Abstract: An important problem in know ledge engineering, particularly in mechanical designing expert systems, is commonsense knowledge representation.In general, commonsense knowledge may be regarded as a collection of propositions.For the reason that the implicit quantifiers in propositions are usually fuzzy, the restrained variables are induced in this paper to represent the meaning of proposition by testing the score of an elastic restraint on the proposition.As the restrained variables are dependent only upon the original desig ning parameters, the decisions made in designing process can be denimished.Based on the idea that the random demarcation points between a proposition and its negation have a Gaussian distribution, an approach to test-score is presented in this paper.

Key words: knowledge representation, restrained variable, random demarcation point, proposition, test score

摘要： 在分析其弹性约束因素的基础上引入约束变量概念,以约束变量测度弹性约束,再用随机分界点思想建立知识模型.

关键词: 知识表示, 约束变量, 随机分界点, 命题, 测度