let to_string object_to_string b =
  let layout = ref [] in
  let rec aux_h current_s =
    function
	[] -> layout := current_s::!layout
      | Box.Text (_,s)::tl -> aux_h (current_s ^ s) tl
      | (Box.Space _)::_ -> assert false
      | Box.H (_,bl)::tl -> aux_h current_s (bl@tl)
      | Box.V (_,[])::tl -> aux_h current_s tl
      | Box.V (_,[b])::tl -> aux_h current_s (b::tl)
      | Box.V (_,b::bl')::tl ->
	  aux_h current_s [b] ; 
	  aux_h (String.make (String.length current_s) ' ') (Box.V([],bl')::tl)
      | Box.Object (_,obj)::tl -> aux_h (current_s ^ (object_to_string obj)) tl
      | (Box.Action _)::tl -> assert false
  in
    aux_h "" [b] ;
    List.rev !layout

let pp_term t = String.concat "\n" (to_string CicAstPp.pp_term (Ast2pres.ast2box t))