state and you can't enumerate that in this summation because 100 to 100 will be far too much to work with and so things we'll see later this lecture is how to deal with this when I would say the equivalent of iterative lqr when it's a nonlinear system but maybe locally it's close to linear and then locally can approximate with linear gaussians and that's the extended column under we already covered that that's extended Kalman filter I said a common file that you covered last lecture and we'll cover next lecture is particle