Example spectra and the fitted synthesis of Ce II lines for 2M12451043+1217401 in the observed infrared spectrum (gray unfilled squares). The printed best-fitted abundance (black thick line) values might not be the same as in Table 1 because the table contains averaged values, not individual fits. The blue and green lines correspond to synthetic spectrum abundance choices that are offset from the best fit by   ±  0.2 dex. The spectrum of the N-rich star is compared to the spectrum of a normal star with [Ce/Fe] = +0.34 dex (the red line corresponds to APOGEE_ID: 2M12251747+1450078, labeled as Normal RGB), with similar stellar parameters.