Scientific Reports:

M. Morak, S. Woltran:
"Preprocessing of Complex Non-Ground Rules in Answer Set Programming";
Report No. DBAI-TR-2011-72, 2011; 14 pages.

English abstract:
In this paper we present a novel method for preprocessing complex non-ground rules for answer set programming (ASP) in such a way that the grounding of such a rule remains small. A single non-ground rule in a logic program is therefore seen as a hypergraph. ASP is a language well known for its clarity and readability, however rules that are easy to read often contain many variables, in which case grounders often generate an unnecessary large grounding. Using a well-known result from the area of conjunctive query evaluation,
hypertree decompositions of such rules can be used for preprocessing in such a way that the grounder is made aware of the structure of the rule, resulting in a better grounding. We propose a preprocessing algorithm that makes use of such hypertree decompositions. Using a prototype implementation and the benchmark suites of the Answer Set Programming Competition 2011, we perform extensive tests of our algorithm that clearly show the improvements in grounding time and size.

Created from the Publication Database of the Vienna University of Technology.