TY - GEN
T1 - Implementing query answering for hybrid MKNF knowledge bases
AU - Gomes, Ana Sofia
AU - Alferes, José Júlio
AU - Swift, Terrance
PY - 2010
Y1 - 2010
N2 - Ontologies and rules are usually loosely coupled in knowledge representation formalisms. In fact, ontologies use open-world reasoning while the leading semantics for rules use non-monotonic, closed-world reasoning. One exception is the tightly-coupled framework of Minimal Knowledge and Negation as Failure (MKNF), which allows statements about individuals to be jointly derived via entailment from an ontology and inferences from rules. Nonetheless, the practical usefulness of MKNF has not always been clear, although recent work has formalized a general resolution-based method for querying MKNF when rules are taken to have the well-founded semantics, and the ontology is modeled by a general Oracle. That work leaves open what algorithms should be used to relate the entailments of the ontology and the inferences of rules. In this paper we provide such algorithms, and describe the implementation of a query-driven system, CDF-Rules, for hybrid knowledge bases combining both (non-monotonic) rules under the well-founded semantics and a (monotonic) ontology, represented by a CDF (ALCQ) theory.
AB - Ontologies and rules are usually loosely coupled in knowledge representation formalisms. In fact, ontologies use open-world reasoning while the leading semantics for rules use non-monotonic, closed-world reasoning. One exception is the tightly-coupled framework of Minimal Knowledge and Negation as Failure (MKNF), which allows statements about individuals to be jointly derived via entailment from an ontology and inferences from rules. Nonetheless, the practical usefulness of MKNF has not always been clear, although recent work has formalized a general resolution-based method for querying MKNF when rules are taken to have the well-founded semantics, and the ontology is modeled by a general Oracle. That work leaves open what algorithms should be used to relate the entailments of the ontology and the inferences of rules. In this paper we provide such algorithms, and describe the implementation of a query-driven system, CDF-Rules, for hybrid knowledge bases combining both (non-monotonic) rules under the well-founded semantics and a (monotonic) ontology, represented by a CDF (ALCQ) theory.
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U2 - 10.1007/978-3-642-11503-5_4
DO - 10.1007/978-3-642-11503-5_4
M3 - Conference contribution
AN - SCOPUS:77749271121
SN - 3642115020
SN - 9783642115028
T3 - Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
SP - 25
EP - 39
BT - Practical Aspects of Declarative Languages - 12th International Symposium, PADL 2010, Proceedings
PB - Springer Verlag
T2 - 12th International Symposium on Practical Aspects of Declarative Languages, PADL 2010
Y2 - 18 January 2010 through 19 January 2010
ER -