Plots depicting three methods of distinguishing O- and C-rich variable stars (from left to right): slope-colour amplitude a_V(amp_VI), slope-K magnitude a_V(K) and slope-J − K colour a_V(J − K), for EROS LMC (top) and SMC (bottom) data. Vertical lines indicate adopted TRGB dividing RGB and AGB stars. See text for a detailed description of the methods and parameters of the boundaries. Black, dark grey, and light grey dots (blue, red, and green in electronic edition) respectively mark O- and C-rich AGB stars and O-rich RGB ones, classified using K magnitudes for AGB/RGB and leftmost panels for O/C content.