Help me deal with the implications. I don’t understand the point, I need a good example.

THIMCHH: It is easy. There are two events: event A (the package) and event B (the consequence).
Suppose event A - you bought your girlfriend a ring with a diamond, event B - he gave you.
If event A is false and event B is false, the follow-up is true. If you didn’t buy her a ring, she might not give you it.
If event A is false, and event B is true, follow-up is true (If you didn’t buy her a ring, she can still give you it).
If the event A is true and the event B is true, the follow-up is true (if you bought her a ring, she will surely give you).
If event A is true and event B is false, follow-up is false.
somehow so.