TítuloControl Techniques for Complex Reasoning: The Case of MILORD II
Publication TypeBook Chapter
Year of Publication2002
AuthorsGodo L, Puyol-Gruart J, Sierra C
EditorMeyer J.-J.Ch., Treur J.
Book TitleHANDBOOK OF DEFEASIBLE REASONING AND UNCERTAINTY MANGEMENT SYSTEMS, VOLUME7: Agent-based Defeasible Control in Dynamic Environments
Paginación65-97
EditorialKluwer Academic Publishers
Resumen

In this paper we survey MILORD II, a KBS design tool. We concentrate on its object level and meta-level languages, with special emphasis on the control techniques and the comunication between both languages. The control, declarative in nature, is based on reflection techniques over a meta-language equipped with a declarative backtracking mechanism. Reflection and subsumption techniques are used to tackle the problem of knowledge incompleteness. This meta-level approach is based on assumptions over the current state of the object deductive process. Reflection makes meta-level deduction effective at the object level. Whenever the assumptions made at the meta-level are proved to be erroneous, a declarative backtracking mechanism retracts them. The deductive calculus at the object level is based on a rule specialization calculus. Complex reasoning tasks can be implemented using a combination of the overall set of MILORD II meta-control techniques. To illustrate the use of such modelling techniques present first a scheduling reasoning system, second a methd for solving a general class of default reasoning problems, and finally a legal reasoning problem involving default rules and priorities.