Mathematics Atlas

How Proof Is Made
Sign In
Text size
100%
Theme
Theorem

Kleene's Recursion Theorem

Logic and Foundations

Kleene's Recursion Theorem states that for any computable function that transforms one program into another, there exists a program that computes the same function as the program it is transformed into, so that every such transformation has a fixed point among the programs. Named for Stephen Kleene, it is a foundational result of computability theory underlying self-referential constructions such as programs that access and act on their own source code.

Facts
Statement
For any partial recursive function Q of two arguments there is an index p such that the partial recursive function computed by program p is equivalent to the function sending y to Q(p, y), so a self-referential program can always be constructed for a given task. 1
Proof Year
1938 1
Sources
1. Kleene's Recursion Theorem (Wikipedia)
Wikimedia Foundation
  • Kleene's second recursion theorem section
    One informal interpretation of the second recursion theorem is that it is possible to construct self-referential programs
  • lead section, second sentence
    The theorems were first proved by Stephen Kleene in 1938 and appear in his 1952 book Introduction to Metamathematics.
View the Source
Comments (0)
No comments yet. Be the first to share a thought.
Reader Challenges (0)
No disputes yet. Spotted an error or a better source? Open the first one.