• Article  

      The computational value of joint consistency 

      Dimopoulos, Yannis (1994)
      In this paper we investigate the complexity of some recent reconstructions of Reiter's Default Logic using graph-theoretical structures. It turns out that requiring joint consistency of the justification of the applied ...
    • Article  

      Default reasoning via negation as failure 

      Kakas, Antonis C. (1994)
      We show how recent developments in the study of negation as failure of Logic Programming can be used to define a general framework for Default Reasoning. Negation as failure can be viewed as a form of hypotheses with which ...
    • Article  

      Graph theoretical structures in logic programs and default theories 

      Dimopoulos, Yannis; Torres, A. (1996)
      In this paper we present a graph representation of logic programs and default theories. We show that many of the semantics proposed for logic programs with negation can be expressed in terms of notions emerging from graph ...
    • Conference Object  

      Preferred arguments are harder to compute than stable extensions 

      Dimopoulos, Yannis; Nebel, B.; Toni, F. (1999)
      Based on an abstract framework for nonmonotonic reasoning, Bondarenko et at. have extended the logic programming semantics of admissible and preferred arguments to other nonmonotonic formalisms such as circumscription, ...