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  1. Janusz Czelakowski, Wiesław Dziobiak & Jacek Malinowski (2011). Foreword. Studia Logica 99 (1-3):1-6.
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  2. Janusz Czelakowski (2006). Fixed-Points for Relations and the Back and Forth Method. Bulletin of the Section of Logic 35 (2/3):63-71.
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  3. Janusz Czelakowski (2006). General Theory of the Commutator for Deductive Systems. Part I. Basic Facts. Studia Logica 83 (1-3):183 - 214.
    The purpose of this paper is to present in a uniform way the commutator theory for k-deductive system of arbitrary positive dimension k. We are interested in the logical perspective of the research — an emphasis is put on an analysis of the interconnections holding between the commutator and logic. This research thus qualifies as belonging to abstract algebraic logic, an area of universal algebra that explores to a large extent the methods provided by the general theory of deductive systems. (...)
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  4. Janusz Czelakowski (2004). Towards the Algebraization of Set Theory. Set-Theoretic Domains. Bulletin of the Section of Logic 33 (3):157-178.
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  5. Janusz Czelakowski (2003). Dunn J. Michael and Hardegree Gary M.. Algebraic Methods in Philosophical Logic. Oxford Logic Guides, No. 41. Clarendon Press, Oxford University Press, Oxford, New York, Etc., 2001, Xv+ 470 Pp. [REVIEW] Bulletin of Symbolic Logic 9 (2):231-234.
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  6. Janusz Czelakowski (2003). John F. Horthy, Agency and Deontic Logic. Erkenntnis 58 (1):116-126.
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  7. Janusz Czelakowski (2003). Logics and Operators. Logic and Logical Philosophy 3:87-100.
    Two connectives are of special interest in metalogical investigations — the connective of implication which is important due to its connections to the notion of inference, and the connective of equivalence. The latter connective expresses, in the material sense, the fact that two sentences have the same logical value while in the strict sense it expresses the fact that two sentences are interderivable on the basis of a given logic. The process of identification of equivalent sentences relative to theories of (...)
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  8. Janusz Czelakowski (2003). The Suszko Operator. Part I. Studia Logica 74 (1-2):181 - 231.
    The paper is conceived as a first study on the Suszko operator. The purpose of this paper is to indicate the existence of close relations holding between the properties of the Suszko operator and the structural properties of the model class for various sentential logics. The emphasis is put on generality both of the results and methods of tackling the problems that arise in the theory of this operator. The attempt is made here to develop the theory for non-protoalgebraic logics.
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  9. Janusz Czelakowski (2002). Uwagi o teorii mnogości (na marginesie dyskusji o książce prof. Ryszarda Wójcickiego). Filozofia Nauki 2.
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  10. Janusz Czelakowski (2001). Protoalgebraic Logics. Kluwer Academic Publishers.
    This book is both suitable for logically and algebraically minded graduate and advanced graduate students of mathematics, computer science and philosophy, and ...
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  11. Janusz Czelakowski & Ramon Jansana (2000). Weakly Algebraizable Logics. Journal of Symbolic Logic 65 (2):641-668.
    In the paper we study the class of weakly algebraizable logics, characterized by the monotonicity and injectivity of the Leibniz operator on the theories of the logic. This class forms a new level in the non-linear hierarchy of protoalgebraic logics.
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  12. Janusz Czelakowski (1996). Filtered Subdirect Products. Bulletin of the Section of Logic 24:92-96.
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  13. Janusz Czelakowski (1992). Books Received. [REVIEW] Studia Logica 51 (1):151-161.
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  14. Janusz Czelakowski & Wiesław Dziobiak (1991). A Deduction Theorem Schema for Deductive Systems of Propositional Logics. Studia Logica 50 (3-4):385 - 390.
    We propose a new schema for the deduction theorem and prove that the deductive system S of a prepositional logic L fulfills the proposed schema if and only if there exists a finite set A(p, q) of propositional formulae involving only prepositional letters p and q such that A(p, p) L and p, A(p, q) s q.
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  15. Janusz Czelakowski & Lawrence S. Moss (1991). Books Received. [REVIEW] Studia Logica 50 (1):425-430.
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  16. Janusz Czelakowski (1990). Relatively Congruence-Distributive Subquasivarieties of Filtral Varieties. Bulletin of the Section of Logic 19 (2):66-70.
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  17. Janusz Czelakowski, Alasdair Urquhart, Ryszard Wójcicki, Jan Woleński, Andrzej Sendlewski & Marcin Mostowski (1990). Books Received. [REVIEW] Studia Logica 49 (1):151-161.
  18. Janusz Czelakowski (1989). Books Received. [REVIEW] Studia Logica 48 (1):151-161.
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  19. Janusz Czelakowski (1988). Books Received. [REVIEW] Studia Logica 47 (1):151-161.
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  20. Janusz Czelakowski (1987). Books Received. [REVIEW] Studia Logica 46 (4):151-161.
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  21. Janusz Czelakowski (1986). Local Deductions Theorems. Studia Logica 45 (4):377 - 391.
    The notion of local deduction theorem (which generalizes on the known instances of indeterminate deduction theorems, e.g. for the infinitely-valued ukasiewicz logic C ) is defined. It is then shown that a given finitary non-pathological logic C admits the local deduction theorem iff the class Matr(C) of all matrices validating C has the C-filter extension property (Theorem II.1).
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  22. Janusz Czelakowski, Roger Maddux, Gerhard Schurz & Kazimierz Trzesicki (1986). Books Received. [REVIEW] Studia Logica 45 (2):425-430.
  23. Janusz Czelakowski (1985). Algebraic Aspects of Deduction Theorems. Studia Logica 44 (4):369 - 387.
    The first known statements of the deduction theorems for the first-order predicate calculus and the classical sentential logic are due to Herbrand [8] and Tarski [14], respectively. The present paper contains an analysis of closure spaces associated with those sentential logics which admit various deduction theorems. For purely algebraic reasons it is convenient to view deduction theorems in a more general form: given a sentential logic C (identified with a structural consequence operation) in a sentential language I, a quite arbitrary (...)
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  24. Janusz Czelakowski (1985). Books Received. [REVIEW] Studia Logica 44 (1):151-161.
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  25. Janusz Czelakowski (1985). Sentential Logics and Maehara Interpolation Property. Studia Logica 44 (3):265 - 283.
    With each sentential logic C, identified with a structural consequence operation in a sentential language, the class Matr * (C) of factorial matrices which validate C is associated. The paper, which is a continuation of [2], concerns the connection between the purely syntactic property imposed on C, referred to as Maehara Interpolation Property (MIP), and three diagrammatic properties of the class Matr* (C): the Amalgamation Property (AP), the (deductive) Filter Extension Property (FEP) and Injections Transferable (IT). The main theorem of (...)
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  26. Janusz Czelakowski & Grzegorz Malinowski (1985). Key Notions of Tarski's Methodology of Deductive Systems. Studia Logica 44 (4):321 - 351.
    The aim of the article is to outline the historical background and the present state of the methodology of deductive systems invented by Alfred Tarski in the thirties. Key notions of Tarski's methodology are presented and discussed through, the recent development of the original concepts and ideas.
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  27. Janusz Czelakowski (1984). Books Received. [REVIEW] Studia Logica 43 (3):151-161.
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  28. Janusz Czelakowski (1984). Filter Distributive Logics. Studia Logica 43 (4):353 - 377.
    The present paper is thought as a formal study of distributive closure systems which arise in the domain of sentential logics. Special stress is laid on the notion of a C-filter, playing the role analogous to that of a congruence in universal algebra. A sentential logic C is called filter distributive if the lattice of C-filters in every algebra similar to the language of C is distributive. Theorem IV.2 in Section IV gives a method of axiomatization of those filter distributive (...)
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  29. Janusz Czelakowski (1983). Matrices, Primitive Satisfaction and Finitely Based Logics. Studia Logica 42 (1):89 - 104.
    We examine the notion of primitive satisfaction in logical matrices. Theorem II. 1, being the matrix counterpart of Baker's well-known result for congruently distributive varieties of algebras (cf [1], Thm. 1.5), links the notions of primitive and standard satisfaction. As a corollary we give the matrix version of Jónsson's Lemma, proved earlier in [4]. Then we investigate propositional logics with disjunction. The main result, Theorem III. 2, states a necessary and sufficient condition for such logics to be finitely based.
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  30. Janusz Czelakowski (1983). Some Theorems on Structural Entailment Relations. Studia Logica 42 (4):417 - 429.
    The classesMatr( ) of all matrices (models) for structural finitistic entailments are investigated. The purpose of the paper is to prove three theorems: Theorem I.7, being the counterpart of the main theorem from Czelakowski [3], and Theorems II.2 and III.2 being the entailment counterparts of Bloom's results [1]. Theorem I.7 states that if a classK of matrices is adequate for , thenMatr( ) is the least class of matrices containingK and closed under the formation of ultraproducts, submatrices, strict homomorphisms and (...)
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  31. Janusz Czelakowski (1982). Logical Matrices and the Amalgamation Property. Studia Logica 41 (4):329 - 341.
    The main result of the present paper — Theorem 3 — establishes the equivalence of the interpolation and amalgamation properties for a large family of logics and their associated classes of matrices.
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  32. Janusz Czelakowski & Wiesław Dziobiak (1982). Another Proof That ISPr(K) is the Least Quasivariety Containing K. Studia Logica 41 (4):343 - 345.
    Let q(K) denote the least quasivariety containing a given class K of algebraic structures. Mal'cev [3] has proved that q(K) = ISP r(K)(1). Another description of q(K) is given in Grätzer and Lakser [2], that is, q(K) = ISPP u(K)2. We give here other proofs of these results. The method which enables us to do that is borrowed from prepositional logics (cf. [1]).
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  33. Janusz Czelakowski (1981). Equivalential Logics (I). Studia Logica 40 (3):227 - 236.
    The class of equivalential logics comprises all implicative logics in the sense of Rasiowa [9], Suszko's logicSCI and many Others. Roughly speaking, a logic is equivalential iff the greatest strict congruences in its matrices (models) are determined by polynomials. The present paper is the first part of the survey in which systematic investigations into this class of logics are undertaken. Using results given in [3] and general theorems from the theory of quasi-varieties of models [5] we give a characterization of (...)
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  34. Janusz Czelakowski (1981). Equivalential Logics (II). Studia Logica 40 (4):355 - 372.
    In the first section logics with an algebraic semantics are investigated. Section 2 is devoted to subdirect products of matrices. There, among others we give the matrix counterpart of a theorem of Jónsson from universal algebra. Some positive results concerning logics with, finite degrees of maximality are presented in Section 3.
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  35. Janusz Czelakowski (1980). A Remark on Free Products. Bulletin of the Section of Logic 9 (3):125-128.
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  36. Janusz Czelakowski (1980). Reduced Products of Logical Matrices. Studia Logica 39 (1):19 - 43.
    The class Matr(C) of all matrices for a prepositional logic (, C) is investigated. The paper contains general results with no special reference to particular logics. The main theorem (Th. (5.1)) which gives the algebraic characterization of the class Matr(C) states the following. Assume C to be the consequence operation on a prepositional language induced by a class K of matrices. Let m be a regular cardinal not less than the cardinality of C. Then Matr (C) is the least class (...)
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  37. Janusz Czelakowski (1979). A Remark on Countable Algebraic Models. Bulletin of the Section of Logic 8 (1):2-4.
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  38. Janusz Czelakowski (1979). Large” Matrices Which Induce Finite Consequence Operations. Bulletin of the Section of Logic 8 (2):79-81.
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  39. Janusz Czelakowski (1979). Partial Boolean Algebras in a Broader Sense. Studia Logica 38 (1):1 - 16.
    The article deals with compatible families of Boolean algebras. We define the notion of a partial Boolean algebra in a broader sense (PBA(bs)) and then we show that there is a mutual correspondence between PBA(bs) and compatible families of Boolean algebras (Theorem (1.8)). We examine in detail the interdependence between PBA(bs) and the following classes: partial Boolean algebras in the sense of Kochen and Specker (§ 2), ortholattices (§ 3, § 5), and orthomodular posets (§ 4), respectively.
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  40. Janusz Czelakowski (1979). Ω-Saturated Matrices. Bulletin of the Section of Logic 8 (3):120-122.
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  41. Janusz Czelakowski (1975). Logics Based on Partial Boolean Σ-Algebras. Studia Logica 34 (1):69 - 86.
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  42. Janusz Czelakowski (1974). Logics Based on Partial Boolean Σ-Algebras (1). Studia Logica 33 (4):371 - 396.
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  43. Janusz Czelakowski (1974). Partial Boolean Σ-Algebras. Bulletin of the Section of Logic 3 (1):45-48.
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  44. Janusz Czelakowski (1974). The Identity Relation and Partial Boolean Algebras. Bulletin of the Section of Logic 3 (3/4):34-36.
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