Agent意图的双子集语义改进模型
An Improved Twin-Subset Semantic Model for Intention of

DOI：

 作者 单位 胡山立 福州大学计算机科学与技术系,福建,福州,350002中国科学院计算机科学重点实验室,北京,100080 石纯一 清华大学计算机科学与技术系,北京,100084

意图是Agent的一个关键的意识属性,在决定理性Agent的行为中起着重要作用.为了克服现有意图逻辑中存在的缺陷,建立了适用于意图的语义表示.讨论了理性Agent性态的形式化中对意图语义的要求以及现有意图逻辑中存在的问题.介绍了在前期工作--真假子集语义基础上开发的双子集语义改进模型及其在Agent意图形式化中的应用,并且证明通过对模型的代数结构施加一定的约束,能获得许多希望得到的性质.在二值逻辑中,真和假是同等重要的.当然,对一个命题,描述了真值也就知道了假值;但对于一类命题却不是这样,对假值的刻画与对真值的刻画具有同等重要的意义.而对意图的描述是对一类命题(Agent意图实现的命题)的刻画.经典的正规模态算子的可能世界语义只重视真,用RI(w)来描述,可看成是单子集语义.而改进的双子集语义真假并重,用RIT(w)来描述真,并用RIF(w)来描述假,从而能更全面地描述二值逻辑中的模态算子.经典的正规模态算子的可能世界语义可以看成是改进的双子集语义当RIF(w)=()时的退化情形.改进的双子集语义不仅避免了基于正规模态逻辑表示的"逻辑全知"问题以及由此带来的副作用等问题,与Konolige和Pollack的意图模型相比,比较简单、自然,且满足K公理和联合一致性原理,而且克服了前期工作真假子集语义和双子集语义表示的缺陷.实际上,改进的双子集语义为非正规模态算子的语义表示提供了一种新的方法,可应用于建立新的合适的Agent逻辑系统.

Intention, a crucial part of the mental states of an agent, plays an important role in determining the behaviors of the rational agent. In order to eliminate the flaws with existing logic of intention and establish a suitable semantic representation for intention, this paper addresses the requests for intention semantics on formal frameworks of rational agents, points out the problems with existing logic of intention, introduces a novel possible world semantics for intention, called the improved twin-subset semantics, which was developed by us recently based on the previous work about the true-false subset semantics, and presents its application in the formalization of intention for agent. It is also proved that some desired properties could be obtained through some restrictions to the algebraic structure of the models. In the two-value logic, the false value is as important as the true value. Of course, to one proposition, once the true values are described in some possible worlds, the false values are just the rest. However, to a set of propositions (the agent intents to do), descriptions to the false values are as important as descriptions to the true values. The representation of intention should describe a set of propositions (the propositions agent intents to achieve), but in the possible world semantics of classical normal modal operator, it merely pays attention to the true-value, which is denoted as RI(w), and can be considered as single-subset semantics. In the improved twin-subset semantics, the false-value is considered as important as the true-value, and RIT(w) is used to describe the true, while RIF(w) the false. Thus this method can describe modal operator in two-value logic completely. In addition, the possible world semantics of the classical normal modal operator can be regarded as the degradation of the improved twin-subset semantics when RIF(w)=?. It not only avoids the logical omniscience problem and other related problems (such as side-effect problem, and etc) but also overcomes the shortcomings of the true-false subset semantics and twin-subset semantics. Compared with Konolige and Pollack’s model of intention, this model not only is simpler and more natural, but also satisfies the K-axiom and the Joint Consistency. Actually, the improved twin-subset semantics provides a new method for semantic representation of non-normal modal operator and can be applied to establish a new proper agent’s logic system.
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