Mass of heavy elements in the core and in the envelopes predicted with MH13+SCvH. The heavy element abundances in the envelopes are indicated by dashed lines in units of the solar abundance of heavy elements. (a) The results of Cases (I) and (II) are displayed in red circles and in blue stars, respectively, reflecting the effect of the different rotation period. (b) The results of Case (III) are displayed according to different helium depletions Y₁ ∕(X₁ + Y₁) as specified in the legend.