Updating intensional predicates in deductive databases

A method for updating deductive databases that allows the insertion or deletion of a fact over intensional predicates in a deterministic manner is presented. It is shown that, contrary to most other approaches, inserting or deleting facts over tensional predicates can always be accomplished without having to make choices. The approach relies on well-founded semantics and on the following two basic approaches: deleted facts are explicitly stored in the database and the inserted and deleted facts may concern any predicate, not just extensional predicates