Minimal Presentations and Embedding into Inefficient Semigroups

• 来源期刊: 代数集刊（英文版）
• 关键词: semigroup presentations chains efficiency embedding
• 年，卷（期）: 2005,（1）
• 页码范围: 59-65
• 页数: 7页
• 语种: 英文

摘要

In this paper, we show that CLn, the chain with n elements, is efficient and that the direct product CLm × CLn is inefficient. Moreover, we embed any finitely presented semigroup S into an inefficient semigroup, namely, the semigroup SU SLn, where SLn is the free semilattice of rank n.