let rec ack = function n -> function m ->
  if (n = 0) 
  then 
    m + 1 
  else
    if (m = 0)
    then 
      ack (n - 1) 1
    else 
      ack (n - 1) (ack n (m - 1)) ;;

let min_list = function l -> match l with
  | [] -> failwith "Liste vide"
  | h::t -> it_list min h t ;;

let min_list = 
  let rec aux = function m -> function
    | [] -> m
    | h::t ->
      if (h < m)
      then aux h t
      else aux m t
  in 
    function l -> match l with 
      | [] -> failwith "Liste vide"
      | h::t -> aux h t ;;