In studying the algebraic structure of semigroups, H. J. HOEHNKE in [I] and [a] has used respresentations of a semigroup S by transformations on a set to introduce a radical, rad S , as a certain congruence on S , and an associated ideal rado S of S , called the 0-radical of S. An internal characte
On 0-Radical of a Semigroup
โ Scribed by M. Satyanarayana
- Publisher
- John Wiley and Sons
- Year
- 1975
- Tongue
- English
- Weight
- 208 KB
- Volume
- 66
- Category
- Article
- ISSN
- 0025-584X
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โฆ Synopsis
I n this note we shall indicate the usefulness of the concepts of q-elements and HOEHNKE'S O-radical by characterizing certain semigroups containing q-elements. I n particular, we characterize completely the left cancellative semigroups with q-elements. We shall also show that the importance of O-radical cannot be over-emphasized because it happens to be trivial or zero in many nice semigroups. According to LA TORRE [a], an element x in a semigroup S is called a g-element if xmb = xnc for every b, c E S and for some integers m, n 2 0. If m or n is 0, then we assume xos = s. I n the works of HOEHNKE [l] and SEIDEL [3], one finds that RadO S , called the 0-radical of a semigroup S , is a maximal yuasiregular ideal i.e., an ideal which is maximal with respect to the property that every element of it is a q-element. This is explicitely stated by LA TORRE [2]. By making simple observations from lemmas 1.2 and 1.3 of SEIDEL [3], we have
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