Abstract
The system of all congruences of an algebra (A, F) forms a lattice, denoted \({{\,\mathrm{Con}\,}}(A, F)\). Further, the system of all congruence lattices of all algebras with the base set A forms a lattice \(\mathcal {E}_A\). We deal with meet-irreducibility in \(\mathcal {E}_A\) for a given finite set A. All meet-irreducible elements of \(\mathcal {E}_A\) are congruence lattices of monounary algebras. Some types of meet-irreducible congruence lattices were already described. In the case when a monounary algebra (A, f) is connected, we prove necessary and sufficient condition under which \({{\,\mathrm{Con}\,}}(A, f)\) is \(\wedge \)-irreducible.
Similar content being viewed by others
References
Aichinger, E.: Congruence lattices forcing nilpotency. J. Algebra Appl. 17(2), 1850033 (2018)
Badawy, A.: Characterization of congruence lattices of principal p-algebras. Math. Slovaca. 67(3), 803–810 (2017)
Berman, J.: On the congruence lattice of unary algebras. Proc. Am. Math. Soc. 36, 34–38 (1972)
Czédli, G.: Lattices with many congruences are planar. Algebra Univ. 80(1), 16 (2019)
Hyndman, J., Nation, J.B., Nishida, J.: Congruence lattices of semilattices with operators. Stud. Log. 104(2), 305–316 (2016)
Jakubíková-Studenovská, D., Janičková, L.: Meet-irreducible congruence lattices. Algebra Univ. 79, 4 (2018)
Jakubíková-Studenovská, D., Pöschel, R., Radeleczki, S.: The lattice of congruence lattices of algebra on a finite set. Algebra Univ. 79(2), 4 (2018)
Jakubíková-Studenovská, D., Pócs, J.: Monounary Algebras. P.J. Šafárik Univ. Košice, Košice (2009)
Roman, S.: Lattices and Ordered Sets. Springer, New York (2008)
Veldsman, S.: Congruences on topological spaces with an application to radical theory. Algebra Univ. 80(2), 25 (2019)
Author information
Authors and Affiliations
Corresponding author
Additional information
Presented by R. Pöschel.
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
This work was supported by Grant VEGA 1/0097/18.
Rights and permissions
About this article
Cite this article
Jakubíková-Studenovská, D., Janičková, L. Congruence lattices of connected monounary algebras. Algebra Univers. 81, 54 (2020). https://doi.org/10.1007/s00012-020-00686-2
Received:
Accepted:
Published:
DOI: https://doi.org/10.1007/s00012-020-00686-2