primitive recursive function

P(n) 的最短證明的長度作為 n 的函數增長得非常快，遠遠快於任何原始遞歸函數（英語：primitive recursive function）或阿克曼函數。 P(n) 所適用的最小 m 同樣隨 n 增長得非常快。 透過合併標籤，弗里德曼定義了一個成長速度更快的函數。[8]對於正整數

Marcus, Solomon; Tevy, Ionel. The first example of a recursive function which is not primitive recursive. Historia Mathematica. 1979, 6 (4): 380–384. doi:10

where the denotations of recursive programs is built up corecursively in this way. In Python, a recursive factorial function can be defined as: def factorial(n):

and recursive function definitions are universal computationally, it is interesting to display the relation between them. The translation of recursive symbolic

to use the traditional LABEL primitive in this interpreter because it is difficult to define several mutually recursive functions using only LABEL. The