An efficient hypothetical reasoning system for predicate-logic knowledge-base

A hypothetical reasoning system & an important framework in the development of advanced knowledge-based systems. It can be effectively applied to many practical problems including model-based diagnosis, and designs. However, the inference speed of its PROLOG-based implementation is slow, and this is particularly because of inefficient backtracking. In order to overcome this problem, a fast hypothetical reasoning mechanism for propositionallogic knowledge has been developed by combining the advantages of forward and backward reasoning styles. This fast mechanism, however, cannot be applied to hypothetical reasoning with predicate-logic knowledge where variables are included as arguments. The paper presents a fast hypothetical reasoning mechanism for predicate-logic knowledge as an extension of the above idea. A reasoning method developed in the deductive database area is effectively utilized to realize this fast mechanism, which can even manipulate recursive rules.