Complexity of nonrecursive logic programs with complex values
Sergei G. Vorobyov, Андрей Воронков · 1998
values should be treated.There are two major approaches.We investigate complexity of the SUCCESS problem for logic query languages with complex values: check whether a query defines a nonempty set.The SUCCESS problem for recursive query languages with complex values is undecidable, so WC study the complexity of nonrecursive queries.By complcx values we understand values such as trees, finite sets, and multlscts.Due to the well-known correspondence between relational query languages and datalog, our results can be considered as results about relational query languages with complex values.The paper gives a complete complexity classification of the SUCCESS problem for nonrecursive logic programs over trees depending on the underlying signature, presence of negation, and range restrictedness.We also prove several results about finite sets and multisets.