Results 1 to 10 of about 470 (76)
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 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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Lattices of quasi-equational theories as congruence lattices of semilattices with operators, Part I [PDF]
, 2012 We show that for every quasivariety K of structures (where both functions and relations are allowed) there is a semilattice S with operators such that the lattice of quasi-equational theories of K (the dual of the lattice of sub-quasivarieties of K) is ...
Adaricheva K. V. +6 more
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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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Singly generated quasivarieties and residuated structures [PDF]
, 2019 A quasivariety K of algebras has the joint embedding property (JEP) iff it is generated by a single algebra A. It is structurally complete iff the free countably generated algebra in K can serve as A.
Anderson A. R. +25 more
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Admissibility in Finitely Generated Quasivarieties [PDF]
, 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 ...
Metcalfe, George +1 more
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Admissibility via Natural Dualities [PDF]
, 2015 It is shown that admissible clauses and quasi-identities of quasivarieties generated by a single finite algebra, or equivalently, the quasiequational and universal theories of their free algebras on countably infinitely many generators, may be ...
Cabrer, Leonardo Manuel +1 more
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Radicals of 0-regular algebras [PDF]
, 2006 We consider a generalisation of the Kurosh--Amitsur radical theory for rings (and more generally multi-operator groups) which applies to 0-regular varieties in which all operations preserve 0.
McConnell, N. R., Stokes, Tim E.
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