type var = int * int
type 'nf i_var_ = [ `I of var * 'nf Listx.listx | `Var of var ]
type 'nf i_n_var_ = [ `N of int | 'nf i_var_ ]
type 'nf i_num_var_ =
    [ `I of var * 'nf Listx.listx
    | `Match of 'nf i_num_var_ * var * int * (int * 'nf) list ref * 'nf list
    | `N of int
    | `Var of var ]
type 'nf nf_ =
    [ `I of var * 'nf Listx.listx
    | `Lam of bool * 'nf nf_
    | `Match of 'nf i_num_var_ * var * int * (int * 'nf) list ref * 'nf list
    | `N of int
    | `Var of var ]
type nf = nf nf_
type i_var = nf i_var_
type i_n_var = nf i_n_var_
type i_num_var = nf i_num_var_
val hd_of_i_var : i_var -> int
val hd_of : i_n_var -> int option
val arity_of_hd : i_n_var -> int
(* put t under n lambdas, lifting t accordingtly *)
val make_lams : nf -> int -> nf
val lift : int -> nf -> nf
val free_vars' : nf -> var list
val free_vars : nf -> int list
module ToScott :
  sig
    val t_of_i_num_var : nf i_num_var_ -> Pure.Pure.t
    val t_of_nf : nf -> Pure.Pure.t
  end
val print : ?l:string list -> nf -> string
val string_of_nf : [<nf] -> string
val cast_to_i_var : [< nf > `I `Var] -> i_var
val cast_to_i_n_var : [< nf > `I `N `Var] -> i_n_var
val cast_to_i_num_var : [< nf > `I `N `Match `Var] -> i_num_var
val set_arity : int -> nf -> nf
val mk_app : nf -> nf -> nf
val mk_appl : nf -> nf list -> nf
val mk_appx : nf -> nf Listx.listx -> nf
val mk_match : nf i_num_var_ -> var -> int -> (int * nf) list ref -> nf list -> nf
val subst : bool -> bool -> int -> nf -> nf -> nf
val eta_compare : nf -> nf -> int
val eta_eq : [< nf ] -> [< nf ] -> bool
val eta_subterm : [< nf ] -> [< nf ] -> bool
val max_arity_tms : int -> [< nf] list -> int option
val compute_arities : int -> int -> nf list -> int list
val minus1 : int -> int