typo in Rfun example program

book.tex

@@ -9137,7 +9137,7 @@ The program applies
 \end{lstlisting}
 \begin{lstlisting}[style=ocaml]
 (define mapvec (f : (int -> int)) (v : (# int int)) : (# int int)
-  (#  (f (! 0 v)) (f (! 1 v)))
+  (#  (f (! 0 v)) (f (! 1 v))))
 
 (define add1 (x : int) : int 
   (+ x 1))