4 papers · 1 filter
Quasiplanar diagrams and slim semimodular lattices
Gábor Czédli
A (Hasse) diagram of a finite partially ordered set (poset) P will be called quasiplanar if for any two incomparable elements u and v, either v is on the left of all maximal chains…
Distributive lattices determined by weighted double skeletons
Gábor Czédli, Joanna Grygiel, Katarzyna Grygiel
Related to his S-glued sum construction, the skeleton S(L) of a finite lattice L was introduced by C. Herrmann in 1973. Our theorem asserts that if D is a finite distributive latti…
Varieties of distributive rotational lattices
Gábor Czédli, Ildikó V. Nagy
A rotational lattice is a structure (L;\vee,\wedge, g) where L=(L;\vee,\wedge) is a lattice and g is a lattice automorphism of finite order. We describe the subdirectly irreducible…
Composition series in groups and the structure of slim semimodular lattices
Gabor Czedli, E. Tamas Schmidt
Let H and K be finite composition series of a group G. The intersections H_i\cap K_j of their members form a lattice CSL(H,\K) under set inclusion. Improving the Jordan-Hölder theo…