Knowledge representation is a key area of modern AI, underlying the development of semantic networks. Description logics are languages that represent knowledge in a structured and formally well-understood way: they are the cornerstone of the Semantic Web. This is the first textbook describing this importan new topic and will be suitable for courses aimed at advanced undergraduate and beginning graduate students, or for self-study. It assumes only a basic knowledge of computer science concepts. After generla introducitons motivating and overviewing the subject, the authors describe a simple DL and how it works and can be used, utilizing a running example that recurs through the book. Methods of reasoning and their implementation and complexity are examined, Finally, the authors provide a non-trivial DL knowledge base and use it to illsutrate featues that have been introduced: this base is available for free online access in a form usable by modern ontology editors.

This book constitutes the refereed proceedings of the 18th International Conference on Rewriting Techniques and Applications, RTA 2007, held in Paris, France in June 2007 in conjunction with TLCA 2007, the 8th International Conference on Typed Lambda Calculi and Applications as part of RDP 2007, the 4th International Conference on Rewriting, Deduction, and Programming.

The 24 revised full papers and 3 systems description papers were carefully reviewed and selected from 69 initial submissions and are presented together with 3 invited talks. The papers cover current research on all aspects of rewriting featuring applications, foundational issues, frameworks, implementations, as well as semantics.

The refereed proceedings of the 19th International Conference on Automated Deduction, CADE 2003, held in Miami Beach, FL, USA in July 2003. The 29 revised full papers and 7 system description papers presented together with an invited paper and 3 abstracts of invited talks were carefully reviewed and selected from 83 submissions. All current aspects of automated deduction are discussed, ranging from theoretical and methodological issues to the presentation of new theorem provers and systems.

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.

Knowledge representation is a key area of modern AI, underlying the development of semantic networks. Description logics are languages that represent knowledge in a structured and formally well-understood way: they are the cornerstone of the Semantic Web. This is the first textbook describing this importan new topic and will be suitable for courses aimed at advanced undergraduate and beginning graduate students, or for self-study. It assumes only a basic knowledge of computer science concepts. After generla introducitons motivating and overviewing the subject, the authors describe a simple DL and how it works and can be used, utilizing a running example that recurs through the book. Methods of reasoning and their implementation and complexity are examined, Finally, the authors provide a non-trivial DL knowledge base and use it to illsutrate featues that have been introduced: this base is available for free online access in a form usable by modern ontology editors.

This textbook offers a unified, self-contained introduction to the field of term rewriting. Baader and Nipkow cover all the basic material--abstract reduction systems, termination, confluence, completion, and combination problems--but also some important and closely connected subjects: universal algebra, unification theory, Gröbner bases, and Buchberger's algorithm. They present the main algorithms both informally and as programs in the functional language Standard ML (An appendix contains a quick and easy introduction to ML). Key chapters cover crucial algorithms such as unification and congruence closure in more depth and develop efficient Pascal programs. The book contains many examples and over 170 exercises. This is also an ideal reference book for professional researchers: results spread over many conference and journal articles are collected here in a unified notation, detailed proofs of almost all theorems are provided, and each chapter closes with a guide to the literature.

Description logics are embodied in several knowledge-based systems and are used to develop various real-life applications. Now in paperback, The Description Logic Handbook provides a thorough account of the subject, covering all aspects of research in this field, namely: theory, implementation, and applications. Its appeal will be broad, ranging from more theoretically oriented readers, to those with more practically oriented interests who need a sound and modern understanding of knowledge representation systems based on description logics. As well as general revision throughout the book, this new edition presents a new chapter on ontology languages for the semantic web, an area of great importance for the future development of the web. In sum, the book will serve as a unique resource for the subject, and can also be used for self-study or as a reference for knowledge representation and artificial intelligence courses.