For example :
Intersect the set by the partition of the universe :
So, after some set operations, we get
Does this help ?
Can someone enlighten me how to marginalize so that I get p(x5) from p(x1, x2, x3, x4, x5)? When summing over x2, x3, x4, and x5 to marginalize, I'm not sure how to write out the conditional probabilities from the joint probability to get down to p(x5).