Description Logic Rules


Abstract. We introduce description logic rules (DL rules) as a new rule-based formalism for knowledge representation in DLs. As a fragment of the Semantic Web Rule Language SWRL, DL rules allow for a tight integration with DL knowledge bases. In contrast to SWRL, however, the combination of DL rules with expressive description logics remains decidable, and we show that the DL SROIQ – the basis for the ongoing standardisation of OWL 1.1 (now OWL 2) – can completely internalise DL rules. On the other hand, DL rules capture many expressive features of SROIQ that are not available in simpler DLs yet. While reasoning in SROIQ is highly intractable, it turns out that DL rules can be introduced to various lightweight DLs without increasing their worst-case complexity. In particular, DL rules enable us to significantly extend the tractable DLs EL++ and DLP.

Published at ECAI2008 (Conference paper)

Download PDF (last update: May 26 2008)

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Further reading and related work

A comprehensive treatment of description logic rules is found in my dissertation.

The above PDF is the extended technical report. You can also download the paper published at ECAI 2008 which is more compact but does not contain all proofs, and of course there is the slide set used for presenting the work at ECAI.

As a follow-up to this work, we have extended the results on tractable languages based on description logic rules, which has lead to ELP as an approach of reconciling DLP and EL++ in one polynomial-time formalism.

DL rules for the case of SROIQ have also been recently investigated independently by Francis Gasse, Uli Sattler, and Volker Haarslev. The contribution "Rewriting Rules into SROIQ Axioms" is presented as a poster at DL Workshop 2008, and a related implementation was presented at OWLED 2008 DC.


In an earlier version of this paper, Proposition 17 (tractability of DLP 2) referred to a «DLP knowledge base» where of course a «DLP 2 knowledge base» was meant.


Description logics, Rule languages