X-Git-Url: http://lambda.jimpryor.net/git/gitweb.cgi?p=lambda.git;a=blobdiff_plain;f=topics%2Fweek4_fixed_point_combinators.mdwn;h=1ed99d2772714a37401cb03168bc651241b858c0;hp=601ad813bdd87e87521b80a0965e8803cbc1219a;hb=5c234a526ad9ecc96ae9d17b6f74de53a0354444;hpb=a29958c3e11fa8ae383aacff54ce7f405def0705

diff --git a/topics/week4_fixed_point_combinators.mdwn b/topics/week4_fixed_point_combinators.mdwn
index 601ad813..1ed99d27 100644
--- a/topics/week4_fixed_point_combinators.mdwn
+++ b/topics/week4_fixed_point_combinators.mdwn
@@ -293,6 +293,7 @@ The strategy we will present will turn out to be a general way of
 finding a fixed point for any lambda term.
 
 
+<a id=deriving-y></a>
 ## Deriving Y, a fixed point combinator ##
 
 How shall we begin?  Well, we need to find an argument to supply to
@@ -553,9 +554,9 @@ then this is a fixed-point combinator:
 For those of you who like to watch ultra slow-mo movies of bullets
 piercing apples, here's a stepwise computation of the application of a
 recursive function.  We'll use a function `sink`, which takes one
-argument.  If the argument is boolean true (i.e., `\x y. x`), it
+argument.  If the argument is boolean true (i.e., `\y n. y`), it
 returns itself (a copy of `sink`); if the argument is boolean false
-(`\x y. y`), it returns `I`.  That is, we want the following behavior:
+(`\y n. n`), it returns `I`.  That is, we want the following behavior:
 
     sink false <~~> I
     sink true false <~~> I