A Semantics for a Stratified Production System Program

这个项目研究的技术，使程序编写 在生产系统（PS）范式中正确推理， 高效地使用位于辅助存储上的大型数据库。一 类的分层PS程序被识别。这类 一个操作语义和一个模型理论 语义学是发展起来的。正确的语义确保了 分层PS程序将对应于一个一致的理论， 程序的执行不会产生错误， 不一致的答案和程序的执行将 终止。分层PS程序的实现技术 使用关系数据结构和关系查询， 以及同时执行的战略， 在分层的PS程序中生产。的结果 研究将为专家系统提供基础，写作 分层的PS程序，以正确和有效地推理， 关系数据库中的数据。

This project investigates techniques that allow programs written in the Production System (PS) paradigm to reason correctly and efficiently with large databases located on secondary storage. A class of stratified PS programs are identified. For this class of programs, an operational semantics and a model theoretic semantics are developed. The correct semantics ensure that a stratified PS program will correspond to a consistent theory, the execution of the program will not produce incorrect, inconsistent answers and execution of the program will terminate. Implementation techniques for stratified PS programs using relational data structures and relational queries are developed as well as strategies for the concurrent execution of productions in stratified PS programs. The results of this research will provide a foundation for expert systems, written as stratified PS programs, to reason correctly and efficiently with data in relational databases.