謝祥云,唐慧慧,王立鋒
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關(guān)于偏序關(guān)于偏序Γ-半群的(m,n)擬理想
謝祥云,唐慧慧,王立鋒
(五邑大學(xué) 數(shù)學(xué)與計(jì)算科學(xué)學(xué)院,廣東 江門(mén) 529020)
引入序半群的擬理想、左理想、右理想的概念,給出它們的生成的表示;證明了序半群上任何擬理想可以分解為一個(gè)左理想和一個(gè)右理想的交,且任何一個(gè)極小的擬理想可以分解為一個(gè)極小左理想和一個(gè)極小右理想的交;給出了擬單偏序半群的刻畫(huà)和偏序半群擬理想、左理想和右理想的刻畫(huà).
擬理想;左理想;右理想;擬單偏序半群
1 引言與預(yù)備知識(shí)
受泛代數(shù)研究的啟發(fā),1986年,印度數(shù)學(xué)家M.K.Sen首先給出了半群的概念[3],隨后,越來(lái)越多的數(shù)學(xué)家從事半群的研究,并取得了一些成果[4-18].半群是一般半群的真推廣并且有著很多與半群平行的概念,如正則半群、單半群、純正半群、逆半群,也有正則元、逆元的概念[3,4,9],半群中的重要工具Green關(guān)系也在半群中找到了類(lèi)似物[5,6,8]. 例如,M.K.Sen和N.K.Saha[3]進(jìn)一步研究了群和正則半群,建立了它們之間的相互關(guān)系,Ansari等[7]研究了半群的理想,進(jìn)一步地,筆者研究了序半群的理想[19].
作為環(huán)和半群理論中單邊理想的推廣,Steifeld分別于1953年和1956年在環(huán)和半群中提出擬理想的概念[20,21],后來(lái)對(duì)擬理想的研究拓展到了不同的代數(shù)結(jié)構(gòu)中,主要成果收集在Steifeld的專(zhuān)著中[22]. 近幾十年這些代數(shù)結(jié)構(gòu)上的擬理想的研究不斷深入,例如研究半群上的擬理想[13,14,23]、序半群上的擬理想[17]、超半群上的擬理想[23,24]、模糊序半群上的擬理想[25]等. 本文研究序半群上擬理想的推廣擬理想,當(dāng)時(shí),擬理想就是擬理想.
定義1[2]180設(shè)2個(gè)非空集合和. 集合稱(chēng)為半群,如果滿(mǎn)足下列條件:
定義2[19]2設(shè)是一個(gè)序半群,對(duì)于任意的. 如果是的一個(gè)子半群,則稱(chēng)是的一個(gè)子序半群,即.
本文中使用但沒(méi)有提及的概念參見(jiàn)文獻(xiàn)[1-3].
推廣定義3得到:
引理1[19]3對(duì)于任意的,設(shè)為序半群的一個(gè)子序半群. 如果,則為的一個(gè)子序半群.
.
所以
另一方面,
類(lèi)似于定理2的證明得到定理4.
且
同理可證ii)和iii).
同理可證ii)和iii).
ii)和iii)同理可證.
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[責(zé)任編輯:熊玉濤]
XIEXiang-yun, TANGHui-hui, WANGLi-feng
(School of Mathematics and Computational Science, Wuyi University, Jiangmen 529020, China)
In this paper, the concepts ofquasi-ideals,left ideals andright ideals of po-semigroups are introduced. The generation theorems ofquasi-ideals,left ideals andright ideals are obtained by every non-emptyset ofpo-semigroups. That anyquasi-idealof po-semigroups can be expressed as the intersection of aleft ideal and aright ideal of po-semigroups is proved. Moreover any minimalquasi-idealof po-semigroups can be expressed as the intersection of a minimalleft ideal and a minimalright ideal of po-semigroups. Finally characterizations ofquasi-simple po-semigroups are given byquasi-ideals. As an application of results of this paper, some results of quasi-ideals, left ideals and right ideals of po-semigroups are obtained.
quasi-ideal;left ideal;right ideal;qusai-simple po-semigroup
1006-7302(2015)01-0001-07
O152.7
A
2014-08-12
國(guó)家自然科學(xué)基金資助項(xiàng)目(11361027,11271040);廣東省自然科學(xué)基金資助項(xiàng)目(S201101000368);安徽省高校優(yōu)秀青年人才基金重點(diǎn)項(xiàng)目(2012SQRL115ZD);安徽省高校自然科學(xué)研究項(xiàng)目(KJ2012B133).
謝祥云(1964—),男,安徽舒城人,教授,博士,碩士生導(dǎo)師,研究方向?yàn)樾虬肴旱拇鷶?shù)理論、模糊代數(shù)、粗糙集理論.