7.3: Recursive Functions
7.3.1: McCarthy's 91 Function
Read the Wikipedia article for a description of the McCarthy 91 function, an example of a recursive function used in computer science as a test case for the performance of formal verification techniques and methods.
7.3.2: The Ackermann Function
Read the Wikipedia article for a description of the Ackermann function, an example of a recursive function that grows very rapidly.