Eunsuk Yang

We study micanorm-based logics with three forms of weak associativity. To be more exact, for $ e \in [0, 1]$, the $[0, e]$-continuous $\nu $-weak-associative uninorm ($\nu $wa-uninorm) logics tuWABUL, tuABUL, and tuSABUL are first introduced as a weak associative generalization of BUL (Basic uninorm logic). Their algebraic semantics and completeness results are then addressed. Next, $[0, e]$-continuous $\nu $wa-uninorms are introduced and related algebraic properties are investigated. Finally, standard completeness results are provided for the logics by a construction of Yang-style.

This paper deals with analogues of two famous theorems of Birkhoff, the subdirect representation and varieties theorems of algebras, in the context of reduced tonoid matrices. More precisely, we first introduce tonoid matrices and isotonic ordered matrices. We next provide subdirect product representations for reduced tonoid and isotonic ordered matrices. We then introduce analogues of the varieties theorems for algebras in the context of reduced tonoid and isotonic ordered matrices. Finally, we extend them to their corresponding quasi-varieties theorems.

Implicational tonoid logics and their extensions with abstract Galois properties have been introduced by Yang and Dunn. They introduced matrix semantics for the implicational tonoid logics but did not do for the extensions. Here we provide such semantics for implicational partial gaggle logics as one sort of such extensions. To this end, first we discuss implicational partial gaggle logics in Hilbert-style. We next introduce one kind of matrix semantics based on Lindenbaum– Tarski matrices for the logics and show that those logics are complete with respect to the matrix semantics. Finally, we further introduce a slightly different kind of matrix semantics based on reduced models for the logics and show that those logics are complete with respect to this matrix semantics.

An involutive micanorm-based logic with a weak form of associativity is introduced and its finite standard completeness is addressed. More precisely, we first introduce the logic WAuIBUL as a [0, u]-continuous wau-uninorm analogue of the involutive logic IBUL. We next discuss its algebraic semantics. We then introduce involutive wau-uninorms as involutive uninorms with weak u-associativity in place of associativity and deal with related properties. We last provide finite strong standard completeness for WAuIBUL using a construction of Yang-style. 약한 형식의 결합 원리를 만족하는 누승적인 미카놈에 기반한 논리 체계를 소개하고 그 체계의 유한 표준 완전성을 다룬다. 보다 구체적으로 논리 체계 WAuIBUL을 누승적 유니놈 논리 IUML의 [0, u]-연속인 wau-유니놈 일반화로 먼저 소개한다. 그리고 이 체계의 대수적 완전성을 다룬다. 다음으로 결합 원리 대신에 약한 u-결합 원리를 만족하는 누승적 유니놈으로 누승적 wau-유니놈을 소개하고 그 성질을 다룬다. 마지막으로 유한 집합 위에서 WAuIBUL의 표준 완전성을 보인다.

This paper deals with substructural nuclear (image-based) logics and their algebraic and Kripke-style semantics. More precisely, we first introduce a class of substructural logics with connective _N_ satisfying nucleus property, called here substructural _nuclear_ logics, and its subclass, called here substructural _nuclear image-based_ logics, where _N_ further satisfies homomorphic image property. We then consider their algebraic semantics together with algebraic characterizations of those logics. Finally, we introduce _operational Kripke-style_ semantics for those logics and provide two sorts of completeness results for them, one of which is based on algebraic completeness for all the logics and the other of which is based on set-theoretic one for the nuclear image-based logics.

In the context of implicational tonoid logics, this paper investigates analogues of Birkhoff’s two theorems, the so-called subdirect representation and varieties theorems, and of Mal’cev’s quasi-varieties theorem. More precisely, we first recall the class of implicational tonoid logics. Next, we establish the subdirect product representation theorem for those logics and then consider some more related results such as completeness. Thirdly, we consider the varieties theorem for them. Finally, we introduce an analogue of Mal’cev’s quasi-varieties theorem for algebras.

This paper combines two classes of generalized logics, one of which is the class of weakly implicative logics introduced by Cintula and the other of which is the class of gaggle logics introduced by Dunn. For this purpose we introduce implicational tonoid logics. More precisely, we first define implicational tonoid logics in general and examine their relation to weakly implicative logics. We then provide algebraic semantics for implicational tonoid logics. Finally, we consider relational semantics, called Routley–Meyer–style semantics, for finitary those logics.

In this paper we investigate some logics with weak Boolean negation , calling wB logics, obtained by dualizing intuitionistic negation . We first provide Routley-Meyer semantics for wB-IC , its neighbors wB-LC, wB-LC* ), and wB-S4, wB-S4c . We give completeness for each of them by using RM semantics. We next provide RM semantics for IC, the Dummett's LC, the wB-S4 with ¬ in place of − , and the pB-S4 with c , and give completeness for each system. Finally, we give a translation of the classical propositional logic PC into wB-IC, and a translation of PC into wB-S4c.1

This paper proposes a new topic in substructural logic for use in research joining the fields of relevance and fuzzy logics. For this, we consider old and new relevance principles. We first introduce fuzzy systems satisfying an old relevance principle, that is, Dunn’s weak relevance principle. We present ways to obtain relevant companions of the weakening-free uninorm systems introduced by Metcalfe and Montagna and fuzzy companions of the system R of relevant implication and its neighbors. The algebraic structures corresponding to the systems are then defined, and completeness results are provided. We next consider fuzzy systems satisfying new relevance principles introduced by Yang. We show that the weakening-free uninorm systems and some extensions and neighbors of R satisfy the new relevance principles.

This paper investigates four-valued Kripke-style semantics (with star (*) operation) for three sorts of logics, which can be regarded as paraconsistent, Ockham, and Boolean neighbors of the most famous relevance systems E of Entailment, R of Relevance, and T of Ticket Entailment. We first introduce some paraconsistent cousins of E and R, provide Kripke-style semantics for them, and prove soundness and completeness. We then further consider Kripke-style semantics with star (*) operation, briefly *-Kripke-style semantics, for them. We next introduce some Ockham neighbors of E and R. After providing Kripke-style semantics for them, we prove soundness and completeness. We finally introduce several Boolean neighbors of E, R, and T. We provide *-Kripke-style semantics for not merely the Boolean neighbors but also the Ockham neighbors, and prove soundness and completeness. © 2011 Elsevier B.V., All rights reserved.

This article investigates Kripke-style semantics for two sorts of logics: pseudo-Boolean and weak-Boolean logics. As examples of the first, we introduce G3 and S53pB.G3 is the three-valued Dummett–Gödel logic; S53pB is the modal logic S5 but with its orthonegation replaced by a pB negation. Examples of wB logic are G3wB and S53wB.G3wB is G3 with a wB negation in place of its pB negation; S53wB is S5 with a wB negation replacing its orthonegation. For each system, we provide a three-valued Kripke-style semantics with and without star operation . We prove soundness and completeness theorems in each case. Note that wB logics may be equivalent to logics with Baaz’s projection Δ. We finally introduce the G3 and the S53pB both with Δ and show that they are equivalent to G3wB and S53wB, respectively