对于数学命题的构造,刊物上已有不少讨论,特别是对于数学命题的否定(直接涉及到反证法)也有许多讨论.但笔者认为,在许多讨论中,对目前存在的问题反驳不力,解释不通俗.人们并不那样愉快地接受.因此,笔者想就此问题,谈一些自己的看法. 一、考察几个错误证明 1.关于“原命题与逆否命题的等价性”证明 这个事实是众所周知的,但是对于此命题的证明在一些书籍和刊物上是不正确的.我们 For the construction of mathematical propositions, there have been many discussions in the journals, and there have been many discussions on the negation of mathematical propositions (which directly involve anti-evidence methods). However, the author believes that in many discussions, the current problems are refuted and the explanations are not. Popularity. People do not accept it so happily. Therefore, the author wants to discuss some of his own views on this issue. First, to investigate several proofs of mistakes. 1. It is well known that the fact that “the equivalence between propositions and negative propositions” proves this fact. , but the proof of this proposition is incorrect in some books and publications.