Stacs 2003

This book constitutes the refereed proceedings of the 20th Annual Symposium on Theoretical Aspects of Computer Science, STACS 2003, held in Berlin, Germany in February/March 2003. The 58 revised full papers presented together with 2 invited papers were carefully reviewed and selected from 253 submissions. The papers address the whole range of theoretical computer science including algorithms and data structures, automata and formal languages, complexity theory, semantics, logic in computer science, as well as current challenges like biological computing, quantum computing, and mobile and net computing.