Computing Least Common Subsumers in Description Logics with Existential Restrictions

Franz BaaderFranz Baader, R. KüstersR. Küsters, R. MolitorR. Molitor

Datei:BaaderKuestersMolitor-LTCS-98-09.ps.gz

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Franz Baader, R. Küsters, R. Molitor
Computing Least Common Subsumers in Description Logics with Existential Restrictions
Technical Report, LuFG Theoretical Computer Science, RWTH Aachen, volume LTCS-98-09, 1998. LTCS-Report

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KurzfassungAbstract
Computing least common subsumers (lcs) is an inference task that can be used to support the "bottom-up" construction of knowledge bases for KR systems based on description logics. Previous work on how to compute the lcs has concentrated on description logics that allow for universal value restrictions, but not for existential restrictions. The main new contribution of this paper is the treatment of description logics with existential restrictions. More precisely, we show that, for the description logic ALE (which allows for conjunction, universal value restrictions, existential restrictions, negation of atomic concepts, as well as the top and the bottom concept), the lcs always exists and can effectively be computed. Our approach for computing the lcs is based on an appropriate representation of concept descriptions by certain trees, and a characterization of subsumption by homomorphisms between these trees. The lcs operation then corresponds to the product operation on trees.
Bemerkung: Note: See http://www-lti.informatik.rwth-aachen.de/Forschung/Papers.html.
Forschungsgruppe:Research Group: AutomatentheorieAutomata Theory

@techreport{ BaaderKuesters+-LTCS-98-09,
  address = {Germany},
  author = {F. {Baader} and R. {K{\"u}sters} and R. {Molitor}},
  institution = {LuFG Theoretical Computer Science, RWTH Aachen},
  note = {See http://www-lti.informatik.rwth-aachen.de/Forschung/Papers.html.},
  number = {LTCS-98-09},
  title = {Computing Least Common Subsumers in Description Logics with Existential Restrictions},
  type = {LTCS-Report},
  year = {1998},
}