"In the study of computational complexity, we often find that the boundaries of what is possible are defined by the limits of our imagination."
出自《魏源集·默觚下·治篇五》。三代以上,天都跟现在的天不一样,地都跟现在的地不一样,人也跟现在的人不一样,物也和现在的物不一样。