A Theory of Diagnosis from First Principles-英文文献.pdf

ARTIFICIAL INTELLIGENCE 57 A Theory of Diagnosis from First Principles Raymond Reiter D e p a r t m e n t o f C o m p u t e r Science, University o f Toronto, T o r o n t o , Ontario, Canada M 5 S 1 A 4 ; The Canadian Institute f o r A d v a n c e d Research Recommended by Johan de Kleer and Daniel G. Bobrow ABSTRACT Suppose one is given a description of a system, together with an observation of the systems behaviour which conflicts with the way the system is meant to behave. The diagnostic problem is to determine those components of the system which, when assumed to befunctioning abnormally, will explain the discrepancy between the observed and correct system behaviour. We propose a general theory for this problem. The theory requires only that the system be described in a suitable logic. Moreover, there are many such suitable logics, e.g. first-order, temporal, dynamic, etc. As a result, the theory accommodates diagnostic reasoning in a wide variety of practical settings, including digital and analogue circuits, medicine, and database updates. The theory leads to an algorithm for computing all diagnoses, and to various results concerning principles of measurement for discriminating among competing diagnoses. Finally, the theory reveals close connections between diagnostic reasoning and nonmonotonic reasoning. I. Introduction In the theory and design of diagnostic reasoning systems there appear to be two quite different approaches in the literature. In the first approach, often referred to as diagnosis from first principles, one