Results for 'A. Hajnal'

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  1.  34
    Axioms of Class Existence.A. Hajnal & Hilary Putnam - 1966 - Journal of Symbolic Logic 31 (4):663.
  2.  32
    Fraenkel's Addition to the Axioms of Zermelo.A. Hajnal & Richard Montague - 1966 - Journal of Symbolic Logic 31 (4):662.
  3.  16
    Some higher-gap examples in combinatorial set theory.A. Hajnal & P. Komjáth - 1987 - Annals of Pure and Applied Logic 33 (C):283-296.
  4.  15
    On chromatic number of graphs and set systems.P. Erdös, A. Hajnal & B. Rothchild - 1973 - In A. R. D. Mathias & H. Rogers (eds.), Cambridge Summer School in Mathematical Logic. New York: Springer Verlag. pp. 531--538.
  5.  16
    Meaningfulness Beats Frequency in Multiword Chunk Processing.Hajnal Jolsvai, Stewart M. McCauley & Morten H. Christiansen - 2020 - Cognitive Science 44 (10):e12885.
    Whereas a growing bulk of work has demonstrated that both adults and children are sensitive to frequently occurring word sequences, little is known about the potential role of meaning in the processing of such multiword chunks. Here, we take a first step toward assessing the contribution of meaningfulness in the processing of multiword sequences, using items that varied in chunk meaningfulness. In a phrasal-decision study, we compared reaction times for triads of three-word sequences, corresponding to idiomatic expressions, compositional phrases, and (...)
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  6.  14
    Azriel Lévy. Comparing the axioms of local and universal choice. Essays on the foundations of mathematics, dedicated to A. A. Fraenkel on his seventieth anniversary, edited by Y. Bar-Hillel, E. I. J. Poznanski, M. O. Rabin, and A. Robinson for The Hebrew University of Jerusalem, Magnes Press, Jerusalem1961, and North-Holland Publishing Company, Amsterdam 1962, pp. 83–90. [REVIEW]A. Hajnal - 1966 - Journal of Symbolic Logic 31 (4):661-662.
  7.  8
    Review: Azriel Levy, Y. Bar-Hillel, E. I. J. Poznanski, M. O. Rabin, A. Robinson, Comparing the Axioms of Local and Universal Choice. [REVIEW]A. Hajnal - 1966 - Journal of Symbolic Logic 31 (4):661-662.
  8.  26
    Richard Montague. Fraenkel's addition to the axioms of Zermelo. Essays on the foundations of mathematics, dedicated to A. A. Fraenkel on his seventieth anniversary, edited by Y. Bar-Hillel, E. I. J. Poznanski, M. O. Rabin, and A. Robinson for The Hebrew University of Jerusalem, Magnes Press, Jerusalem1961, and North-Holland Publishing Company, Amsterdam 1962, pp. 91–114. [REVIEW]A. Hajnal - 1966 - Journal of Symbolic Logic 31 (4):662-662.
  9.  10
    Putnam Hilary. Axioms of class existence. Summaries of talks presented at the Summer Institute for Symbolic Logic, Cornell University, 1957, 2nd edn., Communications Research Division, Institute for Defense Analyses, Princeton, NJ, 1960, pp. 271–274. [REVIEW]A. Hajnal - 1966 - Journal of Symbolic Logic 31 (4):663-663.
  10.  9
    Review: Dana Scott, The Notion of Rank in Set-Theory. [REVIEW]A. Hajnal - 1966 - Journal of Symbolic Logic 31 (4):662-663.
  11.  20
    Scott Dana. The notion of rank in set-theory. Summaries of talks presented at the Summer Institute for Symbolic Logic, Cornell University, 1957, 2nd edn., Communications Research Division, Institute for Defense Analyses, Princeton, NJ, 1960, pp. 267–269. [REVIEW]A. Hajnal - 1966 - Journal of Symbolic Logic 31 (4):662-663.
  12. A logic road from special relativity to general relativity.Hajnal Andréka, Judit X. Madarász, István Németi & Gergely Székely - 2012 - Synthese 186 (3):633 - 649.
    We present a streamlined axiom system of special relativity in first-order logic. From this axiom system we "derive" an axiom system of general relativity in two natural steps. We will also see how the axioms of special relativity transform into those of general relativity. This way we hope to make general relativity more accessible for the non-specialist.
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  13. Modal Languages and Bounded Fragments of Predicate Logic.Hajnal Andréka, István Németi & Johan van Benthem - 1998 - Journal of Philosophical Logic 27 (3):217 - 274.
    What precisely are fragments of classical first-order logic showing “modal” behaviour? Perhaps the most influential answer is that of Gabbay 1981, which identifies them with so-called “finite-variable fragments”, using only some fixed finite number of variables (free or bound). This view-point has been endorsed by many authors (cf. van Benthem 1991). We will investigate these fragments, and find that, illuminating and interesting though they are, they lack the required nice behaviour in our sense. (Several new negative results support this claim.) (...)
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  14.  25
    On a Problem of Erdös and Tarski.W. Hanf, D. Monk, D. Scott & A. Hajnal - 1974 - Journal of Symbolic Logic 39 (2):332-332.
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  15.  89
    Axiomatizing relativistic dynamics without conservation postulates.Hajnal Andréka, Judit Madarász X., István Németi & Gergely Székely - 2008 - Studia Logica 89 (2):163 - 186.
    A part of relativistic dynamics is axiomatized by simple and purely geometrical axioms formulated within first-order logic. A geometrical proof of the formula connecting relativistic and rest masses of bodies is presented, leading up to a geometric explanation of Einstein’s famous E = mc 2. The connection of our geometrical axioms and the usual axioms on the conservation of mass, momentum and four-momentum is also investigated.
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  16.  53
    Mutual definability does not imply definitional equivalence, a simple example.Hajnal Andréka, Judit X. Madarász & István Németi - 2005 - Mathematical Logic Quarterly 51 (6):591-597.
    We give two theories, Th1 and Th2, which are explicitly definable over each other , but are not definitionally equivalent. The languages of the two theories are disjoint.
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  17.  51
    General algebraic logic: A perspective on “what is logic”.Istvan Nemeti & Hajnal Andreka - 1994 - In Dov M. Gabbay (ed.), What is a Logical System? Oxford University Press.
  18.  25
    Complexity of equations valid in algebras of relations part I: Strong non-finitizability.Hajnal Andréka - 1997 - Annals of Pure and Applied Logic 89 (2):149-209.
    We study algebras whose elements are relations, and the operations are natural “manipulations” of relations. This area goes back to 140 years ago to works of De Morgan, Peirce, Schröder . Well known examples of algebras of relations are the varieties RCAn of cylindric algebras of n-ary relations, RPEAn of polyadic equality algebras of n-ary relations, and RRA of binary relations with composition. We prove that any axiomatization, say E, of RCAn has to be very complex in the following sense: (...)
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  19.  38
    On a consistency theorem connected with the generalized continuum problem.András Hajnal - 1956 - Mathematical Logic Quarterly 2 (8-9):131-136.
  20.  22
    On a consistency theorem connected with the generalized continuum problem.András Hajnal - 1956 - Mathematical Logic Quarterly 2 (8‐9):131-136.
  21.  69
    Omitting types for finite variable fragments and complete representations of algebras.Hajnal Andréka, István Németi & Tarek Sayed Ahmed - 2008 - Journal of Symbolic Logic 73 (1):65-89.
    We give a novel application of algebraic logic to first order logic. A new, flexible construction is presented for representable but not completely representable atomic relation and cylindric algebras of dimension n (for finite n > 2) with the additional property that they are one-generated and the set of all n by n atomic matrices forms a cylindric basis. We use this construction to show that the classical Henkin-Orey omitting types theorem fails for the finite variable fragments of first order (...)
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  22.  49
    The lattice of varieties of representable relation algebras.Hajnal Andréka, Steven Givant & István Németi - 1994 - Journal of Symbolic Logic 59 (2):631-661.
    We shall show that certain natural and interesting intervals in the lattice of varieties of representable relation algebras embed the lattice of all subsets of the natural numbers, and therefore must have a very complicated lattice-theoretic structure.
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  23.  18
    Testing Definitional Equivalence of Theories Via Automorphism Groups.Hajnal Andréka, Judit Madarász, István Németi & Gergely Székely - forthcoming - Review of Symbolic Logic:1-22.
    Two first-order logic theories are definitionally equivalent if and only if there is a bijection between their model classes that preserves isomorphisms and ultraproducts (Theorem 2). This is a variant of a prior theorem of van Benthem and Pearce. In Example 2, uncountably many pairs of definitionally inequivalent theories are given such that their model categories are concretely isomorphic via bijections that preserve ultraproducts in the model categories up to isomorphism. Based on these results, we settle several conjectures of Barrett, (...)
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  24. Program verification within and without logic.Hajnal Andreka, Istvan Nemeti & Ildiko Sain - 1979 - Bulletin of the Section of Logic 8 (3):124-128.
    Theorem 1 states a negative result about the classical semantics j= ! of program schemes. Theorem 2 investigates the reason for this. We conclude that Theorem 2 justies the Henkin-type semantics j= for which the opposite of the present Theorem 1 was proved in [1]{[3] and also in a dierent form in part III of [5]. The strongest positive result on j= is Corollary 6 in [3].
     
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  25. Completeness of Floyd logic.Hajnal Andreka & Istvan Nemeti - 1978 - Bulletin of the Section of Logic 7 (3):115-119.
    This is an abstract of our paper \A characterisation of Floyd-provable programs" submitted to Theoretical Computer Science. ! denotes the set of natural numbers. Y =d fyi : i 2 !g is the set of variable symbols. L denotes the set of classical rst order formulas of type t possibly with free variables , where t is the similarity type of arithmetic, i.e. it consists of \+; ; 0; 1" with arities \2; 2; 0; 0".
     
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  26.  68
    Lambek calculus and its relational semantics: Completeness and incompleteness. [REVIEW]Hajnal Andréka & Szabolcs Mikulás - 1994 - Journal of Logic, Language and Information 3 (1):1-37.
    The problem of whether Lambek Calculus is complete with respect to (w.r.t.) relational semantics, has been raised several times, cf. van Benthem (1989a) and van Benthem (1991). In this paper, we show that the answer is in the affirmative. More precisely, we will prove that that version of the Lambek Calculus which does not use the empty sequence is strongly complete w.r.t. those relational Kripke-models where the set of possible worlds,W, is a transitive binary relation, while that version of the (...)
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  27.  35
    Notions of density that imply representability in algebraic logic.Hajnal Andréka, Steven Givant, Szabolcs Mikulás, István Németi & András Simon - 1998 - Annals of Pure and Applied Logic 91 (2-3):93-190.
    Henkin and Tarski proved that an atomic cylindric algebra in which every atom is a rectangle must be representable . This theorem and its analogues for quasi-polyadic algebras with and without equality are formulated in Henkin, Monk and Tarski [13]. We introduce a natural and more general notion of rectangular density that can be applied to arbitrary cylindric and quasi-polyadic algebras, not just atomic ones. We then show that every rectangularly dense cylindric algebra is representable, and we extend this result (...)
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  28.  35
    Nonrepresentable relation algebras from groups.Hajnal Andréka, István Németi & Steven Givant - 2020 - Review of Symbolic Logic 13 (4):861-881.
    A series of nonrepresentable relation algebras is constructed from groups. We use them to prove that there are continuum many subvarieties between the variety of representable relation algebras and the variety of coset relation algebras. We present our main construction in terms of polygroupoids.
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  29.  33
    Complexity of equations valid in algebras of relations part II: Finite axiomatizations.Hajnal Andréka - 1997 - Annals of Pure and Applied Logic 89 (2-3):211-229.
    We study algebras whose elements are relations, and the operations are natural “manipulations” of relations. This area goes back to 140 years ago to works of De Morgan, Peirce, Schröder . Well known examples of algebras of relations are the varieties RCAn of cylindric algebras of n-ary relations, RPEAn of polyadic equality algebras of n-ary relations, and RRA of binary relations with composition. We prove that any axiomatization, say E, of RCAn has to be very complex in the following sense: (...)
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  30.  33
    Binary Relations and Permutation Groups.Hajnal Andréka & Ivo Düntsch - 1995 - Mathematical Logic Quarterly 41 (2):197-216.
    We discuss some new properties of the natural Galois connection among set relation algebras, permutation groups, and first order logic. In particular, we exhibit infinitely many permutational relation algebras without a Galois closed representation, and we also show that every relation algebra on a set with at most six elements is Galois closed and essentially unique. Thus, we obtain the surprising result that on such sets, logic with three variables is as powerful in expression as full first order logic.
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  31.  27
    Two-variable logic has weak, but not strong, Beth definability.Hajnal Andréka & István Németi - 2021 - Journal of Symbolic Logic 86 (2):785-800.
    We prove that the two-variable fragment of first-order logic has the weak Beth definability property. This makes the two-variable fragment a natural logic separating the weak and the strong Beth properties since it does not have the strong Beth definability property.
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  32.  27
    A representation theorem for measurable relation algebras.Steven Givant & Hajnal Andréka - 2018 - Annals of Pure and Applied Logic 169 (11):1117-1189.
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  33. A twist in the geometry of rotating Black holes: Seeking the cause of acausality.Christian Wüthrich, Hajnal Andréka & István Németi - manuscript
    We investigate Kerr–Newman black holes in which a rotating charged ring-shaped singularity induces a region which contains closed timelike curves (CTCs). Contrary to popular belief, it turns out that the time orientation of the CTC is oppo- site to the direction in which the singularity or the ergosphere rotates. In this sense, CTCs “counter-rotate” against the rotating black hole. We have similar results for all spacetimes sufficiently familiar to us in which rotation induces CTCs. This motivates our conjecture that perhaps (...)
     
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  34.  10
    Implicit Mentalizing in Patients With Schizophrenia: A Systematic Review and Meta-Analysis.Timea Csulak, András Hajnal, Szabolcs Kiss, Fanni Dembrovszky, Margit Varjú-Solymár, Zoltán Sipos, Márton Aron Kovács, Márton Herold, Eszter Varga, Péter Hegyi, Tamás Tényi & Róbert Herold - 2022 - Frontiers in Psychology 13.
    IntroductionMentalizing is a key aspect of social cognition. Several researchers assume that mentalization has two systems, an explicit one and an implicit one. In schizophrenia, several studies have confirmed the deficit of explicit mentalizing, but little data are available on non-explicit mentalizing. However, increasing research activity can be detected recently in implicit mentalizing. The aim of this systematic review and meta-analysis is to summarize the existing results of implicit mentalizing in schizophreniaMethodsA systematic search was performed in four major databases: MEDLINE, (...)
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  35.  32
    Groups and algebras of binary relations.Steven Givant & Hajnal Andréka - 2002 - Bulletin of Symbolic Logic 8 (1):38-64.
    In 1941, Tarski published an abstract, finitely axiomatized version of the theory of binary relations, called the theory of relation algebras, He asked whether every model of his abstract theory could be represented as a concrete algebra of binary relations. He and Jonsson obtained some initial, positive results for special classes of abstract relation algebras. But Lyndon showed, in 1950, that in general the answer to Tarski's question is negative. Monk proved later that the answer remains negative even if one (...)
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  36.  24
    On A New Semantics for First-Order Predicate Logic.István Németi, Johan Benthem & Hajnal Andréka - 2017 - Journal of Philosophical Logic 46 (3):259-267.
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  37.  60
    On A New Semantics for First-Order Predicate Logic.István Németi, Johan van Benthem & Hajnal Andréka - 2017 - Journal of Philosophical Logic 46 (3):259-267.
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  38. The Influence of Disclosure and Ethics Education on Perceptions of Financial Conflicts of Interest.Donald F. Sacco, Samuel V. Bruton, Alen Hajnal & Chris J. N. Lustgraaf - 2015 - Science and Engineering Ethics 21 (4):875-894.
    This study explored how disclosure of financial conflicts of interest influences naïve or “lay” individuals’ perceptions of the ethicality of researcher conduct. On a between-subjects basis, participants read ten scenarios in which researchers disclosed or failed to disclose relevant financial conflicts of interest. Participants evaluated the extent to which each vignette represented a FCOI, its possible influence on researcher objectivity, and the ethics of the financial relationship. Participants were then asked if they had completed a college-level ethics course. Results indicated (...)
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  39.  13
    Review: W. Hanf, On a Problem of Erdos and Tarski; D. Monk, D. Scott, Additions to Some Results of Erdos and Tarski; A. Hajnal, Remarks on the Theory of W. P. Hanf. [REVIEW]Jean A. Larson - 1974 - Journal of Symbolic Logic 39 (2):332-332.
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  40.  17
    Hanf W.. On a problem of Erdös and Tarski. Fundamenta mathematicae, vol. 53 no. 3 , pp. 325–334.Monk D. and Scott D.. Additions to some results of Erdös and Tarski. Fundamenta mathematicae, vol. 53 no. 3 , pp. 335–343.Hajnal A.. Remarks on the theory of W. P. Hanf. Fundamenta mathematicae vol. 54 no. 1 , pp. 109–113. [REVIEW]Jean A. Larson - 1974 - Journal of Symbolic Logic 39 (2):332-332.
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  41.  24
    Review: P. Erdos, A. Hajnal, On the Structure of Set-Mappings; P. Erdos, A. Hajnal, Some Remarks Concerning Our Paper "On the Structure of Set-Mappings".-- Non Existence of a two-valued $sigma$-measure for the first uncountable inaccessible cardinal. [REVIEW]W. N. Reinhardt - 1973 - Journal of Symbolic Logic 38 (1):152-153.
  42.  34
    Review: Andras Hajnal, On a Consistency Theorem Connected with the Generalized Continuum Problem; A. Hajnal, On a Consistency Theorem Connected with the Generalized Continuum Problem; Azriel Levy, A Generalization of Godel's Notion of Constructibility. [REVIEW]Thomas Frayne - 1967 - Journal of Symbolic Logic 32 (2):271-272.
  43.  41
    András Hajnal. On a consistency theorem connected with the generalized continuum problem. Zeitschrift für mathematische Logik und Grundlagen der Mathematik, vol. 2 , pp. 131–136. - A. Hajnal. On a consistency theorem connected with the generalized continuum problem. Acta mathematica Academiae Scientiarum Hungaricae, vol. 12 , pp. 321–376. - Azriel Lévy. A generalization of Gödel's notion of constructibility. The journal of symbolic logic, vol. 25 no. 2 , pp. 147–155. [REVIEW]Thomas Frayne - 1967 - Journal of Symbolic Logic 32 (2):271-272.
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  44.  29
    Edwin W. Miller. On a property of families of sets. English with Polish summary. Sprawozdania z posiedzeń Towarzystwa Naukowego Warszawskiego , Class III, vol. 30 , pp. 31–38. - Ben Dushnik and Miller E. W.. Partially ordered sets. American journal of mathematics, vol. 63 , pp. 600–610. - P. Erdős. Some set-theoretical properties of graphs. Revista, Universidad Nacional de Tucumán, Serie A, Matemáticas y física teórica, vol. 3 , pp. 363–367. - G. Fodor. Proof of a conjecture of P. Erdős. Acta scientiarum mathematicarum, vol. 14 no. 4 , pp. 219–227. - P. Erdős and Rado R.. A partition calculus in set theory. Bulletin of the American Mathematical Society, vol. 62 , pp. 427–489. - P. Erdős and Rado R.. Intersection theorems for systems of sets. The journal of the London Mathematical Society, vol. 35 , pp. 85–90. - A. Hajnal. Some results and problems on set theory. Acta mathematica Academiae Scientiarum Hungaricae, vol. 11 , pp. 277–298. - P. Erdős and Hajnal A.. On a property of families. [REVIEW]James E. Baumgartner - 1995 - Journal of Symbolic Logic 60 (2):698-701.
  45.  36
    James E. Baumgartner. Generic graph construction. The journal of symbolic logic, vol. 49 , pp. 234–240. - Matthew Foreman and Richard Laver. Some downwards transfer properties for ℵ2. Advances in mathematics, vol. 67 , pp. 230–238. - Saharon Shelah. Incompactness for chromatic numbers of graphs. A tribute to Paul Erdős, edited by A. Baker, B. Bollobas, and A. Hajnal, Cambridge University Press, Cambridge, New York, and Oakleigh, Victoria, 1990, pp. 361–371. [REVIEW]Péter Komjáth - 2001 - Bulletin of Symbolic Logic 7 (4):539-541.
  46.  29
    Review: James E. Baumgartner, Generic Graph Construction; Matthew Foreman, Richard Laver, Some Downwards Transfer Properties for $mathscr{N}_2$; Saharon Shelah, A. Baker, B. Bollobas, A. Hajnal, Incompactness for Chromatic Numbers of Graphs. [REVIEW]Péter Komjáth - 2001 - Bulletin of Symbolic Logic 7 (4):539-541.
  47.  35
    On a combinatorial principle of Hajnal and komjáth.Dan Velleman - 1986 - Journal of Symbolic Logic 51 (4):1056-1060.
  48.  14
    A Theory of Stationary Trees and the Balanced Baumgartner–Hajnal–Todorcevic Theorem for Trees.Ari Meir Brodsky - 2019 - Bulletin of Symbolic Logic 25 (2):219-219.
  49.  33
    On certain indestructibility of strong cardinals and a question of Hajnal.Moti Gitik & Saharon Shelah - 1989 - Archive for Mathematical Logic 28 (1):35-42.
    A model in which strongness ofκ is indestructible under κ+ -weakly closed forcing notions satisfying the Prikry condition is constructed. This is applied to solve a question of Hajnal on the number of elements of {λ δ |2 δ <λ}.
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  50.  16
    Hajnal Andréka and István Németi on Unity of Science: From Computing to Relativity Theory Through Algebraic Logic.Judit Madarász & Gergely Székely (eds.) - 2021 - Springer.
    This book features more than 20 papers that celebrate the work of Hajnal Andréka and István Németi. It illustrates an interaction between developing and applying mathematical logic. The papers offer new results as well as surveys in areas influenced by these two outstanding researchers. They also provide details on the after-life of some of their initiatives. Computer science connects the papers in the first part of the book. The second part concentrates on algebraic logic. It features a range of (...)
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