edits

diff --git a/week4.mdwn b/week4.mdwn
index 06581f0..8d89a5a 100644 (file)
--- a/week4.mdwn
+++ b/week4.mdwn
@@ -15,6 +15,9 @@ let X = WW in
 X = WW = (\x.T(xx))W = T(WW) = TX
 </pre>
 
+Please slow down and make sure that you understand what justified each
+of the equalities in the last line.
+
 Q: How do you know that for any term T, YT is a fixed point of T?
 
 A: Note that in the proof given in the previous answer, we chose `T`