Die arithmetischen Operationen für geordnete Mengen
Die Dimensionsformel in Halbordnungen.
Die Minimalbasis der Menge aller nicht in die projektive Ebene einbettbaren Graphen.
Dimension stable posets
Dimension theory for cyclically and cocyclically ordered sets
Direct and elementary approach to enumerate topologies on a finite set.
Direct decomposability of tolerances on lattices, semilattices and quasilattices
Direct product decomposition of zero-product-associative rings without nilpotent elements
Directly decomposable tolerances on direct products of lattices and semilattices
Directoids with an antitone involution
We investigate -directoids which are bounded and equipped by a unary operation which is an antitone involution. Hence, a new operation can be introduced via De Morgan laws. Basic properties of these algebras are established. On every such an algebra a ring-like structure can be derived whose axioms are similar to that of a generalized boolean quasiring. We introduce a concept of symmetrical difference and prove its basic properties. Finally, we study conditions of direct decomposability of directoids...
Directoids with sectionally antitone involutions and skew MV-algebras
It is well-known that every MV-algebra is a distributive lattice with respect to the induced order. Replacing this lattice by the so-called directoid (introduced by J. Ježek and R. Quackenbush) we obtain a weaker structure, the so-called skew MV-algebra. The paper is devoted to the axiomatization of skew MV-algebras, their properties and a description of the induced implication algebras.
Directoids with sectionally switching involutions
It is shown that every directoid equipped with sectionally switching mappings can be represented as a certain implication algebra. Moreover, if the directoid is also commutative, the corresponding implication algebra is defined by four simple identities.
Discriminator order algebras
We prove that an order algebra assigned to a bounded poset with involution is a discriminator algebra.
Distance minimale entre partitions et préordonnances dans un ensemble fini
Distances between partially ordered sets
A distance between finite partially ordered sets is studied. It is a certain measure of the difference of their structure.
Distributive associative near lattices
Distributive multisemilattices [Book]
Distributive ordered sets and relative pseudocomplements
Brouwerian ordered sets generalize Brouwerian lattices. The aim of this paper is to characterize (α)-complete Brouwerian ordered sets in a manner similar to that used previously for pseudocomplemented, Stone, Boolean and distributive ordered sets. The sublattice (G(P)) in the Dedekind-Mac~Neille completion (DM(P)) of an ordered set (P) generated by (P) is said to be the characteristic lattice of (P). We can define a stronger notion of Brouwerianicity by demanding that both (P) and (G(P)) be Brouwerian....
Distributive partially ordered sets
Distributivity and wellfounded semilattices.