User blog comment:Jamazzzzzzzz/X^^^X structures DO reach gamma 0/@comment-5150073-20190603145004

Yes, X^^(X^2) is indeed equivalent to zeta_0, because X^^(X^2) is {X^^X}^{X^^X}...{X^^X}^{X^^X}, and every {X^^X} is a new layer of epsilons.

{X^^X}^{2} would be epsilon_1.