Differential (left) and cumulative (right) luminosity (top) and redshift (bottom) distributions of the soft-band extragalactic sky sample computed using different XLFs. The thick solid black curves show predictions based on the default XLF model. Also shown are predictions for the XLF model of Miyaji et al. (2000, Table 3), Hasinger et al. (2005, Table 5, without the exponential redshift cutoff, dotted curve), and Ebrero et al. (2009). To facilitate the comparison of shapes, differential distributions in left panels are normalized to unity.