is a new loss it is not it is a new way of pre training the network for a classification task and so let's look into this so if you look at what does what does mean to build a classifier in this is what you usually do this is supervised cross-entropy training you have an image and the image here is of a dog you put it through your network and you obtain a representation so the representation here R is this last layer or the second-to-last layer and you put that through a classification layer and then a soft Max and what you get as an output