X-Git-Url: http://lambda.jimpryor.net/git/gitweb.cgi?p=lambda.git;a=blobdiff_plain;f=week2.mdwn;h=f9786785d8eb109ccaeb69b3284ae8ab05898015;hp=880583896707504a4419652fdf2cd124d3797ab1;hb=4de03f98830a8404cfdcf256c719661d5ab85787;hpb=5da5bda6005474c49ec76ad89dfd92959388b030

diff --git a/week2.mdwn b/week2.mdwn
index 88058389..f9786785 100644
--- a/week2.mdwn
+++ b/week2.mdwn
@@ -36,10 +36,10 @@ Another way to think of it is to identify expressions not with particular alphab
 A third way to think is to identify the lambda formula not with classes of alphabetic sequences, but rather with abstract structures that we might draw like this:
 
 <pre><code>
-	(&lambda;. &lambda;. z x) y
-    ^  ^  | |
-    |  |__| |
-    |_______|
+	(&lambda;. &lambda;. _ _) y
+     ^  ^  | |
+     |  |__| |
+     |_______|
 </code></pre>
 
 Here there are no bound variables, but there are *bound positions*. We can regard formula like (a) and (b) as just helpfully readable ways to designate these abstract structures.