X-Git-Url: http://lambda.jimpryor.net/git/gitweb.cgi?p=lambda.git;a=blobdiff_plain;f=topics%2Fweek4_fixed_point_combinators.mdwn;h=ed22cfff6225d1841de515a7e2821532aa29be39;hp=b20212d6148776fc9d191d55b835e55d82676ead;hb=6694165ac4d6edab602b3ad3651d0a5931b36a0e;hpb=145310e497b03752f7895ab007bf1b4fdd958ad9

diff --git a/topics/week4_fixed_point_combinators.mdwn b/topics/week4_fixed_point_combinators.mdwn
index b20212d6..ed22cfff 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
@@ -533,7 +534,7 @@ to *the tail* of the list we were evaluating its application to at the previous
 
 ## Fixed-point Combinators Are a Bit Intoxicating ##
 
-[[tatto|/images/y-combinator-fixed.jpg]]
+[[tatto|/images/y-combinator-fixed.png]]
 
 There's a tendency for people to say "Y-combinator" to refer to fixed-point combinators generally. We'll probably fall into that usage ourselves. Speaking correctly, though, the Y-combinator is only one of many fixed-point combinators.