User blog comment:Nayuta Ito/An attempt to well-define OCF as a number notation/@comment-32697988-20190428074647/@comment-35470197-20190429010314

By the way, "S_(k+1)=ψ_Ω([S_0]) for every natural number k" does not make sense. (Maybe S_0 is a typo of S_k, but it is not a problem here.) It is because you just allowed [n] for a positive integer n, but not for an erdinal.