On the consistency of commonsense reasoning
Donald R. Perlis · Computational Intelligence · 1986
Default reasoning is analyzed as consisting (implicitly) of at least three further aspects–oracles, jumps, and fixes‐which in turn are related to the notion of a belief. Beliefs are then discussed in terms of their use in a reasoning agent. Next an idea of Israel is embellished to show that certain desiderata regarding these aspects of default reasoning lead to inconsistent belief sets, and that as a consequence the handling of inconsistencies must be taken as central to commonsense reasoning. Finally, these results are applied to standard cases of default reasoning formalisms in the literature (circumscription, default logic, and nonmonotonic logic), where it turns out that even weaker hypotheses lead to failure to achieve commonsense default conclusions.