+ else raise (Invalid_argument "Array.map3 size not matched.");;
+
+let decorate = fun s -> " Faustine -> " ^ s;;
+
+let xor : bool -> bool -> bool =
+ fun a -> fun b -> (a || b) && (not (a && b));;
+
+let rint : float -> float =
+ fun f ->
+ if (f -. (floor f)) >= 0.5 then ceil f
+ else floor f;;