Mock catalogues mass functions – R_R = R_T = 2 Mpc. The dark green and light green curves refer to the total GSMF, respectively, using z_true and z_phot for the calculation of the mass function. Dark red and light red curves refer to high-density environments, respectively, using ϱ_true, dark red, and using ϱ_rec, light red. Dark blue and light blue curves refer to low-density environments, respectively, using ϱ_true, dark blue, and using ϱ_rec, light blue. The black dashed lines are the mass completeness limits described in the text. The parameter values for the aperture are set to R_R = R_T = 2 Mpc and n = 1.5, with σ_{Δz/ (1 + z)} = 0.01. Error bars refer to estimates.