Comparison for 1.3 M_⊙ models using different mixing prescriptions: Ledoux (blue), Schwarzschild (red) and overshooting (green). Each row of models represents a value of the central hydrogen content (from top to bottom): Xc = 0.65, Xc = 0.45, Xc = 0.25, and Xc = 0.05. Left panels: frequency ratios as defined in Eq. (14). Horizontal lines show a typical observable frequency range for each mixing prescription of radial orders n = 15–27. Central panels: adiabatic sound speed showing the position of the density discontinuity. Right panels: evolutionary tracks for the three selected prescriptions, and the position of the studied models is represented by a filled circle. Error bars have been plotted for reference in the models computed with the Schwarzschild criterion.