brought up is that we we decode Z from the bitstream and that's how we sample from the bit stream is by decoding from it that's how we sample Z but in order for that to really give us a good sample the bits that we that we decode from have to be actually random and so that's not necessarily true and so in a VA II the last Z if you just sort of work out what's going on basically if this KL divergence between this aggregate posterior Q of Z and the prior is small then that means those bits will be random or pretty good and that'll be