Affiliations: Institut für Informatik und Praktische Mathematik, Christian‐Albrechts‐Universität zu Kiel, Kiel, Germany E‐mail: kuesters@ti.informatik.uni‐kiel.de | IT Research and Development Group, Swiss Life, Zurich, Switzerland E‐mail: ralf.molitor@swisslife.ch
Note: [] Corresponding author: R. Küsters, Christian‐Albrechts‐Universität zu Kiel, Institut für Informatik und Praktische Mathematik, Olshausenstraße 40, 24098 Kiel, Germany.
Abstract: Computing the most specific concept (msc) is an inference task that allows to abstract from individuals defined in description logic (DL) knowledge bases. For DLs that allow for existential restrictions or number restrictions, however, the msc need not exist unless one allows for cyclic concepts interpreted with the greatest fixed‐point semantics. Since such concepts cannot be handled by current DL‐systems, we propose to approximate the msc. We show that for the DL ALE, which has concept conjunction, a restricted form of negation, existential restrictions, and value restrictions as constructors, approximations of the msc always exist and can effectively be computed.
Keywords: Description logics, non‐standard inferences, most specific concepts
