A Characterization of Stable Models Using a Non-monotonic Operator
Frank Teusink · Logic Programming and Non-Monotonic Reasoning · 1993
Stable models seem to be a natural way to describe the beliefs of a rational agent. However, the definition of stable models itself is not constructive. It is therefore interesting to find a constructive characterization of stable models, using a fixpoint construction. The operator we define, is based on the work of --among others-- F. Fages. For this operator, every total stable model of a general logic program will coincide with the limit of some (infinite) sequence of interpretations generated by it. Moreover, the set of all stable models will coincide with certain interpretations in these sequences. Furthermore, we will characterize the least fixpoint of the Fitting operator and the well-founded model, using our operator. 1991 Mathematical Subject Classification: 68N17 1991 CR Classification: D.1.6, F.4.1, I.2.3 Keywords and Phrases: Logic Programming, Stable Models, Non-Monotonic Reasoning Note: This Technical Report is an extended version of [Teu93] 1