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On Kripke completeness of some modal predicate logics with the density axiom
P. 559–575.
We prove completeness for some normal modal predicate logics in the standard Kripke semantics with expanding domains. We consider quantified versions of propositional logics with the axiom of density plus some others (transitivity, confluence). The method of proof modifies the technique developed for other cases
(without density) by S. Ghilardi, G. Corsi and D. Skvorstov; but now we arrange the whole construction in a game-theoretic style.
Rybakov M., Shkatov D., Journal of Logic and Computation 2026 Vol. 36 No. 6 Article exag026
We prove Pi-1-1-hardness, and thus lack of recursive axiomatizability, of constant-domain modal predicate logics defined by a class of Dedekind complete linear Kripke frames containing a frame with an infinitely increasing chain of worlds. The result holds even for the language with one unary predicate letter, one propositional letter, and two individual variables. ...
Added: September 1, 2026
Onoprienko A., Математические заметки 2026 Т. 120 № 1 С. 118–139
This paper considers the intuitionistic epistemic logics IEL−, IEL, and IEL+, introduced by S. Artyomov and T. Protopopescu. A translation of the formulas of these logics into the formulas of the classical bimodal logic S4V−M, S4VM, S4V+M, and S4V+MU is constructed. This translation is a generalization of Gödel's translation of intuitionistic logic into S4 logic. ...
Added: June 22, 2026
Rybakov M., / Series arXiv "math". 2025. No. 2505.00524.
The paper considers algorithmic properties of classical and non-classical first-order logics and theories in bounded languages. The main idea is to prove the undecidability of various fragments of classical and non-classical first-order logics and theories indirectly — by extracting it as a consequence of the recursive inseparability of special problems associated with them. First, we ...
Added: May 21, 2025
Onoprienko A., Алгебра и логика 2022 Т. 61 № 6 С. 720–741
The joint logic of problems and propositions QHC introduced by S. A. Melikhov, as well as intuitionistic modal logic QH4, is studied. An immersion of these logics into classical first-order predicate logic is considered. An analog of the Lowenheim-Skolem theorem on the existence of countable elementary submodels for QHC and QH4 is established. ...
Added: November 4, 2023
Agadzhanian I., Rybakov M., Shkatov D., , in: SCAN 2023 Semantical and Computational Aspects of Non-Classical Logics: Moscow + Online, June 13–17, 2023. Abstracts.: M.: ., 2023. P. 13–17.
Added: July 7, 2023
Predicate counterparts of modal logics of provability: High undecidability and Kripke incompleteness
Rybakov M., Logic Journal of the IGPL 2024 Vol. 32 No. 3 P. 465–492
In this paper, the predicate counterparts, defined both axiomatically and semantically by means of Kripke frames, of the modal propositional logics GL, Grz, wGrz and their extensions are considered. It is proved that the set of semantical consequences on Kripke frames of every logic between QwGrz and QGL.3 or between QwGrz and QGrz.3 is Pi-1-1-hard even in languages with ...
Added: July 7, 2023
Valentin Shehtman, Annals of Pure and Applied Logic 2023 Vol. 174 No. 2 Article 103202
The paper studies completeness and incompleteness of modal predicate logics in
Kripke semantics, especially for logics of the form QL, minimal predicate extensions
of modal propositional logics. We show that QL is incomplete for a continual family
of logics above K + \Box(\Box p \rigtharrow p), in particular for well-known K5 and K45. On
the other hand, in some cases ...
Added: January 30, 2023
Shishov K., Логико-философские штудии 2018 Т. 16 № 1-2 С. 137–139
В работе [1] представляется алгебраическая структура QMV-алгебры, которая, опираясь на идеи и результаты [2], характеризуется в качестве обобщения для многозначных алгебр. В качестве множества-носителя этого класса структур выступает частично-упорядоченное множество всех эффектов, в действительном интервале [0,1], где под эффектом понима- ется ограниченный линейный оператор в гильбертовом пространстве. Используя метод, предложенный в [3], предполагается существование реляционной ...
Added: March 22, 2021
Onoprienko A., Математический сборник 2020 Т. 211 № 5 С. 98–125
In this paper we study the propositional fragment of the joint logic of problems and propositions HC introduced by Melikhov. We provide Kripke semantics for this logic and show that HC is complete with respect to those models and has the finite model property. We consider examples of the HC-models usage. In particular, we prove ...
Added: October 20, 2020
Rybakov M., Shkatov D., Journal of Logic and Computation 2020 Vol. 30 No. 7 P. 1305–1329
We study the effect of restricting the number of individual variables, as well as the number and arity of predicate letters, in languages of first-order predicate modal logics of finite Kripke frames on the logics’ algorithmic properties. A finite frame is a frame with a finite set of possible worlds. The languages we consider have ...
Added: August 27, 2020
Rybakov M., Котикова Е. А., Logical Investigations 2015 Vol. 21 No. 1 P. 86–99
For an infinite class of calculi containing CTL and QCL, it is proved that they are Kripke incomplete. ...
Added: July 20, 2020
Rybakov M., Shkatov D., Journal of Logic and Computation 2020 Vol. 30 No. 2 P. 549–560
We investigate the relationship between recursive enumerability and elementary frame definability in first-order predicate modal logic. On the one hand, it is wellknown that every first-order predicate modal logic complete with respect to an elementary class of Kripke frames, i.e., a class of frames definable by a classical first-order formula, is recursively enumerable. On the ...
Added: October 25, 2019
Rybakov M., Shkatov D., , in: Десятые Смирновские чтения: материалы Междунар. науч. конф., Москва, 15–17 июня 2017 г.: М.: Современные тетради, 2017. P. 45–45.
We discuss an example of recursively-enumerable Kripke-complete first-order modal logics that are not Kripke complete with respect to a first-order definable class of frames. ...
Added: October 7, 2019
Rybakov M., Shkatov D., , in: Advances in Modal LogicVol. 12.: College Publications, 2018. P. 531–539.
It is well-known that every quanti ed modal logic complete with respect to a first-order defi nable class of Kripke frames is recursively enumerable. Numerous examples are also known of natural quanti ed modal logics complete with respect to a class of frames de ned by an essentially second-order condition which are not recursively enumerable. It is not, however, known if these ...
Added: October 6, 2019
Shapirovsky I., Zolin E., , in: 7th International Conference on Topology, Algebra and Categories in Logic (TACL 2015).: [б.и.], 2015. P. 1–3.
We give a sufficient condition for Kripke completeness of the extension of a modal logic with the transitive closure modality. More precisely, we show that if a logic is canonical and admits what we call definable filtration (ADF), then such an extension is complete (and again ADF). ...
Added: June 14, 2018
Kikot S., Shapirovsky I., Zolin E., , in: Advances in Modal Logic. Volume 10.: College Publications, 2014. P. 333–352.
Filtration is a standard tool for establishing the finite model property of modal logics. We consider logics and classes of frames that admit filtration, and identify some operations on them that preserve this property. In particular, the operation of adding the inverse or the transitive closure of a relation is shown to be safe in ...
Added: June 14, 2018
Zolin E., Logic Journal of the IGPL 2015 Vol. 23 No. 6 P. 861–880
The celebrated theorem proved by Goldblatt and Thomason in 1974 gives necessary and sufficient conditions for an elementary class of Kripke frames to be modally definable. Here we obtain a local analogue of this result, which deals with modal definability of classes of pointed frames. Furthermore, we generalize it to the case of n-frames, which ...
Added: June 14, 2018
Zolin E., Journal of Logic and Computation 2017 Vol. 27 No. 5 P. 1399–1420
We extend the language of the modal logic K4 of transitive frames with two sorts of modalities. In addition to the usual possibility modality (which means that a formula holds in some successor of a given point), we consider graded modalities (a formula holds in at least n successors) and converse graded modalities (aformula holds ...
Added: June 14, 2018
Shehtman V. B., , in: Advances in Modal Logic, Volume 10.: College Publications, 2014. P. 498–512.
The paper deals with a special type of filtration in modal logic called "canonical". This filtration has been known since the 1970s, but was used only occasionally. Applying it in a systematic way allows us to prove new results on finite model property (and in some cases --- local tabularity) for different polymodal logics. ...
Added: September 18, 2015