ACTLW - An action-based computation tree logic with unless operator

Model checkers for systems represented by labelled transition systems are not as extensively used as those for systems represented by Kripke structures. This is partially due to the lack of an elegant formal language for property specification which would not be as raw as, for example, HML yet also not as complex as, for example, μ-calculus. This paper proposes a new action-based propositional branching-time temporal logic ACTLW, which enhances popular computation tree logic (CTL) with the notion of actions in a similar but more comprehensive way than action-based CTL introduced by De Nicola and Vaandrager [R. De Nicola, F.W. Vaandrager, Action versus logics for transition systems, in: Semantics of Systems of Concurrent Processes, Proceedings LITP Spring School on Theoretical Computer Science, LNCS 469, 1990, pp. 407-419]. ACTLW is defined by using temporal operators until and unless only, whereas all other temporal operators are derived from them. Fixed-point characterisation of the operators together with symbolic algorithms for global model checking are shown. Usage of this new logic is illustrated by an example of verification of mutual-exclusion algorithms.     

Specifying coalgebras with modal logic

We propose to use modal logic as a logic for coalgebras and discuss it in view of the work done on coalgebras as a semantics of object-oriented programming. Two approaches are taken: First, standard concepts of modal logic are applied to coalgebras. For a certain kind of functor it is shown that the logic exactly captures the notion of bisimulation and a complete calculus is given. Examples of verifications of object properties are given. Second, we discuss the relationship of this approach with the coalgebraic logic of Moss (Coalgebraic logic, Ann Pure Appl. Logic 96 (1999) 277–317.).     

模态逻辑中公式的模态真度

在模态逻辑中提出了公式的模态真度理论,即Δ真度与΢真度。先给出在一个给定Kripke模型之下的模态真度理论,此后利用均匀概率思想,提出了更为合理的(n)模态真度理论,定义了两公式之间的(n)模态相似度,并由此导出了(n)模态伪距离,得到了相应的模态度量空间。结果同文[9]相比更能体现模态词的思想特点,从而为在模态逻辑中展开近似推理提供一个可能的框架。     

MOLOG: A system that extends PROLOG with modal logic

In this paper we present an extension of PROLOG using modal logic. A new deduction method is also given based on a rule closer to the classical inference rule of PROLOG.     

On the implication operator in fuzzy logic

We investigate the different possible ways of translating an implication proposition in approximate reasoning. We study a general class of these operators.     

Design of reversible logic based full adder in current-mode logic circuits

Demand of Very Large Scale Integration (VLSI) circuits with very high speed and low power are increased due to communication system's transmission speed increase. During computation, heat is dissipated by a traditional binary logic or logic gates. There will be one or more input and only one output in irreversible gates. Input cannot be reconstructed using those outputs. In low power VLSI, reversible logic is commonly preferred in recent days. Information is not lost in reversible gates and back computation is possible in reversible circuits with reduced power dissipation. Reversible full adder circuits are implemented in the previous work to optimize the design and speed of the circuits. Reversible logic gates like TSG, Peres, Feynman, Toffoli, Fredkin are mostly used for designing reversible circuits. However it does not produced a satisfactory result in terms of static power dissipation. In this proposed research work, reversible logic is implemented in the full adder of MOS Current-Mode Logic (MCML) to achieve high speed circuit design with reduced power consumption. In VLSI circuits, reliable performance and high speed operation is exhibited by a MCML when compared with CMOS logic family. Area and better power consumption can be produced implementing reversible logic in full adder of MCML. Minimum garbage output and constant inputs are used in reversible full adder. The experimental results shows that the proposed designed circuit achieves better performance compared with the existing reversible logic circuits such as Feynman gate based FA, Peres gate based FA, TSG based FA in terms of average power, static power dissipation, static current and area.     

Ultra‐low‐power polysilicon AMLCD with full integration

Abstract— An LTPS TFT‐LCD that only consumes 0.07 mW of power was developed. It is the world's first LCD equipped with all the circuits needed to display still images continuously for up to 1 year on a button battery. At the same time, the panel is capable of displaying 260,000‐color moving pictures.     

Timed tree automata with an application to temporal logic

Finite automata on -sequences and -trees were introduced in the sixties by Büchi, McNaughton and Rabin. Finite automata on timed -sequences were introduced by Alur and Dill. In this paper we extend the theory of timed -sequences to -trees. The main motivation is the introduction of a new way to specify real-time systems and to study, using automata-theoretic techniques, branching-time temporal logics with timing constraints. We study closure properties and decision problems for the obtained classes of timed -tree languages. In particular, we show the decidability of the emptiness problem. As an application of the introduced theory, we give a new decidable branching time temporal logic (STCTL) whose semantics is based upon timed -trees. Received: 8 September 1997 / 27 June 2001     

Proving classical theorems of social choice theory in modal logic

A number of seminal results in the field of social choice theory demonstrate the difficulties of aggregating the preferences of several individual agents for the purpose of making a decision together. We show how to formalise three of the most important impossibility results of this kind—Arrow’s Theorem, Sen’s Theorem, and the Muller–Satterthwaite Theorem—by using a modal logic of social choice functions. We also provide syntactic proofs of these theorems in the same logic. While prior work has been successful in applying tools from logic and automated reasoning to social choice theory, this is the first human-readable formalisation of the Arrovian framework allowing for a direct derivation of the main impossibility theorems of social choice theory. This is useful for gaining a deeper understanding of the foundations of collective decision making, both in human society and in groups of autonomous software agents.     

The Global Properties of Valid Formulas in Modal Logic K

Global property is the necessary condition which must be satisfied by the provable formulas.It can help to find out some unprovable formula that does not satisfy some global property before proving it using formal automated reasoning systems,thus the efficiency of the whole system is improved.This paper presents some global properties of valid formulas in modal logic K.Such properties are structure characters of formulas,so they are simple and easy to check.At the same time,some global properties of K unsatisfiable formula set are also given.     

Belief, information acquisition, and trust in multi-agent systems—A modal logic formulation

In this paper, we consider the influence of trust on the assimilation of acquired information into an agent's belief. By use of modal logic, we semantically and axiomatically characterize the relationship among belief, information acquisition and trust. The belief and information acquisition operators are respectively represented by KD45 and KD normal modalities, whereas trust is denoted by a modal operator with minimal semantics. One characteristic axiom of the basic system is if agent i believes that agent j has told him the truth of p and he trusts the judgement of j on p, then he will also believe p. In addition to the basic system, some variants and further axioms for trust and information acquisition are also presented to show the expressive richness of the logic. The applications of the logic to computer security and database reasoning are also suggested by its connection with some previous works.     

模态逻辑系统S5中相容理论的构造方法

在模态逻辑系统S5中借助公式的状态描述等概念,提出了一种从最简单的原子公式对应的相容理论开始,对于较复杂的公式形式,寻找恰当的状态描述,再将对应的存在状态加入最初的相容理论后仍相容的方法。