Inheritance comes of age: applying nonmonotonic techniques to problems in industry

Nonmonotonic reasoning is virtually absent from industry and has been so since its inception; the result is that the field is becoming increasingly marginalized within Al. We argue that this is largely because researchers in the area focus exclusively on commonsense problems which are irrelevant to industry and because few efficient algorithms or tools have been developed. A sensible strategy is thus to focus on industry problems and to develop solutions within tractable subtheories of nonmonotonic logic. We examine an example of nonmonotonic reasoning in industry-inheritance of business rules in the medical insurance domain - and show how the paradigm of inheritance with exceptions can be extended to a broader and more powerful kind of nonmonotonic reasoning. This is done by introducing formula-augmented semantic networks (FANs), semantic networks which attach well-formed formulae to nodes. The problem of inheriting well-formed formulae within this structure is explored, and an algorithm is given and discussed. Finally we discuss the underlying lessons that can be generalized to other industry problems. (C) 1998 Published by Elsevier Science B.V. All rights reserved.