P of X that allows for easy coding exercise I mention all hearings sometimes still used to encode one when X is Gaussian you can do it as an independent random variables along each axis and each and invariably you could efficiently we've said on the previous slide or maybe for each X we can use an auto Russell model and we know how to do a rest of encoding with arithmetic schemes and so forth these are examples of high dimensional situations where we can encode things efficiently might be more but for now let's just let's go