This volume contains the proceedings of the fIrst workshop held by the Theory and Formal Methods Section ofthe Imperial College Department of Computing. It contains papers from almost every member of the Section, from our long-term academic visitors, and from those who have recently left us. The papers fall into four broad areas: * semantics * concurrency * logic * specification with some papers spanning a number of disciplines. The subject material varies from work on mathematical foundations to practical applications of this theory, expressing the Section's commitment to both the foundations of computer science, and the application of theory to real computing problems. In preparing the workshop and these proceedings, care was taken to ensure that there were papers overviewing a field, as well as ones whose primary aim was to present new scientifIc results. This had a dual purpose: to bring our Section members up to speed in some of the areas being worked on by the Section; and to provide the reader of the proceedings not only with a good introduction to many of the specifIc areas being investigated by the Section, but also with details of some of our latest results. All the papers presented at the workshop were revised following comments made by the workshop participants, and all were subsequently reviewed by at least two people before producing the fInal versions contained in this volume.

The class of programming languages commonly known as functional includes Lisp, Scheme, ML, and Miranda TM. This book explores a subclass known as lazy functional languages, beginning with the theoretical issues and continuing through abstract interpretation and offering improved techniques for implementation.Now that advanced compiler technology has made it possible for lazy functional languages to compare favorably in run-time with more traditional languages such as C and Pascal, this monograph tackles problems of implementation such as time and memory overheads and restrictions on parallelism. Specifically, it describes a more efficient implementation model, the evaluation transformer model, that can be used when information is known about how functions use their arguments, develops a semantically sound analysis technique called abstract interpretation, which can determine this information, and shows how to use the information to compile more efficient code for sequential and parallel machines.Geoffrey Burn is Lecturer at Imperial College of Science, Technology, and Medicine, London.Contents: Introduction. Operational and Denotational Semantics of the Typed Lambda Calculus. A Framework for the Abstract Interpretation of Functional Languages. Some Example Abstract Interpretations. Evaluation Transformers. Implementing Functional Languages on Sequential and Parallel Machines. Relationship to Other Work. Epilogue. Appendixes: Additional Proofs. The Spineless G-Machine.