We give a graph theoretical characterization of answer sets of normal logic programs. We show that there is a one-to-one correspondence between answer sets and a special, non-stan...
Consider the following problem: For given graphs G and F1, . . . , Fk, find a coloring of the edges of G with k colors such that G does not contain Fi in color i. For example, if e...
Given a fixed multigraph H with V (H) = {h1, . . . , hm}, we say that a graph G is H-linked if for every choice of m vertices v1, . . . , vm in G, there exists a subdivision of H i...
We consider the class of graphs that contain no bull, no odd hole, and no antihole of length at least five. We present a new algorithm that colors optimally the vertices of every g...