针对命题逻辑系统L^*,以及增加一元联结词△后的系统L^*Δ,研究了该逻辑系统有效集的特征,进而以有效集为工具得到公式集F(S)的一类分划,即可将L^*与L^*Δ中的公式集F(S)分别分为16和20个等价类;最后给出了L^*中对MP规则封闭的有效集的特征。
In this paper the characterization of validation set in L^* and L^* are discussed. Using this concept a new kind classification of F(S) is given, we can get sixteen and twenty equivalence classes. In the end the validation sets that satisfies the MP rule are discussed.