Ebook: Appendix S1: G¨odel’s Consistency-Proof for Arithmetic (supplement to "Lambda-Calculus and Combinators, an Introduction")

This Supplement is a continuation of Hindley and Seldin 2008, from which it was omitted to avoid delaying that book’s publication and increasing its length unacceptably. Its aim is to describe a combinator-based account of G¨odel’s proof of
the consistency of first-order arithmetic [G¨od58]. It is a revised version of [HS86, Ch.18] and its predecessors, [HLS72, Ch.11] and [Hin68, Ch.5]. The notation in this Supplement is from Hindley and Seldin 2008.