The theory of computation is not just about solving problems, but also about understanding the limits of what can be computed.

Illustrations should not just decorate the text; they should expand it.

意志不坚强的人，智慧也不会高到哪里去；说话不算数的人，做事也不会果敢痛快。

"Sometimes, the only way to win is to refuse to play the game."

"The lifeblood of any business is its customers."