More Church-Rosser Proofs in BELUGA

Abstract

We report on yet another formalization of the Church-Rosser property in lambda-calculi, carried out with the proof environment Beluga. After the well-known proofs of confluence for beta-reduction in the untyped settings, with and without Takahashi's complete developments method, we concentrate on eta-reduction and obtain the result for beta-eta modularly. We further extend the analysis to typed-calculi, in particular System F. Finally, we investigate the idea of pursuing the encoding directly in Beluga's meta-logic, as well as the use of Beluga's logic programming engine to search for counterexamples.