GLF in the B band for the BCG1 region of Abell 3376, obtained by selecting galaxies along the red sequence in a (B − V) versus V colour–magnitude diagram (green points). The units are galaxy counts in bins of 0.5 magnitude and per square degree. The best fit is obtained by summing a Gaussian (in blue) at the bright end, and a Schechter function (in red) at the faint end; their sum is shown as a black dashed line. The GLF obtained by statistical subtraction in the same region is shown as blue points, displaced by −0.1 mag to avoid overlapping.