`type t`
`val print : Stdlib.Format.formatter -> t -> unit`
`val equal : t -> t -> bool`
`val idx : t -> int`
`val of_idx : int -> t`
`val to_string : ?origin:t -> t -> string`
`val fresh : unit -> t`
`val fresh_n : string -> t`
`val fork : t -> t`
`val count : unit -> int`
`val compare : t -> t -> int`
`val loc : t -> Parse_info.t -> unit`
`val get_loc : t -> Parse_info.t option`
`val get_name : t -> string option`
`val name : t -> string -> unit`
`val propagate_name : t -> t -> unit`
`val reset : unit -> unit`
`val set_pretty : bool -> unit`
`val set_stable : bool -> unit`
`module Set : Stdlib.Set.S with type elt = t`
`module Map : Stdlib.Map.S with type key = t`
`module Tbl : sig ... end`
`module ISet : sig ... end`