User blog comment:Kyodaisuu/English description of Fish numbers/@comment-25418284-20131102173245/@comment-24061664-20131103182044

I think you might be right that you can have a FOST expression for Rayo function. However, if you write FOST expression which exceeds Rayo function, that expression does not specify any number because of contradiction. Therefore, it is true that there is an expression, but that expression does not work effectively to exceed Rayo function.