ON A PROBLEM OF M. KAMBITES REGARDING ABUNDANT SEMIGROUPS

被引:6
作者
Araujo, Joao [1 ,2 ]
Kinyon, Michael [3 ]
机构
[1] Univ Aberta, Lisbon, Portugal
[2] Univ Lisbon, Ctr Algebra, P-1649003 Lisbon, Portugal
[3] Univ Denver, Dept Math, Denver, CO USA
关键词
Abundant semigroups; Adequate semigroups; Amiable semigroups;
D O I
10.1080/00927872.2011.610072
中图分类号
O1 [数学];
学科分类号
0701 ; 070101 ;
摘要
A semigroup is regular if it contains at least one idempotent in each R-class and in each L-class. A regular semigroup is inverse if it satisfies either of the following equivalent conditions: (i) there is a unique idempotent in each R-class and in each L-class, or (ii) the idempotents commute. Analogously, a semigroup is abundant if it contains at least one idempotent in each R*-class and in each L*-class. An abundant semigroup is adequate if its idempotents commute. In adequate semigroups, there is a unique idempotent in each R* and L*-class. M. Kambites raised the question of the converse: in a finite abundant semigroup such that there is a unique idempotent in each R* and L*-class, must the idempotents commute? In this note, we provide a negative answer to this question.
引用
收藏
页码:4439 / 4447
页数:9
相关论文
共 7 条
[1]  
Araujo J., P ROYAL SOC IN PRESS
[2]  
Clifford A. H., 1961, MATH SURVEYS, V7
[3]  
FOUNTAIN J, 1982, P LOND MATH SOC, V44, P103
[4]   ADEQUATE SEMIGROUPS [J].
FOUNTAIN, J .
PROCEEDINGS OF THE EDINBURGH MATHEMATICAL SOCIETY, 1979, 22 (JUN) :113-125
[5]  
Kambites M., J AUST MATH IN PRESS
[6]   On certain finite semigroups of order-decreasing transformations I [J].
Laradji, A ;
Umar, A .
SEMIGROUP FORUM, 2004, 69 (02) :184-200
[7]  
McCune W., 2009, PROVER9 MACE4 VERSIO