It is the most flexible evaluation strategy. Rules are reified into the meta-level component as meta-predicates of type rule (see Section 5.1.1). If the query is a path, contains a function or appears in the import interface, then the behaviour is as in the eager case. Otherwise, all the deduction is made at the meta-level, and the value of the query will be the result of the reflection of a K meta-predicate.
All the procedures of eager evaluation are performed except that of point 3 of the Update procedure (deduction by means of rules).