HRD of a primary star in the subsample from the ZAMS to the end of the CHeB stage computed with BINARY_C V2.2.3. The CEE begins when the primary star has a helium-core mass of about 0.279 M_⊙ (arrow in the figure), and it ends with the ejection of 1.12 M_⊙ of material from the system. The simulation begins with a 1.60 M_⊙ ZAMS primary star orbiting a 0.25 M_⊙ companion in almost 32 days. The primary star begins the CHeB stage at the age of 2.41 Gyr and a mass of 0.70 M_⊙. In black we plot the observed values for KIC4937011 (see also Table 3).