无前提规范闭缺省理论的扩充的构造

On the Construction of Extensions of Closed Normal Default Theories Without Antecedents

文针对有限的无前提规范闭缺省理论的扩充进行了较系统的研究。首先,对相容扩充进行了分类;其次,给出了相容扩充的特征刻画;再次,建立了一种制作相容扩充的准构造性方法;最后,对缺省规则固定时,缺省理论可能有的不同相容扩张的个数进行了估计。

The present paper systematically investigates extensions of closed normal default theories without antecedents. First, a classification theorem of consistent extensions is proven, Second, certain characterization theorems for extensions are provided, Third, a quasi-constructive method for con- structing extensions is proposed, Moreover, possible numbers of different extensions of a default theory is estimated. Lastly, a short conclusion is given at the end.