
Chapter
8:
Intelligent Query Answering
305
This is a particularly good class of queries for which we can apply rule
transformation. Indeed, in this case we only have to compute the closure
of
1-rules
(at compile time) by symbolic execution of the set of rules. It
is a good idea to label each rule with its derivation tree (i.e., from which
rules and how it was derived). In such a case we may also be able to
eliminate some redundancies after rule transformation has been com-
pleted and possibly further decrease the number of rules which have to be
evaluated prior to query evaluation. In general, rules that cannot be trans-
formed will have to b ...