A brain-burning double negative logic problem

If you can't find the original editing document, the blogger will be lazy, just go to the picture.
In fact, it doesn’t matter who A and B tells the truth or who tells lies, because for passers-by, it is just a code name. The question can be changed to "One A and B tells the truth, the other tells lies..." The
core is: ①Double negation② Computer thinking-judgment table (especially when it is binary)
PS: Thinking training is a long-term project for IT people. I don’t know if you understand it.