All right, so that notion of abstraction and we're going to come back to multiple times -- during the term-- and it's not just abstraction, -- it's the idea of a specification.

现在就试试,这就是抽象的概念,我回过来说，我们将要多次提到这个术语。

麻省理工公开课 - 计算机科学及编程导论课程节选