for from X 2 and now you concatenate these two channels together and you get your actual input again and you want to make sure that this version matches your original version so so this way it's like ensuring a backward consistency in some sense because it's not just about predicting the color from your grayscale it's also like hey the a B channel should also make sense like whatever you predict from your a B channels your L channel that the and what are we predicting I'll channel to a beach on together if you look at it it should