Results 41 to 50 of about 439 (93)

Coverings in the lattice of quasivarieties of ℓ-groups

Siberian Mathematical Journal, 1992
See the review in Zbl 0772.06013.
Isaeva, O. V., Medvedev, N. Ya.
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Finite distributive lattices of quasivarieties

Algebra and Logic, 1983
The paper contains an answer to the question: Is it possible to represent every finite distributive lattice by a lattice of quasivarieties? The answer is: For any distributive lattice L there exists a finitely generated, locally finite quasivariety M of finite type such that the lattice L is isomorphic to the lattice \(L_ q(M)\) of all subvarieties of ...
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Quasivarieties of lattice-ordered groups

1994
An implication of the signature l = {·, -1, e, ∨, ∧} is a formula φ of the predicate calculus of the form $$\left( {\forall {x_1}} \right) \ldots \left( {\forall {x_n}} \right)\left( {{w_1}\left( {{x_1}, \ldots ,{x_n}} \right) = e\& \ldots \& {w_k}\left( {{x_1}, \ldots {x_n}} \right) = e \Rightarrow \Rightarrow {w_{k + 1}}\left( {{x_{1,}} \ldots ...
V. M. Kopytov, N. Ya. Medvedev
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Lattices of quasivarieties of unars

Siberian Mathematical Journal, 1986
Translation from Sib. Mat. Zh. 26, No.3(151), 49-62 (Russian) (1985; Zbl 0569.08005).
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Quasivarieties of orthomodular lattices and Bell inequalities

Reports on Mathematical Physics, 1996
zbMATH Open Web Interface contents unavailable due to conflicting licenses.
D'Andrea, Anna Bruna, Pulmannová, Sylvia   +1 more
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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 ...
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The lattice of quasivarieties of semigroups

Algebra Universalis, 1985
A quasivariety is a class of similar algebras which is closed under the formation of subalgebras, products and ultra-products (equivalently, definable by ''quasi-identities'' or ''implications''). The quasivariety generated by an algebra A is denoted Q(A). The lattice of subquasivarieties of a quasivariety \({\mathcal K}\) is denoted L(\({\mathcal K}).\
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A quasivariety lattice of torsion-free soluble groups

Algebra and Logic, 2011
zbMATH Open Web Interface contents unavailable due to conflicting licenses.
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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 ...
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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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