Homomorphisms to oriented cycles
An oriented cycle is a graph obtained form an undirected cycle by orienting its edges. In the paper the authors give a characterization of those digraphs that admit a homomorphism to a special class of oriented cycles. On the basis of the result they give, in a subsequent paper, a characterization of multiplicative cycles (a graph \(G\) is called multiplicative if the class of graphs which are non-homomorphic to \(G\) is closed with respect to the categorical product).
scientific article; zbMATH DE number 522713