53 search results - page 2 / 11 » Dualities in full homomorphisms |
EJC
2008
13 years 6 months ago
2008
The motivation for this paper is three-fold. First, we study the connectivity properties of the homomorphism order of directed graphs, and more generally for relational structures...
TCS
2010
13 years 4 months ago
2010
We study non-uniform constraint satisfaction problems definable in monadic Datalog stratified by the use of non-linearity. We show how such problems can be described in terms of...
EJC
2008
13 years 6 months ago
2008
We study certain constraint satisfaction problems which are the problems of deciding whether there exists a homomorphism from a given relational structure to a fixed structure with...
CPC
2006
13 years 6 months ago
2006
The adaption of combinatorial duality to infinite graphs has been hampered by the fact that while cuts (or cocycles) can be infinite, cycles are finite. We show that these obstruc...
CORR
2007
Springer
13 years 6 months ago
2007
Springer
For digraphs G and H, a homomorphism of G to H is a mapping f : V (G)→V (H) such that uv ∈ A(G) implies f(u)f(v) ∈ A(H). If, moreover, each vertex u ∈ V (G) is associated ...