This book constitutes the proceedings of the 25th Seminar on Current Trends in Theory and Practice of Informatics, SOFSEM'98, held in Jasna, Slovakia, in November 1998. The volume presents 19 invited survey articles by internationally well-known authorities together with 18 revised full research papers carefully reviewed and selected for inclusion in the book. The areas covered include history of models of computation, algorithms, formal methods, practical aspects of software engineering, database systems, parallel and distributed systems, electronic commerce, and electronic documents and...