摘要
设自然数n≥3,PHn是自然序集Xn={1,2,3,…,n}上的保降序且保序有限部分奇异变换半群,对0≤r≤n-1时,记P(n,r)={α∈PHn:|imα|≤r}为半群PHn的双边星理想。通过对其幂等元的分析,分别刻划了半群P(n,r)的极小幂等生成集,秩和幂等元秩。进一步证明了当0≤l≤r时,半群P(n,r)关于它的每个星理想P(n,l)的相关秩。
Let PHn be the semigroups of order-decreasing and order-preserving finite partial singular transformations on the natural order set Xn={1,2,3,…,n}, if n ≥ 3, and let P( n, r) = {α∈PHn:Iimα≤r} be the two-sided star ideal of the semigroup PHn if 0 ≤ r ≤ n-1. By analyzing the idempotent elements, the minimal idempotent generating set, rank and idempotent rank of the semigroup P( n, r) are characterized, respectively. Furthermore, it is shown that for 0 ≤ l≤ r, the relative rank of the semigroup P(n,r) with respect to itself each star ideal P(n,l).
出处
《山东大学学报(理学版)》
CAS
CSCD
北大核心
2013年第2期42-48,共7页
Journal of Shandong University(Natural Science)
基金
贵州省科学技术基金资助项目(黔科合J字LKS(2009)02号)
贵州省科学技术基金资助项目(黔科合J字LKS(2011)16号)
关键词
保降序
保序
奇异变换半群
秩和幂等元秩
相关秩
order-decreasing
order-preserving
singular transformation semigroup
rank and idempotent rank
relativerank