Introduction to logical information systems

Logical Information Systems (LIS) use logic in a uniform way to describe theircontents, to query it, to navigate through it, to analyze it, and to maintain it.They can be given an abstract specification that does not depend on the choiceof a particular logic, and concrete instances can be obtained by instantiating this specification with a particular logic. In fact, a logic plays in a LIS the role of aschema in data-bases. We present the principles of logical information systems, theconstraints they impose on the expression of logics, and hints for their effective implementation.