Über unnormale Vögel, anwendbare Regeln und einen Default-Beweiser

Abstract

This paper presents the most important approaches to formalizing nonmonotonic reasoning and discusses some difficulties involved in these approaches. For avoiding specific problems arising in applying default rules, a representation form for these rules is suggested which allows the explicit control of their applicability. On the one hand, this helps to avoid unplausible results, on the other, the defaults are maintained in a form familiar to the user.

Default rules of this type are also used in Faulty, a prover for a decidable subset of the nonmonotonic (predicate) logic developed by McDermott and Doyle. Wellknown weaknesses of this logic are avoided by restricting to specific theories that are however sufficient for default reasoning purposes.

An English version of this paper is available from the author.

You can’t always get what you want,

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