Molecular mass functions derived in this work using the parameters of the bivariates’ K-band luminosity-H₂ mass. The red refers to the H₂ MF derived for a luminosity dependent X_CO factor, while the pink curve corresponds to that derived for a constant X_CO. The blue curves refer to the models reported in Lagos et al. (2015), while the green curve corresponds to that by Popping et al. (2014). The dark grey bars refer to the values of the H₂ MF by Fletcher et al. (2020), taken from their fiducial model. The errorbar boxes have been slightly displaced along the x-axis to avoid confusion with overlapping colours.