edits

diff --git a/week7.mdwn b/week7.mdwn
index 78a4150..d3e4b47 100644 (file)
--- a/week7.mdwn
+++ b/week7.mdwn
@@ -6,6 +6,10 @@ Towards Monads: Safe division
 
 [This section used to be near the end of the lecture notes for week 6]
 
 
 [This section used to be near the end of the lecture notes for week 6]
 

+We begin by reasoning about what should happen when someone tries to
+divide by zero.  This will lead us to a general programming technique
+called a *monad*, which we'll see in many guises in the weeks to come.
+

 Integer division presupposes that its second argument
 (the divisor) is not zero, upon pain of presupposition failure.
 Here's what my OCaml interpreter says:
 Integer division presupposes that its second argument
 (the divisor) is not zero, upon pain of presupposition failure.
 Here's what my OCaml interpreter says: