User blog comment:JHeroJr/A computable function/@comment-35470197-20190623231332/@comment-35470197-20190623234849

There is only one hierarchy named FGH, which is itself uncomputable. When we work in computable googology, we use a computable segment of it using a recursive system of fundamental sequence.

Well, what you added is the definiton of FGH, but is not the definition of the language of FGH. Do you know the mathematical definition of "language"? If no, I recommend you to use stuffs whose definitions you actually know in order to avoid the ill-definedness due to the lack of the knowledge of the definitions.