20 citations · 41 across the 14 of their papers we have counts for
6 papers · 1 filter
Revisiting Faigle geometries from a perspective of semimodular lattices
Gábor Czédli
In 1980, U. Faigle introduced a sort of finite geometries on posets that are in bijective correspondence with finite semimodular lattices. His result has almost been forgotten in l…
(1+1+2)-generated lattices of quasiorders
Delbrin Ahmed, Gábor Czédli
A lattice is -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 of all quas…
Four-element generating sets of partition lattices and their direct products
Gábor Czédli, Lillian Oluoch
Let be a natural number. By a 1975 result of H. Strietz, the lattice Part of all partitions of an -element set has a four-element generating set. In 1983, L. Zádori g…
A note and a short survey on supporting lines of compact convex sets in the plane
Gábor Czédli, László L. Stachó
After surveying some known properties of compact convex sets in the plane, we give a two rigorous proofs of the general feeling that supporting lines can be slide-turned slowly and…
Representing convex geometries by almost-circles
Gábor Czédli, János Kincses
Finite convex geometries are combinatorial structures. It follows from a recent result of M.\ Richter and L.G.\ Rogers that there is an infinite set of planar convex polyg…
Swing lattice game and a short proof of the swing lemma for planar semimodular lattices
Gábor Czédli, Géza Makay
The swing lemma, due to G. Grätzer for slim semimodular lattices and extended by G. Czédli and G. Grätzer for all planar semimodular lattices, describes the congruence generated by…