TY - GEN
T1 - Concept and role forgetting in ALC ontologies
AU - Wang, Kewen
AU - Wang, Zhe
AU - Topor, Rodney
AU - Pan, Jeff Z.
AU - Antoniou, Grigoris
PY - 2009/12/1
Y1 - 2009/12/1
N2 - Forgetting is an important tool for reducing ontologies by eliminating some concepts and roles while preserving sound and complete reasoning. Attempts have previously been made to address the problem of forgetting in relatively simple description logics (DLs) such as DL-Lite and extended εL. The ontologies used in these attempts were mostly restricted to TBoxes rather than general knowledge bases (KBs). However, the issue of forgetting for general KBs in more expressive description logics, such as ALC and OWL DL, is largely unexplored. In particular, the problem of characterizing and computing forgetting for such logics is still open. In this paper, we first define semantic forgetting about concepts and roles in ALC ontologies and state several important properties of forgetting in this setting. We then define the result of forgetting for concept descriptions in ALC , state the properties of forgetting for concept descriptions, and present algorithms for computing the result of forgetting for concept descriptions. Unlike the case of DL-Lite, the result of forgetting for an ALC ontology does not exist in general, even for the special case of concept forgetting. This makes the problem of how to compute forgetting in ALC more challenging. We address this problem by defining a series of approximations to the result of forgetting for ALC ontologies and studying their properties and their application to reasoning tasks. We use the algorithms for computing forgetting for concept descriptions to compute these approximations. Our algorithms for computing approximations can be embedded into an ontology editor to enhance its ability to manage and reason in (large) ontologies.
AB - Forgetting is an important tool for reducing ontologies by eliminating some concepts and roles while preserving sound and complete reasoning. Attempts have previously been made to address the problem of forgetting in relatively simple description logics (DLs) such as DL-Lite and extended εL. The ontologies used in these attempts were mostly restricted to TBoxes rather than general knowledge bases (KBs). However, the issue of forgetting for general KBs in more expressive description logics, such as ALC and OWL DL, is largely unexplored. In particular, the problem of characterizing and computing forgetting for such logics is still open. In this paper, we first define semantic forgetting about concepts and roles in ALC ontologies and state several important properties of forgetting in this setting. We then define the result of forgetting for concept descriptions in ALC , state the properties of forgetting for concept descriptions, and present algorithms for computing the result of forgetting for concept descriptions. Unlike the case of DL-Lite, the result of forgetting for an ALC ontology does not exist in general, even for the special case of concept forgetting. This makes the problem of how to compute forgetting in ALC more challenging. We address this problem by defining a series of approximations to the result of forgetting for ALC ontologies and studying their properties and their application to reasoning tasks. We use the algorithms for computing forgetting for concept descriptions to compute these approximations. Our algorithms for computing approximations can be embedded into an ontology editor to enhance its ability to manage and reason in (large) ontologies.
UR - http://www.scopus.com/inward/record.url?scp=78650504261&partnerID=8YFLogxK
U2 - 10.1007/978-3-642-04930-9_42
DO - 10.1007/978-3-642-04930-9_42
M3 - Published conference contribution
AN - SCOPUS:78650504261
SN - 364204929X
SN - 9783642049293
T3 - Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
SP - 666
EP - 681
BT - The Semantic Web, ISWC 2009 - 8th International Semantic Web Conference, ISWC 2009, Proceedings
A2 - Bernstein, Abraham
A2 - Karger, David R
A2 - Heath, Tom
A2 - Feigenbaum, Lee
A2 - Maynard, Diana
A2 - Motta, Enrico
A2 - Thirunarayan, Krishnaprasad
PB - Springer
T2 - 8th International Semantic Web Conference, ISWC 2009
Y2 - 25 October 2009 through 29 October 2009
ER -