• Journal of the Korean Operations Research and Management Science Society
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• v.27 no.4
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• pp.87-109
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• 2002

A satisfiability problem in propositional logic is the problem of checking for the existence of a set of truth values of atomic prepositions that renders an input propositional formula true. This paper describes an empirical investigation of a particular integer programming approach, using the set covering model, to solve satisfiability problems. Our satisfiability engine, SETSAT, is a fully integrated, linear programming based, branch and bound method using various symbolic routines for the reduction of the logic formulas. SETSAT has been implemented in the integer programming shell MINTO which, in turn, uses the CPLEX linear programming system. The logic processing routines were written in C and integrated into the MINTO functions. The experiments were conducted on a benchmark set of satisfiability problems that were compiled at the University of Ulm in Germany. The computational results indicate that our approach is competitive with the state of the art.

• East Asian mathematical journal
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• v.23 no.3
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• pp.313-326
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• 2007

The purpose of education of propositional logic is to understand the basic structure of the mathematics and to improve the logical thinking in normal life. But in the seventh curriculum, some basic terms, for examples $\wedge$ and $\vee$, are not introduced, the proposition $p{\\rightarrow}q$ is not defined properly, and use the wrong term $\Rightarrow$ so that it is difficult to understand the propositional logic. In this paper, we present a suitable content for the propositional logic in high-school mathematical class. We also present a proper definition of the proposition $p{x}{\Rightarrow}q{x}$ without using the notation $\rightarrow$. We finally give proper definitions of necessary conditions, sufficient conditions, and necessary and sufficient conditions.

• Korean Journal of Logic
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• v.12 no.1
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• pp.89-110
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• 2009

This paper investigates generalizations of weakening-free uninorm logics not assuming associativity of intensional conjunction (so called fusion) &, as non-associative fuzzy-relevance logics. First, the strong t-associative monoidal uninorm logic StAMUL and its schematic extensions are introduced as non-associative propositional fuzzy-relevance logics. (Non-associativity here means that, differently from classical logic, & is no longer associative.) Then the algebraic structures corresponding to the systems are defined, and algebraic completeness results for them are provided. Next, predicate calculi corresponding to the propositional systems introduced here are considered.

• Korean Journal of Logic
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• v.21 no.2
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• pp.231-268
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• 2018

Wittgenstein asserts in the Tractatus Logico-Philosophicus 5.542 that "A believes that p" is of the form "'p' says p" and "here we have no co-ordination of a fact and an object, but a co-ordination of facts by means of a co-ordination of their objects." What does, then, it mean exactly that 'p' says p? What are "facts" and "a co-ordination" in the expression "a co-ordination of facts"? Are propositional attitude statements significant propositions or not? Furthermore, what is the point of Wittgenstein's criticism of Russell's theory of judgement? In this paper, I will answer these questions on the basis of Wittgenstein's explication of the concept of thought and Ramsey's relevant remark on propositional attitude. Meanwhile propositional attitude statements are bound up with solipsism of the Tractatus Logico-Philosophicus and some of them have senses. Hence both of assertions that all the propositional attitude statements are significant and all of them are nonsense in the Tractatus Logico-Philosophicus are not correct.

• Journal of KIISE:Software and Applications
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• v.37 no.2
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• pp.148-154
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• 2010

In the study of the formal semantics of uncertain databases, we typically take an algebraic approach by mapping an uncertain database to possible worlds which are a set of relational databases. In this paper, we present a new semantics for uncertain databases which takes a logical approach by translating uncertain databases into logical theories. A characteristic feature of our semantics is that it uses linear logic, instead of propositional logic, as its logical foundation. Linear logic is suitable for a logical interpretation of uncertain information because unlike propositional logic, it treats logical formulae not as persistent facts but as consumable resources. As the main result, we show that our semantics is faithful to the operational account of uncertain databases in the algebraic approach.

• Journal of applied mathematics & informatics
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• v.14 no.1_2
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• pp.69-80
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• 2004

We present a construction of the linear reduction of Hilbert type proof systems for propositional logic to if-then-else equational logic. This construction is an improvement over the same result found in [4] in the sense that the technique used in the construction can be extended to the linear reduction of first-order logic to if-then-else equational logic.

• Korean Journal of Logic
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• v.5 no.2
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• pp.1-21
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• 2002

A semantics for logical necessity, based on Carnap's criterion of adequacy, is given with respect to the ontology of logical atomism. A calculus for sentential (propositional) modal logic is described and shown to be complete with respect to this semantics. The semantics is then modified in terms of a restricted notion of 'all possible worlds' in the interpretation of necessity and shown to yield a completeness theorem for the modal logic S5. Such a restricted notion introduces material content into the meaning of necessity so that, in addition to atomic facts, there are "modal facts" that distinguish one world from another.

• Journal of Internet Computing and Services
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• v.3 no.1
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• pp.51-59
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• 2002

The conventional procedure to verify rule bases are corresponding to the propositional logic-level knowledge representation. Building knowledge bases, in real applications, we utilize the predicate logic-level rules. In this paper, we present a verification algorithm of rule bases using Pr/T nets which represent the predicate logic-level rules naturally.

• Journal of the Korean Mathematical Society
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• v.51 no.3
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• pp.527-543
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• 2014

The theory of random variable structures was first studied by Ben Yaacov in [2]. Ben Yaacov's axiomatization of the theory of random variable structures used an early result on the completeness theorem for Lukasiewicz's [0, 1]-valued propositional logic. In this paper, we give an elementary approach to axiomatizing the theory of random variable structures. Only well-known results from probability theory are required here.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.16 no.3
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• pp.147-156
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• 2016

A modalized Łukasiewicz three-valued propositional logic will be proposed in this paper which there are three modalities [t]; [m]; [f] to represent the three values t; m; f; respectively. And a Gentzen-typed deduction system will be given so that the the system is sound and complete with respect to the Łukasiewicz three-valued semantics Ł$_3$, which are given in soundness theorem and completeness theorem.