Semantics for possibilistic answer set programs: Uncertain rules versus rules with uncertain conclusions

  • Authors:

  • Kim Bauters;Steven Schockaert;Martine De Cock;Dirk Vermeir

  • Affiliations:

  • Department of Applied Mathematics and Computer Science, Universiteit Gent, Krijgslaan 281 (S9), 9000 Gent, Belgium;School of Computer Science & Informatics, Cardiff University, 5 The Parade, Cardiff CF24 3AA, United Kingdom;Department of Applied Mathematics and Computer Science, Universiteit Gent, Krijgslaan 281 (S9), 9000 Gent, Belgium;Department of Computer Science, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussel, Belgium

  • Venue:
  • International Journal of Approximate Reasoning
  • Year:
  • 2014

Quantified Score

Hi-index 0.00

Visualization

Abstract

Although Answer Set Programming (ASP) is a powerful framework for declarative problem solving, it cannot in an intuitive way handle situations in which some rules are uncertain, or in which it is more important to satisfy some constraints than others. Possibilistic ASP (PASP) is a natural extension of ASP in which certainty weights are associated with each rule. In this paper we contrast two different views on interpreting the weights attached to rules. Under the first view, weights reflect the certainty with which we can conclude the head of a rule when its body is satisfied. Under the second view, weights reflect the certainty that a given rule restricts the considered epistemic states of an agent in a valid way, i.e. it is the certainty that the rule itself is correct. The first view gives rise to a set of weighted answer sets, whereas the second view gives rise to a weighted set of classical answer sets.