Abundance ratio [F/O] as a function of [O/H] in the solar neighborhood for the two-infall chemical evolution model. The blue line represents the model F1 of Table 1 in which fluorine is assumed to be produced by both AGB stars and SNe Ia and SNe II. The model similar to the F7 model but with the W-R yields multiplied by a factor of 2 is indicated with the black line. The magenta line represents the model F9 in which the contribution of SNe II and SNe Ia are considered along with W-R stars. In this model the AGB yields are multiplied by a factor of 2. Observational data of Jönsson et al. (2017a) are indicated with cyan circles.