it's the it's the minimum of some more elementary energy function over some latent variable Z and we'll come back to models of this type so we have a energy function which is a reconstruction error so it's the squared distance between a data point Y and its reconstruction and its reconstruction is the product of a prototype matrix where the columns are bunch of prototypes multiplied by Z vector which is a latent variable and that Z vector is constrained to be a one hot vector so it's a vector with all zeros except it has a one at one