Language features for flexible handling of exceptions in information systems
ACM Transactions on Database Systems (TODS)
Artificial Intelligence
Making believers out of computers
Artificial Intelligence
On generating all maximal independent sets
Information Processing Letters
Updating logical databases
Structure identification in relational data
Artificial Intelligence - Special volume on constraint-based reasoning
On the complexity of propositional knowledge base revision, updates, and counterfactuals
Artificial Intelligence
Propositional circumscription and extended closed-world reasoning are &Pgr;p2-complete
Theoretical Computer Science
Horn approximations of empirical data
Artificial Intelligence
Identifying the Minimal Transversals of a Hypergraph and Related Problems
SIAM Journal on Computing
Knowledge compilation and theory approximation
Journal of the ACM (JACM)
On the complexity of dualization of monotone disjunctive normal forms
Journal of Algorithms
Computers and Intractability: A Guide to the Theory of NP-Completeness
Computers and Intractability: A Guide to the Theory of NP-Completeness
On the semantics of updates in databases
PODS '83 Proceedings of the 2nd ACM SIGACT-SIGMOD symposium on Principles of database systems
On Horn Envelopes and Hypergraph Transversals
ISAAC '93 Proceedings of the 4th International Symposium on Algorithms and Computation
Complexity aspects of knowledge representation
Complexity aspects of knowledge representation
Computing intersections of Horn theories for reasoning with models
AAAI '98/IAAI '98 Proceedings of the fifteenth national/tenth conference on Artificial intelligence/Innovative applications of artificial intelligence
New results on monotone dualization and generating hypergraph transversals
STOC '02 Proceedings of the thiry-fourth annual ACM symposium on Theory of computing
Disjunctions of Horn Theories and Their Cores
ISAAC '98 Proceedings of the 9th International Symposium on Algorithms and Computation
Hypergraph Transversal Computation and Related Problems in Logic and AI
JELIA '02 Proceedings of the European Conference on Logics in Artificial Intelligence
On the complexity of monotone dualization and generating minimal hypergraph transversals
Discrete Applied Mathematics
New Results for Horn Cores and Envelopes of Horn Disjunctions
Proceedings of the 2008 conference on ECAI 2008: 18th European Conference on Artificial Intelligence
Horn complements: towards horn-to-horn belief revision
AAAI'08 Proceedings of the 23rd national conference on Artificial intelligence - Volume 1
On the diffvierence of horn theories
STACS'99 Proceedings of the 16th annual conference on Theoretical aspects of computer science
Deciding monotone duality and identifying frequent itemsets in quadratic logspace
Proceedings of the 32nd symposium on Principles of database systems
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Approximating a general formula from above and below by Horn formulas (its Horn envelope and Horn core, respectively) was proposed by Selman and Kautz (1991, 1996) as a form of "knowledge compilation," supporting rapid approximate reasoning; on the negative side, this scheme is static in that it supports no updates, and has certain complexity drawbacks pointed out by Kavvadias, Papadimitriou and Sideri (1993). On the other hand, the many frameworks and schemes proposed in the literature for theory update and revision are plagued by serious complexity-theoretic impediments, even in the Horn case, as was pointed out by Eiter and Gottlob (1992), and is further demonstrated in the present paper. More fundamentally, these schemes are not inductive, in that they may lose in a single update any positive properties of the represented sets of formulas (small size, Horn structure, etc.). In this paper we propose a new scheme, incremental recompilation, which combines Horn approximation and model-based updates; this scheme is inductive and very efficient, free of the problems facing its constituents. A set of formulas is represented by an upper and lower Horn approximation. To update, we replace the upper Horn formula by the Horn envelope of its minimum-change update, and similarly the lower one by the Horn core of its update; the key fact which enables this scheme is that Horn envelopes and cores are easy to compute when the underlying formula is the result of a minimum-change update of a Horn formula by a clause. We conjecture that efficient algorithms are possible for more complex updates.