This volume contains papers presented at the firstinternational workshop onword equations and related topicsheld at the University of T}bingen in October 1990. Wordequations, the central topic of this annual workshop, lieatthe intersection of several important areas of computerscience, suchas unification theory, combinatorics on words,list processing, and constraint logic programming. Theworkshop is a forum where researchers fromthese differentdomains may present and discuss results and ideas, therebysupporting interaction and cross-fertilization betweentheoretical questions and practical applications. The volumecollects papers which:- contain new and relevant results,- describe a new approach to a subject, or- give a survey of main developments in an area.Papers cover investigations on free groups, associativeunification and Makanin's algorithm to decide thesolvability of equations in free semigroups, generalunification theory and its relationship to algebra and modeltheory, Thue systems, and finitely presented groups.
Investigations on equations in a free group.- An analysis of Makanin's algorithm deciding solvability of equations in free groups.- Implementation of Makanin's Algorithm.- Makanin's algorithm for word equations-two improvements and a generalization.- Unification theory.- Algebraic and logical aspects of unification.- Model-theoretic aspects of unification.- Complete equational unification based on an extension of the Knuth-Bendix completion procedure.- Unification in varieties of completely regular semigroups.- A note on confluent Thue systems.- Confluence of one-rule Thue systems.- Systems of equations over a finite set of words and automata theory.- New systems of defining relations of the braid group.