Locations in the diagram of light curves with trends, determined analytically from Eqs. (2), (3), and (5), using ΔT = 4 y, n = 1000, ΔT_sub = 100 d, and various trend parameters β. Blue markers connected with a continuous blue line (upper line) locate light curves with no variability pattern in the detrended component (i.e., ). Red markers connected with a dashed red line (lower line) assume the presence of a variability pattern in the detrended component with . The markers on each line locate time series with increasing trend parameter β of, from right to left, 0 to 10 by steps of 1, then from 10 to 640 by multiplication factors of 2. The black cross markers labeled a, b, and c locate the simulated time series shown in the top, middle, and bottom panels of Fig. 4, respectively. The horizontal dashed line is an guideline to and the diagonal dashed line an guideline to .