Samson Abramsky – författare

This handbook volume covers fundamental topics of semantic modelling in logic and computation. The chapters (some monographic in length), were written following years of coordination and follow a thematic point of view. The volume brings the reader up to front line research, and is indispensable to any serious worker in the areas.

This handbook volume covers fundamental topics of semantics in logic and computation. The chapters (some monographic in length), were written following years of co-ordination and follow a thematic point of view. The volume brings the reader up to front line research, and is indispensable to any serious worker in the areas.

The author presents a theory of concurrent processes where three different semantic description methods that are usually studied in isolation are brought together. Petri nets describe processes as concurrent and interacting machines; algebraic process terms describe processes as abstract concurrent processes; and logical formulas specify the intended communication behaviour of processes. At the heart of this theory are two sets of transformation rules for the top-down design of concurrent processes. The first set can be used to transform stepwise logical formulas into process terms, whilst process terms can be transformed into Petri nets by the second set. These rules are based on novel techniques for the operational and denotational semantics of concurrent processes. Various results and relationships between nets, terms and formulas starting with formulas and illustrated by examples. The use of transformations is demonstrated in a series of case studies, and the author also identifies directions for research.

Classical logic has proved inadequate in various areas of computer science, artificial intelligence, mathematics, philosopy and linguistics. This is an introduction to extensions of first-order logic, based on the principle that many-sorted logic (MSL) provides a unifying framework in which to place, for example, second-order logic, type theory, modal and dynamic logics and MSL itself. The aim is two fold: only one theorem-prover is needed; proofs of the metaproperties of the different existing calculi can be avoided by borrowing them from MSL. To make the book accessible to readers from different disciplines, whilst maintaining precision, the author has supplied detailed step-by-step proofs, avoiding difficult arguments, and continually motivating the material with examples. Consequently this can be used as a reference, for self-teaching or for first-year graduate courses.

This book develops the theory of typed feature structures, a data structure that generalizes both first-order terms and feature structures of unification-based grammars to include inheritance, typing, inequality, cycles and intensionality. The resulting synthesis serves as a logical foundation for grammars, logic programming and constraint-based reasoning systems. A logical perspective is adopted which employs an attribute-value description language along with complete equational axiomatizations of the various systems of feature structures. At the same time, efficiency concerns are kept in mind and complexity and representability results are provided. The application of feature structures to phrase structure grammars is described and completeness results are shown for standard evaluation strategies. Definite clause logic programs are treated as a special case of phrase structure grammars. Constraint systems are introduced and an enumeration technique is developed for solving arbitrary attribute-value logic constraints. This book, with its innovative approach to data structure, will be essential reading for researchers in computational linguistics, logic programming and knowledge representation. Its self-contained presentation makes it flexible enough to serve as both a research tool and a text book.

Reasoning under uncertainty, that is, making judgements with only partial knowledge, is a major theme in artificial intelligence. Professor Paris provides here an introduction to the mathematical foundations of the subject. It is suited for readers with some knowledge of undergraduate mathematics but is otherwise self-contained, collecting together the key results on the subject and formalizing within a unified framework the main contemporary approaches and assumptions. The author has concentrated on giving clear mathematical formulations, analyses, justifications and consequences of the main theories about uncertain reasoning, so the book can serve as a textbook for beginners or as a starting point for further basic research into the subject. It will be welcomed by graduate students and research workers in logic, philosophy and computer science as an account of how mathematics and artificial intelligence can complement and enrich each other.

This book is concerned with techniques for formal theorem-proving, with particular reference to Cambridge LCF (Logic for Computable Functions). Cambridge LCF is a computer program for reasoning about computation. It combines the methods of mathematical logic with domain theory, the basis of the denotational approach to specifying the meaning of program statements. Cambridge LCF is based on an earlier theorem-proving system, Edinburgh LCF, which introduced a design that gives the user flexibility to use and extend the system. A goal of this book is to explain the design, which has been adopted in several other systems. The book consists of two parts. Part I outlines the mathematical preliminaries, elementary logic and domain theory, and explains them at an intuitive level, giving reference to more advanced reading; Part II provides sufficient detail to serve as a reference manual for Cambridge LCF. It will also be a useful guide for implementors of other programs based on the LCF approach.

Artificial intelligence has recently turned to formal logic in the search for powerful yet well-behaved knowledge representation languages. This book covers the background of classical logic, including the major meta-theorems, and the state of the art in theorem proving including Bibel's connection method. Also covered are the advanced adaptations of classical logic now being used in artificial intelligence - temporal and modal logics, reason maintenance and intensional logic. First published in 1988, the book covers a wider range of topics than the currently available books in this area, and is more directly aimed at workers in artificial intelligence.

Now in paperback, Topology via Logic is an advanced textbook on topology for computer scientists. Based on a course given by the author to postgraduate students of computer science at Imperial College, it has three unusual features. First, the introduction is from the locale viewpoint, motivated by the logic of finite observations: this provides a more direct approach than the traditional one based on abstracting properties of open sets in the real line. Second, the methods of locale theory are freely exploited. Third, there is substantial discussion of some computer science applications. Although books on topology aimed at mathematics exist, no book has been written specifically for computer scientists. As computer scientists become more aware of the mathematical foundations of their discipline, it is appropriate that such topics are presented in a form of direct relevance and applicability. This book goes some way towards bridging the gap.

Chaitin, the inventor of algorithmic information theory, presents in this book the strongest possible version of Gödel's incompleteness theorem, using an information theoretic approach based on the size of computer programs. One half of the book is concerned with studying the halting probability of a universal computer if its program is chosen by tossing a coin. The other half is concerned with encoding the halting probability as an algebraic equation in integers, a so-called exponential diophantine equation.

This book tackles the problems of update algorithms for databases. How can one construct and maintain a database of facts, capable of incorporating new information and getting rid of all outdated information, and yet in the process not disturb any other information in the database? The author has produced a formal method for specifying the desired change intentionally, using a 'formula-based' approach to updating needs rather than a 'model-based' technique. The complexity of the algorithms, choice of semantics and a means of enforcing integrity constraints are also discussed. The book will be of value to all involved in database research.

All traditional implementation techniques for functional languages (mostly based on supercombinators, environments or continuations) fail to avoid useless repetition of work; they are not 'optimal' in their implementation of sharing, often causing a catastrophic, exponential explosion in reduction time. Optimal reduction is an innovative graph reduction technique for functional expressions, introduced by Lamping in 1990, that solves the sharing problem. This book, the first in the subject, is a comprehensive account by two of its leading exponents. Practical implementation aspects are fully covered as are the mathematical underpinnings of the subject. The relationship to the pioneering work of Lévy and to Girard's more recent Geometry of Interaction are explored; optimal reduction is thereby revealed as a prime example of how a beautiful mathematical theory can lead to practical benefit. The book is essentially self-contained, requiring no more than basic familiarity with functional languages. It will be welcomed by graduate students and research workers in lambda calculus, functional programming or linear logic.

This volume is based on the 2008 Clifford Lectures on Information Flow in Physics, Geometry and Logic and Computation, held March 12-15, 2008, at Tulane University in New Orleans, Louisiana. The varying perspectives of the researchers are evident in the topics represented in the volume, including mathematics, computer science, quantum physics and classical and quantum information. A number of the articles address fundamental questions in quantum information and related topics in quantum physics, using abstract categorical and domain-theoretic models for quantum physics to reason about such systems and to model spacetime. Readers can expect to gain added insight into the notion of information flow and how it can be understood in many settings. They also can learn about new approaches to modeling quantum mechanics that provide simpler and more accessible explanations of quantum phenomena, which don't require the arcane aspects of Hilbert spaces and the cumbersome notation of bras and kets.

In this volume, different aspects of logics for dependence and independence are discussed, including both the  logical and computational aspects of dependence logic, and also applications  in a number of areas, such as statistics, social choice theory, databases, and computer security.  The contributing authors represent leading experts in this relatively new field, each of whom was invited to write a chapter based on talks given at seminars held at the Schloss Dagstuhl Leibniz Center for Informatics in Wadern, Germany (in February 2013 and June 2015) and an Academy Colloquium at the Royal Netherlands Academy of Arts and Sciences (March 2014).  Altogether, these chapters provide the most up-to-date look at this developing and highly interdisciplinary field and will be of interest to a broad group of logicians, mathematicians, statisticians, philosophers, and scientists. Topics covered includea comprehensive survey of many propositional, modal, and first-order variants of dependence logic;new results concerning expressive power of several variants of dependence logic with different sets of logical connectives and generalized dependence atoms;connections between inclusion logic and the least-fixed point logic;an overview of dependencies in databases by addressing the relationships between implication problems for fragments of statistical conditional independencies, embedded multivalued dependencies, and propositional logic;various Markovian models used to characterize dependencies and causality among variables in multivariate systems;applications of dependence logic in social choice theory; andan introduction to the theory of secret sharing, pointing out connections to dependence and independence logic.

In this volume, different aspects of logics for dependence and independence are discussed, including both the  logical and computational aspects of dependence logic, and also applications  in a number of areas, such as statistics, social choice theory, databases, and computer security.  The contributing authors represent leading experts in this relatively new field, each of whom was invited to write a chapter based on talks given at seminars held at the Schloss Dagstuhl Leibniz Center for Informatics in Wadern, Germany (in February 2013 and June 2015) and an Academy Colloquium at the Royal Netherlands Academy of Arts and Sciences (March 2014).  Altogether, these chapters provide the most up-to-date look at this developing and highly interdisciplinary field and will be of interest to a broad group of logicians, mathematicians, statisticians, philosophers, and scientists. Topics covered includea comprehensive survey of many propositional, modal, and first-order variants of dependence logic;new results concerning expressive power of several variants of dependence logic with different sets of logical connectives and generalized dependence atoms;connections between inclusion logic and the least-fixed point logic;an overview of dependencies in databases by addressing the relationships between implication problems for fragments of statistical conditional independencies, embedded multivalued dependencies, and propositional logic;various Markovian models used to characterize dependencies and causality among variables in multivariate systems;applications of dependence logic in social choice theory; andan introduction to the theory of secret sharing, pointing out connections to dependence and independence logic.

This book constitutes the refereed proceedings of the 5th International Conference on Typed Lambda Calculi and Applications, TLCA 2001, held in Krakow, Poland in May 2001. The 28 revised full papers presented were carefully reviewed and selected from 55 submissions. The volume reports research results on all current aspects of typed lambda calculi. Among the topics addressed are type systems, subtypes, coalgebraic methods, pi-calculus, recursive games, various types of lambda calculi, reductions, substitutions, normalization, linear logic, cut-elimination, prelogical relations, and mu calculus.

The papers in this volume were presented at the fourthbiennial Summer Conference on Category Theory and ComputerScience, held in Paris, September3-6, 1991. Category theorycontinues to be an important tool in foundationalstudies incomputer science. It has been widely applied by logicians toget concise interpretations of many logical concepts. Linksbetween logic and computer science have been developed nowfor over twenty years, notably via the Curry-Howardisomorphism which identifies programs with proofs and typeswith propositions. The triangle category theory - logic -programming presents a rich world of interconnections. Topics covered in this volume include the following. Typetheory: stratification of types and propositions can bediscussed in a categorical setting. Domain theory: syntheticdomain theory develops domain theory internally in theconstructive universe of the effective topos. Linear logic:the reconstruction of logic based on propositions asresources leads to alternatives to traditional syntaxes. Theproceedings of the previous three category theoryconferences appear as Lecture Notes in Computer ScienceVolumes 240, 283 and 389.

ICALP 2010, the 37th edition of the International Colloquium on Automata, Languages and Programming was held July 6-10, 2010 in Bordeaux, France. ICALP is a series of annual conference of the European Association for Th- retical Computer Science (EATCS) which ?rst took place in 1972, organized by MauriceNivatandhiscolleaguesinParis.Thisyear,theprogramconsistedofthe established trackA, focusing on Algorithms,Complexity and Games, chairedby Paul G. Spirakis; Track B, focusing on Logic, Semantics, Automata and Theory of Programming, chaired by Samson Abramsky; Track C focusing this year on Foundations of Networked Computation: Models, Algorithms and Information Management, chaired by Friedhelm Meyer auf der Heide. The three Program Committees received a total of 389 submissions: 222 for TrackA,114forTrackBand53forTrackC,writtenbyauthorsfrom45di?erent countries. Of these, 60, 30 and 16, respectively, were selected for inclusion in the scienti?c program. Each paper got on average 3.5 referee reports. The Programalsoincluded six invitedtalks byPierreFraigniaud(CNRS and Univ.ParisDiderot),JeanGoubault-Larrecq(ENSCachanandLSV),Burkhard Monien (Univ. Paderborn), Joel Ouaknine (Oxford Univ.Computing Lab.), Roger Wattenhofer (ETH Zurich), and Emo Welzl (ETH Zurich). These 112 contributed and invited papers are presented in two proceedings volumes. The ?rst contains the contributed papers of Track A and the invited talks of Burkhard Monien and Emo Welzl. The second volume contains the contributed papers of Tracks B and C as well as the invited talks of Pierre Fraigniaud, Jean Goubault-Larrecq, Joel Ouaknine and Roger Wattenhofer.