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. And it completely makes sense that this is going to be the same thing as the probability of A and B. Clearly, this is the probability of both of these, both A and B happening, and you can go the other way around. The probability of A given B times the probability of B, that would also be, so we're saying B needs to be true, and that given that B is true, that A needs to be true as well.