Upper: schematic illustration showing how shifted ICMFs (colored curves) combine to produce a top-heavy CMF (black curve). The upper shifted ICMFs represent newly formed cores, while the accretion process shifts the mass function of older cores toward higher masses, forming right-shifted ICMFs. Lower: cumulative functions of the observed CMFs for three time bins, together with the corresponding modeled CMFs (see upper panel), where the x axis values are linearly scaled to match the observations.