Hostname: page-component-84b7d79bbc-dwq4g Total loading time: 0 Render date: 2024-07-29T15:25:12.405Z Has data issue: false hasContentIssue false

Congruence intersection properties for varieties of algebras

Published online by Cambridge University Press:  09 April 2009

Paolo Agliano
Affiliation:
Dipartimento di Matematica Via del Capitano 15 53100 Siena Italy e-mail: agliano@unisi.it
Kirby A. Baker
Affiliation:
Department of Mathematics UCLA Los Angeles CA 90095-1555 USA e-mail: baker@math.ucla.edu
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

It is shown that a variety ν has distributive congruence lattices if and only if the intersection of two principal congruence relations is definable by equations involving terms with parameters. The nature of the terms involved then provides a useful classification of congruence distributive varieties. In particular, the classification puts into proper perspective two stronger properties. A variety is said to have the Principal Intersection Property if the intersection of any two principal congruence relations is principal, or the Compact Intersection Property if the intersection of two compact congruence relations is compact. For non-congruence-distributive varieties, it is shown that some useful constuctions are nevertheless possible.

Type
Research Article
Copyright
Copyright © Australian Mathematical Society 1999

References

[1]Adams, M. E. and Priestley, H. A., ‘Equational bases for varieties of Ockham algebras’, Algebra Universalis 32 (1994), 368397.CrossRefGoogle Scholar
[2]Agliano, P. and Baker, K. A., ‘Idempotent discriminators’, Technical report (Univ. of Siena, 1997).Google Scholar
[3]Agliano, P. and Baker, K. A., ‘Two-generated varieties’, Technical report (Univ. of Siena, 1998).Google Scholar
[4]Baker, K. A., ‘Primitive satisfaction and equational problems for lattices and other algebras’, Trans. Amer. Math. Soc. 190 (1974), 125150.CrossRefGoogle Scholar
[5]Baker, K. A., ‘Finite equational bases for finite algebras in a congruence-distributive equational class’, Adv. Math. 24 (1977), 207243.CrossRefGoogle Scholar
[6]Berman, J., ‘Distributive lattices with an additional unary operation’, Aequationes Math. 16 (1977), 165171.CrossRefGoogle Scholar
[7]Blok, W. J., Köhler, P. and Pigozzi, D., ‘On the structure of varieties with equationally definable principal congruences II’, Algebra Universalis 18 (1984), 334379.CrossRefGoogle Scholar
[8]Blok, W. J. and Pigozzi, D., ‘On the structure of varieties with equationally definable principal congruences I’, Algebra Universalis 15 (1982), 195227.CrossRefGoogle Scholar
[9]Blok, W. J. and Pigozzi, D., ‘A finite basis theorem for quasivarities’, Algebra Universalis 13 (1986), 113.CrossRefGoogle Scholar
[10]Blok, W. J. and Pigozzi, D., ‘On the structure of varieties with equationally definable principal congruences III’, Algebra Universalis 32 (1994), 545608.CrossRefGoogle Scholar
[11]Blok, W. J. and Pigozzi, D., ‘On the structure of varieties with equationally definable principal congruences IV’, Algebra Universalis 31 (1994), 135.CrossRefGoogle Scholar
[12]Bulman-Fleming, S. and Werner, H., ‘Equational compactness in quasi-primal varieties’, Algebra Universalis 7 (1977), 3346.CrossRefGoogle Scholar
[13]Burris, S. and Sankappanavar, H. P., A course in universal algebra (Springer, New York, 1981).CrossRefGoogle Scholar
[14]Cornish, W. H., Antimorphic action. Categories of algebraic structures with involutions or antiendomorphisms, R&E Research and Exposition in Mathematics, 12 (Helderman, Berlin, 1986).Google Scholar
[15]Gratzer, G., Universal algebra, second edition (Springer, New York, 1979).CrossRefGoogle Scholar
[16]Magari, R., ‘Varietà a quozienti filtrali’, Ann. Univ. Ferrara. Sez. VII 14 (1969), 520.CrossRefGoogle Scholar
[17]Magari, R., ‘The classification of idealizable varieties’, J. Algebra 26 (1973), 152165.CrossRefGoogle Scholar
[18]McKenzie, R., McNulty, G. and Taylor, W., Algebras, lattices, varieties, vol. I (Wadsworth and Brooks/Cole, Belmont, 1987).Google Scholar