User blog comment:Nedherman1/Is it possible something like omega^...(n)...^omega?/@comment-39541634-20191214192519/@comment-30004975-20191214215408

It's generally accepted that w^^^w=the limit of {w^^w,w^^(w^^w),w^^(w^^(w^^w)),...}. The hard part is defining expressions like w^^(w+1).