An important means of allowing non-expert end-users to pose ad hoc queries — whether over single databases or data integration systems — is through keyword search. Given a set...
We consider the problem of querying data sources that have limited capabilities and can thus only be accessed by complying with certain binding patterns for their attributes. This ...
Abstract. We prove in this paper that there exists some infinitary rational relations which are 0 3-complete Borel sets and some others which are 0 3-complete. These results give a...
We construct a finite language L such that the largest language commuting with L is not recursively enumerable. This gives a negative answer to the question raised by Conway in 1...
In this paper we analyze the relationship between cyclic definitions and consistency in GelfondLifschitz's answer sets semantics (initially defined as `stable model semantics...