week2 tweak

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

diff --git a/week2.mdwn b/week2.mdwn
index 13d1d44..8805838 100644 (file)
--- a/week2.mdwn
+++ b/week2.mdwn
@@ -36,9 +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>
 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;. &lambda;. z x) 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.
 </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.