2 given X 1 and then X 3 given X 1 and X 2 and so on until we finally have a distribution over the final member of the vector given all of the other members of the vector so this goes back to a paper by Brendan Freund 1996 but has had several other advancements in the meantime the current most popular member of this model family is the pixel CNN and I show here some samples of elephants that it generated the primary disadvantage of this approach is that generating a sample is very slow each time we want to sample a different X I