I am reposting, because few people have seen (at least I think, because there was only one person comment), if you want me to delete this, there is no problem, so as not to be just a copy of my other post, I'll put some other information on this.
Note: In the penultimate example, I used any symbol to represent an ordinal which is an infinite "tower" of the last example, in this case an infinite tower of Gamma 0.
To demonstrate how powerful this is, if we use 2f!, we have a number greater than the G64!