认知逻辑与认识论之研究现状

在某种程度上说,认知逻辑似乎有些脱离一般的认识论研究。本文旨在说明介于这两个领域之间的“桥梁”依然存在。而且,事实上它们之间的联系十分紧密。文章通过分析下面的一些实例对此加以论证,即,知识和证据演算的关系,怀疑主义,信息的动态性,学习和证实,多主体或群体问题等等。作者试图通过以上分析来表明下面的观点:知识不应被定义成命题的某种本质特征,我们应当根据知识在认知活动中所起的作用来对它加以理解。     

A New Game Equivalence,its Logic and Algebra

We present a new notion of game equivalence that captures basic powers of interacting players. We provide a representation theorem, a complete logic, and a new game algebra for basic powers. In doing so, we establish connections with imperfect information games and epistemic logic. We also identify some new open problems concerning logic and games.

     

Dynamic Update with Probabilities

Current dynamic-epistemic logics model different types of information change in multi-agent scenarios. We generalize these logics to a probabilistic setting, obtaining a calculus for multi-agent update with three natural slots: prior probability on states, occurrence probabilities in the relevant process taking place, and observation probabilities of events. To match this update mechanism, we present a complete dynamic logic of information change with a probabilistic character. The completeness proof follows a compositional methodology that applies to a much larger class of dynamic-probabilistic logics as well. Finally, we discuss how our basic update rule can be parameterized for different update policies, or learning methods.     

Multimo dal Logics of Products of Topologies

We introduce the horizontal and vertical topologies on the product of topological spaces, and study their relationship with the standard product topology. We show that the modal logic of products of topological spaces with horizontal and vertical topologies is the fusion S4 ⊕ S4. We axiomatize the modal logic of products of spaces with horizontal, vertical, and standard product topologies.We prove that both of these logics are complete for the product of rational numbers ℚ × ℚ with the appropriate topologies. AMS subject classification : 03B45, 54B10 The last author’s research was supported by a Social Sciences and Humanities Research Council of Canada grant number: 725-2000-2237. Presented by Melvin Fitting     

Modal Frame Correspondences and Fixed-Points

Taking Löb's Axiom in modal provability logic as a running thread, we discuss some general methods for extending modal frame correspondences, mainly by adding fixed-point operators to modal languages as well as their correspondence languages. Our suggestions are backed up by some new results – while we also refer to relevant work by earlier authors. But our main aim is advertizing the perspective, showing how modal languages with fixed-point operators are a natural medium to work with.     

Everything Else Being Equal: A Modal Logic for <Emphasis Type="Italic">Ceteris Paribus</Emphasis> Preferences

This paper presents a new modal logic for ceteris paribus preferences understood in the sense of “all other things being equal”. This reading goes back to the seminal work of Von Wright in the early 1960’s and has returned in computer science in the 1990’s and in more abstract “dependency logics” today. We show how it differs from ceteris paribus as “all other things being normal”, which is used in contexts with preference defeaters. We provide a semantic analysis and several completeness theorems. We show how our system links up with Von Wright’s work, and how it applies to game-theoretic solution concepts, to agenda setting in investigation, and to preference change. We finally consider its relation with infinitary modal logics.     

中国古代的推理模型

文章主要针对中国古代语言和论证的一些重要方面进行探讨,特别地,我们重点考察了儒家和墨家的观点。我们主张使用轻型的逻辑模型方法（不引进全部的现代逻辑演算）对一些重要的概念提供解释。我们所关注的问题主要有：情景辨别和做出反应、根据合适的反应来正名、以及通过＂法＂和＂因＂两个方面讨论类的外延。我们尝试使用博弈模型来表示古代论证的实际情形,重点讨论关于对象和类之间关系的争辩。在文章的最后,我们讨论了使用博弈建模方法对于理解古代中国推理实践潜在的可能性。