Results for 'transitive modal logics'

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  1.  20
    Best Unifiers in Transitive Modal Logics.Vladimir V. Rybakov - 2011 - Studia Logica 99 (1-3):321-336.
    This paper offers a brief analysis of the unification problem in modal transitive logics related to the logic S4 : S4 itself, K4, Grz and Gödel-Löb provability logic GL . As a result, new, but not the first, algorithms for the construction of ‘best’ unifiers in these logics are being proposed. The proposed algorithms are based on our earlier approach to solve in an algorithmic way the admissibility problem of inference rules for S4 and Grz . (...)
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  2.  10
    A Syntactic Approach to Unification in Transitive Reflexive Modal Logics.Rosalie Iemhoff - 2016 - Notre Dame Journal of Formal Logic 57 (2):233-247.
    This paper contains a proof-theoretic account of unification in transitive reflexive modal logics, which means that the reasoning is syntactic and uses as little semantics as possible. New proofs of theorems on unification types are presented and these results are extended to negationless fragments. In particular, a syntactic proof of Ghilardi’s result that $\mathsf {S4}$ has finitary unification is provided. In this approach the relation between classical valuations, projective unifiers, and admissible rules is clarified.
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  3.  22
    Products of 'Transitive' Modal Logics.David Gabelaia, Agi Kurucz, Frank Wolter & Michael Zakharyaschev - 2005 - Journal of Symbolic Logic 70 (3):993-1021.
    We solve a major open problem concerning algorithmic properties of products of ‘transitivemodal logics by showing that products and commutators of such standard logics as K4, S4, S4.1, K4.3, GL, or Grz are undecidable and do not have the finite model property. More generally, we prove that no Kripke complete extension of the commutator [K4,K4] with product frames of arbitrary finite or infinite depth (with respect to both accessibility relations) can be decidable. In particular, if.
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  4.  6
    Products of ‘TransitiveModal Logics.David Gabelaia, Agi Kurucz, Frank Wolter & Michael Zakharyaschev - 2005 - Journal of Symbolic Logic 70 (3):993-1021.
    We solve a major open problem concerning algorithmic properties of products of ‘transitivemodal logics by showing that products and commutators of such standard logics as K4, S4, S4.1, K4.3, GL, or Grz are undecidable and do not have the finite model property. More generally, we prove that no Kripke complete extension of the commutator [K4,K4] with product frames of arbitrary finite or infinite depth can be decidable. In particular, if.
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  5.  8
    Unifiers in Transitive Modal Logics for Formulas with Coefficients.V. Rybakov - 2013 - Logic Journal of the IGPL 21 (2):205-215.
  6.  7
    Projective Unification in Transitive Modal Logics.Sławomir Kost - 2018 - Logic Journal of the IGPL 26 (5):548-566.
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  7.  38
    A Loop-Free Decision Procedure for Modal Propositional Logics K4, S4 and S.Dorota Leszczyńska-Jasion - 2009 - Journal of Philosophical Logic 38 (2):151 - 177.
    The aim of this paper is to present a loop-free decision procedure for modal propositional logics K4, S4 and S5. We prove that the procedure terminates and that it is sound and complete. The procedure is based on the method of Socratic proofs for modal logics, which is grounded in the logic of questions IEL.
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  8.  4
    Non-Primitive Recursive Decidability of Products of Modal Logics with Expanding Domains.David Gabelaia, Agi Kurucz, Frank Wolter & Michael Zakharyaschev - 2006 - Annals of Pure and Applied Logic 142 (1):245-268.
    We show that—unlike products of ‘transitivemodal logics which are usually undecidable—their ‘expanding domain’ relativisations can be decidable, though not in primitive recursive time. In particular, we prove the decidability and the finite expanding product model property of bimodal logics interpreted in two-dimensional structures where one component—call it the ‘flow of time’—is • a finite linear order or a finite transitive tree and the other is composed of structures like • transitive trees/partial orders/quasi-orders/linear orders (...)
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  9.  4
    Olivier Gasquet and Andreas Herzig.From Classical to Normal Modal Logics - 1996 - In H. Wansing (ed.), Proof Theory of Modal Logic. Kluwer Academic Publishers.
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  10.  51
    Cut-Free Tableau Calculi for Some Propositional Normal Modal Logics.Martin Amerbauer - 1996 - Studia Logica 57 (2-3):359 - 372.
    We give sound and complete tableau and sequent calculi for the prepositional normal modal logics S4.04, K4B and G 0(these logics are the smallest normal modal logics containing K and the schemata A A, A A and A ( A); A A and AA; A A and ((A A) A) A resp.) with the following properties: the calculi for S4.04 and G 0are cut-free and have the interpolation property, the calculus for K4B contains a restricted (...)
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  11.  35
    Modal Logics for Parallelism, Orthogonality, and Affine Geometries.Philippe Balbiani & Valentin Goranko - 2002 - Journal of Applied Non-Classical Logics 12 (3-4):365-397.
    We introduce and study a variety of modal logics of parallelism, orthogonality, and affine geometries, for which we establish several completeness, decidability and complexity results and state a number of related open, and apparently difficult problems. We also demonstrate that lack of the finite model property of modal logics for sufficiently rich affine or projective geometries (incl. the real affine and projective planes) is a rather common phenomenon.
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  12. Post Completeness in Congruential Modal Logics.Peter Fritz - 2016 - In Lev Beklemishev, Stéphane Demri & András Máté (eds.), Advances in Modal Logic, Volume 11. College Publications. pp. 288-301.
    Well-known results due to David Makinson show that there are exactly two Post complete normal modal logics, that in both of them, the modal operator is truth-functional, and that every consistent normal modal logic can be extended to at least one of them. Lloyd Humberstone has recently shown that a natural analog of this result in congruential modal logics fails, by showing that not every congruential modal logic can be extended to one in (...)
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  13. Inconsistency-Adaptive Modal Logics. On How to Cope with Modal Inconsistency.Hans Lycke - 2010 - Logic and Logical Philosophy 19 (1-2):31-61.
    In this paper, I will characterize a new class of inconsistency-adaptive logics, namely inconsistency-adaptive modal logics. These logics cope with inconsistencies in a modal context. More specifically, when faced with inconsistencies, inconsistency-adaptive modal logics avoid explosion, but still allow the derivation of sufficient consequences to adequately explicate the part of human reasoning they are intended for.
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  14.  33
    Swap Structures Semantics for Ivlev-Like Modal Logics.Marcelo E. Coniglio & Ana Claudia Golzio - forthcoming - Soft Computing.
    In 1988, J. Ivlev proposed some (non-normal) modal systems which are semantically characterized by four-valued non-deterministic matrices in the sense of A. Avron and I. Lev. Swap structures are multialgebras (a.k.a. hyperalgebras) of a special kind, which were introduced in 2016 by W. Carnielli and M. Coniglio in order to give a non-deterministic semantical account for several paraconsistent logics known as logics of formal inconsistency, which are not algebraizable by means of the standard techniques. Each swap structure (...)
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  15.  41
    Modular Sequent Calculi for Classical Modal Logics.David R. Gilbert & Paolo Maffezioli - 2015 - Studia Logica 103 (1):175-217.
    This paper develops sequent calculi for several classical modal logics. Utilizing a polymodal translation of the standard modal language, we are able to establish a base system for the minimal classical modal logic E from which we generate extensions in a modular manner. Our systems admit contraction and cut admissibility, and allow a systematic proof-search procedure of formal derivations.
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  16.  23
    Halldén Completeness for Relevant Modal Logics.Takahiro Seki - 2015 - Notre Dame Journal of Formal Logic 56 (2):333-350.
    Halldén completeness closely resembles the relevance property. To prove Halldén completeness in terms of Kripke-style semantics, the van Benthem–Humberstone theorem is often used. In relevant modal logics, the Halldén completeness of Meyer–Fuhrmann logics has been obtained using the van Benthem–Humberstone theorem. However, there remain a number of Halldén-incomplete relevant modal logics. This paper discusses the Halldén completeness of a wider class of relevant modal logics, namely, those with some Sahlqvist axioms.
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  17.  34
    Simplified Kripke Style Semantics for Some Very Weak Modal Logics.Andrzej Pietruszczak - 2009 - Logic and Logical Philosophy 18 (3-4):271-296.
    In the present paper we examine very weak modal logics C1, D1, E1, S0.5◦, S0.5◦+(D), S0.5 and some of their versions which are closed under replacement of tautological equivalents (rte-versions). We give semantics for these logics, formulated by means of Kripke style models of the form , where w is a «distinguished» world, A is a set of worlds which are alternatives to w, and V is a valuation which for formulae and worlds assigns the truth-vales such (...)
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  18.  56
    Actuality, Tableaux, and Two-Dimensional Modal Logics.Fabio Lampert - 2018 - Erkenntnis 83 (3):403-443.
    In this paper we present tableau methods for two-dimensional modal logics. Although models for such logics are well known, proof systems remain rather unexplored as most of their developments have been purely axiomatic. The logics herein considered contain first-order quantifiers with identity, and all the formulas in the language are doubly-indexed in the proof systems, with the upper indices intuitively representing the actual or reference worlds, and the lower indices representing worlds of evaluation—first and second dimensions, (...)
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  19.  17
    Labeled Sequent Calculi for Modal Logics and Implicit Contractions.Pierluigi Minari - 2013 - Archive for Mathematical Logic 52 (7-8):881-907.
    The paper settles an open question concerning Negri-style labeled sequent calculi for modal logics and also, indirectly, other proof systems which make (more or less) explicit use of semantic parameters in the syntax and are thus subsumed by labeled calculi, like Brünnler’s deep sequent calculi, Poggiolesi’s tree-hypersequent calculi and Fitting’s prefixed tableau systems. Specifically, the main result we prove (through a semantic argument) is that labeled calculi for the modal logics K and D remain complete w.r.t. (...)
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  20.  54
    Free-Variable Tableaux for Propositional Modal Logics.Bernhard Beckert & Rajeev GorÉ - 2001 - Studia Logica 69 (1):59-96.
    Free-variable semantic tableaux are a well-established technique for first-order theorem proving where free variables act as a meta-linguistic device for tracking the eigenvariables used during proof search. We present the theoretical foundations to extend this technique to propositional modal logics, including non-trivial rigorous proofs of soundness and completeness, and also present various techniques that improve the efficiency of the basic naive method for such tableaux.
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  21.  29
    Labelled Modal Logics: Quantifiers. [REVIEW]David Basin, Seán Matthews & Luca Viganò - 1998 - Journal of Logic, Language and Information 7 (3):237-263.
    In previous work we gave an approach, based on labelled natural deduction, for formalizing proof systems for a large class of propositional modal logics that includes K, D, T, B, S4, S4.2, KD45, and S5. Here we extend this approach to quantified modal logics, providing formalizations for logics with varying, increasing, decreasing, or constant domains. The result is modular with respect to both properties of the accessibility relation in the Kripke frame and the way domains (...)
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  22.  25
    Reasoning About Minimal Knowledge in Nonmonotonic Modal Logics.Rosati Riccardo - 1999 - Journal of Logic, Language and Information 8 (2):187-203.
    We study the problem of embedding Halpern and Moses's modal logic of minimal knowledge states into two families of modal formalism for nonmonotonic reasoning, McDermott and Doyle's nonmonotonic modal logics and ground nonmonotonic modal logics. First, we prove that Halpern and Moses's logic can be embedded into all ground logics; moreover, the translation employed allows for establishing a lower bound (3p) for the problem of skeptical reasoning in all ground logics. Then, we (...)
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  23.  55
    On the Mosaic Method for Many-Dimensional Modal Logics: A Case Study Combining Tense and Modal Operators. [REVIEW]Carlos Caleiro, Luca Viganò & Marco Volpe - 2013 - Logica Universalis 7 (1):33-69.
    We present an extension of the mosaic method aimed at capturing many-dimensional modal logics. As a proof-of-concept, we define the method for logics arising from the combination of linear tense operators with an “orthogonal” S5-like modality. We show that the existence of a model for a given set of formulas is equivalent to the existence of a suitable set of partial models, called mosaics, and apply the technique not only in obtaining a proof of decidability and a (...)
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  24.  20
    Admissibility of Cut in Congruent Modal Logics.Andrzej Indrzejczak - 2011 - Logic and Logical Philosophy 20 (3):189-203.
    We present a detailed proof of the admissibility of cut in sequent calculus for some congruent modal logics. The result was announced much earlier during the Trends in Logic Conference, Toruń 2006 and the proof for monotonic modal logics was provided already in Indrzejczak [5]. Also some tableau and natural deduction formalizations presented in Indrzejczak [6] and Indrzejczak [7] were based on this result but the proof itself was not published so far. In this paper we (...)
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  25.  36
    Encoding Modal Logics in Logical Frameworks.Arnon Avron, Furio Honsell, Marino Miculan & Cristian Paravano - 1998 - Studia Logica 60 (1):161-208.
    We present and discuss various formalizations of Modal Logics in Logical Frameworks based on Type Theories. We consider both Hilbert- and Natural Deduction-style proof systems for representing both truth (local) and validity (global) consequence relations for various Modal Logics. We introduce several techniques for encoding the structural peculiarities of necessitation rules, in the typed -calculus metalanguage of the Logical Frameworks. These formalizations yield readily proof-editors for Modal Logics when implemented in Proof Development Environments, such (...)
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  26.  12
    The Decision Problem of Modal Product Logics with a Diagonal, and Faulty Counter Machines.C. Hampson, S. Kikot & A. Kurucz - 2016 - Studia Logica 104 (3):455-486.
    In the propositional modal treatment of two-variable first-order logic equality is modelled by a ‘diagonal’ constant, interpreted in square products of universal frames as the identity relation. Here we study the decision problem of products of two arbitrary modal logics equipped with such a diagonal. As the presence or absence of equality in two-variable first-order logic does not influence the complexity of its satisfiability problem, one might expect that adding a diagonal to product logics in general (...)
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  27.  40
    On Combinations of Propositional Dynamic Logic and Doxastic Modal Logics.Renate A. Schmidt & Dmitry Tishkovsky - 2008 - Journal of Logic, Language and Information 17 (1):109-129.
    We prove completeness and decidability results for a family of combinations of propositional dynamic logic and unimodal doxastic logics in which the modalities may interact. The kind of interactions we consider include three forms of commuting axioms, namely, axioms similar to the axiom of perfect recall and the axiom of no learning from temporal logic, and a Church–Rosser axiom. We investigate the influence of the substitution rule on the properties of these logics and propose a new semantics for (...)
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  28.  19
    Note on Extending Congruential Modal Logics.Lloyd Humberstone - 2016 - Notre Dame Journal of Formal Logic 57 (1):95-103.
    It is observed that a consistent congruential modal logic is not guaranteed to have a consistent extension in which the Box operator becomes a truth-functional connective for one of the four one-place truth functions.
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  29.  26
    Hilbert-Style Presentations of Two Logics Associated to Tetravalent Modal Algebras.Marcelo E. Coniglio & Martín Figallo - 2014 - Studia Logica 102 (3):525-539.
    We analyze the variety of A. Monteiro’s tetravalent modal algebras under the perspective of two logic systems naturally associated to it. Taking profit of the contrapositive implication introduced by A. Figallo and P. Landini, sound and complete Hilbert-style calculi for these logics are presented.
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  30.  25
    Modal Extensions of Sub-Classical Logics for Recovering Classical Logic.Marcelo E. Coniglio & Newton M. Peron - 2013 - Logica Universalis 7 (1):71-86.
    In this paper we introduce non-normal modal extensions of the sub-classical logics CLoN, CluN and CLaN, in the same way that S0.5 0 extends classical logic. The first modal system is both paraconsistent and paracomplete, while the second one is paraconsistent and the third is paracomplete. Despite being non-normal, these systems are sound and complete for a suitable Kripke semantics. We also show that these systems are appropriate for interpreting □ as “is provable in classical logic”. This (...)
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  31.  36
    Hierarchies of Modal and Temporal Logics with Reference Pointers.Valentin Goranko - 1996 - Journal of Logic, Language and Information 5 (1):1-24.
    We introduce and study hierarchies of extensions of the propositional modal and temporal languages with pairs of new syntactic devices: point of reference-reference pointer which enable semantic references to be made within a formula. We propose three different but equivalent semantics for the extended languages, discuss and compare their expressiveness. The languages with reference pointers are shown to have great expressive power (especially when their frugal syntax is taken into account), perspicuous semantics, and simple deductive systems. For instance, Kamp's (...)
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  32.  4
    Analyzing Completeness of Axiomatic Functional Systems for Temporal × Modal Logics.Alfredo Burrieza, Inmaculada P. de Guzmán & Emilio Muñoz-Velasco - 2010 - Mathematical Logic Quarterly 56 (1):89-102.
    In previous works, we presented a modification of the usual possible world semantics by introducing an independent temporal structure in each world and using accessibility functions to represent the relation among them. Different properties ofthe accessibility functions have been considered and axiomatic systems which define these properties have been given. Only a few ofthese systems have been proved tobe complete. The aim ofthis paper is to make a progress in the study ofcompleteness for functional systems. For this end, we use (...)
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  33. Polynomial Ring Calculus for Modal Logics: A New Semantics and Proof Method for Modalities: Polynomial Ring Calculus for Modal Logics.Juan C. Agudelo - 2011 - Review of Symbolic Logic 4 (1):150-170.
    A new proof style adequate for modal logics is defined from the polynomial ring calculus. The new semantics not only expresses truth conditions of modal formulas by means of polynomials, but also permits to perform deductions through polynomial handling. This paper also investigates relationships among the PRC here defined, the algebraic semantics for modal logics, equational logics, the Dijkstra???Scholten equational-proof style, and rewriting systems. The method proposed is throughly exemplified for S 5, and can (...)
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  34.  25
    Relational Semantics for Kleene Logic and Action Logic.Katalin Bimbó & J. ~Michael Dunn - 2005 - Notre Dame Journal of Formal Logic 46 (4):461-490.
    Kleene algebras and action logic were proposed to be solutions to the finite axiomatization problem of the algebra of regular sets (of strings). They are treated here as nonclassical logics—with Hilbert-style axiomatizations and semantics. We also provide intuitive accounts in terms of information states of the semantics which provide further insights into the formalisms. The three types of "Kripke-style'' semantics which we define develop insights from gaggle theory, and from our four-valued and generalized Kripke semantics for the minimal substructural (...)
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  35.  11
    Prefinitely Axiomatizable Modal and Intermediate Logics.Marcus Kracht - 1993 - Mathematical Logic Quarterly 39 (1):301-322.
    A logic Λ bounds a property P if all proper extensions of Λ have P while Λ itself does not. We construct logics bounding finite axiomatizability and logics bounding finite model property in the lattice of intermediate logics and in the lattice of normal extensions of K4.3. MSC: 03B45, 03B55.
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  36.  61
    Completeness and Decidability Results for Some Propositional Modal Logics Containing “Actually” Operators.Dominic Gregory - 2001 - Journal of Philosophical Logic 30 (1):57-78.
    The addition of "actually" operators to modal languages allows us to capture important inferential behaviours which cannot be adequately captured in logics formulated in simpler languages. Previous work on modal logics containing "actually" operators has concentrated entirely upon extensions of KT5 and has employed a particular modeltheoretic treatment of them. This paper proves completeness and decidability results for a range of normal and nonnormal but quasi-normal propositional modal logics containing "actually" operators, the weakest of (...)
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  37.  39
    Strongly Millian Second-Order Modal Logics.Bruno Jacinto - 2017 - Review of Symbolic Logic (3):1-58.
    The most common first- and second-order modal logics either have as theorems every instance of the Barcan and Converse Barcan formulae and of their second-order analogues, or else fail to capture the actual truth of every theorem of classical first- and second-order logic. In this paper we characterise and motivate sound and complete first- and second-order modal logics that successfully capture the actual truth of every theorem of classical first- and second-order logic and yet do not (...)
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  38.  21
    Some Metacomplete Relevant Modal Logics.Takahiro Seki - 2013 - Studia Logica 101 (5):1115-1141.
    A logic is called metacomplete if formulas that are true in a certain preferred interpretation of that logic are theorems in its metalogic. In the area of relevant logics, metacompleteness is used to prove primeness, consistency, the admissibility of γ and so on. This paper discusses metacompleteness and its applications to a wider class of modal logics based on contractionless relevant logics and their neighbours using Slaney’s metavaluational technique.
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  39.  18
    Denumerably Many Post-Complete Normal Modal Logics with Propositional Constants.Rohan French - 2012 - Notre Dame Journal of Formal Logic 53 (4):549-556.
    We show that there are denumerably many Post-complete normal modal logics in the language which includes an additional propositional constant. This contrasts with the case when there is no such constant present, for which it is well known that there are only two such logics.
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  40.  6
    The Lattice of Belnapian Modal Logics: Special Extensions and Counterparts.Sergei P. Odintsov & Stanislav O. Speranski - 2016 - Logic and Logical Philosophy 25 (1):3-33.
    Let K be the least normal modal logic and BK its Belnapian version, which enriches K with ‘strong negation’. We carry out a systematic study of the lattice of logics containing BK based on: • introducing the classes of so-called explosive, complete and classical Belnapian modal logics; • assigning to every normal modal logic three special conservative extensions in these classes; • associating with every Belnapian modal logic its explosive, complete and classical counterparts. We (...)
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  41.  9
    Hybrid Formulas and Elementarily Generated Modal Logics.Ian Hodkinson - 2006 - Notre Dame Journal of Formal Logic 47 (4):443-478.
    We characterize the modal logics of elementary classes of Kripke frames as precisely those modal logics that are axiomatized by modal axioms synthesized in a certain effective way from "quasi-positive" sentences of hybrid logic. These are pure positive hybrid sentences with arbitrary existential and relativized universal quantification over nominals. The proof has three steps. The first step is to use the known result that the modal logic of any elementary class of Kripke frames is (...)
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  42.  23
    BK-Lattices. Algebraic Semantics for Belnapian Modal Logics.Sergei P. Odintsov & E. I. Latkin - 2012 - Studia Logica 100 (1-2):319-338.
    Earlier algebraic semantics for Belnapian modal logics were defined in terms of twist-structures over modal algebras. In this paper we introduce the class of BK -lattices, show that this class coincides with the abstract closure of the class of twist-structures, and it forms a variety. We prove that the lattice of subvarieties of the variety of BK -lattices is dually isomorphic to the lattice of extensions of Belnapian modal logic BK . Finally, we describe invariants determining (...)
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  43.  32
    General Frames for Relevant Modal Logics.Takahiro Seki - 2003 - Notre Dame Journal of Formal Logic 44 (2):93-109.
    General frames are often used in classical modal logic. Since they are duals of modal algebras, completeness follows automatically as with algebras but the intuitiveness of Kripke frames is also retained. This paper develops basics of general frames for relevant modal logics by showing that they share many important properties with general frames for classical modal logic.
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  44.  18
    An Algebraic Proof of the Admissibility of Γ in Relevant Modal Logics.Takahiro Seki - 2012 - Studia Logica 100 (6):1149-1174.
    The admissibility of Ackermann's rule γ is one of the most important problems in relevant logics. The admissibility of γ was first proved by an algebraic method. However, the development of Routley-Meyer semantics and metavaluational techniques makes it possible to prove the admissibility of γ using the method of normal models or the method using metavaluations, and the use of such methods is preferred. This paper discusses an algebraic proof of the admissibility of γ in relevant modal (...) based on modern algebraic models. (shrink)
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  45.  22
    Proving Unprovability in Some Normal Modal Logics.Valentin Goranko - 1991 - Bulletin of the Section of Logic 20 (1):23-29.
    This note considers deductive systems for the operator a of unprovability in some particular propositional normal modal logics. We give thus complete syntactic characterization of these logics in the sense of Lukasiewicz: for every formula  either `  or a  (but not both) is derivable. In particular, purely syntactic decision procedure is provided for the logics under considerations.
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  46.  17
    Inessential Features, Ineliminable Features, and Modal Logics for Model Theoretic Syntax.Hans-Jörg Tiede - 2008 - Journal of Logic, Language and Information 17 (2):217-227.
    While monadic second-order logic (MSO) has played a prominent role in model theoretic syntax, modal logics have been used in this context since its inception. When comparing propositional dynamic logic (PDL) to MSO over trees, Kracht (1997) noted that there are tree languages that can be defined in MSO that can only be defined in PDL by adding new features whose distribution is predictable. He named such features “inessential features”. We show that Kracht’s observation can be extended to (...)
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  47.  55
    Toward Model-Theoretic Modal Logics.Minghui Ma - 2010 - Frontiers of Philosophy in China 5 (2):294-311.
    Adding certain cardinality quantifiers into first-order language will give substantially more expressive languages. Thus, many mathematical concepts beyond first-order logic can be handled. Since basic modal logic can be seen as the bisimular invariant fragment of first-order logic on the level of models, it has no ability to handle modally these mathematical concepts beyond first-order logic. By adding modalities regarding the cardinalities of successor states, we can, in principle, investigate modal logics of all cardinalities. Thus ways of (...)
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    A Unified Semantics for a Family of Modal Logics with Propositional Constants.Matteo Pascucci - 2016 - Logica Universalis 10 (1):45-66.
    This article concerns the metatheory of a class of modal logics whose language includes propositional constants of various kinds. The main novelties are the use of general frames with specific restrictions and the definition of the strict range of a formula. Many examples from the literature are treated within the framework provided and some traditional model-theoretic issues such as preservation results concerning the validity of formulas and definability results concerning frame properties are addressed.
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    Automorphisms of the Lattice of Classical Modal Logics.Adrian Soncodi - 2016 - Studia Logica 104 (2):249-276.
    In this paper we analyze the propositional extensions of the minimal classical modal logic system E, which form a lattice denoted as CExtE. Our method of analysis uses algebraic calculations with canonical forms, which are a generalization of the normal forms applicable to normal modal logics. As an application, we identify a group of automorphisms of CExtE that is isomorphic to the symmetric group S4.
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    Predicate Modal Logics Do Not Mix Very Well.Olivier Gasquet - 1998 - Mathematical Logic Quarterly 44 (1):45-49.
    The problem of completeness for predicate modal logics is still under investigation, although some results have been obtained in the last few years . As far as we know, the case of multimodal logics has not been addressed at all. In this paper, we study the combination of modal logics in terms of combining their semantics. We demonstrate by a simple example that in this sense predicate modal logics are not so easily manipulated (...)
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