Left panel: adimensional sound speed profile as a function of the adimensional stellar radius for two models (Model₁₂ and Model₁₃ in Table 1) of Kepler-444 with (green) and without (red) overshooting. Right panel: frequency ratios as a function of the observed radial frequency. The upper symbols are related to the r_0, 2 ratios while the lower ones are related to the r_0, 1 ratios. The blue symbols are related to the observed values of the ratios while their theoretical counterparts are plotted in green and red for Model₁₃ and Model₁₂ with and without overshooting, respectively.