
Chapter 9: Database Integrity 341
finitely. Thus, assuming that our method is as complete as SLDNF, we can
conclude that the transaction satisfies the constraint.
In the search spaces, we have abbreviated the predicate symbol "Eligible-
for-state-pension" to "E-f-s-p." Each of the three search spaces consists of a
single derivation. The second search space consists only of the top clause, and
the third consists of two clauses.
Updates
that Are
Additions
or
Deletions
of
Integrity
Constraints
It is easy to deal with additions and deletions of integrity constraints. Additions
of constraints are handled exactly as additions of deductive rules. Thus ...