This just means hexadecimal notation, which we'll come back to before long so really it just means it's returning the 0 address zero.

这表示的是16进制,我们等下还会讨论，表示的是返回,地址。

哈佛公开课 - 计算机科学课程节选

We put it more graphically before but that's fine. Two more outcomes.

这条我们用矩阵表示的,还差两个

耶鲁公开课 - 博弈论课程节选