(* A Lying Interface *) let ap : (int -> int) -> int -> int = fun (f: int -> int) -> fun (x: int) -> f (f x) (* f is used twice here, despite what iap2 claims *) let iap2 = (ap :> (int -o int) -> int -o int) let inc : int -> int = fun (y: int) -> (fun (g: int -o int) -> iap2 g y) (fun (z: int) -> z + 1) in print (inc 5)