Halo mass function derived from the simulation described in Sect. 5.1, restricted to galaxies in the HD and LD environment (violet and orange symbols, respectively). Different symbols are estimated in the three redshift bins quoted in the bottom-left corner of the plot, with error bars obtained from the variance among the 10 mock catalogues. The mass function of haloes in the entire box ( side), at snapshots consistent with our redshift bins, is shown as reference with solid lines (darker colour at lower z).