Trends of the photometric parameters of the inner and outer discs with the antitruncation radius, compared to real data on Type III S0 galaxies (E08; G11). Top: R-band scalelengths of the inner and outer discs vs.  R_brkIII (left and right panels, respectively). The fits performed to observations in these planes are two of the three simple scaling relations from which the relations observed in the rest of photometric planes can be derived (see Sect. 3.6), so they have been remarked in red. Data of the antitruncations formed in the minor merger simulations by Y07 are overplotted for comparison. Bottom: R-band central surface brightness of the inner and outer discs vs. R_brkIII (left and right panels). Solid lines: linear fits to our simulations sample. Dashed lines: linear fits to the observational data by E08 and G11. Dotted-dashed line: expected relations assuming the simple scaling relations h_i ∝ R_brkIII, h_o ∝ R_brkIII, and μ_brkIII ∝ R_brkIII obtained from data (see Sect. 3.6). Consult the legend in the figure. (Color version online.)