anchor.diff:  
   /// Prints a ((hol_type * hol_type) list) to formatter.
   let pp_print_list_typtyp fmt (al : (hol_type * hol_type) list) =
  +    // CLEAN : Use List.iter instead of a recursive function here.
       let rec pp_print_list_typtypInner fmt al =
           match al with
           | [] -> ()
  
positive.code: let string_of_list_typtyp = print_to_string pp_print_list_typtyp
  
  (* ------------------------------------------------------------------------- *)
  (* Install all the printers.                                                 *)
  (* ------------------------------------------------------------------------- *)
  
  
negative.code:         fun tm ->
              try
                  print_term 0 tm
              with Failure _ as ex ->
                  (* NOTE :   We currently suppress certain exceptions which may be raised during
                              printing; however, we do log them for diagnostics purposes. *)
                  logger.DebugException ("Suppressed exception in 'pp_print_term'.", ex)
  