[X/Fe] versus [Fe/H] abundance patterns for Si, Y, Ba, and Eu as predicted by the three-infall model at R_GC = 6, 8, 12 kpc compared to the sample of OCs (colored dots) and field (grey dots) stars in the inner, solar, and outer regions, respectively. Results of the synthetic model, as well as OCs, are plotted only for Age ≤3 Gyr. In the lower right panel, for the prediction of the [Eu/Fe] versus [Fe/H] in the outer regions, the filled magenta circles indicate the [Eu/Fe] at a given age.