线性逻辑和态极逻辑引论(Ⅱ)

本文是《线性逻辑和态极逻辑引论》一文的第二部分。文章致力于证明网(第1节)和态极逻辑(第2,3,4和5节)证明网部分尽管局限于其积线性逻辑框架,但仍不失其重要性。线性逻辑和态极逻辑均为Girard所创建,近期所发展起来的态极逻辑旨在于进一步揭示计算和逻辑的基本交互作用的本质。我们希望本文能对这一新的理论带来一些计算机科学方面的启示。     

Semantics and pragmatics of fuzzy sets and systems

A philosophical formalism of a new methodological aspect of humanistic systems design and evaluation is given. A requisite concept of context-dependency is highlighted, and some approaches to fuzzy sets and linguistics subsequently extended. It is consequently shown that a mathematical theory of pragmatic fuzzy subsets is not only conceptually possible but practically implementable in man-machine studies as well. Thus, the important context-dependent implication of the subjective nature of Zadeh's theory of fuzzy sets can be better exploited.As a pragmatic theory, the approach here is a seeming connection between pragmatism and ontology, concepts that are traditionally diametrically opposed to each other. The attitude adopted has been the equation of pragmatism and psychophysical measurements of ontological objects (noumena). Pragmatism is tacitly defined as a form of empiricism whereby linguistic constructs (i.e., linguistic-variable denotions) that represent any aspect(s) of a humanistic system are nothing more than an operational procedure used to achieve psychophysical measurements of the aspect(s). In this fashion, pragmatism would enable the contents of assertions, which are made through declarative propositions, about humanistic systems to be deciphered within relevant contexts. For pragmatism, direct sense experience provides both the meaning and the criterion of reality judgements. The context-dependent nature of the physical reality of ontological entities is, therefore, better understood pragmatically vis-a-vis the appropriate evaluative criteria and interpretative conventions.By emphasizing the distinction between a fuzzy system (naturally fuzzified) and a fuzzified mathematical structure (meta-mathematically fuzzified), the use of the standard fuzzy topologies is justified although it is conceptually possible to develop a yet more general topology or perhaps an alternative one especially in the case of a meta-mathematically fuzzified structure. However, for the express purpose of machine implementation, a naturally fuzzified system, such as a (complex) humanistic system, is more amenable to an initial test of the philosophy of pragmatic fuzzy subsets. Consequently, the fuzzy topology and spaces employed are intended to be devoid of extensive generalities, in this instance.     

The distribution semantics for normal programs with function symbols

The distribution semantics integrates logic programming and probability theory using a possible worlds approach. Its intuitiveness and simplicity have made it the most widely used semantics for probabilistic logic programming, with successful applications in many domains. When the program has function symbols, the semantics was defined for special cases: either the program has to be definite or the queries must have a finite number of finite explanations. In this paper we show that it is possible to define the semantics for all programs. We also show that this definition coincides with that of Sato and Kameya on positive programs. Moreover, we highlight possible approaches for inference, both exact and approximate.     

皮肤热疼痛热力学的统一模型

由热刺激而引致的皮肤疼痛是在日常生活以及医学上广泛应用的热治疗手段中常见的问题. 然而,有关皮肤热疼痛的物理机制并不明晰,也很少有模型分析. 该文提出了一种量化皮肤热疼痛感知的统一模型,涵盖3个相互关联的环节:(1)有害刺激的外部调节模型,将有害刺激通过神经脉冲转化为电能;(2)信号传输模型,将这些神经信号从皮肤的转换位置传导到脊髓和大脑;(3)神经信号在脊髓和大脑中的接收与调节模型. 利用这些模型,可以建立起有害刺激(如热刺激)和皮肤疼痛感知之间的直接联系.      

Kripke‐style Semantics of Orthomodular Logics

We present here a Kripke‐style semantics for propositional orthomodular logics that is based on the representation theorem for orthomodular lattices by D.J. Foulis ([2]), in which a sort of semigroups is employed. This semantics can characterize the logics above the orthomodular logic by some elementary conditions.     

A bipolar model of assertability and belief

Valuation pairs are introduced as a bipolar model of the assertability of propositions. These correspond to a pair of dual valuation functions, respectively, representing the strong property of definite assertability and the dual weaker property of acceptable assertability. In the case where there is uncertainty about the correct valuation pair for a language then a probability distribution is defined on possible valuation pairs. This results in two measures, μ⁺ giving the probability that a sentence is definitely assertable, and μ⁻ giving the probability that a sentence is acceptable to assert. It is shown that μ⁺ and μ⁻ can be determined directly from a two dimensional mass function m defined on pairs of sets of propositional variables. Certain natural properties of μ⁺ and μ⁻ are easily expressed in terms of m, and in particular we introduce certain consonance or nestedness assumptions. These capture qualitative information in the form of assertability orderings for both the propositional variables and the negated propositional variables. On the basis of these consonance assumptions we show that label semantics, intuitionistic fuzzy logic and max-min fuzzy logic can all be viewed as special cases of this bipolar model. We also show that bipolar belief measures can be interpreted within an interval-set model.     

A spatial modal logic with a location interpretation

A spatial modal logic (SML) is introduced as an extension of the modal logic S4 with the addition of certain spatial operators. A sound and complete Kripke semantics with a natural space (or location) interpretation is obtained for SML. The finite model property with respect to the semantics for SML and the cut‐elimination theorem for a modified subsystem of SML are also presented. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)