sig
type 'a ty = 'a Type.t
type t
val create : int -> Type.StringTbl.t
val add : Type.StringTbl.t -> string -> 'a Type.StringTbl.ty -> 'a -> 'a
exception Unbound_value of string
exception Incompatible_type of string
val find : Type.StringTbl.t -> string -> 'a Type.StringTbl.ty -> 'a
end