Proof checking

Reduction

Computing a term according to the core language's evaluation rules.

Definition

Reduction

Reduction replaces a term with a computationally simpler term allowed by the calculus.

Function application can substitute an argument into a body, and pattern matching can select a constructor case. Kernels use reduction when deciding definitional equality.

01

Example

Applying the function fun x => x + 1 to 2 reduces to 2 + 1 and then to 3.

02

Important distinction

Reduction follows built-in computation rules. It does not apply every proved mathematical equality automatically.

After reading this article, you should be able to

  • Define Reduction in the sense used on this site.
  • Perform one beta-reduction and explain why it preserves the term's meaning.