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...
In this paper, we present a precise characterization of the existence of a convergent transfer subgraph in an edge colored directed acyclic graph. Based on the characterization, l...
We investigate rule dependency graphs and their colorings for characterizing the computation of answer sets of logic programs. To this end, we develop a series of operational chara...
We present a general method to improve computation of answer sets by analyzing structural properties of normal logic programs. Therefore we use labeled directed graphs associated t...
Loops and the corresponding loop formulas play an important role in answer set programming. On the one hand, they are used for guaranteeing correctness and completeness in SAT-base...