fix links to v4 lists

Signed-off-by: Jim Pryor <profjim@jimpryor.net>

diff --git a/week4.mdwn b/week4.mdwn
index 5e21948..e3f0fb9 100644 (file)
--- a/week4.mdwn
+++ b/week4.mdwn
@@ -437,7 +437,7 @@ of the list multiplied to, because that would affect the answer you passed
 along to the continue-leftwards handler.
 
 A **version 5** list encodes the kind of fold operation we're envisaging here, in
-the same way that v3 (and [v4](/advanced/#v4)) lists encoded the simpler fold operation.
+the same way that v3 (and [v4](/advanced/#index1h1)) lists encoded the simpler fold operation.
 Roughly, the list `[5;4;3;2;1]` would look like this:
 
 
@@ -566,6 +566,6 @@ detail](http://okmij.org/ftp/Streams.html#enumerator-stream).
                                larger_computation
 
 3.     To extract tails efficiently, too, it'd be nice to fuse the apparatus developed
-       in these v5 lists with the ideas from [v4](/advanced/#v4) lists.
+       in these v5 lists with the ideas from [v4](/advanced/#index1h1) lists.
        But that also is left as an exercise.