Results 1 to 10 of about 74 (69)
Existentially prime Jonsson quasivarieties and their Jonsson spectra [PDF]
Қарағанды университетінің хабаршысы. Математика сериясы, 2022 This article is devoted to the study of Jonsson quasivarieties in a signature enriched with new predicate and constant symbols. New concepts of semantic Jonsson quasivariety and fragment-conservativeness of the center of the Jonsson theory are ...
A. R. Yeshkeyev +2 more
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On Robinson spectrum of the semantic Jonsson quasivariety of unars [PDF]
Қарағанды университетінің хабаршысы. Математика сериясы, 2023 Given article is devoted to the study of semantic Jonsson quasivariety of universal unars of signature containing only unary functional symbol. The first section of the article consists of basic necessary concepts. There were defined new notions
A.R. Yeshkeyev +3 more
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Some non-standard quasivarieties of lattices [PDF]
Қарағанды университетінің хабаршысы. Математика сериясы, 2023 The questions of the standardness of quasivarieties have been investigated by many authors. The problem "Which finite lattices generate a standard topological prevariety?" was suggested by D.M. Clark, B.A. Davey, M.G. Jackson and J.G.
S.M. Lutsak +3 more
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On categoricity questions for universal unars and undirected graphs under semantic Jonsson quasivariety [PDF]
Қарағанды университетінің хабаршысы. Математика сериясы, 2023 The article is devoted to the study of semantic Jonsson quasivarieties of universal unars and undirected graphs. The first section of the article consists of basic necessary concepts from Jonsson model theory.
A.R. Yeshkeyev +2 more
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On quasi-identities of finite modular lattices. II [PDF]
Қарағанды университетінің хабаршысы. Математика сериясы, 2023 The existence of a finite identity basis for any finite lattice was established by R. McKenzie in 1970, but the analogous statement for quasi-identities is incorrect.
A.O. Basheyeva, S.M. Lutsak
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On quasi-identities of finite modular lattices
Вестник КазНУ. Серия математика, механика, информатика, 2022 In 1970 R. McKenzie proved that any finite lattice has a finite basis of identities. However the similar result for quasi-identities is not true. That is there is a finite lattice that has no finite basis of quasi-identities.
S. Lutsak, O. Voronina, G. Nurakhmetova
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Structure of Quasivariety Lattices. IV. Nonstandard Quasivarieties
Siberian Mathematical Journal, 2021 Let \(\sigma\) be a finite signature and let \(\mathcal M\) be a quasivariety of signature \(\sigma\). According to Definition 4 of the paper, a class \(\mathcal A=\{\mathbb A_X\;|\;X\in {\mathcal P}_{\textrm{fin}}(\omega)\}\subseteq {\mathcal M}\) of finite \(\sigma\)-structures is called a \textit{finite \(B\)-class} with respect to \(\mathcal M\) if
Kravchenko, A. V. +2 more
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Acta Scientiarum Mathematicarum, 2020 15 ...
Lehtonen, Erkko, Pöschel, Reinhard
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Categorical Dualities for Some Two Categories of Lattices: An Extended Abstract
Bulletin of the Section of Logic, 2022 The categorical dualities presented are: (first) for the category of bi-algebraic lattices that belong to the variety generated by the smallest non-modular lattice with complete (0,1)-lattice homomorphisms as morphisms, and (second) for the category of ...
Wiesław Dziobiak, Marina Schwidefsky
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On Jonsson varieties and quasivarieties
Қарағанды университетінің хабаршысы. Математика сериясы, 2021 In this paper, new objects of research are identified, both from the standpoint of model theory and from the standpoint of universal algebra. Particularly, the Jonsson spectra of the Jonsson varieties and the Jonsson quasivarieties are considered. Basic
A.R. Yeshkeyev
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