Statistics of Intuitionistic versus Classical Logics

For the given logical calculus we investigate the proportion of the number of true formulas of a certain length n to the number of all formulas of such length. We are especially interested in asymptotic behavior of this fraction when n tends to infinity. If the limit exists it is represented by a real number between 0 and 1 which we may call the density of truth for the investigated logic. In this paper we apply this approach to the intuitionistic logic of one variable with implication and negation. The result is obtained by reducing the problem to the same one of Dummett's intermediate linear logic of one variable (see [2]). Actually, this paper shows the exact density of intuitionistic logic and demonstrates that it covers a substantial part (more than 93%) of classical prepositional calculus. Despite using strictly mathematical means to solve all discussed problems, this paper in fact, may have a philosophical impact on understanding how much the phenomenon of truth is sporadic or frequent in random mathematics sentences.     

A Predicate Logical Extension of a Subintuitionistic Propositional Logic

We develop a predicate logical extension of a subintuitionistic propositional logic. Therefore a Hilbert type calculus and a Kripke type model are given. The propositional logic is formulated to axiomatize the idea of strategic weakening of Kripke's semantic for intuitionistic logic: dropping the semantical condition of heredity or persistence leads to a nonmonotonic model. On the syntactic side this leads to a certain restriction imposed on the deduction theorem. By means of a Henkin argument strong completeness is proved making use of predicate logical principles, which are only classically acceptable.     

Individual Concepts in Modal Predicate Logic

The article deals with the interpretation of propositional attitudes in the framework of modal predicate logic. The first part discusses the classical puzzles arising from the interplay between propositional attitudes, quantifiers and the notion of identity. After comparing different reactions to these puzzles it argues in favor of an analysis in which evaluations of de re attitudes may vary relative to the ways of identifying objects used in the context of use. The second part of the article gives this analysis a precise formalization from a model- and proof-theoretic perspective. This material has grown out of Chapters 2 and 4 of my PhD thesis Quantification under Conceptual Covers.     

Braine心理逻辑理论述评

该文对Braine提出的在推理心理学研究领域占居重要地位的“心理逻辑理论”做了综合述评。“心理逻辑理论”主要包括三方面内容:构成“心理逻辑理论”基础的一组推理规则图式、将推理规则图式应用于推理过程的推理方案、实际应用意义。Braine认为他和他的同事于1984年设计并实施的以“自然推理系统”所含各推理规则为实验材料的实验结果支持该理论的基本观点。     

Quantified Propositional Logic and the Number of Lines of Tree-Like Proofs

There is an exponential speed-up in the number of lines of the quantified propositional sequent calculus over Substitution Frege Systems, if one considers proofs as trees. Whether this is true also for the number of symbols, is still an open problem. This revised version was published online in June 2006 with corrections to the Cover Date.     

概率逻辑与模糊逻辑在精细化学习诊断中的对比研究

精细化学习诊断有助于客观准确探究学生学习现状,为实施有针对性的补救教学提供理论和数据支持。本文对比研究概率逻辑与模糊逻辑在精细化学习诊断中的表现。首先,从“概念”视角介绍和对比两种逻辑。其次,介绍两个分别基于上述两逻辑的代表性模型：HO-PINC和Fuzzy-DINA。然后,对比两模型在五个实证数据上表现。最后,通过模拟研究进一步对比两模型的心理计量学性能。DIC等模型-数据拟合指标和RMSE等参数返真性指标的结果表明两模型对同一批数据有较一致的分析结果。建议实践者忽略模型选择对数据分析的影响,从概念或思辨视角入手选择使用概率逻辑或模糊逻辑来定义属性。     

一种应用于中医阴阳五行诊断学说的次协调逻辑(英文)

中医阴阳五行学说博大情深,是中医辨证论治的理论基础,也是指导中医临床诊断与治疗的基本原理,因此对于中医的理论与实践都有着十分重要的价值。但长期以来,一直缺乏对该学说进行严格的形式化研究,使之难以与不断发展中的中医现代化进程相适应。本文就是在这一学说核心内容的基础上,介绍引入次协调逻辑、缺省推理逻辑等先进逻辑来与中医诊断学结合的思想和方法,这样的目的是为今后构造一种符合中医诊断原则的中医阴阳五行推演逻辑系统作准备,该逻辑系统将用来描述基本的中医辨证推演过程。     

An Operational Logic of Proofs with Positive and Negative Information

The logic of proofs was introduced by Artemov in order to analize the formalization of the concept of proof rather than the concept of provability. In this context, some operations on proofs play a very important role. In this paper, we investigate some very natural operations, paying attention not only to positive information, but also to negative information (i.e. information saying that something cannot be a proof). We give a formalization for a fragment of such a logic of proofs, and we prove that our fragment is complete and decidable.     

Standard Quantification Theory in the Analysis of English

Standard first-order logic plus quantifiers of all finite orders (SFOL) faces four well-known difficulties when used to characterize the behavior of certain English quantifier phrases. All four difficulties seem to stem from the typed structure of SFOL models. The typed structure of SFOL models is in turn a product of an asymmetry between the meaning of names and the meaning of predicates, the element-set asymmetry. In this paper we examine a class of models in which this asymmetry of meaning is removed. The models of this class permit definitions of the quantifiers which allow a desirable flexibility in fixing the domain of quantification. Certain SFOL type restrictions are thereby avoided. The resulting models of English validate all of the standard first-order logical truths and are free of the four deficiencies of SFOL models.     

Logic and Philosophy of Logic in Wittgenstein

This essay discusses Wittgenstein's conception of logic, early and late, and some of the types of logical system that he constructed. The essay shows that the common view according to which Wittgenstein had stopped engaging in logic as a philosophical discipline by the time of writing Philosophical Investigations is mistaken. It is argued that, on the contrary, logic continued to figure at the very heart of later Wittgenstein's philosophy; and that Wittgenstein's mature philosophy of logic contains many interesting thoughts that have gone widely unnoticed.     

The Relation between Formal and Informal Logic

The issue of the relationship between formal and informal logic depends strongly on how one understands these two designations. While there is very little disagreement about the nature of formal logic, the same is not true regarding informal logic, which is understood in various (often incompatible) ways by various thinkers. After reviewing some of the more prominent conceptions of informal logic, I will present my own, defend it and then show how informal logic, so understood, is complementary to formal logic.     

Logic Without Contraction as Based on Inclusion and Unrestricted Abstraction

On the one hand, the absence of contraction is a safeguard against the logical (property theoretic) paradoxes; but on the other hand, it also disables inductive and recursive definitions, in its most basic form the definition of the series of natural numbers, for instance. The reason for this is simply that the effectiveness of a recursion clause depends on its being available after application, something that is usually assured by contraction. This paper presents a way of overcoming this problem within the framework of a logic based on inclusion and unrestricted abstraction, without any form of extensionality. This revised version was published online in June 2006 with corrections to the Cover Date.     

Vladimir Alexandrovich Smirnov as a Founder of Research Schools in Logic and Methodology of Science in the USSR and Russia

The article gives a short account of V.A. Smirnovs scientific biography, including his work in Tomsk University in Siberia and in the Department of Logic of the Institute of Philosophy in Moscow.     

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.     

Logic of primary-conditionals and secondary-conditionals

Firstly, the authors analyzed the properties of primary-onditionals and secondary-conditionals, establish the minimum system C2L _m of primary-conditionals and secondary-conditionals, and then prove some of the formal theorems of the system which have important intuitive meanings. Secondly, the authors constructed the neighborhood semantics, prove the soundness of C2L _m, introduce a general concept of canonical model by the neighborhood semantics, and then prove the completeness of C2L _m by the canonical model. Finally, according to the technical results of the minimum system C2L _m, the authors discuss some of the important problems concerning primary-conditionals and secondary-onditionals. __________ Translated from Luoji Yu Renzhi 逻辑与认知 (Logic and Cognition) (online journal), 2004 (3)     

脑的逻辑功能的核磁共振成像及其哲学意义

国际上关于逻辑对应的脑物理特征的功能核磁共振成像（fMRI）研究的主要成就在于：建立了高级精神活动和低级神经活动的关联关系的试验方法;提出了高级精神活动的（判断和推理）神经计算模型建立方法。这些研究的实验结果表明,逻辑与神经活动具有确定性的对应关系,它证明了强人工智能的观点：导致意识的可验证的实体（或者称为“意识关联物”）就是意识本身。意识的运行方式是可计算的,思维的本质可以还原为机械性的操作步骤,人工智能和人的天然智能在本质上并无二致。     

The Logic and Meaning of Plurals. Part II

In this sequel to “The logic and meaning of plurals. Part I”, I continue to present an account of logic and language that acknowledges limitations of singular constructions of natural languages and recognizes plural constructions as their peers. To this end, I present a non-reductive account of plural constructions that results from the conception of plurals as devices for talking about the many. In this paper, I give an informal semantics of plurals, formulate a formal characterization of truth for the regimented languages that results from augmenting elementary languages with refinements of basic plural constructions of natural languages, and account for the logic of plural constructions by characterizing the logic of those regimented languages.

A Davidsonian Reconciliation of Internalism, Objectivity, and the Belief-desire Theory

This paper argues that Donald Davidson's account ofassertions of evaluative judgments contains ahere-to-fore unappreciated strategy forreconciling the meta-ethical ``inconsistenttriad.' The inconsistency is thought to resultbecause within the framework of thebelief-desire theory assertions of moraljudgments must have conceptual connections withboth desires and beliefs. The connection withdesires is necessary to account for theinternal connection between such judgments andmotivation to act, while the connection withbeliefs is necessary to account for theapparent objectivity of such judgments.Arguments abound that no class of utterancescan coherently be understood as having suchconceptual connections to attitudes of bothsorts, hence that an inconsistency results. Buton Davidson's account assertions of evaluativejudgments have just such connections to boththe relevant desire and a belief concerning anevaluative matter of fact. I argue that thisaccount has the resources to respond tostandard objections, and at least meritsconsideration as one among other plausiblealternatives.     

论推类逻辑与中国古代医学

推类逻辑就是基于“推类”的中国古代逻辑。易数推类为中医科学提供了一个有效工具,提供了一个有效地认识自然、机体（肌体）、疾病的方法。取象比类是中医思维的核心,推类是中国古代医学辨证论治的基本方法。推类具有很强的具象性,并以比类为基础。