%0 Journal Article
%@ 2064-8316
%A  Ahmed Delbrin
%A  Czédli Gábor
%C Szeged
%D 2021
%F acta:75848
%J Acta scientiarum mathematicarum
%K Matematika, Algebra
%N 3-4
%P 415-427
%T (1 + 1 + 2)-generated lattices of quasiorders
%U http://acta.bibl.u-szeged.hu/75848/
%V 87
%X A lattice is (1 + 1 + 2)-generated if it has a four-element generating set such that exactly two of the four generators are comparable. We prove that the lattice Quo(n) of all quasiorders (also known as preorders) of an n-element set is (1 + 1 + 2)-generated for n = 3 (trivially), n = 6 (when Quo(6) consists of 209 527 elements), n = 11, and for every natural number n ≥ 13. In 2017, the second author and J. Kulin proved that Quo(n) is (1 + 1 + 2)-generated if either n is odd and at least 13 or n is even and at least 56. Compared to the 2017 result, this paper presents twenty-four new numbers n such that Quo(n) is (1 + 1 + 2)-generated. Except for Quo(6), an extension of Zádori’s method is used.
%Z Bibliogr.: 427. p. ; összefoglalás angol nyelven