Artificial Intelligence Logic Programming and Deductive Databases

这项研究涵盖了逻辑程序设计和演绎数据库的理论研究、实验工作和实用技术。研究了逻辑程序的良基语义扩展到一般良基逻辑程序，进而扩展到析取良基逻辑程序。研究了它们的模型论、证明论和不动点语义。计划实施证明程序。在演绎数据库中，研究了空值的其他定义，并发展了它们的模型论、证明论和不动点语义。考虑实施所制定的证明程序。在析取演绎数据库领域，研究了自底向上和自顶向下的计算方法，研究了与蕴涵无关的算法，最后讨论了具有蕴涵的一般情况。还研究了对否定查询的答案计算以及在析取数据库中合理计算答案的条件。在单独的努力中，对析取逻辑程序的近似答案进行了调查，并对并行推理系统进行了研究。这项研究将有助于开发知识库系统和演绎数据库，在这些系统中，应用需要将析取作为理论的一部分。

The research covers theoretical investigations, experimental work, and practical techniques in logic programming and deductive databases. Research is conducted on extending well-founded semantics of logic programs to general well-founded logic programs and then to disjunctive well-founded logic programs. Their model theoretic, proof theoretic and fixpoint semantics are investigated. Proof procedures are planned for implementation. In deductive databases, alternative definitions of null values and to develop their model theoretic, proof theoretic and fixpoint semantics are investigated. Proof procedures that are developed are considered for implementation. In the area of disjunctive deductive databases, bottom-up and top-down computation methods are to be investigated, algorithms that are free of implications are studied, and finally the general case with implications is considered. Computing answers to negated queries and conditions under which one might reasonably compute answers in disjunctive databases are also investigated. In separate efforts, investigations into approximate answers to disjunctive logic programs and research in parallel inference systems are conducted. The research will be useful for the development of knowledge base systems and deductive databases in which the application requires disjuncts as part of the theory.