计算理论为理解什么可以计算、什么不能计算提供了基础。
All that we see or seem is but a dream within a dream.
"The past is not a place to live, but a place to learn from."
You think it will never happen to you, that it cannot happen to you, that you are the only person in the world to whom none of these things will ever happen, and then, one by one, they all begin to happen to you, in the same way they happen to everyone else.