Details
| Original language | English |
|---|---|
| Title of host publication | Foundations of Knowledge Representation and Reasoning |
| Editors | Gerhard Lakemeyer, Bernhard Nebel |
| Publisher | Springer Verlag |
| Pages | 250-274 |
| Number of pages | 25 |
| ISBN (print) | 9783540581079 |
| Publication status | Published - 1994 |
| Event | Workshop on Theoretical Foundations of Knowledge Representation and Reasoning held in conjunction with 10th European Conference on Artificial Intelligence, ECAI 1992 - Vienna, Austria Duration: 3 Aug 1992 → 7 Aug 1992 |
Publication series
| Name | Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) |
|---|---|
| Volume | 810 LNAI |
| ISSN (Print) | 0302-9743 |
| ISSN (electronic) | 1611-3349 |
Abstract
The AGM rationality postulates for belief revision play an important role in the formalization of subjunctive queries over knowledge bases. However, the well known triviality results by Gardenfors in connection with the Ramsey Test make defining a query semantics corresponding to these rationality postulates a difficult task. While existing approaches avoid the triviality results by restricting the postulates in certain ways, we show that an exact translation into a query semantics is possible. The resulting semantics allows for the first time the integration of subjunctive queries evaluated according to a revision semantics corresponding to the AGM rationality postulates with an update operator corresponding to the update semantics formalized by Katsuno, Mendelzon and Grahne. The query semantics extends usual conditional implication by defining the concepts of possibility and necessity relative to a knowledge base. Additionally, based on this semantics, we present a formal account of splitting a knowledge base into two parts. We propose a specific revision function and show that this function is optimal in the sense, that after revision as few conditional consequences as possible are changed.
ASJC Scopus subject areas
- Mathematics(all)
- Theoretical Computer Science
- Computer Science(all)
- General Computer Science
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Foundations of Knowledge Representation and Reasoning. ed. / Gerhard Lakemeyer; Bernhard Nebel. Springer Verlag, 1994. p. 250-274 (Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics); Vol. 810 LNAI).
Research output: Chapter in book/report/conference proceeding › Conference contribution › Research › peer review
}
TY - GEN
T1 - Asking about possibilities — revision and update semantics for subjunctive queries (Extended report)
AU - Nejdl, Wolfgang
AU - Banagl, Markus
N1 - Publisher Copyright: © 1994, Springer Verlag. All rights reserved.
PY - 1994
Y1 - 1994
N2 - The AGM rationality postulates for belief revision play an important role in the formalization of subjunctive queries over knowledge bases. However, the well known triviality results by Gardenfors in connection with the Ramsey Test make defining a query semantics corresponding to these rationality postulates a difficult task. While existing approaches avoid the triviality results by restricting the postulates in certain ways, we show that an exact translation into a query semantics is possible. The resulting semantics allows for the first time the integration of subjunctive queries evaluated according to a revision semantics corresponding to the AGM rationality postulates with an update operator corresponding to the update semantics formalized by Katsuno, Mendelzon and Grahne. The query semantics extends usual conditional implication by defining the concepts of possibility and necessity relative to a knowledge base. Additionally, based on this semantics, we present a formal account of splitting a knowledge base into two parts. We propose a specific revision function and show that this function is optimal in the sense, that after revision as few conditional consequences as possible are changed.
AB - The AGM rationality postulates for belief revision play an important role in the formalization of subjunctive queries over knowledge bases. However, the well known triviality results by Gardenfors in connection with the Ramsey Test make defining a query semantics corresponding to these rationality postulates a difficult task. While existing approaches avoid the triviality results by restricting the postulates in certain ways, we show that an exact translation into a query semantics is possible. The resulting semantics allows for the first time the integration of subjunctive queries evaluated according to a revision semantics corresponding to the AGM rationality postulates with an update operator corresponding to the update semantics formalized by Katsuno, Mendelzon and Grahne. The query semantics extends usual conditional implication by defining the concepts of possibility and necessity relative to a knowledge base. Additionally, based on this semantics, we present a formal account of splitting a knowledge base into two parts. We propose a specific revision function and show that this function is optimal in the sense, that after revision as few conditional consequences as possible are changed.
UR - http://www.scopus.com/inward/record.url?scp=25144505744&partnerID=8YFLogxK
U2 - 10.1007/3-540-58107-3_15
DO - 10.1007/3-540-58107-3_15
M3 - Conference contribution
AN - SCOPUS:25144505744
SN - 9783540581079
T3 - Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
SP - 250
EP - 274
BT - Foundations of Knowledge Representation and Reasoning
A2 - Lakemeyer, Gerhard
A2 - Nebel, Bernhard
PB - Springer Verlag
T2 - Workshop on Theoretical Foundations of Knowledge Representation and Reasoning held in conjunction with 10th European Conference on Artificial Intelligence, ECAI 1992
Y2 - 3 August 1992 through 7 August 1992
ER -