The most important property of a program is whether it accomplishes the intention of its user.

从n对观测值的样本中获得的相关系数的可能误差是sqrt((1-r²)/(n-2))。

"In times of crisis, true leaders emerge by making tough decisions with conviction."

如果一个社会中的大部分成员贫穷而悲惨，那么这个社会就谈不上繁荣幸福。

书写历史就是与幽灵搏斗。