Light-curve pair distribution function p(τ) = [N(τ)/N(0)]² for the continuum and line-emission light curves of HE0413 (solid blue line) and HE0435 (dashed green line), where N(τ) is the total number of continuum and line-emission data points for the time delay τ (time step is 1 day). Vertical dotted lines stand for the expected time delays in the observer’s frame inferred from the MgII R–L relation; see Fig. 12 for the best-fit relation based on 94 measurements. The values of p(τ) at these time delays are above the 0.5 level for both quasars.