Truth maintenance systems for problem solving
Truth maintenance systems for problem solving

Author: Jon Doyle

Publisher:

Published: 1978

Total Pages: 31

ISBN-13:

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The thesis developed in this paper is that reasoning programs which take care to record the logical justifications for program beliefs can apply several powerful, but simple, domain-independent algorithms to: (1) maintain the consistency of program beliefs; (2) realize substantial search efficiencies; and (3) automatically summarize explanations of program beliefs. This report describes techniques for representing, recording, maintaining, and using justifications for beliefs. Also presented is an annotated implementation of a domain-independent program.

Building Problem Solvers
Building Problem Solvers

Author: Kenneth D. Forbus

Publisher: MIT Press

Published: 1993

Total Pages: 726

ISBN-13: 9780262061575

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After working through Building Problem Solvers, readers should have a deep understanding of pattern directed inference systems, constraint languages, and truth maintenance systems.

A Truth Maintenance System
A Truth Maintenance System

Author: Jon Doyle

Publisher:

Published: 1979

Total Pages: 45

ISBN-13:

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To choose their actions, reasoning programs must be able to make assumptions and subsequently revise their beliefs when discoveries contradict these assumtions. The Truth Maintenance System (TMS) is a problem solver subsystem for performing these functions by recording and maintaining the reasons for program beliefs. Such recorded reasons are useful in constructing explanations for program actions and in guiding the course of action of a problem solver. This paper describes (1) the representations and structure of the TMS, (2) the mechanisms used to revise the current set of beliefs, (3) how dependency-directed backtracking changes the current set of assumptions, (4) techniques for summarizing explanations of beliefs, (5) how to organize problem solvers into 'dialectically arguing' modules, (6) how to revise models of the belief systems of others, and (7) methods for embedding control structures in patterns of assumptions. We stress the need of problem solvers to choose between alternate systems of beliefs, and outline a mechanism by which a problem solver can employ rules guiding choices of what to believe, what to want, and what to do. (Author).

A Three Valued Truth Maintenance System
A Three Valued Truth Maintenance System

Author: David A. McAllester

Publisher:

Published: 1978

Total Pages: 32

ISBN-13:

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Truth maintenace systems have been used in recently developed problem solving systems. A truth maintenance system (TMS) is designed to be used by deductive systems to maintain the logical relations among the beliefs which those systems manipulate. These relations are used to incrementally modify the belief structure when premises are changed, giving a more flexible context mechanism than has been present in earlier artificial intelligence systems. The relations among beliefs can also be used to directly trace the source of contradictions or failures, resulting in far more efficient backtracking. In this paper a new approach is taken to truth maintenance algorithms. Each belief, or proposition, can be in any one of three truth states, true, false, or unknown. The relations among propositions are represented in disjunctive classes. By representing an implication in a clause the same algorithm that is used to deduce its consequent can be used to deduce the negation of antecedents that would lead to contradictions. A simple approach is also taken to the handling of assumptions and back tracking which does not involve the non-monotonic dependency structures present in other truth maintenance systems. (Author).

Truth Maintenance Systems
Truth Maintenance Systems

Author: João P. Martins

Publisher: Springer Science & Business Media

Published: 1991-07-24

Total Pages: 196

ISBN-13: 9783540543053

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The Truth Maintenance Workshop was held in August 1990 during the European Conference on Artificial Intelligence in Stockholm, Sweden. Ten selected papers, eight of them presented at the workshop, are included in this volume. The papers can be grouped into four main areas: - Meta-level control: the goal here is to specify some meta-criteria to control the behavior of the TMS. - Extensions of TMS: here the aim is to incorporate new mechanisms into TMS-like systems. - Foundations: there is now much interest in providing formal descriptions of TMS, proving results about them, and relating them with other non-monotonic formalisms. - Belief revision: TMS can be considered as providing support to manage the more general problem of belief revision.