Comparative plots of stellar model interiors. Left: mixing profiles for two stellar models of 3 M_⊙ and X_c = 0.3 for the convective core (grey), convective boundary region (CBM, blue) and radiative envelope region (REM, green) plotted against the logarithm of the mass coordinate q = m/M_⋆. The model with mixing profiles indicated as hatched regions has eight times higher CBM and 100 times higher REM than the other model, leading to an increase in core mass of 36.5%. Right: logarithm of N² of the two models plotted against the logarithm of the mass coordinate q. The solid red line denotes N² of the model with a minimum amount of interior mixing, while the dashed black line denotes N² of the model with eight times higher CBM and 100 times higher REM.