Representations of ordered semigroups and lattices by binary relations
Representative properties of the quasi-ordered set
Representing lattices by homotopy groups of graphs
In this paper we represent every lattice by subgroups of free groups using the concept of the homotopy group of a graph.
Semigroups and their lattice of congruences.
Semigroups and their lattice of congruences II.
Semigroups and their subsemigroup lattices.
Semigroups with Boolean Congruence Lattices.
Semimodularity and weak modularity in subalgebra lattices of completely simple semigroups.
Separation properties in congruence lattices of lattices
We investigate the congruence lattices of lattices in the varieties . Our approach is to represent congruences by open sets of suitable topological spaces. We introduce some special separation properties and show that for different n the lattices in have different congruence lattices.
Some finite congruence lattices, I
Some properties of an ordering relation on certain classes of functors
Strong compact elements in multiplicative lattices
Su una classe di gruppi con molti sottogruppi quasinormali
Sublattices of topologically represented lattices.
Sur une opérade ternaire liée aux treillis de Tamari
On introduit une opérade anticyclique définie par une présentation ternaire quadratique. On montre qu’elle admet une base indexée par les arbres binaires planaires. On relie cette construction à la famille des treillis de Tamari en construisant un isomorphisme entre et le groupe de Grothendieck de la catégorie qui envoie la base de sur les classes des modules projectifs et qui transforme la structure anticyclique de en la transformation de Coxeter de la catégorie dérivée de . La dualité...
Symmetric embedding of finite lattices into finite partition lattices
The lattice of R-unipotent congruences on a regular semigroup.
The lattice R-tors for perfect rings.
The subalgebra lattice of a finite algebra
The aim of this paper is to characterize pairs (L, A), where L is a finite lattice and A a finite algebra, such that the subalgebra lattice of A is isomorphic to L. Next, necessary and sufficient conditions are found for pairs of finite algebras (of possibly distinct types) to have isomorphic subalgebra lattices. Both of these characterizations are particularly simple in the case of distributive subalgebra lattices. We do not restrict our attention to total algebras only, but we consider the more...
Two Congruence Lattices of Completely Simple Semigroups.