NP完全性的概念为理解问题的复杂性提供了一个强大的工具。

The only way to discover the limits of the possible is to go beyond them into the impossible.

摧毁人民最有效的方式是否认和抹杀他们对自己历史的理解。

The power is in the balance: we are our injuries, as much as we are our successes.

数学的目标不是解决问题，而是理解问题。