摘要
人们在求解问题的过程中，往往交换地使用正向和逆向思维方式．为了模仿这种思维方式，本文提出在产生式系统中引入元级推理构成二级推理；分析了影响推理方向的因素，根据这些因素建立了选择推理方向的估价函数；讨论了确定交换时机和实现推理方向交换等具体技术①．
Human is accustomed to changing thinking pattern, that is the posihve direchon rea son alternationg inverse direction one or by turns,in the course of solving problem.In or der to imitate the thinking pattern two levels of reason was constituted with meta--level and object-level after adding meta -level knowledge into produchon system.Having analysed factor influencing reason's direction, in terms of the factors,estimahng funchon was con structed.In this paper some methods and technicalihes that were used to achieve the ex change of reason's direction and deciding of the direction were discussed.
关键词
知识表示
自动推理
专家系统
knowledge representation
automatic reason
expert system
