Pushing Efficient Evaluation of HEX Programs by Modular Decomposition

  • Thomas Eiter
  • Michael Fink
  • Giovambattista Ianni
  • Thomas Krennwallner
  • Peter Schüller
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 6645)


The evaluation of logic programs with access to external knowledge sources requires to interleave external computation and model building. Deciding where and how to stop with one task and proceed with the next is a difficult problem, and existing approaches have severe scalability limitations in many real-world application scenarios. We introduce a new approach for organizing the evaluation of logic programs with external knowledge sources and describe a configurable framework for dividing the non-ground program into overlapping possibly smaller parts called evaluation units. These units will then be processed by interleaving external evaluations and model building according to an evaluation and a model graph, and by combining intermediate results. Experiments with our prototype implementation show a significant improvement of this technique compared to existing approaches. Interestingly, even for ordinary logic programs (with no external access), our decomposition approach speeds up existing state of the art ASP solvers in some cases, showing its potential for wider usage.


Logic Program Evaluation Unit Evaluation Graph Stable Model Semantic Modular Decomposition 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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Copyright information

© Springer-Verlag Berlin Heidelberg 2011

Authors and Affiliations

  • Thomas Eiter
    • 1
  • Michael Fink
    • 1
  • Giovambattista Ianni
    • 2
  • Thomas Krennwallner
    • 1
  • Peter Schüller
    • 1
  1. 1.Institut für InformationssystemeTechnische Universität WienViennaAustria
  2. 2.Dipartimento di Matematica, Cubo 30BUniversità della CalabriaRendeItaly

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