From: jim Date: Sat, 14 Feb 2015 23:23:19 +0000 (-0500) Subject: add Lennon link X-Git-Url: http://lambda.jimpryor.net/git/gitweb.cgi?p=lambda.git;a=commitdiff_plain;h=f41c2c72434b36288f17c652f010cb6e29e56f73;ds=sidebyside add Lennon link --- diff --git a/topics/week3_church_arithmetic.mdwn b/topics/week3_church_arithmetic.mdwn index 55f5ab22..8907c12a 100644 --- a/topics/week3_church_arithmetic.mdwn +++ b/topics/week3_church_arithmetic.mdwn @@ -71,3 +71,5 @@ Interestingly, `mul l r` defined in that second way eta-reduces to `\f. r (l f)` If we continue in this direction, we end up defining `l^r` (where `2^5` is `32`) either as `r (mul l) one` or as the *application* `r l` of `r` to `l`. Not all of the arithmetic encodings are so neat and elegant, however. As we mentioned, `pred` takes some ingenuity. We'll also have you define `zero?` and ≤ for homework. + +Here is an example of [some programmers having fun with Church numbers](http://www.schemers.org/Miscellaneous/imagine.txt).