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diff --git a/topics/_week7_monads.mdwn b/topics/_week7_monads.mdwn
index 75bc2051..da0b0080 100644
--- a/topics/_week7_monads.mdwn
+++ b/topics/_week7_monads.mdwn
@@ -48,5 +48,23 @@ We'll often write box types as a box containing the value of the free
 type variable.  So if our box type is `α List`, and `α == Int`, we
 would write
 
-<table border=2px><td>Int</td></table>
+<u>Int</u>
 
+for the type of a boxed Int.
+
+At the most general level, we'll talk about *Kleisli arrows*:
+
+P -> <u>Q</u>
+
+A Kleisli arrow is the type of a function from objects of type P to
+objects of type box Q, for some choice of type expressions P and Q.
+For instance, the following are arrows:
+
+Int -> <u>Bool</u>
+
+Int List -> <u>Int List</u>
+
+Note that the left-hand schema can itself be a boxed type.  That is,
+if `α List` is our box type, we can write the second arrow as
+
+<u>Int</u> -> <u><u>Int</u></u>