This volume contains the proceedings of the 14th International Conference onApplication and Theory of Petri Nets. The aim of the Petri net conferences is to create a forum for discussing progress in the application and theory of Petri nets. Typically, the conferences have 150-200 participants, one third of whom come from industry, while the rest are from universities and research institutes. The volume includes three invited papers, "Modeling and enactment of workflow systems" (C.A. Ellis, G.J. Nutt), "Interleaving functional and performance structural analysis of net models" (M. Silva), and "FSPNs: fluid stochastic Petri nets" (K.S. Trivedi, V.G. Kulkarni), together with 26 full papers (selected from 102 submissions) and 6 project papers.

Logic programming enjoys a privileged position. It is firmly rooted in mathematical logic, yet it is also immensely practical, as a growing number of users in universities, research institutes, and industry are realizing. Logic programming languages, specifically Prolog, have turned out to be ideal as prototyping and application development languages. This volume presents the proceedings of the Second Logic Programming Summer School, LPSS'92. The First Logic Programming Summer School, LPSS '90, addressed the theoretical foundations of logic programming. This volume focuses onthe relationship between theory and practice, and on practical applications. The introduction to the volume is by R. Kowalski, one of the pioneers in the field. The following papers are organized into sections on constraint logic programming, deductive databases and expert systems, processing of natural and formal languages, software engineering, and education.

This volume comprises the proceedings of the First All-Berlin Workshop on Nonclassical Logics and Information Processing, held at the Free University of Berlin, November 9-10, 1990. The scope of the ten papers in the volume is broad, covering various different subfields of logic - particularly nonclassical logic - and its applications in artificial intelligence. The papers are grouped according to the four major topics that emerged at the meeting: modal systems, logic programming, nonmonotonic logics, and proof theory. The classification is only a rough guide since the four areas overlap considerably.

This volume contains lectures and papers delivered at Meta 92, the Third International Workshop on Metaprogramming in Logic, held in Uppsala, Sweden, June 1992. The topics covered include foundations of metaprogramming in logic, proposals for metaprogramming languages, techniques for knowledgerepresentation and belief systems, and program transformation and analysis in logic. Particular topics include belief revision systems, intensionaldeduction, belief systems and metaprogramming, principles of partial deduction, termination in logic programs, semantics of the "vanilla" metainterpreter, a complete resolution method for metaprogramming, semanticsof "demo," hierarchical metalogics, the naming relation in metalevel systems, modules, reflective agents, compiler optimizations, metalogic and object-oriented facilities, parallel logic languages, the use of metaprogramming for legal reasoning, representing objects and inheritance, transformation of normal programs, negation in automatically generated logic programs, reordering of literals in deductive databases, abstract interpretations, and interarguments in constraint logic programs.

This volume contains papers presented at the first international workshop onword equations and related topics held at the University of T}bingen in October 1990. Word equations, the central topic of this annual workshop, lieat the intersection of several important areas of computer science, suchas unification theory, combinatorics on words, list processing, and constraint logic programming. The workshop is a forum where researchers fromthese different domains may present and discuss results and ideas, thereby supporting interaction and cross-fertilization between theoretical questions and practical applications. The volume collects papers which: - contain new and relevant results, - describe a new approach to a subject, or - give a survey of main developments in an area. Papers cover investigations on free groups, associative unification and Makanin's algorithm to decide the solvability of equations in free semigroups, general unification theory and its relationship to algebra and model theory, Thue systems, and finitely presented groups.

This book presents state-of-the-art research results in the area of formal methods for real-time and fault-tolerant systems. The papers consider problems and solutions in safety-critical system design and examine how wellthe use of formal techniques for design, analysis and verification serves in relating theory to practical realities. The book contains papers on real-time and fault-tolerance issues. Formal logic, process algebra, and action/event models are applied: - to specify and model qualitative and quantitative real-time and fault-tolerant behavior, - to analyze timeliness requirements and consequences of faulthypotheses, - to verify protocols and program code, - to formulate formal frameworks for development of real-time and fault-tolerant systems, - to formulate semantics of languages. The integration and cross-fertilization of real-time and fault-tolerance issues have brought newinsights in recent years, and these are presented in this book.

Attribute grammars have shown themselves to be a useful formalism for specifying the syntax and the static semantics of programming languages. They are also useful for implementing syntax-directed editors, compilers, translator writing systems and compiler generators, and any application that has a strong syntactic base. However, no textbooks are available that cover the entire field. To redress this imbalance, anInternational Summer School on Attribute Grammars, Applications and Systems was held in Prague, Czechoslovakia in June 1991. The course aimed at teaching the state of the art in attribute grammars, and their relation to other language specification methods. This volume presents the proceedings of the school. The papers are well suited for self-study, and a selection of them can be used for introductory courses in attribute grammars.

This volume contains the proceedings of the second workshop on Computer Aided Verification, held at DIMACS, Rutgers University, June 18-21, 1990. Itfeatures theoretical results that lead to new or more powerful verification methods. Among these are advances in the use of binary decision diagrams, dense time, reductions based upon partial order representations and proof-checking in controller verification. The motivation for holding a workshop on computer aided verification was to bring together work on effective algorithms or methodologies for formal verification - as distinguished, say, from attributes of logics or formal languages. The considerable interest generated by the first workshop, held in Grenoble, June 1989 (see LNCS 407), prompted this second meeting. The general focus of this volume is on the problem of making formal verification feasible for various models of computation. Specific emphasis is on models associated with distributed programs, protocols, and digital circuits. The general test of algorithm feasibility is to embed it into a verification tool, and exercise that tool on realistic examples: the workshop included sessionsfor the demonstration of new verification tools.

The workshop Computer Science Logic '90 was held at the Max-Planck-Haus in Heidelberg, Germany, October 1-5, 1990. It was the fourth in a series of worskhops, following CSL '89 at the University of Kaiserslautern (see LNCS 440), CSL '88 at the University of Duisberg (see LNCS 385), and CSL '87 at the University of Karlsruhe (see LNCS 329). This volume contains 24 papers, chosen by means of a review procedure from the 35 papers presented at the workshop, some of which were invited and some selected from a total of 89 submissions. The papers cover a wide range of topics arising from the applications of logic to computer science.

This volume presents the papers selected for the Symposium Logic at Tver '92, held at Sokol, near Tver, Russia in July 1992. It is the second in a series of international symposia on logical foundations of computer science held in Russia. The meeting is a joint effort of scholars from both the former Soviet Union and the West, and indicates a new era of international cooperation. Sponsors of the meeting include: the Association for Computing Machinery, the Association for Symbolic Logic, andthe Committee on Mathematical Foundations of Computer Science of IEEE. The book is a unique source of information on the state of computer science research in the former Soviet Union and presents important discoveries in the area of logical foundations of computer science.

This volume contains the papers which have been accepted for presentation atthe Third International Symposium on Programming Language Implementation andLogic Programming (PLILP '91) held in Passau, Germany, August 26-28, 1991. The aim of the symposium was to explore new declarative concepts, methods and techniques relevant for the implementation of all kinds of programming languages, whether algorithmic or declarative ones. The intention was to gather researchers from the fields of algorithmic programming languages as well as logic, functional and object-oriented programming. This volume contains the two invited talks given at the symposium by H. Ait-Kaci and D.B. MacQueen, 32 selected papers, and abstracts of several system demonstrations. The proceedings of PLILP '88 and PLILP '90 are available as Lecture Notes in Computer Science Volumes 348 and 456.

Number theory as studied by the logician is the subject matter of the book. This first volume can stand on its own as a somewhat unorthodox introduction to mathematical logic for undergraduates, dealing with the usual introductory material: recursion theory, first-order logic, completeness, incompleteness, and undecidability. In addition, its second chapter contains the most complete logical discussion of Diophantine Decision Problems available anywhere, taking the reader right up to the frontiers of research (yet remaining accessible to the undergraduate). The first and third chapters also offer greater depth and breadth in logico-arithmetical matters than can be found in existing logic texts. Each chapter contains numerous exercises, historical and other comments aimed at developing the student's perspective on the subject, and a partially annotated bibliography.

Category theory is unmatched in its ability to organize and layer abstractions and to find commonalities between structures of all sorts. No longer the exclusive preserve of pure mathematicians, it is now proving itself to be a powerful tool in science, informatics, and industry. By facilitating communication between communities and building rigorous bridges between disparate worlds, applied category theory has the potential to be a major organizing force. This book offers a self-contained tour of applied category theory. Each chapter follows a single thread motivated by a real-world application and discussed with category-theoretic tools. We see data migration as an adjoint functor, electrical circuits in terms of monoidal categories and operads, and collaborative design via enriched profunctors. All the relevant category theory, from simple to sophisticated, is introduced in an accessible way with many examples and exercises, making this an ideal guide even for those without experience of university-level mathematics.

These proceedings contain research and survey papers from many subfields of recursion theory, with emphasis on degree theory, in particular the development of frameworks for current techniques in this field. Other topics covered include computational complexity theory, generalized recursion theory, proof theoretic questions in recursion theory, and recursive mathematics.

The aim of this book is to reflect the substantial re- search done in Artificial Intelligence on sorts and types. The main contributions come from knowledge representation and theorem proving and important impulses come from the "application areas," i.e. natural language (understanding) systems, computational linguistics, and logic programming. The workshop brought together researchers from logic, theoretical computer science, theorem proving, knowledge representation, linguistics, logic programming and qualitative reasoning.

The courses given at the 1st C.I.M.E. Summer School of 1988 dealt with the main areas on the borderline between applied logic and theoretical computer science. These courses are recorded here in five expository papers: S. Homer: The Isomorphism Conjecture and its Generalization.- A. Nerode: Some Lectures on Intuitionistic Logic.- R.A. Platek: Making Computers Safe for the World. An Introduction to Proofs of Programs. Part I. - G.E. Sacks: Prolog Programming.- A. Scedrov: A Guide to Polymorphic Types.

This volume contains several invited papers as well as a selection of the other contributions. The conference was the first meeting of the Soviet logicians interested in com- puter science with their Western counterparts. The papers report new results and techniques in applications of deductive systems, deductive program synthesis and analysis, computer experiments in logic related fields, theorem proving and logic programming. It provides access to intensive work on computer logic both in the USSR and in Western countries.

This volume contains the papers presented at the International Scientific Symposium "Natural Language and Logic" held in Hamburg in May 1989. The aim of the papers is to present and discuss latest developments in the application of logic-based meth- ods for natural language understanding. Logic-based methods have gained in importance in the field of computational linguistics as well as for representing various types of knowledge in natural language understanding systems. The volume gives an overview of recent results achieved within the LILOG project (LInguistic and LOgic methods for understanding German texts) - one of the largest research projects in the field of text understanding - as well as within related natural language understanding systems.

The volume contains the proceedings of the 16th Spring School on Theoretical Computer Science held in Ramatuelle, France, in May 1988. It is a unique combination of research level articles on various aspects of the theory of finite automata and its applications. Advances made in the last five years on the mathematical foundations form the first part of the book. The second part is devoted to the important problems of the theory including star-height, concatenation hierarchies, and connections with logic and word problems. The last part presents a large variety of possible applications: number theory, distributed systems, algorithms on strings, theory of codes, complexity of boolean circuits and others.

These proceedings include the papers presented at the logic meeting held at the Research Institute for Mathematical Sciences, Kyoto University, in the summer of 1987. The meeting mainly covered the current research in various areas of mathematical logic and its applications in Japan. Several lectures were also presented by logicians from other countries, who visited Japan in the summer of 1987.

Rewriting has always played an important role in symbolic manipulation and automated deduction systems. The theory of rewriting is an outgrowth of Combinatory Logic and the Lambda Calculus. Applications cover broad areas in automated reasoning, programming language design, semantics, and implementations, and symbolic and algebraic manipulation. The proceedings of the third International Conference on Rewriting Techniques and Applications contain 34 regular papers, covering many diverse aspects of rewriting (including equational logic, decidability questions, term rewriting, congruence-class rewriting, string rewriting, conditional rewriting, graph rewriting, functional and logic programming languages, lazy and parallel implementations, termination issues, compilation techniques, completion procedures, unification and matching algorithms, deductive and inductive theorem proving, GrAbner bases, and program synthesis). It also contains 12 descriptions of implemented equational reasoning systems. Anyone interested in the latest advances in this fast growing area should read this volume.

The papers collected in this volume are most of the material presented at the Advanced School on Mathematical Models for the Semantics of Parallelism, held in Rome, September 24- October 1, 1986. The need for a comprehensive and clear presentation of the several semantical approaches to parallelism motivated the stress on mathematical models, by means of which comparisons among different approaches can also be performed in a perspicuous way.

This book provides an introduction to the theory of existentially closed groups, for both graduate students and established mathematicians. It is presented from a group theoretical, rather than a model theoretical, point of view. The recursive function theory that is needed is included in the text. Interest in existentially closed groups first developed in the 1950s. This book brings together a large number of results proved since then, as well as introducing new ideas, interpretations and proofs. The authors begin by defining existentially closed groups, and summarizing some of the techniques that are basic to infinite group theory (e.g. the formation of free products with amalgamation and HNN-extensions). From this basis the theory is developed and many of the more recently discovered results are proved and discussed. The aim is to assist group theorists to find their way into a corner of their subject which has its own characteristic flavour, but which is recognizably group theory.