Program Extraction from Proofs of Weak Head Normalization

Magorzata Biernacka
Olivier Danvy
Kristian StÝvring

April 2005


We formalize two proofs of weak head normalization for the simply typed lambda-calculus in first-order minimal logic: one for normal-order reduction, and one for applicative-order reduction in the object language. Subsequently we use Kreisel's modified realizability to extract evaluation algorithms from the proofs, following Berger; the proofs are based on Tait-style reducibility predicates, and hence the extracted algorithms are instances of (weak head) normalization by evaluation, as already identified by Coquand and Dybjer

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Last modified: 2005-05-02 by webmaster.