Examples of reverse Algol evolution. Left panel: Model that undergoes nuclear-timescale, slow, Case A mass transfer in the reverse Algol configuration. The initial donor mass, mass ratio, and orbital period of the model are 63.0 M_⊙, 0.5, and 100 d, respectively. Right panel: Model that detaches after fast Case A mass transfer. The initial donor mass, mass ratio, and orbital period of the model are 44.6 M_⊙, 0.5, and 7.9 d, respectively. We show selected stellar parameters as a function of time, where t = 0 denotes the ZAMS of both stars. (a): Donor (red) and accretor (blue) mass. (b): Mass transfer rate Ṁ_t (thick red line) and wind mass-loss rate of the donor (− Ṁ_w,d, red dotted line). (c): Ratio of the donor and accretor radius to their respective Roche lobe radii. (d): Orbital period. (e): Orbital velocity of donor and accretor. (f): Central helium mass fraction of donor and accretor. (g): Surface helium mass fraction. (h): Surface nitrogen mass fraction enhancement factor.