Well, it means that they both happened. But that's the same way as saying, well, what's the probability of, let's just say A is happening. Well, now for B and A to happen, it's just going to be that times the probability that B is true given that A is true, because you could kind of say, well, we're already kind of constraining it, we're already multiplying by the probability of A being true, and now we're multiplying by the probability that B is true given A is true. I actually often like to swap these around, just it gets a little bit clearer in my head. So this one, let's just write it like this. The probability of B given A times the probability of A. So this is the probability that event A is true, and this is the probability that B, event B is true, given that we know that A is true.