所有正整数等于0# Joke - 肚皮舞运动
h*3
1 楼
归纳法
1. when k = 0, it's 0.
2. Assume m = 0, m = 0, 1, 2,...,k. when k > 0. Then k + 1 = i + j where 0 <
= i <= k and 0 <= j <= k, so k + 1 = 0.
1. when k = 0, it's 0.
2. Assume m = 0, m = 0, 1, 2,...,k. when k > 0. Then k + 1 = i + j where 0 <
= i <= k and 0 <= j <= k, so k + 1 = 0.