A Revised Concept of Safety for General Answer Set Programs

  • Pedro Cabalar
  • David Pearce
  • Agustín Valverde
Part of the Lecture Notes in Computer Science book series (LNCS, volume 5753)


To ensure a close relation between the answer sets of a program and those of its ground version, some answer set solvers deal with variables by requiring a safety condition on program rules. If we go beyond the syntax of disjunctive programs, for instance by allowing rules with nested expressions, or perhaps even arbitrary first-order formulas, new definitions of safety are required. In this paper we consider a new concept of safety for formulas in quantified equilibrium logic where answer sets can be defined for arbitrary first-order formulas. The new concept captures and generalises two recently proposed safety definitions: that of Lee, Lifschitz and Palla (2008) as well as that of Bria, Faber and Leone (2008). We study the main metalogical properties of safe formulas.


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Copyright information

© Springer-Verlag Berlin Heidelberg 2009

Authors and Affiliations

  • Pedro Cabalar
    • 1
  • David Pearce
    • 2
  • Agustín Valverde
    • 3
  1. 1.Universidade da CoruñaSpain
  2. 2.Universidad Politécnica de MadridSpain
  3. 3.Universidad de MálagaMálagaSpain

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