Predicate Completion Convention: “The information given about a predicate P is all and only the relevant information about P”, I.e., the information about P is necessary as well as sufficient. Result: Establishes truth/falsity of every instance of predicate P in the KB. Minimizes the instances of predicate P to those that are forced to be true by the KB. Applications: various, e.g., default reasoning, taxonomic reasoning (e.g., minimize ab), abductive reasoning, ... Syntactic restrictions: only works for Solitary clauses (+ a few other special cases) Comment: Is subsumed by circumscription. Collapses to CWA in certain instances.