This text constitutes the thoroughly refereed post-workshop proceedings of the 14th International Workshop on Algebraic Development Techniques, WADT'99, held in Toulouse, France in September 1999. The 23 revised full papers presented together with three invited papers were carefully reviewed and selected from 69 workshop presentations. The papers address the following topics: algebraic specification and other specification formalisms; test and validation; concurrent processes applications; logic and validation; combining formalisms; subsorts and partiality; structuring; rewriting; co-algebras...

This book constitutes the refereed proceedings of the International Conference IFIP TCS 2000 held in Sendai, Japan in August 2000.The 32 revised full papers presented together with nine invited contributions were carefully reviewed and selected from a total of 70 submissions. The papers are organized in two tracks on algorithms, complexity, and models of computation and on logics, semantics, specification, and verification. The book is devoted to exploring new frontiers of theoretical informatics and addresses all current topics in theoretical computer science.