A. 30 4. Logic is not sufficient for describing general laws, such as in the following, for example: Premise 1: All human beings are mortal.
The complexity of the classifier depends very sensitively on the expressive power of the language elements. The language structures described above (slightly extended, see Fig. 2 in [Brachman 83]) very probably lead to a superexponential complexity ofthe classifier, which can be reduced at least to O(n 2 ) by leaving out the value restrictions for roles. However, a classifier may work quite well in "normal" cases even if the complexity is super-exponential. One should therefore carefully choose the best compromise between the required expressive power of the language and the efficiency of the classifier [Levesque 85].