Subtraction of the synthetic composite spectrum (red line) from the observed spectrum of the SB2 S 492 (black dots), which leaves only the chromospheric emission in the Hα core (blue line in the bottom panel) and emphasizes the Li Iλ6708 Å absorption lines of the two components (blue line in the top panel). The green and magenta dotted lines superimposed on the residual spectrum represent Gaussian fits used to deblend the Li I lines of the two components. The two components cannot be separated in the Hα, and the full residual Hα emission can be integrated to provide a total (green hatched area in the bottom panel).