Allowed configurations for companions for a1, a2, a3, and c for the case of two WR stars with identical spectra. The probabilities that the ratios between the largest and smallest FWHM values for the N IV λ4058 line are less than the observed values are shown (Fig. 7). The 5% and 50% thresholds are marked. The probabilities drop sharply in comparison with the RV case (Fig. 12). See the main text for details.