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Modeling Rational Agents within a BDIArchitecture
, 1991
"... Intentions, an integral part of the mental state of an agent, play an important role in ..."
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Cited by 814 (21 self)
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Intentions, an integral part of the mental state of an agent, play an important role in
A Correspondence Theory for Terminological Logics: Preliminary Report
 In Proc. of IJCAI91
, 1991
"... We show that the terminological logic ALC comprising Boolean operations on concepts and value restrictions is a notational variant of the propositional modal logic K (m) . To demonstrate the utility of the correspondence, we give two of its immediate byproducts. Namely, we axiomatize ALC and give a ..."
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Cited by 255 (0 self)
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We show that the terminological logic ALC comprising Boolean operations on concepts and value restrictions is a notational variant of the propositional modal logic K (m) . To demonstrate the utility of the correspondence, we give two of its immediate byproducts. Namely, we axiomatize ALC and give a simple proof that subsumption in ALC is PSPACEcomplete, replacing the original sixpage one. Furthermore, we consider an extension of ALC additionally containing both the identity role and the composition, union, transitivereflexive closure, range restriction, and inverse of roles. It turns out that this language, called T SL, is a notational variant of the propositional dynamic logic converse PDL. Using this correspondence, we prove that it suffices to consider finite T SLmodels, show that T SLsubsumption is decidable, and obtain an axiomatization of T SL. By discovering that features correspond to deterministic programs in dynamic logic, we show that adding them to T SL preserves...
Belief, awareness, and limited reasoning
 ARTIFICIAL INTELLIGENCE
, 1988
"... Several new logics for belief and knowledge are introduced and studied, all of which have the property that agents are not logically omniscient. In particular, in these logics, the set of beliefs of an agent does not necessarily contain all valid formulas. Thus, these logics are more suitable than t ..."
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Cited by 122 (12 self)
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Several new logics for belief and knowledge are introduced and studied, all of which have the property that agents are not logically omniscient. In particular, in these logics, the set of beliefs of an agent does not necessarily contain all valid formulas. Thus, these logics are more suitable than traditional logics for modelling beliefs of humans (or machines) with limited reasoning capabilities. Our first logic is essentially an extension of Levesque's logic of implicit and explicit belief, where we extend to allow multiple agents and higherlevel belief (i.e., beliefs about beliefs). Our second logic deals explicitly with "awareness," where, roughly speaking, it is necessary to be aware of a concept before one can have beliefs about it. Our third logic gives a model of "local reasoning," where an agent is viewed as a "society of minds," each with its own cluster of beliefs, which may contradict each other.
Programming Simultaneous Actions Using Common Knowledge
 Algorithmica
, 1988
"... This work applies the theory of knowledge in distributed systems to the design of efficient faulttolerant protocols. We define a large class of problems requiring coordinated, simultaneous action in synchronous systems, and give a method of transforming specifications of such problems into protocol ..."
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Cited by 92 (28 self)
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This work applies the theory of knowledge in distributed systems to the design of efficient faulttolerant protocols. We define a large class of problems requiring coordinated, simultaneous action in synchronous systems, and give a method of transforming specifications of such problems into protocols that are optimal in all runs: for every possible input to the system and faulty processor behavior, these protocols are guaranteed to perform the simultaneous actions as soon as any other protocol could possibly perform them. This transformation is performed in two steps. In the first step, we extract directly from the problem specification a highlevel protocol programmed using explicit tests for common knowledge. In the second step, we carefully analyze when facts become common knowledge, thereby providing a method of efficiently implementing these protocols in many variants of the omissions failure model. In the generalized omissions model, however, our analysis shows that testing for common knowledge is NPhard. Given the close correspondence between common knowledge and simultaneous actions, we are able to show that no optimal protocol for any such problem can be computationally efficient in this model. The analysis in this paper exposes many subtle differences between the failure models, including the precise point at which this gap in complexity occurs.
Interpolation in Modal Logic
, 1999
"... The interpolation property and Robinson's consistency property are important tools for applying logic to software engineering. We provide a uniform technique for proving the Interpolation Property, using the notion of bisimulation. For modal logics, this leads to simple, easytocheck conditions ..."
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Cited by 83 (6 self)
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The interpolation property and Robinson's consistency property are important tools for applying logic to software engineering. We provide a uniform technique for proving the Interpolation Property, using the notion of bisimulation. For modal logics, this leads to simple, easytocheck conditions on the logic which imply interpolation. We apply this result to fibering of modal logics and to modal logics of knowledge and belief.
Social Plans: A Preliminary Report
, 1992
"... The formalization of multiagent autonomous systems requires a rich ontology for capturing a variety of collective behaviours and a powerful semantics for distinguishing between collective agents having, executing, and jointly intending a plan. In this paper, we introduce the notion of social agents ..."
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Cited by 70 (6 self)
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The formalization of multiagent autonomous systems requires a rich ontology for capturing a variety of collective behaviours and a powerful semantics for distinguishing between collective agents having, executing, and jointly intending a plan. In this paper, we introduce the notion of social agents and social plans. A definition of joint intentions is provided that avoids some of the problems encountered by previous formalizations. In particular, it models cooperation by requiring that agents adopt a joint goal and a joint plan of action before forming a joint intention. The paper also stresses the planning capability of agents and outlines a process for meansend reasoning by multiple agents. 1 Introduction Situated agents are systems embedded in dynamic environments; they continuously sense their environment and effect changes to it by performing actions. These agents have to balance the time they devote to thinking against the time they take acting. Also they need to balance the...
Downward Refinement and the Efficiency of Hierarchical Problem Solving
 Artificial Intelligence
, 1993
"... Analysis and experiments have shown that hierarchical problemsolving is most effective when the hierarchy satisfies the downward refinement property (DRP), whereby every abstract solution can be refined to a concretelevel solution without backtracking across abstraction levels. However, the DRP i ..."
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Cited by 56 (1 self)
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Analysis and experiments have shown that hierarchical problemsolving is most effective when the hierarchy satisfies the downward refinement property (DRP), whereby every abstract solution can be refined to a concretelevel solution without backtracking across abstraction levels. However, the DRP is a strong requirement that is not often met in practice. In this paper we examine the case when the DRP fails, and provide an analytical model of search complexity parameterized by the probability of an abstract solution being refinable. Our model provides a more accurate picture of the effectiveness of hierarchical problemsolving. We then formalize the DRP in Abstripsstyle hierarchies, providing a syntactic test that can be applied to determine if a hierarchy satisfies the DRP. Finally, we describe an algorithm called Highpoint that we have developed. This algorithm builds on the Alpine algorithm of Knoblock in that it automatically generates abstraction hierarchies. However, it uses th...
Understanding Natural Language Instructions: The Case of Purpose Clauses
, 1992
"... This paper presents an analysis of purpose clauses in the context of instruction understanding. Such analysis shows that goals affect the interpretation and / or execution of actions, lends support to the proposal of using generation and enablement to model relations between actions, and sheds light ..."
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Cited by 52 (9 self)
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This paper presents an analysis of purpose clauses in the context of instruction understanding. Such analysis shows that goals affect the interpretation and / or execution of actions, lends support to the proposal of using generation and enablement to model relations between actions, and sheds light on some inference processes necessary to interpret purpose clauses.