Examples of magnification maps for image A of RX J1131−1231 in the three left panels, with the corresponding IMFs in the right panel. All maps are 20⟨R_Ein⟩ on a side, corresponding to 8192² pixels. The r factor corresponds to the ratio between the upper and lower bound of the mass interval, so that r = 1 indicates single-mass IMFs. The magnification probability distributions are shown in Fig. 2.