Lambda Calculus in de Bruijn's Notation

This theory defines lambda-calculus terms with de Bruijn indixes and proves confluence of beta, eta and beta+eta.

Beta is proved confluent both in the traditional way (see Barendregt's book) and also following Takahashi's elegant version using developments.

A report describing the whole theory with the exception of eta-reduction is found here: More Church-Rosser Proofs (in Isabelle).