模型检查的挑战不仅在于发现错误，还在于理解它们为何发生。

And what I noted, since the really big ideas carry 95 percent of the freight, it wasn’t at all that hard for me to pick up all the big ideas and all the big disciplines and make them a standard part of my mental routines. Once you have the ideas, of course, they are no good if you don’t practice. You don’t practice, you lose it.

当下总是在变，但过去是固定的。

写作的艺术在于在平凡中发现美。

The freedom then of man, and liberty of acting according to his own will, is grounded on his having reason, which is able to instruct him in that law he is to govern himself by, and make him know how far he is left to the freedom of his own will.

A thief is a poor man's best friend.

我发现了！（据传是阿基米德发现浮力原理时的感叹）