sig
  type implem_state = Loaded | Not_initialized | Check_inited of int
  type filename = string
  type linking_error =
      Undefined_global of string
    | Unavailable_primitive of string
    | Uninitialized_global of string
  type error =
      Not_a_bytecode_file of string
    | Inconsistent_import of string
    | Unavailable_unit of string
    | Unsafe_file
    | Linking_error of string * Dynlink_types.linking_error
    | Corrupted_interface of string
    | Cannot_open_dynamic_library of exn
    | Library's_module_initializers_failed of exn
    | Inconsistent_implementation of string
    | Module_already_loaded of string
    | Private_library_cannot_implement_interface of string
  exception Error of Dynlink_types.error
  val error_message : Dynlink_types.error -> string
end