Results 1 to 10 of about 95 (81)

Finite Lattices Generating Not Finitely–Based and Nonstandard Quasivarieties

Journal of Mathematics
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, A. O. Basheyeva, S. M. Lutsak   +2 more
doaj   +2 more sources

Admissibility in Finitely Generated Quasivarieties [PDF]

Logical Methods in Computer Science, 2013
Checking the admissibility of quasiequations in a finitely generated (i.e., generated by a finite set of finite algebras) quasivariety Q amounts to checking validity in a suitable finite free algebra of the quasivariety, and is therefore decidable ...
George Metcalfe, Christoph Röthlisberger   +1 more
doaj   +3 more sources

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, I.O. Tungushbayeva, S.M. Amanbekov   +2 more
doaj   +3 more sources

On Jonsson varieties and quasivarieties [PDF]

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.
A.R. Yeshkeyev
doaj   +3 more sources

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, A.O. Basheyeva, A.M. Asanbekov, O.A. Voronina   +3 more
doaj   +3 more sources

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. So, there is a finite lattice that does not have a finite quasi-identity basis
A.O. Basheyeva, S.M. Lutsak
doaj   +3 more sources

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, A.R. Yarullina, S.M. Amanbekov   +2 more
doaj   +2 more sources

Localizations of varieties and quasivarieties

Journal of Pure and Applied Algebra, 2000
It is well known that varieties (= monadic categories over sets) are nothing but exact categories having a regular projective regular generator with copowers. It is also well known that quasivarieties (= regular epireflective full subcategories of varieties) are nothing but regular categories having coequalizers of equivalence relations and a regular ...
PEDICCHIO, MARIA CRISTINA, J. ROSICKY
exaly   +3 more sources

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., Nurakunov, A. M., Schwidefsky, M. V.   +2 more
openaire   +2 more sources

Monadic Effect Algebras

Journal of Mathematics, Volume 2022, Issue 1, 2022., 2022
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
wiley   +1 more source