Discussiones
Mathematicae General Algebra and Applications 20(2) (2000) 219-231
DOI: https://doi.org/10.7151/dmgaa.1019
CONGRUENCES ON PSEUDOCOMPLEMENTED SEMILATTICES
Zuzana Heleyová
College of Business and Management, Technical
University
Technicka 2, 616 69 Brno, Czech Republic
e-mail:zheleyova@iol.cz
Abstract
It is known that congruence lattices of pseudocomplemented semilattices are pseudocomplemented [4]. Many interesting properties of congruences on pseudocomplemented semilattices were described by Sankappanavar in [4], [5], [6]. Except for other results he described congruence distributive pseudocomplemented semilattices [6] and he characterized pseudocomplemented semilattices whose congruence lattices are Stone, i.e. belong to the variety B1 [5].
In this paper we give a partial solution to a more general question: Under what condition on a pseudocomplemented semilattice its congruence lattice is element of the variety Bn (n > 2)?
In the last section we widen the Sankappanavar's result to obtain the description of pseudocomplemented semilattices with relative Stone congruence lattices. A partial solution of the description of pseudocomplemented semilattices with relative (Ln)-congruence lattices (n > 2) is also given.
Keywords: pseudocomplemented semilattice, congruence lattice, p-algebra, Stone algebra, (relative) (Ln)-lattice.
1991 Mathematics Subject Classification: Primary 06D15, 06A99; Secondary 08A30
References
[1] | G. Grätzer, General Lattice Theory, Birkhäuser-Verlag, Basel 1978. |
[2] | M. Haviar and T. Katrinák, Semi-discrete lattices with (Ln)-congruence lattices, Contribution to General Algebra 7 (1991), 189-195. |
[3] | K.B. Lee, Equational classes of distributive pseudo-complemented lattices, Canad. J. Math. 22 (1970), 881-891. |
[4] | H.P. Sankappanavar, Congruence lattices of pseudocomplemented semilattices, Algebra Universalis 9 (1979), 304-316. |
[5] | H.P. Sankappanavar, On pseudocomplemented semilattices with Stone congruence lattices, Math. Slovaca 29 (1979), 381-395. |
[6] | H.P. Sankappanavar, On pseudocomplemented semilattices whose congruence lattices are distributive, (preprint). |
Received 27 October 1998
Revised 1 October 1999
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