A Graph-Theoretic Generalization of the Least Common Subsumer and the Most Specific Concept in the Description Logic EL

Franz Baader

Abstract: In two previous papers we have investigates the problem of computing the least common subsumer (lcs) and the most specific concept (msc) for the description logic \(\mathcal{EL}\) in the presence of terminological cycles that are interpreted with descriptive semantics, which is the usual first-order semantics for description logics. In this setting, neither the lcs nor the msc needs to exist. We were able to characterize the cases in which the lcs/msc exists, but it was not clear whether this characterization yields decidability of the existence problem.