@article{Støvring_2006, title={Extending the Extensional Lambda Calculus with Surjective Pairing is Conservative}, volume={13}, url={https://tidsskrift.dk/brics/article/view/21911}, DOI={10.7146/brics.v13i5.21911}, abstractNote={We answer Klop and de Vrijer’s question whether adding surjective-pairing axioms to the extensional lambda calculus yields a conservative extension. The answer is positive. As a byproduct we obtain the first ``syntactic’’ proof that the extensional lambda calculus with surjective pairing is consistent.}, number={5}, journal={BRICS Report Series}, author={Støvring, Kristian}, year={2006}, month={Mar.} }