That's why your operating systems and your personal computers often crash for no apparent reason. Just because two things happen to, once in a while, occur at the same time.

这就是为什么你的电脑或者操作系统,经常会毫无预兆的崩溃了,这是因为两件事情正好同时发生了，通常还有人工输入。

麻省理工公开课 - 计算机科学及编程导论课程节选