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Extracting a Normalization Algorithm in Isabelle/HOL

  • Stefan Berghofer
Part of the Lecture Notes in Computer Science book series (LNCS, volume 3839)

Abstract

We present a formalization of a constructive proof of weak normalization for the simply-typed λ-calculus in the theorem prover Isabelle/HOL, and show how a program can be extracted from it. Unlike many other proofs of weak normalization based on Tait’s strong computability predicates, which require a logic supporting strong eliminations and can give rise to dependent types in the extracted program, our formalization requires only relatively simple proof principles. Thus, the program obtained from this proof is typable in simply-typed higher-order logic as implemented in Isabelle/HOL, and a proof of its correctness can automatically be derived within the system.

Keywords

Normal Form Normalization Algorithm Introduction Rule Typing Judgement Typing Derivation 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Springer-Verlag Berlin Heidelberg 2006

Authors and Affiliations

  • Stefan Berghofer
    • 1
  1. 1.Institut für InformatikTechnische Universität MünchenGarchingGermany

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