ELP: Tractable Rules for OWL 2

  • Markus Krötzsch
  • Sebastian Rudolph
  • Pascal Hitzler
Part of the Lecture Notes in Computer Science book series (LNCS, volume 5318)


We introduce \(\text{\sf{ELP}}\) as a decidable fragment of the Semantic Web Rule Language (SWRL) that admits reasoning in polynomial time. \(\text{\sf{ELP}}\) is based on the tractable description logic \(\mathcal{EL}^{\mathord{+}\mathord{+}}\), and encompasses an extended notion of the recently proposed DL rules for that logic. Thus \(\text{\sf{ELP}}\) extends \(\mathcal{EL}^{\mathord{+}\mathord{+}}\) with a number of features introduced by the forthcoming OWL 2, such as disjoint roles, local reflexivity, certain range restrictions, and the universal role. We present a reasoning algorithm based on a translation of \(\text{\sf{ELP}}\) to Datalog, and this translation also enables the seamless integration of DL-safe rules into \(\text{\sf{ELP}}\). While reasoning with DL-safe rules as such is already highly intractable, we show that DL-safe rules based on the Description Logic Programming (DLP) fragment of OWL 2 can be admitted in \(\text{\sf{ELP}}\) without losing tractability.


Rule Base Description Logic Conjunctive Query Concept Product Concept Atom 
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Copyright information

© Springer-Verlag Berlin Heidelberg 2008

Authors and Affiliations

  • Markus Krötzsch
    • 1
  • Sebastian Rudolph
    • 1
  • Pascal Hitzler
    • 1
  1. 1.Institut AIFBUniversität KarlsruheGermany

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