And this puzzle piece here colored in blue because it's a Boolean expression is just something that--whose answer is either a yes or no, 0 true or false, one or zero.

这个拼图染成蓝色,因为它是布尔表达式,它的结果只可能是肯定或否定，对或错，1或者。

哈佛公开课 - 计算机科学课程节选