则半群是一类重要的正则半群.就带逆断面的正则半群类引入强模糊同余的概念,进而用所谓的强模糊同余三元组抽象地刻画带逆断面的正则半群上的强模糊同余.     

Left Reductive Congruences on Semigroups

A semigroup S is called a left reductive semigroup if, for all elements a,b∈S, the assumption “xa=xb for all x∈S” implies a=b. A congruence α on a semigroup S is called a left reductive congruence if the factor semigroup S/α is left reductive. In this paper we deal with the left reductive congruences on semigroups. Let S be a semigroup and ? a congruence on S. Consider the sequence ? ⁽⁰⁾?? ⁽¹⁾???? ⁽ⁿ⁾?? of congruences on S, where ? ⁽⁰⁾=? and, for an arbitrary non-negative integer n, ? ⁽ⁿ⁺¹⁾ is defined by (a,b)∈? ⁽ⁿ⁺¹⁾ if and only if (xa,xb)∈? ⁽ⁿ⁾ for all x∈S. We show that $\bigcup_{i=0}^{\infty}\varrho^{(i)}\subseteq \mathit{lrc}(\varrho )$ for an arbitrary congruence ? on a semigroup S, where lrc(?) denotes the least left reductive congruence on S containing ?. We focuse our attention on congruences ? on semigroups S for which the congruence $\bigcup_{i=0}^{\infty}\varrho^{(i)}$ is left reductive. We prove that, for a congruence ? on a semigroup S, $\bigcup_{i=0}^{\infty}\varrho^{(i)}$ is a left reductive congruence of S if and only if $\bigcup_{i=0}^{\infty}\iota_{(S/\varrho)}^{(i)}$ is a left reductive congruence on the factor semigroup S/? (here ι _(S/?) denotes the identity relation on S/?). After proving some other results, we show that if S is a Noetherian semigroup (which means that the lattice of all congruences on S satisfies the ascending chain condition) or a semigroup in which S ⁿ =S ⁿ⁺¹ is satisfied for some positive integer n then the universal relation on S is the only left reductive congruence on S if and only if S is an ideal extension of a left zero semigroup by a nilpotent semigroup. In particular, S is a commutative Noetherian semigroup in which the universal relation on S is the only left reductive congruence on S if and only if S is a finite commutative nilpotent semigroup.     

Congruences on *-Regular Semigroups

In this paper we study the congruences of *-regular semigroups, involution semigroups in which every element is p-related to a projection (an idempotent fixed by the involution). The class of *-regular semigroups was introduced by Drazin in 1979, as the involutorial counterpart of regular semigroups. In the standard approach to *-regular semigroup congruences, one ,starts with idempotents, i.e. with traces and kernels in the underlying regular semigroup, builds congruences of that semigroup, and filters those congruences which preserve the involution. Our approach, however, is more evenhanded with respect to the fundamental operations of *-regular semigroups. We show that idempotents can be replaced by projections when one passes from regular to *-regular semigroup congruences. Following the trace-kernel balanced view of Pastijn and Petrich, we prove that an appropriate equivalence on the set of projections (the *-trace) and the set of all elements equivalent to projections (the *-kernel) fully suffice to reconstruct an (involution-preserving) congruence of a *-regular semigroup. Also, we obtain some conclusions about the lattice of congruences of a *-regular semigroup. This revised version was published online in June 2006 with corrections to the Cover Date.     

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.