Coverings in the lattice of quasivarieties of ℓ-groups

2000 ◽  
Vol 41 (2) ◽  
pp. 276-280
Author(s):  
O. V. Isaeva ◽  
N. Ya. Medvedev
Keyword(s):  
Lattice Of Quasivarieties

A Lattice of Quasivarieties of Normal Cryptogroups

2007 ◽  
Vol 75 (1) ◽  
pp. 45-69 ◽  
Author(s):  
Mario Petrich
Keyword(s):  
Lattice Of Quasivarieties

On a cardinality of the lattice of quasivarieties of nilpotent groups

1999 ◽  
Vol 38 (3) ◽  
pp. 202-206 ◽  
Author(s):  
S. A. Shakhova
Keyword(s):  
Nilpotent Groups ◽  
Lattice Of Quasivarieties

ON FILTERS IN THE LATTICE OF QUASIVARIETIES OF GROUPS

1989 ◽  
Vol 33 (1) ◽  
pp. 201-207 ◽  
Author(s):  
A I Budkin
Keyword(s):  
Lattice Of Quasivarieties

Coverings in the lattice of quasivarieties of groups

1987 ◽  
Vol 27 (3) ◽  
pp. 327-332
Author(s):  
A. I. Budkin
Keyword(s):  
Lattice Of Quasivarieties

On atoms in the lattice of quasivarieties

1987 ◽  
Vol 24 (1-2) ◽  
pp. 32-35 ◽  
Author(s):  
Wles?aw Dziobiak
Keyword(s):  
Lattice Of Quasivarieties

UNREASONABLE LATTICES OF QUASIVARIETIES

2012 ◽  
Vol 22 (03) ◽  
pp. 1250006 ◽  
Author(s):  
A. M. NURAKUNOV
Keyword(s):  
Complete Lattice ◽  
Finite Lattice ◽  
Algebraic Structures ◽  
Universal Horn Class ◽  
Constant Operation ◽  
Quasivariety Lattice ◽  
Lattice Of Quasivarieties

A quasivariety is a universal Horn class of algebraic structures containing the trivial structure. The set [Formula: see text] of all subquasivarieties of a quasivariety [Formula: see text] forms a complete lattice under inclusion. A lattice isomorphic to [Formula: see text] for some quasivariety [Formula: see text] is called a lattice of quasivarieties or a quasivariety lattice. The Birkhoff–Maltsev Problem asks which lattices are isomorphic to lattices of quasivarieties. A lattice L is called unreasonable if the set of all finite sublattices of L is not computable, that is, there is no algorithm for deciding whether a finite lattice is a sublattice of L. The main result of this paper states that for any signature σ containing at least one non-constant operation, there is a quasivariety [Formula: see text] of signature σ such that the quasivariety lattice [Formula: see text] is unreasonable. Moreover, there are uncountable unreasonable lattices of quasivarieties. We also present some corollaries of the main result.

The lattice of quasivarieties of lattices

1979 ◽  
Vol 9 (1) ◽  
pp. 102-115 ◽  
Author(s):  
G. Grätzer ◽  
H. Lakser
Keyword(s):  
Lattice Of Quasivarieties

The lattice of quasivarieties of undirected graphs

2002 ◽  
Vol 47 (1) ◽  
pp. 7-11 ◽  
Author(s):  
M. E. Adams ◽  
W. Dziobiak
Keyword(s):  
Undirected Graphs ◽  
Lattice Of Quasivarieties

A lattice of quasivarieties of nilpotent groups

1994 ◽  
Vol 33 (1) ◽  
pp. 14-21 ◽  
Author(s):  
A. I. Budkin
Keyword(s):  
Nilpotent Groups ◽  
Lattice Of Quasivarieties

The lattice of quasivarieties of semigroups

1985 ◽  
Vol 21 (2-3) ◽  
pp. 172-180 ◽  
Author(s):  
M. V. Sapir
Keyword(s):  
Lattice Of Quasivarieties
Sign in / Sign up

Export Citation Format

Share Document