Which number is larger:(10 to the 87th minus 1) factorial or Tree(4)?

[DPRK]

Rayo says

…there is to be a `gentleman’s agreement’, to the effect that each new entry must name a number big enough so as to not be reachable in practice using only methods introduced earlier in the game. (This means that it would be considered unsporting to win by adding one to your opponent’s last entry.)

[k9bfriender]

@Steven_Estes

ME: any “arrow number” can be surpassed by simply adding 1.

SAFFTER: No, Graham’s number is an arrow number

ME: 4↑↑↑↑4, for example, is not writable in our usual mathematical notation m in the known universe.

But is’t’ 4↑↑↑↑4t still a number identical to a number not writeable in our known universe, but still a (non-writable)number in our usual mathematical notation(which we’ll call x).

If so, isn’t x+1 larger than 4↑↑↑↑4?

And Graham’s number can be surpassed simply by adding 1 as well.