 \(A^{\star}(P)\) expresses that P satisfies A, and that no smaller predicate does. Let \(Px\) be the predicate “x is abnormal,” and let \(A(P)\) be the sentence “All birds that are not abnormal fly.” Then the sentence “Tweety is a bird,” together with \(A^{\star}(P)\) implies “Tweety flies,” for the circumscription axiom forces the extension of P to be empty, so that “Tweety is normal” is automatically true. 