Operational aspects of untyped Normalisation by Evaluation

  • Authors:
  • Klaus Aehlig;Felix Joachimski

  • Affiliations:
  • Mathematisches Institut der Ludwig-Maximilians-Universität München, Theresienstrasse 39, 80333 München, Germany;Mathematisches Institut der Ludwig-Maximilians-Universität München, Theresienstrasse 39, 80333 München, Germany

  • Venue:
  • Mathematical Structures in Computer Science
  • Year:
  • 2004

Quantified Score

Hi-index 0.00

Visualization

Abstract

A purely syntactic and untyped variant of Normalisation by Evaluation for the $\lambda$-calculus is presented in the framework of a two-level $\lambda$-calculus with rewrite rules to model the inverse of the evaluation functional. Among its operational properties there is a standardisation theorem that formally establishes the adequacy of implementation in functional programming languages. An example implementation in Haskell is provided. The relation to the usual type-directed Normalisation by Evaluation is highlighted, using a short analysis of $\eta$-expansion that leads to a perspicuous strong normalisation and confluence proof for $\beta\eta\!\up$-reduction as a byproduct.