Fix a typo in the run function.

diff --git a/matthijs/introduction.lhs b/matthijs/introduction.lhs
index 6a55aa26a0b386dc53c280f83dd99124027a732b..2fb28466b0e51fc835ccb41c4735c970ef2fbb93 100644 (file)
--- a/matthijs/introduction.lhs
+++ b/matthijs/introduction.lhs
@@ -180,7 +180,7 @@ in (State sum, sum)
 
   \begin{block}{Recursive run function}
     run f (i:is) s = let
-      (o, s') = f i s
+      (s', o) = f i s
     in o : (run f is s')
   \end{block}