- 533 名前：１３２人目の素数さん mailto:sage [2020/06/18(木) 20:55:34.92 ID:pULdTssQ.net]
- f(x,y)=(x+y)/(1-xy) とかもOKみたい
((x+y)/(1-xy)+z)/(1- (x+y)z/(1-xy)) -(x+(z+y)/(1-zy))/(1-x(z+y)/(1-zy))=0
https://www.wolframalpha.com/input/?i=%28%28x%2By%29%2F%281-xy%29%2Bz%29%2F%281-+%28x%2By%29z%2F%281-xy%29%29+-%28x%2B%28z%2By%29%2F%281-zy%29%29%2F%281-x%28z%2By%29%2F%281-zy%29%29&wal=header&lang=ja
