Results 1 - 10 of 174

Another perspective on Default Reasoning

by Daniel Lehmann - Ann. Math. Artif. Intell , 1992
"... The lexicographic closure of any given finite set D of normal defaults is defined. A conditional assertion a b is in this lexicographic closure if, given the defaults D and the fact a, one would conclude b. The lexicographic closure is essentially a rational extension of D, and of its rational ..."
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closure, defined in a previous paper. It provides a logic of normal defaults that is different from the one proposed by R. Reiter and that is rich enough not to require the consideration of non-normal defaults. A large number of examples are provided to show that the lexicographic closure corresponds

On the comparison of theories: preferring the most specific explanation

by David L Poole - In Proceedings of IJCAI-85 , 1985
"... Default reasoning is reasoning with generalised knowledge which we want to use if there is no more specific knowledge also applicable. This pa-per presents a formal, model-theoretic characterisation of default reasoning. Defaults are treated as possible hypotheses in a “scientific ” theory to explai ..."
Abstract - Cited by 120 (7 self) - Add to MetaCart
-vated non-normal defaults, and provides a semantics for correct inheritance in inheritance systems, where we want choose the result supported by the most specific knowledge. We also show how to produce a general computa-tional mechanism in terms of normal first order predicate calculus deduction systems. 1

An Extended Framework for Default Reasoning

by Nait Abdallah , 1989
"... In this paper, we investigate the proof theory of default reasoning. We generalize Reiter's framework to a monotonic reasoning system, and in particular allow formulae with nested defaults. We give proof rules for this extended default logic, called default ionic logic, and give deduction theo ..."
Abstract - Cited by 3 (0 self) - Add to MetaCart
theorems. We also give examples of applications of our framework to some well-known problems: weak implication, disjunctive information, default transformation, and normal versus non-normal defaults. 1 Introduction In this paper we investigate the proof theory of default reasoning. We have as a goal a

unknown title

by unknown authors
"... Default reasoning is reasoning with generalised knowledge which we want to use if there is no more specific knowledge also applicable. This paper presents a formal, model-theoretic characterisation of default reasoning. Defaults are treated as possible hypotheses in a "scientific " ..."
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which motivated non-normal defaults, and provides a semantics for correct inheritance in inheritance systems, where we want choose the result supported by the most specific knowledge. We also show how to produce a general computational mechanism in terms of normal first order predicate calculus

Stable Closures, Defeasible Logic and Contradiction Tolerant Reasoning

by Paul Morris - Proceedings of the 7th National Conference on Artificial Intelligence , 1988
"... A solution to the Yale shooting problem has been previously proposed that uses so-called non-normal defaults. This approach produces a single extension. One disadvantage, however, is. that new conflicting information causes the extension to collapse. In this paper we propose a new formal counterpart ..."
Abstract - Cited by 2 (0 self) - Add to MetaCart
A solution to the Yale shooting problem has been previously proposed that uses so-called non-normal defaults. This approach produces a single extension. One disadvantage, however, is. that new conflicting information causes the extension to collapse. In this paper we propose a new formal

Representation Theory for Default Logic

by V. Wiktor Marek , Jan Treur, Miros/law Truszczynski - ANNALS OF MATHEMATICS AND ARTIFICIAL INTELLIGENCE , 1997
"... Default logic can be regarded as a mechanism to represent families of belief sets of a reasoning agent. As such, it is inherently second-order. In this paper, we study the problem of representability of a family of theories as the set of extensions of a default theory. We give a complete solution to ..."
Abstract - Cited by 17 (7 self) - Add to MetaCart
to the problem of representability by means of default theories with finite set of defaults, and by means of normal default theories. We obtain partial results on representability by arbitrary (infinite, nonnormal) default theories. We construct examples of denumerable families of non-including theories

Power Defaults

by William C. Rounds, Guo-Qiang Zhang , 1997
"... We show how two general notions of domain theory, the logic induced from the Scott topology on a domain, together with the Smyth powerdomain, interact with the theory of default reasoning introduced by Reiter [19]. We define extensions, which are fixed points of a certain non-monotonic operator on ..."
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We show how two general notions of domain theory, the logic induced from the Scott topology on a domain, together with the Smyth powerdomain, interact with the theory of default reasoning introduced by Reiter [19]. We define extensions, which are fixed points of a certain non-monotonic operator

Testing the Integrity of Non-Monotonic Knowledge Bases Containing SemiNormal Defaults

by Neli P. Zlatareva - In: Proc. of the 17th International Florida Artificial Intelligence Research Society Conference (FLAIRS), AAAI Press , 2004
"... This paper presents a methodology for testing general non-monotonic knowledge bases for logical and semantic inconsistencies. It extends the CTMS-based verification framework introduced in our previous work with an additional integrity test. This test aims to ensure that a logically consistent non-m ..."
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This paper presents a methodology for testing general non-monotonic knowledge bases for logical and semantic inconsistencies. It extends the CTMS-based verification framework introduced in our previous work with an additional integrity test. This test aims to ensure that a logically consistent non

Testing the Integrity of Non-monotonic Knowledge Bases Containing Semi-normal Defaults

by unknown authors
"... This paper presents a methodology for testing general non-monotonic knowledge bases for logical and semantic inconsistencies. It extends the CTMS-based verification framework introduced in our previous work with an additional integrity test. This test aims to ensure that a logically consistent non-m ..."
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This paper presents a methodology for testing general non-monotonic knowledge bases for logical and semantic inconsistencies. It extends the CTMS-based verification framework introduced in our previous work with an additional integrity test. This test aims to ensure that a logically consistent non

Representation Theory for Default Logic

by V. Wiktor, Marek Jan Treur , 1999
"... Default logic can be regarded as a mechanism to represent families of belief sets of a reasoning agent. As such, it is inherently second-order. In this paper, we study the problem of representability of a family of theories as the set of extensions of a default theory. We give a complete solution to ..."
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to the representability by means of normal default theories. We obtain partial results on representability by arbitrary default theories. We construct examples of denumerable families of non-including theories that are not representable. We also study the concept of equivalence between default theories. 1
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