Mass density distribution, color coded in M_⊙ kpc⁻², of the central region of the Cluster-1 mock used for our functional tests, loosely based on the Caminha et al. (2017b) lens model for the cluster MACS J1206.2−0847 at redshift z = 0.439. Green circles denote the cluster galaxies with measured velocity dispersion within apertures of radius R = 0.8″. The brightest galaxies with and without measured velocity dispersion are labeled in green and red, respectively. Cyan crosses denote the position of observed multiple images. In the inset, a galaxy-scale multiple-image system is shown around the cluster member Gal(7) (labeled in magenta). The critical lines computed for the redshift, z₂ = 2.539, of the second family of multiple images are shown in white.