Using Integrity Constraints as Deletion Rules

Integrity constraints can be used to specify properties of predicate deenitions in deductive databases and logic programs. Written in if-then form, they lend themselves to generate, in forward reasoning (propagation) style, logically redundant information which is computa-tionally useful. But similarly they may also be used to delete logically redundant information which is useless and possibly slows down the computation due to its presence. This paper focuses on several ways of using integrity constraints in the latter way, i.e. as deletion rules, and also addresses the question whether and how deletion rules can generally be understood as or transformed into logically correct integrity constraints.