to be a forward model for a control problem of driving a car for example so if you drive a car you might want to be able to predict what the cars around you are going to do and it's not deterministic so if you are if you are this guy you have this car these are all the cars around you this is a little rectangle extracted around around yourself and it might be useful to predict what the cars around you are going to do if you want to plan a kind of trajectory that will avoid you know the probability of future accidents so