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» Homomorphism bounded classes of graphs
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GC
2010
Springer
14 years 10 months ago
Integer Functions on the Cycle Space and Edges of a Graph
A directed graph has a natural Z-module homomorphism from the underlying graph’s cycle space to Z where the image of an oriented cycle is the number of forward edges minus the n...
Daniel C. Slilaty
IPL
2008
169views more  IPL 2008»
14 years 11 months ago
Oriented colorings of partial 2-trees
A homomorphism from an oriented graph G to an oriented graph H is an arc-preserving mapping f from V(G) to V(H), that is f(x)f(y) is an arc in H whenever xy is an arc in G. The or...
Pascal Ochem, Alexandre Pinlou
IPL
2006
153views more  IPL 2006»
14 years 11 months ago
Oriented vertex and arc colorings of outerplanar graphs
A homomorphism from an oriented graph G to an oriented graph H is an arc-preserving mapping from V (G) to V (H), that is (x)(y) is an arc in H whenever xy is an arc in G. The orie...
Alexandre Pinlou, Eric Sopena
FCT
2005
Springer
15 years 5 months ago
Exact Algorithms for Graph Homomorphisms
Graph homomorphism, also called H-coloring, is a natural generalization of graph coloring: There is a homomorphism from a graph G to a complete graph on k vertices if and only if ...
Fedor V. Fomin, Pinar Heggernes, Dieter Kratsch
EJC
2008
14 years 11 months ago
Majority constraints have bounded pathwidth duality
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...
Víctor Dalmau, Andrei A. Krokhin