System Description: DLV with Aggregates

DLV is an efficient Answer Set Programming (ASP) system implementing the (consistent) answer set semantics [GL91] with various language extensions like weak constraints [BLR00], queries, and built-in predicates. A strong point of DLV is the high expressiveness of its language, which is able to express very complex problems, even problems which are hard for the complexity class \(\Delta_3^P\). The language of DLV is therefore strictly more expressive than normal logic programming which cannot express any problem beyond NP. Another strong point of DLV is its robust and efficient implementation, which integrates algorithms and heuristics from the field of nonmonotonic reasoning with several optimization techniques from the field of deductive databases.