The Good, the Bad, and the Odd: Cycles in Answer-Set Programs

  • Johannes Klaus Fichte
Part of the Lecture Notes in Computer Science book series (LNCS, volume 7415)


Backdoors of answer-set programs are sets of atoms that represent “clever reasoning shortcuts” through the search space. Assignments to backdoor atoms reduce the given program to several programs that belong to a tractable target class. Previous research has considered target classes based on notions of acyclicity where various types of cycles (good and bad cycles) are excluded from graph representations of programs. We generalize the target classes by taking the parity of the number of negative edges on bad cycles into account and consider backdoors for such classes. We establish new hardness results and non-uniform polynomial-time tractability relative to directed or undirected cycles.


Answer-Set Programming Non-monotonic Reasoning 


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Copyright information

© Springer-Verlag Berlin Heidelberg 2012

Authors and Affiliations

  • Johannes Klaus Fichte
    • 1
  1. 1.Institute of Information SystemsVienna University of TechnologyViennaAustria

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