Harold Boley - Böcker

The Semantic Web is a worldwide endeavor to advance the Web by enriching its content with semantic metainformation that can be processed by inferen- enabled Web applications. Taxonomies and rules, along with their automated reasoning techniques, are the main components of Semantic Web ontologies. Rule systems are considered to be a major area in the further development of the Semantic Web. On one hand, rules can specify declarative knowledge in ontology languages, expressing constraints or transformations, either in conju- tionwith,orasanalternativeto,descriptionlogics.Ontheotherhand,rulescan specify behavioral knowledge, enforcing policies or reacting to events/changes. Finally, rule markup languages such as RuleML allow us to publish rules on the Web, to process rules in general XML environments as well as special rule engines, to exchange rules between di?erent applications and tools via XSLT translators, as well as to embed rules into other XML content and vice versa. This workshop was dedicated to all aspects of rules and rule markup l- guages for the Semantic Web.RuleML 2004 was the third in a series of wo- shops that was initiated with the International Semantic Web Conference. The previous workshops were held on Sardinia, Italy (2002), and on Sanibel Island, USA (2003). Thisyearwehad25submissions,ofwhich11wereacceptedasregularpapers and another ?ve as short papers describing tools. Wearegratefultoourtwoinvitedspeakers,MikeDeanfromBBNandChr- tine Golbreich from the University of Rennes. Our thanks also go to all subm- ters and reviewers without whom the workshop and these proceedings could not have succeeded.

This volume presents the proceedings of an internationalworkshop on the processing of declarative knowledge. Theworkshop was organized and hosted by the German ResearchCenter for Artificial Intelligence (DFKI) in cooperationwith the Association for Logic Programming (ALP) and theGesellschaft fr Informatik (GI). Knowledge is often represented using definite clauses,rules, constraints, functions, conceptual graphs, andrelated formalisms. The workshop addressed such high-levelrepresentations and their efficient implementation requiredfor declarative knowledge bases. Many of the papers treatrepresentation methods, mainly concept languages, and manytreat implementation methods, such as transformationtechniques and WAM-like abstract machines. Several papersdescribe implemented knowledge-processing systems. Thecompetition between procedural and declarative paradigms wasdiscussed in a panel session, and position statements of thepanelists are included in the volume.