User blog comment:Googology Noob/Question Mark Notation/@comment-25337554-20160102223947/@comment-27173506-20160103055712

Thanks for looking!

However, I don't think this is the case with this notation. I actually have 3 different possible extensions, one of which reaches at least e_1, and two which reach e_w. zeta_0 seems a much harder barrier to me, though I believe that with a proper extension of one of my extensions I can reach it without much trouble.