作 者: ;
机构地区: 南开大学哲学院
出 处: 《河南大学学报(自然科学版)》 2003年第4期25-28,共4页
摘 要: 模态公式4、E和B是直观上难以确认是否成立的一类模态公式 文献[6]证明了:在模型〈VB,R,‖‖〉下,当R是VB上的任意一个二元关系时,模态公式4、E和B的布尔值不能确定 本文证明:当R是VB上自返的二元关系时,模态公式4、E和B的布尔值为1 因此,模态系统S4。 Visually, it is difficult to make sure whether the modal formulae 4、E and B come into existence. The literature \ proves that under the conditions of the model, when R is any 2-ary relation on V^(B), the Boolean value of the modal formulae 4、E and B can not be decided. The paper proves that when R is a reflexive 2-ary relation on V^(B), the Boolean value of the modal formulae 4、E and B are 1. Therefore,the modal system S_4、S_5 and B are of consistency.