不可能前提为真，结论为假，但是你们不明白，因为他循环，所以有效。

There's no possible situation where the premises are true and the conclusion false but what you don't see that it is only valid because it's circular.

youdao

因此，即使用户没有通过 cookie 检查，$authorized 后来在 foreach 循环中引用时，仍然会被验证为真。

Therefore, even if the user fails the cookie check, $authorized, when referenced later in the foreach loop, will still evaluate to true.

youdao

否则测试结果就会一直为真，我们需要离开这个测试，否则就会一直执行循环。

Otherwise the test is always going to be true, we're going to go off here, but this would loop forever if I did that.

youdao

So here I've hardcoded the word true which is actually deliberately inducing what we called what last week.

所以在这里我们可以把条件写死,也就是我们上周提到过的，故意让循环条件,一直为真。

哈佛公开课 - 计算机科学课程节选

Otherwise the test is always going to be true, we're going to go off here, but this would loop forever if I did that.

否则测试结果就会一直为真，我们需要离开这个测试，否则就会一直执行循环。

麻省理工公开课 - 计算机科学及编程导论课程节选

swap I'm going to keep track of a little variable called swap, it's initially true, and as long as it's true, I'm going to keep going, but inside of the loop I'm going to set it to false, and only if I do a swap will I set it to true.

我打算跟踪一个小的变量称为,初始值为真，只要它是真的,算法就会继续，但是在循环里,我打算把他设为假,除非交换发生，就把它设为真。

麻省理工公开课 - 计算机科学及编程导论课程节选