There are two ways of constructing a software design: One way is to make it so simple that there are obviously no deficiencies, and the other way is to make it so complicated that there are no obvious deficiencies.
The best way to learn mathematics is to do mathematics.
抽象的目的不是模糊,而是创建一个新的语义层次,在这个层次上可以绝对精确。