Subtraction of the non-active, lithium-poor template (red line) from the spectrum of SO 583 (black dots), which reveals the complex structure of the Hβ and Hα lines (blue lines in the upper and central panel, respectively) and emphasizes the Li Iλ6707.8 Å absorption line, removing the nearby blended lines (bottom panel). The He Iλ6678.2 Å emission line clearly emerges in the subtracted spectrum.