User blog comment:Nayuta Ito/Is this bigger than Rayo's number?/@comment-27513631-20180504234554/@comment-25337554-20180505002453

>I can barely interpret what f is defined as.

I guess I should rewrite this.

>A is used both as an arbitrary axiom and as Peano arithmetic, so it's unclear what this actually means.

A connotes PA, but A is not PA itself.

>A_ZFC is not the standard notation of any theory, regardless of A.

A_ZFC is "ZFC axioms combined by AND operator in FOL".

I will ask the rest of questions to the original author.