Every problem in NP can be reduced to the satisfiability problem, which is the cornerstone of computational complexity theory.

避免麻烦的最好方法就是远离它。

个体只有使自我向高于人的心灵权威臣服，才能赋予自己的生命以特质和意义。

感谢一位改变了你生活的老师。

The great secret that all old people share is that you really haven't changed in seventy or eighty years. Your body changes, but you don't change at all. And that, of course, causes great confusion.