A relevance terminological logic for information retrieval

A Terminological Logic is presented as an information retrieval model, with a four-valued semantics that gives to its inference relation the avour of relevance, that is a strict connection in meaning between the premises and the conclusion of the arguments licensed by the logic. The logic also permits the expression of meta-knowledge enforcing a closed-world reading of the knowledge concerning specified individuals and primitive concepts. A Gentzen-style, sound and complete calculus for reasoning in the logic is given, thus establishing the basis for an information retrieval engine.