To finish off this treatment of ordinal collapsing functions, I go back to the fastgrowing hierarchy and just look at a few little bits of what the expansion of f(alpha,3) would involve when alpha is the BachmannHoward ordinal, the limit of the simplest version of an OCF. Future videos may include: Rayo's number, Loader's number, more intricate OCFs, and the Busy Beaver function, but I'll take a break for now.