let p s n = print_string (s^string_of_int n^"\n"); flush stdout

(*version 1*)
let acc f init =
    let vR = ref init in
    let fApp x =
	let newX = f !vR x in
	vR := newX;
	newX in
    fApp

let f1 = acc (+) 0

let _ = p "f1:" (f1 1)
let _ = p "f1:" (f1 1)
let _ = p "f1:" (f1 1)

(*version 2*)
let acc' f init =
    let vR = ref init in
    let fApp x =
	let newX = f !vR x in
	vR := newX;
	newX
    and fIni x = (vR := x) in
    (fApp,fIni)

let (f1a,f1i) = acc' (+) 0

let _ = p "f1a:" (f1a 1)
let _ = p "f1a:" (f1a 1)
let _ = p "f1a:" (f1a 1)
let _ = f1i (-5)
let _ = p "f1a:" (f1a 1)
let _ = p "f1a:" (f1a 1)
let _ = p "f1a:" (f1a 1)