This volume contains the proceedings of ICALP 90, the International Colloquium on Automata, Languages and Programming sponsored by the European Association for Theoretical Computer Science (EATCS). This annual conference series covers all important areas of theoretical computer science, such as computability, automata, formal languages, analysis of algorithms, computational complexity, data types and data structures, theory of data bases and knowledge bases, semantics of programming languages, program specification, transformation and verification, foundations of logic programming, theory of...