内部変数なしの論理プログラムへの変換

概要

論文の詳細を見る
Negation As Failure is the rule for the implementation method of negation which is mostly used in present logic programming languages such as Prolog. However, one of the fatal defects is that it can not bind variables appearing in a negative literal to other terms. Therefore, how to bind variables occuring in a negative literal also is an important problem for the implementation of negation. Negation Technique proposed by Dr. Sato is an effective method to deal with this problem. But this method is not applicable to the programs containing internal variables. In this paper, we discuss the possibility of eliminating internal variables appearing in logic programs by using program transformations. Firstly, we give a dynamic necessary condition and a static necessary condition for eliminationing internal variables and state their relation. Then, we prove two sufficient conditions for this purpose. We also illustrate several cases together with examples which satisfy these sufficient conditions. As a significant result, we find out that possessing folding correspondence is the necessary and sufficient condition for the purpose of transforming into non-internal variable logic programs. The minimal model of the non-internal variable program transformed is the same as the original one.
社団法人人工知能学会の論文
1989-07-20