Extenseurs
Finite hull systems and their implication bases. (Endliche Hüllensysteme und ihre Implikationenbasen.)
Frattini sublattices in varieties of lattices
General algebraic geometry and formal concept analysis.
Gosset polytopes in integral octonions
We study the integral quaternions and the integral octonions along the combinatorics of the -cell, a uniform polytope with the symmetry , and the Gosset polytope with the symmetry . We identify the set of the unit integral octonions or quaternions as a Gosset polytope or a -cell and describe the subsets of integral numbers having small length as certain combinations of unit integral numbers according to the or actions on the or the -cell, respectively. Moreover, we show that each...
Graph automorphisms of multilattices
In the present paper we generalize a result of a theorem of J. Jakubík concerning graph automorphisms of lattices to the case of multilattices of locally finite length.
Implications partielles dans un contexte
Nous présentons une extension de la théorie des implications entre attributs binaires aux implications partielles. A partir de données expérimentales on s'intéresse non seulement aux implications (globales), mais aussi aux «implications avec quelques contre exemples». Les implications partielles offrent une possibilité d'extraire des informations supplémentaires. Elles permettent de «modéliser» la fréquence relative d'une implication, non-valide pour toutes les données, et donnent par conséquent...
Induced pseudoorders
Integer partitions, tilings of -gons and lattices
In this paper, we study two kinds of combinatorial objects, generalized integer partitions and tilings of -gons (hexagons, octagons, decagons, etc.). We show that the sets of partitions, ordered with a simple dynamics, have the distributive lattice structure. Likewise, we show that the set of tilings of a -gon is the disjoint union of distributive lattices which we describe. We also discuss the special case of linear integer partitions, for which other dynamical models exist.
Integer Partitions, Tilings of 2D-gons and Lattices
In this paper, we study two kinds of combinatorial objects, generalized integer partitions and tilings of 2D-gons (hexagons, octagons, decagons, etc.). We show that the sets of partitions, ordered with a simple dynamics, have the distributive lattice structure. Likewise, we show that the set of tilings of a 2D-gon is the disjoint union of distributive lattices which we describe. We also discuss the special case of linear integer partitions, for which other dynamical models exist.
Lattice isomorphisms of alternative algebras
Mac Neille completion of centers and centers of Mac Neille completions of lattice effect algebras
If element of a lattice effect algebra is central, then the interval is a lattice effect algebra with the new top element and with inherited partial binary operation . It is a known fact that if the set of central elements of is an atomic Boolean algebra and the supremum of all atoms of in equals to the top element of , then is isomorphic to a subdirect product of irreducible effect algebras ([18]). This means that if there exists a MacNeille completion of which is its extension...
Maximale Gegenketten im Verband
Measures on coallocation and normal lattices.
Metrics and tolerances
Modular and metric multilattices
Modular functions on multilattices
We prove that every modular function on a multilattice with values in a topological Abelian group generates a uniformity on which makes the multilattice operations uniformly continuous with respect to the exponential uniformity on the power set of .
Near lattices
On a sum of observables in a logic
On a theorem of Cantor-Bernstein type for algebras
Freytes proved a theorem of Cantor-Bernstein type for algbras; he applied certain sequences of central elements of bounded lattices. The aim of the present paper is to extend the mentioned result to the case when the lattices under consideration need not be bounded; instead of sequences of central elements we deal with sequences of internal direct factors of lattices.