par Pirotte, Alain ;Roelants, Dominique;Zimanyi, Esteban
Référence IEEE transactions on knowledge and data engineering, 3, 2, page (221-236)
Publication Publié, 1991
Article révisé par les pairs
Résumé : Intensional answers are conditions that tuples of values must satisfy to belong to the usual extensional answer of a query addressed to a deductive database. This paper motivates the concept of intensional answers and introduces a general method for generating them as logical consequences of the query and of deduction rules. It then shows how integrity constraints can filter out inadequate answers and produce simpler and more informative answers. An efficient organization for the combination of answers and constraints is described. Then, we study the introduction of negation in queries and in the body of deduction rules. Beyond the mechanics of answer generation, the interest of the approach also depends on a strategy for selecting answers to a user submitting a query. This requires techniques for user modeling and dialogue management similar to those required for expert systems. © 1991 IEEE