Comparison between observed [Ba/Fe], [La/Fe], and [Ce/Fe] vs. [Fe/H] trends and the predictions of the Pareto optima models (magenta lines). The thicker magenta lines show the predicted [Ba/Fe], [La/Fe], and [Ce/Fe] vs. [Fe/H] trends for the Pareto optimal model with the smallest distance to the ideal point (0, 0, 0) in objective space. The dashed black curves represent the best-fit model to the specific element. The lower, light blue lines represent the results of the model in case there is only the s-process contribution. Grey circles with error bars show the average observational values in metallicity bins. Residual relative to the binned observations are displayed in the lower panels. Symbols for the observational data are the same as in Figure 3.