In this 1991 book the author gives a broad overview of different areas of research in nonmonotonic reasoning, and presents some results and ideas based on his research. The guiding principles are: clarification of the different research activities in the area, which have sometimes been undertaken independently of each other, and appreciation of the fact that these research activities often represent different means to the same ends, namely sound theoretical foundations and efficient computation. The book begins with a discussion of the various types of nonmonotonic reasoning, their applications and their logics. Theorem proving techniques for these logics are also described. There then follow chapters dealing with formulations of nonmonotonic inheritance, and nonmonotonic reasoning based on nonmonotonic rules. The final chapter discusses the achievements in the field in the light of the famous Yale shooting example. The book will be welcomed by researchers in theoretical computer science and artificial intelligence.

This volume contains the contributions to the Joint German/Austrian Con- rence on Arti?cial Intelligence, KI 2001, which comprises the 24th German and the 9th Austrian Conference on Arti?cial Intelligence. They are divided into the following categories: - 2 contributions by invited speakers of the conference; - 29 accepted technical papers, of which 5 where submitted as application papers and 24 as papers on foundations of AI; - 4 contributions by participants of the industrial day, during which companies working in the ?eld presented their AI applications. After a long period of separate meetings, the German and Austrian Societies for Arti?cial Intelligence, KI and OGAI, decided to hold a joint conference in Vienna in 2001. The two societies had previously held one joint conference. This took place in Ottstein, a small town in Lower Austria, in 1986. At that time, the rise of expert system technology had also renewed interest in AI in general, with quite some expectations for future advances regarding the use of AI techniques in applications pervading many areas of our daily life. Since then ?fteen years have passed, and we may want to comment, at the beginning of a newcentury, on the progress that has been made in this direction.

Logics have, for many years, laid claim to providing a formal basis for the study of arti?cial intelligence. With the depth and maturity of methodologies, formalisms, procedures, implementations, and their applications available today, this claim is stronger than ever, as witnessed by increasing amount and range of publications in the area, to which the present proceedings accrue. The European series of Workshops on Logics in Arti?cial Intelligence (or Journ'ees Europ'eennes sur la Logique en Intelligence Arti?cielle - JELIA) began in response to the need for a European forum for the discussion of emerging work in this burgeoning ?eld. JELIA 2000 is the seventh such workshop in the series, following the ones held in Rosco?, France (1988); Amsterdam, Netherlands ' (1990); Berlin, Germany (1992); York, U.K. (1994); Evora, Portugal (1996); and Dagstuhl, Germany (1998). JELIA 2000 will take place in M' alaga, Spain, from 29 September to 2 - tober 2000. The workshop is organized and hosted by the Research Group of Mathematics Applied to Computing of the Department of Applied Mathematics of the University of Mal ' aga. As in previous workshops, the aim is to bring together researchers involved in all aspects of logic in arti?cial intelligence. Additional sponsorship was provided by the ESPRIT NOE Compulog-Net.

In this book the author gives a broad overview of different areas of research in nonmonotonic reasoning, and presents some new results and ideas based on his research. The guiding principles are: clarification of the different research activities in the area, which have sometimes been undertaken independently of each other; and appreciation of the fact that these research activities often represent different means to the same ends, namely sound theoretical foundations and efficient computation. The book begins with a discussion of the various types of nonmonotonic reasoning, their applications and their logics. Theorem proving techniques for these logics are also described. The following chapters deal with formulations of nonmonotonic inheritance, and nonmonotonic reasoning based on nonmonotonic rules. The final chapter discusses the achievements in the field in the light of the Yale shooting example. The book will be welcomed by researchers in theoretical computer science and artificial intelligence.

This book constitutes the refereed proceedings of the 21st Annual German Conference on Artificial Intelligence, KI-97, held in Freiburg, Germany, in September 1997.
The volume presents revised versions of 26 full papers and 10 posters selected from around 70 submissions from more than 15 countries. Also included are three excellent invited contributions by Anthony G. Cohn, Kurt Konolige, and Pat Langley. The papers are organized in topical sections on theorem proving, nonclassical logics, knowledge representation, spatial reasoning, computational linguistics, computer perception and neural nets, and on planning, diagnosis and search.

This proceedings volume contains a selection of revised and extended papers presented at the Second International Workshop on Nonmonotonic and InductiveLogic, NIL '91, which took place at Reinhardsbrunn Castle, December 2-6, 1991. The volume opens with an extended version of a tutorial on nonmonotonic logic by G. Brewka, J. Dix, and K. Konolige. Fifteen selected papers follow, on a variety of topics. The majority of papers belong either to the area of nonmonotonic reasoning or to the field of inductive inference, but some papers integrate research from both areas. The first workshop in this series was held at the University of Karlsruhe in December 1990 and its proceedings were published as Lecture Notes in Artificial Intelligence Volume 543. The series of workshops was made possible by financial support from Volkswagen Stiftung, Hannover. This workshop was also supported by IBM Deutschland GmbH and Siemens AG.

This book constitutes the refereed proceedings of the 9th International Conference on Logic Programming and Nonmonotonic Reasoning, LPNMR 2007, held in Tempe, AZ, USA in May 2007.

The 18 revised full papers, 5 revised poster papers, and 7 system descriptions presented together with 2 invited papers were carefully reviewed and selected for presentation. As a forum for exchanging ideas on declarative logic programming, nonmonotonic reasoning, and knowledge representation, LPNMR encompasses theoretical studies, design and implementation of logic based programming languages and database systems, and development of experimental systems. Also contained in this volume are the results of this year's answer set programming competition.

The publication of the seminal special issue on nonmonotonic logics by the Artificial Intelligence Journal in 1980 resulted in a new area of research in knowledge representation and changed the mainstream paradigm of logic that originated in antiquity. It led to discoveries of connections between logic, knowledge representation and computation, and attracted not only computer scientists but also logicians, mathematicians and philosophers. Nonmonotonic reasoning concerns situations when information is incomplete or uncertain. Thus, conclusions drawn lack iron-clad certainty that comes with classical logic reasoning. New information, even if the original one is retained, may change conclusions. Formal ways to capture mechanisms involved in nonmonotonic reasoning, and to exploit them for computation as in the answer set programming paradigm are at the heart of this research area. The conference NonMon@30 - Thirty Years of Nonmonotonic Reasoning, held in Lexington, KY, USA, October 22-25, 2010, aimed to sum up the experience of the first 30 years of nonmonotonic logics and to map paths into the future. It comprised eighteen invited talks and several technical presentations. The present volume consists of the texts based on twelve of the invited presentations. These papers offer unique insights into the key questions that have been driving the development of nonmonotonic reasoning and suggest problems worthy of consideration in the future. They paint the picture of the field that has a well-established tradition, and remains vibrant and relevant to long-term goals of artificial intelligence.

Nonmonotonic reasoning in its broadest sense is reasoning to conclusions on the basis of incomplete information. Given more information, previously drawn inferences may be retracted. Commonsense reasoning has a nonmonotonic component; it has been argued that almost all commonsense inferences are of this sort. From the end of the 1980s to the present there has been an explosion in research in nonmonotonic reasoning. It is now possible to understand more clearly the properties of the major formalisms from a metatheoretical point of view, the relationships among the formalisms and their connection to independently developed proof methods. The goal of this monograph is to make this understanding more accessible.

The book contains a collection of eight survey papers written by some of the best researchers in foundations of knowledge representation and reasoning. It covers topics like theories of uncertainty, nonmonotonic and causal reasoning, logic programming, abduction, inductive logic programming, description logics, complexity in Artificial Intelligence, and model-based diagnosis. It thus provides an up-to-date coverage of recent approaches to some of the most challenging problems underlying knowledge representation and Artificial Intelligence in general.