该问题共收稿4篇,见识不一,从中选出两篇刊登如后,供读者参考.选登1“至多有一个”(“顶多有一个”)与“至少有两个”互为否定,这是数理逻辑中的定理之一.要精确表达并严格证明这个定理需先了解“至多有一个”与“至少有两个”的真意.所谓“至多有一个”乃指“如果有,则不多于 A total of 4 questions have been collected and different opinions have been drawn, and two of them have been selected for readers’ reference. “” There is at most one “(” at most one “) and” at least two “ Negation, which is one of the theorems in mathematical logic, to accurately express and strictly prove that the theorem needs to understand the true meaning of ”at least one“ and ”at least two.“ The so-called ”at least one“ means ”if any, No more than