Extending the Extensional Lambda Calculus with Surjective Pairing is Conservative

摘要

We answer Klop and de Vrijer's question whether adding surjective-pairingaxioms to the extensional lambda calculus yields a conservative extension. Theanswer is positive. As a byproduct we obtain a "syntactic" proof that theextensional lambda calculus with surjective pairing is consistent.