Circumscription by Inference Rules with Priority
نویسندگان
چکیده
This paper shows how to express circumscription in terms of priority logic, where a theory consists of a set of logic programming like (monotonic) inference rules and a priority relation among them. Priorities determine when such an inference rule can or cannot be applied. Specifically, we show that circumscribing any existential quantifier free theory can be described precisely by a process of monotonic inferences constrained by a priority relation. This result gives a very different view of “jumping to conclusion” in circumscription.
منابع مشابه
A Linear Transformation from Prioritized Circumscription to Disjunctive Logic Programming
Introduction. The stable model semantics of disjunctive logic programs (DLPs) is based on minimal models which assign atoms false by default. While this feature is highly useful—leading to concise problem encodings—it occasionally renders knowledge representation with disjunctive rules difficult. Reiter-style minimal diagnoses [1] provide a good example in this respect. This problem can be alle...
متن کاملOn Reducing Parallel Circumscription
Three levels of circumscription have been proposed by McCathy to formalize common sense knowledge and non-monotonic reasoning in general-purpose database and knowledge base systems. That is, basic circumscription, parallel circumscription, and priority circumscription. Basic circumscription is a special case of parallel circumscription while parallel circumscription is a special case of priorit...
متن کاملInference in Action
Inference entangled with other information sources In the 1980s, several interesting nonstandard notions of consequence P C emerged, claiming to reflect features of our common sense reasoning. Circumscription in AI looked at conclusions C true only in minimal models of the premises P, with minimality measured by some comparison order for model size or predicate interpretation. General non-monot...
متن کاملReasoning about Dynamic Preferences in Circumscriptive Theory by Logic Programming
To treat dynamic preferences correctly is inevitably required in the legal reasoning. In this paper, we present a method which enables us to handle some class of dynamic preferences in the framework of circumscription and to compute consistently its metalevel and object-level reasoning by expressing them in an extended logic program. This is achieved on the basis of policy axioms and priority a...
متن کاملImplementing Prioritized Circumscription by Computing Disjunctive Stable Models
The stable model semantics of disjunctive logic programs is based on minimal models which assign atoms false by default. While this feature is highly useful and leads to concise problem encodings, it occasionally makes knowledge representation with disjunctive rules difficult. Lifschitz’ parallel circumscription provides a remedy by introducing atoms that are allowed to vary or to have fixed va...
متن کامل