Equivalent to Figure 5 for a 20 M_⊙ model. Not all primary EEPs are shown in both panels. Note that in the T_c–ρ_cplane two pairs of primary EEPs are nearly coincident: ZAMS and IAMS; RGBTip and ZACHeB. The RGBTip primary EEP does not have the same significance in such high-mass stars but is maintained for consistency, as noted in the text.