sig
exception Typing_error of string
exception Not_yet of string
val untypable : string -> 'a
val not_yet : string -> 'a
val handle : ('a -> 'a) -> 'a -> 'a
val generic_handle : ('a -> 'b) -> 'b -> 'a -> 'b
val nb_untypable : unit -> int
val nb_not_yet : unit -> int
end