This work offers concise coverage of the structure theory of semigroups. It examines constructions and descriptions of semigroups and emphasizes finite, commutative, regular and inverse semigroups. Many structure theorems on regular and commutative semigroups are introduced.;College or university bookstores may order five or more copies at a special student price which is available upon request from Marcel Dekker, Inc.

The structure of regular semigroups is studied in full generality. The principal tool used in this is the concept of a (regular) biordered set which abstractly characterizes the set of idempotents of a regular semigroup. The category of inductive groupoids is then defined as the category whose objects are pairs consisting of an ordered groupoid and an order-preserving functor of the chain groupoid of a biordered set whose vertex map is a bijection, and whose morphisms are certain commutative diagrams in the category of ordered groupoids. It is shown by an explicit construction that every regular semigroup can be constructed from an inductive groupoid and that the category of inductive groupoids is equivalent to the category of all regular semigroups. This construction is then applied to obtain the structure of all fundamental regular semigroups and all idempotent generated regular semigroups. The paper ends with a study of biordered sets of some important classes of regular semigroups.

This book is a collection of selected papers presented at the International Conference on Semigroups and Applications, held at the Cochin University of Science and Technology, India, from December 9–12, 2019. This book discusses the recent developments in semigroups theory, category theory and the applications of these in various areas of research, including structure theory of semigroups, lattices, rings and partial algebras. This book presents chapters on ordering orders and quotient rings, block groups and Hall’s relations, quotients of the Booleanization of inverse semigroup, Markov chains through semigroup graph expansions, polycyclic inverse monoids and Thompson group, balanced category and bundle category. This book will be of much value to researchers working in areas of semigroup and operator theory.

This volume contains contributions from leading experts in the rapidly developing field of semigroup theory. The subject, now some 60 years old, began by imitating group theory and ring theory, but quickly developed an impetus of its own, and the semigroup turned out to be the most useful algebraic object in theoretical computer science.

Present a systematic treatment of completely regular semigroups, from introductory to research level, comprised of preliminaries on lattices, semigroups, varieties, and complete regularity; congruences and relations on the congruence lattice; and varieties of completely regular semigroups through kernals, and traces of congruences and Malcev products.