Illustration of the N-body model used for checking the method for extracting the fraction of retrograde thick-disc stars. Upper left panel: frame edge-on snapshot of the simulated disc, while the other two frames display the thin and thick components separately (each with 10⁶ particles). Upper right frame: combined LOS-averaged rotation curves: black and grey lines correspond to the circular velocities at z/h_R = 0 and 0.9, respectively, while the circles indicate the same for stars. Lower right frame: combined vertical velocity and velocity dispersion profiles, averaged over the radial range 1.8 − 2.2 h_R, indicated by the white box on the N-body snapshot. The dashed line stands for the circular velocity, open circles for , and squares for σ. The continuous blue and dash-dot red curves show and σ for the thin and thick discs, respectively.