History of convective core extent during the core helium burning phase for a non-rotating 3  M _☉ star with various mixing options, as in Figure 13. Time is measured relative to the onset of the convective core burning. Efficient semiconvection (α _sc = 0.01) and inefficient overshooting ( f _ov = 10 ⁻⁵) coincide with the pure Schwarzschild model. The filled (open) circle indicates the time for which we display a profile detailing semiconvection (overshooting) in Figure 11.