Results 31 to 40 of about 153 (86)
A lattice of quasivarieties of nilpotent groups
Algebra and Logic, 1994 Let \(qG\) denote the quasivariety generated by a group \(G\). \textit{A. Fedorov} [VINITI, No. 5489-B87, Moscow (1987)] classified all finite nilpotent groups of class 2 generating quasivarieties which contain only finitely many subquasivarieties, and showed that for any other finite nilpotent group \(H\) of class 2, \(qH\) contains uncountably many ...
A. I. Budkin
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The lattice of quasivarieties of commutative moufang loops
Algebra and Logic, 1998 Previously, the author proved [Algebra Logika 30, No. 6, 726-734 (1991; Zbl 0778.20027)] that a quasivariety generated by a finitely generated commutative Moufang loop \(L\) has a finite basis of quasi-identities if and only if \(L\) is a group. In the article under review, it is proven that the lattice of quasivarieties of an arbitrary variety ...
V. I. Ursu
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Coverings in the lattice of quasivarieties of groups
Siberian Mathematical Journal, 1987 Let P be an infinite set of odd primes and M(P) the quasivariety of groups defined by quasi-identities \([x,y^ i,x]=1\to [x,y^ j,x]=1\) where i,j\(\in P\). Then M(P) has continuum covers in the lattice \(L_ q\) of quasivarieties of groups. There exist continuum quasivarieties of groups Q which have continuum covers in \(L_ q\) and satisfy any of the ...
A. I. Budkin
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Congruence properties of lattices of quasivarieties
Algebra and Logic, 1997 Summary: The congruence properties close to lower boundedness in the sense of McKenzie are treated. In particular, an affirmative answer is obtained to a known question as to whether finite lattices of quasivarieties are lower bounded in the case where quasivarieties are congruence-Noetherian and locally finite.
Adaricheva, K. V. +2 more
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On a cardinality of the lattice of quasivarieties of nilpotent groups
Algebra and Logic, 1999 Given a class \(\mathcal R\) of groups, denote by \(q{\mathcal R}\) the quasivariety generated by this class. Let \(L_{q}(q{\mathcal R})\) be the lattice of quasivarieties contained in \(q{\mathcal R}\). The author computes the cardinality of the lattice of quasivarieties \(L_{q}(q{\mathcal N})\) for every quasivariety \(\mathcal N\) of nilpotent ...
S. A. Shakhova
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On coatoms in lattices of quasivarieties of algebraic systems
algebra universalis, 2001 Let \(qK\) stand for the quasivariety of algebraic systems generated by a class \(K\), let \(L_q(M)\) be the lattice of subquasivarieties contained in a quasivariety \(M\). Coatoms in the lattice \(L_q(M)\) for a finite set \(K\) of finite algebraic systems were studied by \textit{A.\ I.\ Budkin} and \textit{V.\ A.\ Gorbunov} [Algebra Logika 14, 123 ...
A. I. Budkin
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Complexity of quasivariety lattices for varieties of differential groupoids. II
Siberian Advances in Mathematics, 2009 Summary: We continue the study of the lattice of quasivarieties of differential groupoids [for part I see Mat. Tr. 12, No. 1, 26-39 (2009); translation in Sib. Adv. Math. 19, No. 3, 162-171 (2009; Zbl 1249.08012)]. We suggest a method for constructing differential groupoids from graphs.
A. V. Kravchenko
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On the lattice of quasivarieties of Sugihara algebras
Studia Logica, 1986 A Sugihara algebra is any algebra belonging to the variety \({\mathcal S}\) generated by the following algebra: \({\mathfrak S}=(Z,\wedge,\vee,\to,^-)\), where Z is the set of integers with the usual ordering, \(\bar x=-x\) and \(x\to y=\bar x\vee y\) if \(x\leq y\), \(x\to y=\bar x\wedge y\) otherwise.
Blok, W. J., Dziobiak, W.
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The lattice of quasivarieties of metabelian groups
Algebra and Logic, 1996 The author proves that the lattice of quasivarieties contained in the quasivariety of torsion-free groups satisfying the identity \(\forall x\forall y\;([x^2,y^2]=1)\) has the cardinality of the continuum.
S. V. Lenyuk
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Coverings in the lattice of quasivarieties ofl-groups
Algebra and Logic, 1996 We investigate the structure of the lattice of quasivarieties of lattice-ordered groups (l-groups). Series of coverings for certain particular quasivarieties of l-groups are constructed.
N. V. Bayanova
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