This monograph thoroughly explores the development of the theory of varieties of semigroups and of two related algebras: involution semigroups and monoids. Through this in-depth analysis, readers will attain a deeper understanding of the differences between these three types of varieties, which may otherwise seem counterintuitive. New results with detailed proofs are also presented that answer previously unsolved fundamental problems. Featuring both a comprehensive overview as well as highlighting the author's own significant contributions to the area, this book will help establish this subfield as a matter of timely interest. Advances in the Theory of Varieties of Semigroups will appeal to researchers in universal algebra and will be particularly valuable for specialists in semigroups.
"This book can serve as a well-written introduction for mastering methods of a well-developed theory and can be recommended to beginning researchers as well as to experienced researchers." (Grigory I. Mashevitzky, Mathematical Reviews, August, 2024)
"The monograph by Edmond W. H. Lee is a significant contribution to the research of semigroup varieties and varieties of semigroups equipped with additional unary or 0-ary operations. It will undoubtedly be interesting and useful to all researchers involved in the theory of varieties of semigroups, the theory of semigroups as a whole and related branches of general algebra." (Boris M. Vernikov, Semigroup Forum, Vol. 107 (2), 2023)
"The monograph by Edmond W. H. Lee is a significant contribution to the research of semigroup varieties and varieties of semigroups equipped with additional unary or 0-ary operations. It will undoubtedly be interesting and useful to all researchers involved in the theory of varieties of semigroups, the theory of semigroups as a whole and related branches of general algebra." (Boris M. Vernikov, Semigroup Forum, Vol. 107 (2), 2023)