User blog comment:Mh314159/Natural number recursion - first 4 rule sets/@comment-37224188-20191020010014/@comment-37556263-20191031204846

Superscripts typically refer to recursion (eg. \(f^3_2(3)\) means to iterate \(f_2(3)\) three times, meaning \(f^3_2(3) = f_2(f_2(f_2(3)))\) ), and subscripts usually are ways to enumerate, or give a numerical label to something (eg. \(f^3_2(3)\) refers to the FGH indexed by the ordinal 2, just one in an infinite number of other ordinals, because remember it's the fast-growing hierarchy).

Do you understand this?