User blog comment:Kyodaisuu/English description of Fish numbers/@comment-1605058-20131102141329/@comment-24061664-20131102144315

Do you mean that by writing FOST in FOST, it is similar to writing oracle formula f(a)=b? Maybe yes, and maybe no, because Rayo function is the function that is larger than any FOST formula, which implements FOST in FOST. Rayo function diagonizes all over the FOST, which already implements FOST in FOST in FOST ... in FOST. Therefore, implementing Rayo function as oracle formula is stronger than FOST in FOST. It is difficult and I don't have confidence.