Correctness in hierarchical knowledge-based requirements

As expert system technology gains broader acceptance, the need to build and maintain large-scale knowledge bases will assume greater importance. Traditional approaches to knowledge-based systems (KBSs) verification have generally adopted a pairwise comparison of rules, making them slow for large-scale KBSs. This paper introduces the least fixpoint semantics of a predicate/transition (pr/t) net model into the KBSs for the purposes of speeding up the computation and saving the design time of KBSs. An efficient fault diagnosis algorithm is presented to locate some fault(s) made in the KBS design. The significance of this work is that frame- and rule-based hardware description language (FARHDL) can easily form a KBS, and the pr/t net model provides a T-invariant technique to verify the correctness of KBS requirements. Thus, the performance of a computer-aided design (CAD) tool for digital systems can be improved to some extent.