N-Schrägverbände und Quasiordnungen
-Lattices of varieties of algebras of different types
On -lattices
On varieties of graphs
In this paper, we introduce the notion of a variety of graphs closed under isomorphic images, subgraph identifications and induced subgraphs (induced connected subgraphs) firstly and next closed under isomorphic images, subgraph identifications, circuits and cliques. The structure of the corresponding lattices is investigated.
On varieties of orgraphs
In this paper we investigate varieties of orgraphs (that is, oriented graphs) as classes of orgraphs closed under isomorphic images, suborgraph identifications and induced suborgraphs, and we study the lattice of varieties of tournament-free orgraphs.
A metric on a system of ordered sets
In [3] a metric on a system of isomorphism classes of ordered sets was defined. In this paper we define another metric on the same system and investigate some of its properties. Our approach is motivated by a problem from practice.
Constructions of cell algebras
A construction of cell algebras is introduced and some of their properties are investigated. A particular case of this construction for lattices of nets is considered.
Some characteristics of the edge distance between graphs
Page 1