Applying restriction constraints to deductive databases

An operation for restricting deductive databases represented as logic programs is introduced. The constraints are coded in a separate database, and the operator puts the two databases together in order to provide a restricted view of the original database. The operator is given a semantics in terms of the immediate consequence operator. Then a transformational implementation is given and its correctness is proved with respect to the abstract semantics. The approach is presented at first for positive programs and it is then extended to take negation as failure into account