diff --git a/Algo/Courses/Chapter 6 - Lists (Exercises).md b/Algo/Courses/Chapter 6 - Lists (Exercises).md
index e5e8947..d5fd561 100644
--- a/Algo/Courses/Chapter 6 - Lists (Exercises).md	
+++ b/Algo/Courses/Chapter 6 - Lists (Exercises).md	
@@ -120,7 +120,7 @@ let rec arith_list n a1 r =
 	if n <= 0 then
 		invalid_arg "invalid rank n"
 	else
-		let rec f ai = function
+		let rec f a i = function
 			| 0 -> []
 			| i -> (a1+(n-i)+r)::f(ai+r) (i-1)
 		in f ai n;;