DLCs of QSO B1413+117 from LT observations in the r-band. To construct the DLCs in the top panel, the light curves of the B-D images have been shifted by the time delays and magnitude offsets relative to the image A, and the original brightness record of A haslater been subtracted from the shifted curves (only BA, CA, and DA pairs separated by ≤7 d were considered to compute the differences). Bottom panel: recent mean-subtracted DLCs.