CEMP-s/r star CS22898–027. Points with error bars: observed abundances, in black the elements adopted in Eq. (1), in grey the other elements. Red solid line: the best-fitting model found with model set A, M_1,i = 1.5 M_⊙ and M_PMZ = 6.66 × 10^-4M_⊙. Blue dashed line: alternative model with M_1,i = 2 M_⊙ and M_PMZ = 4 × 10^-3M_⊙. Lower panel: the residuals of the two models, computed with Eq. (2), are shown as red plus signs with error bars and blue triangles, respectively.