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Finite Semilattices with Many Congruences

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Abstract

For an integer n ≥ 2, let NCSL(n) denote the set of sizes of congruence lattices of n-element semilattices. We find the four largest numbers belonging to NCSL(n), provided that n is large enough to ensure that |NCSL(n)|≥ 4. Furthermore, we describe the n-element semilattices witnessing these numbers.

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Acknowledgments

This research was supported by the Hungarian Research Grant KH 126581

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  1. Bolyai Institute, University of Szeged, Szeged, 6720, Hungary

    Gábor Czédli

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  1. Gábor Czédli
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Correspondence to Gábor Czédli.

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Czédli, G. Finite Semilattices with Many Congruences. Order 36, 233–247 (2019). https://doi.org/10.1007/s11083-018-9464-5

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  • DOI: https://doi.org/10.1007/s11083-018-9464-5

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