Semi-equilibrium models for paracoherent answer set programs

摘要: The answer set semantics may assign a logic program to model, due logical contradiction or unstable negation, which is caused by cyclic dependency of an atom on its negation. While contradictions can be handled with traditional techniques from paraconsistent reasoning, instability requires other methods. We consider resorting paracoherent semantics, in 3-valued interpretations are used where third truth value besides true and false expresses that believed true. This at the basis semi-stable model was defined using transformation. In this paper, we give model-theoretic characterization models, makes more accessible. Motivated some anomalies respect basic epistemic properties, propose amendment satisfies these properties. latter has both transformational reveals it as relaxation equilibrium logic, reconstruction thus called semi-equilibrium semantics. refinements modularity rules, based splitting sets, major tool for modeling evaluating programs. that, single out classes canonical models amenable customary bottom-up evaluation programs, option switch mode when lack detected. A complexity analysis reasoning tasks shows harder than sets (i.e., models), global minimization step keeping gap between atoms small possible. Our results contribute foundations programming, gains increasing importance inconsistency management, same time provide algorithm development integration into solvers.