直言命题换位推理的欧拉图析

Analysis on Conversion Inference of Categorical Proposition by Eulerian Graph

直言命题换位推理应当同时满足的三个条件实际上是对此变形推理所涉及的词项关系的制约,欧拉图可以很直观地反映这一点。在直言命题换位推理三种有效形式之外的SOP换位问题,长久以来一直是传统逻辑的禁区,但运用欧拉图解析可以发现,在赋予若干条件后SOP能换位为POS。

Matching up to the three indispensable conditions to conversion inference of categorical proposition in traditional logic is in fact proved to be the restriction of interrelation between lexical items that the conversion inference concerns, as is visually cleared by Eulerian graph. The topic concerning SOP conversion out of the three valid forms of conversion inference of categorical proposition has been regarded as the forbidden zone of traditional logic for long. However, through resorting to Eulerian graph, it will be found out that SOP can be transformed into POS at the time of endowing some conditions.