Results 1 to 10 of about 51 (44)
Finite Lattices Generating Not Finitely–Based and Nonstandard Quasivarieties
There are two well-known and closely related problems in lattice theory: Which finite lattices generate finitely-based quasivarieties? and Which finite lattices generate standard quasivarieties?
M. A. Arapbay +2 more
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Existentially prime Jonsson quasivarieties and their Jonsson spectra [PDF]
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]
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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On categoricity questions for universal unars and undirected graphs under semantic Jonsson quasivariety [PDF]
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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Some non-standard quasivarieties of lattices [PDF]
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 quasi-identities of finite modular lattices. II [PDF]
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
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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The main goal of this paper is to introduce and investigate the related theory on monadic effect algebras. First, we design the axiomatic system of existential quantifiers on effect algebras and then use it to give the definition of the universal quantifier and monadic effect algebras.
Yuxi Zou, Xiaolong Xin, Li Guo
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Categorical Dualities for Some Two Categories of Lattices: An Extended Abstract
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
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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