here is how you train an image based model there you show it an x and y you find the Z that minimizes the the reconstruction error okay and if that's not perfect and we're one step O's to caste gradient descent you update the parameters of whatever functions you're using to make this small okay this works great except there's a there's a slight problem with this which is that imagine that Z has the same dimension as Y okay so in C are the same dimension as Y and the decoder is not you know the generate function then it's kind of a powerful