This book constitutes the refereed proceedings of the Fourth International Symposium on Theoretical Aspects of Computer Software, TACS 2001, held in Sendai, Japan, in October 2001.
The book presents 21 selected and revised full papers. Also included are six invited papers plus one open lecture by internationally leading scientists. Among the topics addressed are automata theory, concurrency, control-flow analysis, lambda calculi, model checking and program logic.