One solution is to let one person choose the horse and the other person get the rest. In this way, no matter how the first person chooses, he will get more horses than the second person. For example, if the first person chooses 1/2 horses, he will get 1/3 horses; If the first person chooses 1/3 horses, then he will get 1/4 horses; And so on. In this way, no matter how the first person chooses, he will get more horses than the second person.
Although this method looks simple, it actually requires some mathematical knowledge to understand. It uses the concept and properties of infinite series. Specifically, it takes advantage of the fact that for any positive integer n, 1/(n+ 1).
In a word, the correctness of the law of dividing horses can be proved by mathematical methods. It uses the concept and properties of infinite series and combines some simple logical reasoning. Although this problem seems simple, it actually needs some mathematical knowledge to understand.