A reflexive graph is a simple undirected graph where a loop has been added at each vertex. If G and H are reflexive graphs and U V (H), then a vertex map f : U V (G) is called n...
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...
d Abstract) Pascal Ochem∗, Alexandre Pinlou† LaBRI, Université Bordeaux 1, 351, Cours de la Libération, 33405 Talence Cedex, France March 16, 2007 A homomorphism from an ori...
For digraphs D and H, a mapping f : V (D)V (H) is a homomorphism of D to H if uv A(D) implies f(u)f(v) A(H). If, moreover, each vertex u V (D) is associated with costs ci(u), i...
Tension-continuous (shortly TT) mappings are mappings between the edge sets of graphs. They generalize graph homomorphisms. From another perspective, tension-continuous mappings a...