there's the conditional version and the unconditional version which only consists in taking X out ok so that's that's what the model looks like you have observe variable variable you need to predict and some latent variable you have to minimize over now why is that interesting latent variables are interesting because they are an essential tool for making a system be able to predict multiple outputs instead of just one so if I build a system out of deterministic functions here I have you know a neural net with a few layers