let p = fn x -> fn xs -> pair x xs in
let list = p 1 (p 2 (p 3 (p 0 (p 4 (p 5 Unit))))) in
let mult = fn xs -> fn k ->
  begin 
    set (triple 1 xs Unit); 
    while isPair (snd3 get) do begin
      let r = fst3 get in 
      let xs = snd3 get in 
      let o = thd3 get in
      let n = fst xs in
      let ys = snd xs in
      if n==0 then k 0
      else set (triple (r*n) ys (o ++ " " ++ n))
    end; 
    fst3 get 
  end in 
let result = callcc (fn k -> mult list k) in
get