回复：f(1,1,1,1)=5意思是1,1,1,1用加减乘除算不出5。问题是怎样证明算不出5？

来源: 于 2010-07-19 17:50:37 [旧帖] [给我悄悄话] 本文已被阅读：次

You are right,It is very hard to verify "impossibility."Find the bound is possible...