Diverging Approaches to Skeptical Inference in Non-monotonic Reasoning

Our paper addresses the problem of a two-fold approach to skeptical inferences in the context non-monotonic logics. We tackle the problem through the analysis of ambiguous theories, such as the Nixon Diamond, as instantiated in non-monotonic inheritance networks, and the notion of an extension. Our paper presents a detailed description of the inner mechanisms underlying both approaches to skeptical inference, i.e. direct and indirect skepticism, and how each information processing policy is applied to ambiguous networks like the Nixon Diamond. Finally, we discuss the extent and limitation of each approach, and we propose an alternative stance towards the existence of diverging implementations to skeptical inferences in non-monotonic reasoning.