This function was made in 2007 by a Japanese googologist named Taro, which finally described and defined in 2013 by Fish. It is an extension of a two variable Ackermann function, which is covered in the previous section. It exhibits a growth rate of ω^ω in fast-growing hierarchy, which is on par with most linear array notations of any kind.
What makes it different with Ackermann function is that this function can be extended up to 3 arguments, while the Ackermann function is only limited to 2 arguments. Yet, somehow, Taro managed to define this notation so that it will grow up to ω^ω level in fast-growing hierarchy. So, let's get started with the definition, shall we?
There are multiple rules for creating this function:
Let X = vector of integers