Upper panel: decomposition of the quasar spectrum into a macrolensed-only component (F_M, black line) and a component both macro- and microlensed (F_Mμ, blue line) by applying MmD to the spectra of images B and D. F_Mμ is shifted upward by three units. The spectrum of image B (F_B, grey line), assumed to be unaltered by microlensing, is shifted downward till its continuum intensity is null and is superimposed on F_M. The spectra are filtered with a five-pixel-wide median filter for clarity. The vertical dotted line indicates the redshifted rest wavelength of the Hα line. Lower panel: same for the pair of spectra of images B and A.