Syntactic and Rees Indices of Subsemigroups
Syntactic and Rees Indices of Subsemigroups
复制标题
子半群的句法指数和 Rees 指数
DOI：
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发表时间：
1998
期刊：
影响因子：
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通讯作者：
R. Thomas
中科院分区：
文献类型：
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作者：
N. Ruškuc;R. Thomas
本文对半群的子半群定义了两种不同的指标：（右）句法指标和Rees指标。我们研究了它们之间的关系，并与集团指数。特别是，我们表明，句法指数是一个概括的组指数和里斯指数。我们使用这个事实来证明进一步的相似性之间的组索引和里斯指数。然而，事实证明，组索引的好属性很少被语法索引继承。
Abstract We define two different notions of index for subsemigroups of semigroups: the (right) syntactic index and the Rees index. We investigate the relationships between them and with the group index. In particular, we show that the syntactic index is a generalisation of both the group index and the Rees index. We use this fact to prove further similarities between the group index and the Rees index. It turns out, however, that very few of the nice properties of the group index are inherited by the syntactic index.