Interschema knowledge in cooperative information

Managing interschema knowledge is an essential task when dealing with cooperative information systems. We propose a logical approach to the problem of both expressing interschema knowledge, and reasoning about it. In particular, we set up a logical language for expressing semantic interdependencies between, classes belonging to different database schemas, and show that reasoning over such interdependencies is decidable. This yields the possibility of building a logic-based module that can, draw useful inferences whenever the need arises of both checking coherence between the knowledge represented in different schemas, and answering queries posed to the cooperative information systems.<>