return_frag.ml

(* correct types *)
val time: ptr time_t @-> returning time_t
val difftime: time_t @-> time_t @-> returning double
(* part 1 *)
(* incorrect types *)
val time: ptr time_t @-> time_t
val difftime: time_t @-> time_t @-> double
(* part 2 *)
val curried : int -> int -> int
(* part 3 *)
val curried : int -> (int -> int)