An Introduction to Universal Algebra

This book is a short introduction to Universal Algebra. After some preliminary chapters on complete lattices, closure operators, closure systems and Galois connections the basic notions of Universal Algebra are introduced, such as algebra, subalgebra, homomorphism, congruence and direct product, and properties of these notions are presented. Moreover, classes of algebras are studied and the fundamental Galois connection between classes of algebras and sets of identities is presented. The book finishes with chapters on Maltsev conditions, congruence classes, function algebras and pseudovarieties.