概念代数—新一代数据库系统的理论

念代数ＣＡ是Ｎｉｌｓｓｏｎ教授以格（ｌａｔｔｉｃｅ）理论为数学背景提出的一个新的代数系统。在ＣＡ中，关系范型、ＯＯ范型、逻辑程序设计和框架知识表示获得了统一的表示－概念项，项进一步组成句子。一个完整的知识库就由这样折的项和句子组成。推理操作是一组被称为重写规则的代数公理。目前的ＣＡ还只是个代数系统雏形，有很多方面有待扩充。本文对概念代数进行综述，并给出初步的扩充。

CONCEPT ALGEBRA-A THEORY FOR NEW GENERATION DATABASE SYSTEMS

The CA (Concept Algebra), founded by Prof. Nilsson and based on the lattice theory,is a new algebra system in its early stage. In CA, the,relational and OO paradigm,logic programming, and the frame formalism of knowledge representation are incorporated into one uniform representation form: concept term. Terms further comprise sentences, and a knowledge base is made up of such terms and sentences. Inference operations are represented as a group of algebraic axioms referred to as rewriting rules. At present, the CA is far from perfection, and remains to be extended. This paper surveys the CA and makes some basic extension.