add Church encodings

diff --git a/topics/_assignment2.mdwn b/topics/_assignment2.mdwn
index e223cd1..bacd676 100644 (file)
--- a/topics/_assignment2.mdwn
+++ b/topics/_assignment2.mdwn
@@ -163,7 +163,10 @@ Numbers
 
 26. Given that we've agreed to Church's encoding of the numbers:
 
-    BLAH
+    <code>0 &equiv; \f z. z  
+    <code>1 &equiv; \f z. f z  
+    <code>2 &equiv; \f z. f (f z)  
+    <code>3 &equiv; \f z. f (f (f z))  
+    <code>...</code>
 
     How would you express the `succ` function in the Lambda Calculus?
-