Grzegorczyk hierarchy

The Grzegorczyk hierarchy is a classification of functions based on their computability in the context of mathematical logic and computability theory. It provides a way to categorize certain classes of total recursive functions, which are functions that are defined for all natural numbers. The hierarchy is named after the Polish mathematician and logician Andrzej Grzegorczyk, who introduced it in the context of studying the structure of computable functions.