The book is a fairly complete and up-to-date survey of projectivity and its generalizations in the class of Boolean algebras. Although algebra adds its own methods and questions, many of the results presented were first proved by topologists in the more general setting of (not necessarily zero-dimensional) compact spaces.
An appendix demonstrates the application of advanced set-theoretic methods to the field.
The intended readers are Boolean and universal algebraists. The book will also be useful for general topologists wanting to learn about kappa-metrizable spaces and related classes. The text is practically self-contained but assumes experience with the basic concepts and techniques of Boolean algebras.

This volume presents the proceedings of the 7th International Workshop on Higher Order Logic Theorem Proving and Its Applications held in Valetta, Malta in September 1994.
Besides 3 invited papers, the proceedings contains 27 refereed papers selected from 42 submissions. In total the book presents many new results by leading researchers working on the design and applications of theorem provers for higher order logic. In particular, this book gives a thorough state-of-the-art report on applications of the HOL system, one of the most widely used theorem provers for higher order logic.

This volume constitutes the proceedings of the First International Conference on Constraints in Computational Logics, CCL '94, held in Munich, Germany in September 1994. Besides abstracts or full papers of the 5 invited talks by senior researchers, the book contains revised versions of the 21 accepted research papers selected from a total of 52 submissions. The volume assembles high quality original papers covering major theoretical and practical issues of combining and extending programming paradigms, preferably by using constraints. The topics covered include symbolic constraints, set constraints, numerical constraints, multi-paradigm programming, combined calculi, constraints in rewriting, deduction, symbolic computations, and working systems.

This volume contains the thoroughly refereed and revised papers accepted for presentation at the IJCAI '91 Workshops on Fuzzy Logic and Fuzzy Control, held during the International Joint Conference on AI at Sydney, Australia in August 1991. The 14 technical contributions are devoted to several theoretical and applicational aspects of fuzzy logic and fuzzy control; they are presented in sections on theoretical aspects of fuzzy reasoning and fuzzy control, fuzzy neural networks, fuzzy control applications, fuzzy logic planning, and fuzzy circuits. In addition, there is a substantial introduction by the volume editors on the latest developments in the field that brings the papers presented into line.

This volume presents the refereed papers accepted for the international symposium Logical Foundations of Computer Science '94, Logic at St. Petersburg, held in St. Petersburg, Russia in July 1994. The symposium was the third in a series of joint efforts of logicians from both the former Soviet Union and the West.
The volume reflects that the interaction of logic and computer science is an especially fertile ground for interdisciplinary work providing mutual understanding and benefits. The totally 35 papers are devoted to topics as linear logic, Horn clauses, model-checking, lambda-calculi, modal logic, and problem complexity.

This book constitutes the proceedings of the 8th International Conference on Higher Order Logic Theorem Proving and Its Applications, held in Aspen Grove, Utah, USA in September 1995.
The 26 papers selected by the program committee for inclusion in this volume document the advances in the field achieved since the predecessor conference. The papers presented fall into three general categories: representation of formalisms in higher order logic; applications of mechanized higher order logic; and enhancements to the HOL and other theorem proving systems.

The subject of the book is an approach to the modeling of and the reasoning under uncertainty. It develops the Dempster-Shafer Theory as a theory of the reliability of reasoning with uncertain arguments. A particular interest of this approach is that it yields a new synthesis and integration of logic and probability theory. The reader will benefit from a new view at uncertainty modeling which extends classical probability theory.

This volume contains revised refereed versions of the best papers presented during the CSL '94 conference, held in Kazimierz, Poland in September 1994; CSL '94 is the eighth event in the series of workshops held for the third time as the Annual Conference of the European Association for Computer Science Logic.
The 38 papers presented were selected from a total of 151 submissions. All important aspects of the methods of mathematical logic in computer science are addressed: lambda calculus, proof theory, finite model theory, logic programming, semantics, category theory, and other logical systems. Together, these papers give a representative snapshot of the area of logical foundations of computer science.

Formal specifications were first used in the description of program ming languages because of the central role that languages and their compilers play in causing a machine to perform the computations required by a programmer. In a relatively short time, specification notations have found their place in industry and are used for the description of a wide variety of software and hardware systems. A formal method - like VDM - must offer a mathematically-based specification language. On this language rests the other key element of the formal method: the ability to reason about a specification. Proofs can be empioyed in reasoning about the potential behaviour of a system and in the process of showing that the design satisfies the specification. The existence of a formal specification is a prerequisite for the use of proofs; but this prerequisite is not in itself sufficient. Both proofs and programs are large formal texts. Would-be proofs may therefore contain errors in the same way as code. During the difficult but inevitable process of revising specifications and devel opments, ensuring consistency is a major challenge. It is therefore evident that another requirement - for the successful use of proof techniques in the development of systems from formal descriptions - is the availability of software tools which support the manipu lation of large bodies of formulae and help the user in the design of the proofs themselves."

This volume contains the proceedings of the 15th International Conference on Application and Theory of Petri Nets, held at Zaragoza, Spain in June 1994. The annual Petri net conferences are usually visited by some 150 - 200 Petri net experts coming from academia and industry all over the world.
The 28 full papers were selected out of in total 85 submissions from 18 countries. Together with the 3 invited contributions, these papers give a state-of-the-art report on all relevant aspects of Petri nets.

Techniques for reasoning about actions an change in the physical world is one of the classical research topics in artificial intelligence. It is motivated by the needs of autonomous robots which must be able to anticipate their immediate future, to plan their future actions, and to figure out what went wrong in case of problems. It is also motivated by the needs of common-sense reasoning for example in the understanding of natural language texts, where processes and change over time is an ever-present phenomenon. The same set of problems arises in several other areas of computing such as in conceptual modelling for data bases, and in the rapidly growing area of intelligent control. The present research monograph presents and uses a novel methodology for reasoning about actions and change. Traditional research contributions have proposed new logic variants which were only supported by episodical examples. THe work described here uses a systematic methodology for identifying the exact range of applicability of a given logic. For a number of previously proposed logics, as well as for some new ones, the present work characterizes exactly the class where it does not. This book will be a necessary source of reference for researchers in knowledge representation, cognitive robotics, and intelligent control in the years to come. Particularly because of its emphasis on a strict and systematic methodology, it can also be recommended as a textbook for graduate university courses in these areas.

Imre Lakatos's Proofs and Refutations is an enduring classic, which has never lost its relevance. Taking the form of a dialogue between a teacher and some students, the book considers various solutions to mathematical problems and, in the process, raises important questions about the nature of mathematical discovery and methodology. Lakatos shows that mathematics grows through a process of improvement by attempts at proofs and critiques of these attempts, and his work continues to inspire mathematicians and philosophers aspiring to develop a philosophy of mathematics that accounts for both the static and the dynamic complexity of mathematical practice. With a specially commissioned Preface written by Paolo Mancosu, this book has been revived for a new generation of readers.

This volume presents the proceedings of the Computer Science Logic Workshop CSL '92, held in Pisa, Italy, in September/October 1992. CSL '92 was the sixth of the series and the first one held as Annual Conference of the European Association for Computer Science Logic (EACSL). Full versions of the workshop contributions were collected after their presentation and reviewed. On the basis of 58 reviews, 26 papers were selected for publication, and appear here in revised final form. Topics covered in the volume include: Turing machines, linear logic, logic of proofs, optimization problems, lambda calculus, fixpoint logic, NP-completeness, resolution, transition system semantics, higher order partial functions, evolving algebras, functional logic programming, inductive definability, semantics of C, classes for a functional language, NP-optimization problems, theory of types and names, sconing and relators, 3-satisfiability, Kleene's slash, negation-complete logic programs, polynomial-time oracle machines, and monadic second-order properties.

This volume contains work on the decision problem done in Kazan (Russia), Tallinn (Estonia), and Vienna (Austria). The authors met several times to discuss and exchange their results and finally decided to write this monograph together. Besides a unified treatment of previously published results there are many new results first presented in this volume. The monograph opens with an introduction and a chapter on terminology, followed by chapters on: - Semantic clash resolution as decision procedure, - Completeness of ordering refinements, - Semantic tree based resolution variants, - Deciding the class K by an ordering refinement, - A resolution based method for building finite models. A final chapter on applications completes the volume.

The lambda calculus was developed in the 1930s by Alonzo Church. The calculus turned out to be an interesting model of computation and became theprototype for untyped functional programming languages. Operational and denotational semantics for the calculus served as examples for otherprogramming languages. In typed lambda calculi, lambda terms are classified according to their applicative behavior. In the 1960s it was discovered that the types of typed lambda calculi are in fact appearances of logical propositions. Thus there are two possible views of typed lambda calculi: - as models of computation, where terms are viewed as programs in a typed programming language; - as logical theories, where the types are viewed as propositions and the terms as proofs. The practical spin-off from these studies are: - functional programming languages which are mathematically more succinct than imperative programs; - systems for automated proof checking based on lambda caluli. This volume is the proceedings of TLCA '93, the first international conference on Typed Lambda Calculi and Applications, organized by the Department of Philosophy of Utrecht University. It includes29 papers selected from 51 submissions.

This volume presents the proceedings of the workshop CSL '91 (Computer Science Logic) held at the University of Berne, Switzerland, October 7-11, 1991. This was the fifth in a series of annual workshops on computer sciencelogic (the first four are recorded in LNCS volumes 329, 385, 440, and 533). The volume contains 33 invited and selected papers on a variety of logical topics in computer science, including abstract datatypes, bounded theories, complexity results, cut elimination, denotational semantics, infinitary queries, Kleene algebra with recursion, minimal proofs, normal forms in infinite-valued logic, ordinal processes, persistent Petri nets, plausibility logic, program synthesis systems, quantifier hierarchies, semantics of modularization, stable logic, term rewriting systems, termination of logic programs, transitive closure logic, variants of resolution, and many others.

This volume contains papers presented at the second International Workshop on Word Equations and Related Topics (IWWERT '91), held at the University ofRouen in October 1991. The papers are on the following topics: general solution of word equations, conjugacy in free inverse monoids, general A- and AX-unification via optimized combination procedures, wordequations with two variables, a conjecture about conjugacy in free groups, acase of termination for associative unification, theorem proving by combinatorial optimization, solving string equations with constant restriction, LOP (toward a new implementation of Makanin's algorithm), word unification and transformation of generalizedequations, unification in the combination of disjoint theories, on the subsets of rank two in a free monoid (a fast decision algorithm), and a solution of the complement problem in associative-commutative theories.

This volume contains the proceedings of JELIA '92, les Journ es Europ ennes sur la Logique en Intelligence Artificielle, or the Third European Workshop on Logics in Artificial Intelligence. The volume contains 2 invited addresses and 21 selected papers covering such topics as: - Logical foundations of logic programming and knowledge-based systems, - Automated theorem proving, - Partial and dynamic logics, - Systems of nonmonotonic reasoning, - Temporal and epistemic logics, - Belief revision. One invited paper, by D. Vakarelov, is on arrow logics, i.e., modal logics for representing graph information. The other, by L.M. Pereira, J.J. Alferes, and J.N. Apar cio, is on default theory for well founded semantics with explicit negation.

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 book principally concerns the rapidly growing area of what might be termed "Logical Complexity Theory": the study of bounded arithmetic, propositional proof systems, length of proof, and similar themes, and the relations of these topics to computational complexity theory. Issuing from a two-year international collaboration, the book contains articles concerning the existence of the most general unifier, a special case of Kreisel's conjecture on length-of-proof, propositional logic proof size, a new alternating logtime algorithm for boolean formula evaluation and relation to branching programs, interpretability between fragments of arithmetic, feasible interpretability, provability logic, open induction, Herbrand-type theorems, isomorphism between first and second order bounded arithmetics, forcing techniques in bounded arithmetic, and ordinal arithmetic in *L *D o. Also included is an extended abstract of J.P. Ressayre's new approach concerning the model completeness of the theory of real closed exponential fields. Additional features of the book include the transcription and translation of a recently discovered 1956 letter from Kurt Godel to J. von Neumann, asking about a polynomial time algorithm for the proof in k-symbols of predicate calculus formulas (equivalent to the P-NP question); and an open problem list consisting of seven fundamental and 39 technical questions contributed by many researchers, together with a bibliography of relevant references. This scholarly work will interest mathematical logicians, proof and recursion theorists, and researchers in computational complexity.