(* Imbrication de if then else *)

let number : int ref = ref 0 in

if !number = 0 then
    print_string "zero"
else 
if !number > 0 then 
    if true then 
      print_string "positif" 
    else 
      print_string "??"
else
if !number < 0 then
    print_string "negatif"
;;