User blog comment:P進大好きbot/Proposal to Choose an Official Standard OCF in This Wiki/@comment-11227630-20191219030804/@comment-28606698-20191219202526

I’m not familiar with Rathjen's OCF for Π3-reflection, but I noticed on the page 8 Rathjen directly noted: Closure of C(α,β) under ξ↦Ω_ξ is only demanded for technical convenience. This closure property does not contribute to the strength of the intended ordinal notation system. Likewise, it would suffice to demand only closure under ξ↦ω^ξ instead of ϕ.