Foundations of logic programming
Foundations of logic programming
Semantical considerations on nonmonotonic logic
Artificial Intelligence
Applications of circumscription to formalizing common-sense knowledge
Artificial Intelligence
Journal of Logic Programming
Extended stable semantics for normal and disjunctive programs
Logic programming
General logical databases and programs: default logic semantics and stratification
Information and Computation
Negation by default and unstratifiable logic programs
Selected papers of the workshop on Deductive database theory
Well-founded semantics coincides with three-valued stable semantics
Fundamenta Informaticae
The well-founded semantics for general logic programs
Journal of the ACM (JACM)
The alternating fixpoint of logic programs with negation
PODS '89 Selected papers of the eighth ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems
Tabled evaluation with delaying for general logic programs
Journal of the ACM (JACM)
Characterizations of the Disjunctive Well-Founded Semantics: Confluent Calculi and Iterated GCWA
Journal of Automated Reasoning
WFS + Branch and Bound = Stable Models
IEEE Transactions on Knowledge and Data Engineering
HySpirit - A Probabilistic Inference Engine for Hypermedia Retrieval in Large Databases
EDBT '98 Proceedings of the 6th International Conference on Extending Database Technology: Advances in Database Technology
Computing and Comparing Semantics of Programs in Four-Valued Logics
MFCS '99 Proceedings of the 24th International Symposium on Mathematical Foundations of Computer Science
Improving the Alternating Fixpoint: The Transformation Approach
LPNMR '97 Proceedings of the 4th International Conference on Logic Programming and Nonmonotonic Reasoning
Epistemological problems of artificial intelligence
IJCAI'77 Proceedings of the 5th international joint conference on Artificial intelligence - Volume 2
Annals of Mathematics and Artificial Intelligence
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A precise meaning or semantics must be associated with any logic program or deductive database, and that even in presence of incomplete information. The different semantics that can be assigned to a logic program correspond to different assumptions made concerning the atoms whose logical values cannot be inferred from the rules. Thus, the well-founded semantics corresponds to the assumption that every such atom is false, while the Kripke-Kleene semantics corresponds to the assumption that every such atom is unknown. However, these assumptions are uniform in the sense that they always assign the same default value to all atoms: either everything is supposed to be false by default (closed world assumption) or everything is supposed to be unknown by default (open world assumption). In several application environments, however, including information retrieval and information integration, such uniformity is not realistic. In this paper, we propose to unify and extend the assumption-based approaches by allowing assumptions to be nonuniform. To deal with such assumptions, we extend the concept of unfounded set of Van Gelder to the notion of support of a hypothesis. Based on the support of a hypothesis, we define our hypothesis-founded semantics and show that this semantics generalizes both the Kripke-Kleene semantics and the well-founded semantics of Datalog programs with negation.