Richness function of CODEX clusters in the 0.1 <  z <  0.3 (left panel) and 0.1 <  z <  0.6 range (right panel). The solid gray histogram shows the data; the dotted histogram shows the contribution to the total counts from the clusters detected through their AGN activity; the dashed histogram shows the contribution from clusters detected through their thermal emission; and the solid histogram shows the total expected number of detection, which provides a good match to the data. The dotted gray histogram shows the data with excision of points deviating beyond the 2σ from the richness−L_X relation.