53 search results - page 1 / 11 » Dualities in full homomorphisms |
EJC
2010
13 years 5 months ago
2010
Abstract. In this paper we study dualities of graphs and, more generally, relational structures with respect to full homomorphisms, that is, mappings that are both edge- and non-ed...
DAGSTUHL
2008
13 years 6 months ago
2008
In a nutshell, a duality for a constraint satisfaction problem equates the existence of one homomorphism to the non-existence of other homomorphisms. In this survey paper, we give ...
EJC
2008
13 years 4 months ago
2008
We study restricted homomorphism dualities in the context of classes with bounded expansion. This presents a generalization of restricted dualities obtained earlier for bounded deg...
COMBINATORICA
2007
13 years 4 months ago
2007
A colored graph is a complete graph in which a color has been assigned to each edge, and a colorful cycle is a cycle in which each edge has a different color. We first show that ...
MFCS
2007
Springer
13 years 11 months ago
2007
Springer
We show that every NP problem is polynomially equivalent to a simple combinatorial problem: the membership problem for a special class of digraphs. These classes are defined by me...