質問変換に基づく並列サーカムスクリプションの計算手法

概要

論文の詳細を見る
In this paper, we give a new method for computing parallel circumscription based on an equivalent transformation of queries. Circ [A;Γ;Δ] ⊧ B, is equivalent to A ⊧ B if B has no negative occurrences of predicates of Γ and no occurrences of predicates of Δ. Therefore, if B satisfies these conditions, then the computation of Circ [A;Γ;Δ] ⊧ B can be reduced into the first-order computation of A ⊧ B. In general, the queries B don't satisfy the above conditions, but, sometimes, they can be transformed into the above computational sentences. In this paper, we present an equivalent transformation method of queries into the above computational sentences, and formalize it in the form of the resolution. This transformation method replaces a negative occurrence of a minimized predicate with the formula representing its minimal extension. It is similar to the unfolding in logic programming. This transformation method is intuitionally very clear, and can deal with theories consisting of both recursive and non-definite clauses.
1990-09-01