The Nature of Nonmonotonic Reasoning

Conclusions reached using common sense reasoning from a set of premises are often subsequently revised when additional premises are added. Because we do not always accept previous conclusions in light of subsequent information, common sense reasoning is said to be nonmonotonic. But in the standard formal systems usually studied by logicians, if a conclusion follows from a set of premises, that same conclusion still follows no matter how the premise set is augmented; that is, the consequence relations of standard logics are monotonic. Much recent research in AI has been devoted to the attempt to develop nonmonotonic logics. After some motivational material, we give four formal proofs that there can be no nonmonotonic consequence relation that is characterized by universal constraints on rational belief structures. In other words, a nonmonotonic consequence relation that corresponds to universal principles of rational belief is impossible. We show that the nonmonotonicity of common sense reasoning is a function of the way we use logic, not a function of the logic we use. We give several examples of how nonmonotonic reasoning systems may be based on monotonic logics.     

基于四值语义的缺省逻辑

基于公式变换,给出一组缺省理论的变换方法,将命题语言L中的缺省理论变换到对应的命题语言L^-＋中,保证了所得到的缺省理论的所有扩张均不平凡,并通过一种弱变换可同时保证缺省扩张的存在性．为缺省理论定义了各种四值模型,使得缺省逻辑具有非单调超协调推理能力,并证明了L^-＋中的缺省扩张与L中缺省理论的四值模型之间具有一一对应关系．四值模型描述了公式变换的语义,基于四值语义的缺省推理通过缺省理论的变换技术能在标准的缺省逻辑中实现．     

逻辑函数的双逻辑综合与优化

针对传统布尔逻辑在电路面积优化中存在的不足,提出了一种用传统布尔逻辑和Reed-Muller(RM)逻辑相结合的双逻辑优化算法.通过将原逻辑函数的乘积项转化为不相交乘积项,并利用不相交乘积项的位操作,将逻辑函数的覆盖分成2个部分,使之分别适合布尔逻辑综合和RM逻辑综合;同时提出了适合双逻辑函数的逻辑功能验证方法.双逻辑优化算法用C语言编程实现并用MCNC标准电路进行测试.实验结果表明,与单一的布尔逻辑综合结果相比,在绝大多数情况下文中算法可使电路面积获得进一步优化.     

Intuitionistic hybrid logic: Introduction and survey

Intuitionistic hybrid logic is hybrid modal logic over an intuitionistic logic basis instead of a classical logical basis. In this short paper we introduce intuitionistic hybrid logic and we give a survey of work in the area.     

Naming Worlds in Modal and Temporal Logic

In this paper we suggest adding to predicate modal and temporal logic a locality predicate W which gives names to worlds (or time points). We also study an equal time predicate D(x, y)which states that two time points are at the same distance from the root. We provide the systems studied with complete axiomatizations and illustrate the expressive power gained for modal logic by simulating other logics. The completeness proofs rely on the fairly intuitive notion of a configuration in order to use a proof technique similar to a Henkin completion mixed with a tableau construction. The main elements of the completeness proofs are given for each case, while purely technical results are grouped in the appendix. This revised version was published online in August 2006 with corrections to the Cover Date.     

超协调限制逻辑

本文给出了一阶超协调限制逻辑ＬＰｓ的定义，并证明了它与悖论逻辑（ＬＰ与ＬＰｍ）和限制逻辑（ＣＩＲＣ）的关系，ＬＰ作为一种非单调超协调逻辑具有非单逻辑和超协调逻辑的优点，而用能解决非单调逻辑和超协调逻辑存在的问题，它可作为在不完全与不协调知识下常识推理的形式化，因此它的知识表示中具有广泛的应用。     

概率逻辑、不确定逻辑和模糊逻辑之比较

通过一个实例分析比较了概率逻辑、主观概率逻辑、不确定逻辑和模糊逻辑的思想方法。提出了自己的观点：基于数据统计的概率逻辑是最科学的。不确定逻辑比主观概率逻辑更科学。当具有不确定性的原子命题具有独立性时,不确定逻辑和模糊逻辑的观点是一致的。而对于处理带有不确定性的相关性命题,不确定逻辑比模糊逻辑更科学。但是模糊逻辑在建立推理理论方面见长。     

Mediative fuzzy logic: a new approach for contradictory knowledge management

In this paper we are proposing a novel fuzzy method that can handle imperfect knowledge in a broader way than Intuitionistic (in the sense of Atanassov) fuzzy logic does (IFL). This fuzzy method can manage non- contradictory, doubtful, and contradictory information provided by experts, providing a mediated solution, so we called it Mediative Fuzzy Logic (MFL). We are comparing results of MFL, with IFL and traditional Fuzzy logic (FL).     

人工智能中概率逻辑的研究

概率论是在不完备的、不确定的数据中进行推理的,它是度量不确定性的重要手段。在人工智能中,研究者结合概率和逻辑各自的优点,进行概率逻辑的研究。本文介绍了传统概率逻辑的三大派别,阐述了二值逻辑概率和三值逻辑概率的发展;最后介绍了泛逻辑,通过对概率逻辑和泛逻辑学的研究,将概率逻辑纳入泛逻辑学的框架内。     

Synthesis of quaternary reversible/quantum comparators

Multiple-valued quantum circuits are promising choices for future quantum computing technology, since they have several advantages over binary quantum circuits. Quaternary logic has the advantage that classical binary functions can be very easily represented as quaternary functions by grouping two bits together into quaternary values. Grover’s quantum search algorithm requires a sub-circuit called oracle, which takes a set of inputs and gives an output stating whether a given search condition is satisfied or not. Equality, less-than, and greater-than comparisons are widely used as search conditions. In this paper, we show synthesis of quaternary equality, less-than, and greater-than comparators on the top of ion-trap realizable 1-qudit gates and 2-qudit Muthukrishnan–Stroud gates.     

Temporal Languages for Epistemic Programs

This paper adds temporal logic to public announcement logic (PAL) and dynamic epistemic logic (DEL). By adding a previous-time operator to PAL, we express in the language statements concerning the muddy children puzzle and sum and product. We also express a true statement that an agent’s beliefs about another agent’s knowledge flipped twice, and use a sound proof system to prove this statement. Adding a next-time operator to PAL, we provide formulas that express that belief revision does not take place in PAL. We also discuss relationships between announcements and the new knowledge agents thus acquire; such relationships are related to learning and to Fitch’s paradox. We also show how inverse programs and hybrid logic each can be used to help determine whether or not an arbitrary structure represents the play of a game. We then add a past-time operator to DEL, and discuss the importance of adding yet another component to the language in order to prove completeness.     

人工智能中概率逻辑的研究

概率论是在不完备的、不确定的数据中进行推理的,它是度量不确定性的重要手段。在人工智能中,研究者结合概率和逻辑各自的优点,进行概率逻辑的研究。本文介绍了传统概率逻辑的三大派别,阐述了二值逻辑概率和三值逻辑概率的发展;最后介绍了泛逻辑,通过对概率逻辑和泛逻辑学的研究,将概率逻辑纳入泛逻辑学的框架内。     

Logic programming with infinite sets

Using the ideas from current investigations in Knowledge Representation we study the use of a class of logic programs for reasoning about infinite sets. Our programs reason about the codes for various infinite sets. Depending on the form of atoms allowed in the bodies of clauses we obtain a variety of completeness results for various classes of arithmetic sets of integers.AMS subject classification 68T27, 03B70     

What can we do with a linear optical logic gate?

In an earlier paper [H.J. Caulfield, J. Westphal, The logic of optics and the optics of logic, Information Sciences 162 (2004) 21-33], we considered a simple interferometer (initially conceived as Mach-Zehnder) with two uniform intensity mutually coherent inputs. By encoding those inputs with phases 0 and π representing Boolean 0 and 1 and identifying the detected values of the outputs as logical Boolean values, we found that the outputs could be identified as the Boolean operations XOR and COINC (sometimes called XNOR). Here, we show that this seemingly simple interferometer can perform many additional functions if we use phases to interpret its outputs. But the XOR/COINC are the only non-trivial logic gate we can get no matter how we cascade Mach-Zehnder interferometers. We also generalize those operations upwards (to three or four arguments). We show that the three argument interferometer or four-argument interferometer cannot produce a Fredkin gate or its variation.     

常识问题——常识推理的逻辑基础

本文主要讨论常识推理的逻辑基础，基于一条从非单调推理到常识推理的技术途径，由此指出在更一般意义上形式化常识推是的一些结果，它建立常识逻辑和解决常识问题提供了有用的基础工具。     

Display Calculi for Logics with Relative Accessibility Relations

We define cut-free display calculi for knowledge logics wherean indiscernibility relation is associated to each set of agents, andwhere agents decide the membership of objects using thisindiscernibility relation. To do so, we first translate the knowledgelogics into polymodal logics axiomatised by primitive axioms and thenuse Kracht's results on properly displayable logics to define thedisplay calculi. Apart from these technical results, we argue thatDisplay Logic is a natural framework to define cut-free calculi for manyother logics with relative accessibility relations.     

A proof-theoretic foundation of abortive continuations

We give an analysis of various classical axioms and characterize a notion of minimal classical logic that enforces Peirce’s law without enforcing Ex Falso Quodlibet. We show that a “natural” implementation of this logic is Parigot’s classical natural deduction. We then move on to the computational side and emphasize that Parigot’s λ μ corresponds to minimal classical logic. A continuation constant must be added to λ μ to get full classical logic. The extended calculus is isomorphic to a syntactical restriction of Felleisen’s theory of control that offers a more expressive reduction semantics. This isomorphic calculus is in correspondence with a refined version of Prawitz’s natural deduction. This article is an extended version of the conference article “Minimal Classical Logic and Control Operators” (Ariola and Herbelin, Lecture Notes in Computer Science, vol. 2719, pp. 871–885, 2003). A longer version is available as a technical report (Ariola et al., Technical Report TR608, Indiana University, 2005). Z.M. Ariola supported by National Science Foundation grant number CCR-0204389. A. Sabry supported by National Science Foundation grant number CCR-0204389, by a Visiting Researcher position at Microsoft Research, Cambridge, U.K., and by a Visiting Professor position at the University of Genova, Italy.     

A Logical Analysis of the Relationship between Commitment and Obligation

In this paper, we analyze the relationship between commitment and obligation from a logical viewpoint. The principle of commitment implying obligation is proven in a specific logic of action preference which is a generalization of Meyer's dynamic deontic logic. In the proposed formalism, an agent's commitment to goals is considered as a special kind of action which can change one's deontic preference andone's obligation to take some action is based on the preference and the effects of the action. In this logic, it is shown that an agent has the obligation to take any action which is necessary for achieving as many committed goals as possible. The semantics of our logic is based on the possible world models for the dynamic logic of actions. A binary preference relation between possible worlds is associated with the model. Then the preference between actions are determined by comparing that of their consequences. According to the semantics, while the preference will influence the agent's choice of action, commitment is a kind of action that will change the agent's preference. Thus we can show how obligations arise from commitments via updating of deontic preference. The integrated semantics make it possible to express and reason about the mutual relationship among these mental attitudes in a common logic. This revised version was published online in August 2006 with corrections to the Cover Date.     

Axioms for classical, intuitionistic, and paraconsistent hybrid logic

In this paper we give axiom systems for classical and intuitionistic hybrid logic. Our axiom systems can be extended with additional rules corresponding to conditions on the accessibility relation expressed by so-called geometric theories. In the classical case other axiomatisations than ours can be found in the literature but in the intuitionistic case no axiomatisations have been published. We consider plain intuitionistic hybrid logic as well as a hybridized version of the constructive and paraconsistent logic N4.     

人工智能科学中的概率逻辑

人工智能科学,从其诞生之日起便与逻辑学密不可分。本文首先对逻辑学的分类、相互关系以及泛逻辑的概念等进行了讨论,并对人工智能中逻辑学的应用及发展进行了必要的分析。然后讲述了逻辑学与概率论两大理论基础之上的不确定性推理方法——概率逻辑,重点研究了二值概率逻辑与三值概率逻辑。最后阐述了概率逻辑在人工智能科学中的应用以及对它的思考。