src/HOL/Nominal/nominal_package.ML

internal inductive: fresh theorem group;

(*  Title:      HOL/Nominal/nominal_package.ML
    ID:         $Id$
    Author:     Stefan Berghofer and Christian Urban, TU Muenchen

Nominal datatype package for Isabelle/HOL.
*)

signature NOMINAL_PACKAGE =
sig
  val add_nominal_datatype : bool -> string list -> (string list * bstring * mixfix *
    (bstring * string list * mixfix) list) list -> theory -> theory
  type descr
  type nominal_datatype_info
  val get_nominal_datatypes : theory -> nominal_datatype_info Symtab.table
  val get_nominal_datatype : theory -> string -> nominal_datatype_info option
  val mk_perm: typ list -> term -> term -> term
  val perm_of_pair: term * term -> term
  val mk_not_sym: thm list -> thm list
  val perm_simproc: simproc
  val fresh_const: typ -> typ -> term
end

structure NominalPackage : NOMINAL_PACKAGE =
struct

val finite_emptyI = thm "finite.emptyI";
val finite_Diff = thm "finite_Diff";
val finite_Un = thm "finite_Un";
val Un_iff = thm "Un_iff";
val In0_eq = thm "In0_eq";
val In1_eq = thm "In1_eq";
val In0_not_In1 = thm "In0_not_In1";
val In1_not_In0 = thm "In1_not_In0";
val Un_assoc = thm "Un_assoc";
val Collect_disj_eq = thm "Collect_disj_eq";
val empty_def = thm "empty_def";
val empty_iff = thm "empty_iff";

open DatatypeAux;
open NominalAtoms;

(** FIXME: DatatypePackage should export this function **)

local

fun dt_recs (DtTFree _) = []
  | dt_recs (DtType (_, dts)) = List.concat (map dt_recs dts)
  | dt_recs (DtRec i) = [i];

fun dt_cases (descr: descr) (_, args, constrs) =
  let
    fun the_bname i = Sign.base_name (#1 (valOf (AList.lookup (op =) descr i)));
    val bnames = map the_bname (distinct op = (List.concat (map dt_recs args)));
  in map (fn (c, _) => space_implode "_" (Sign.base_name c :: bnames)) constrs end;


fun induct_cases descr =
  DatatypeProp.indexify_names (List.concat (map (dt_cases descr) (map #2 descr)));

fun exhaust_cases descr i = dt_cases descr (valOf (AList.lookup (op =) descr i));

in

fun mk_case_names_induct descr = RuleCases.case_names (induct_cases descr);

fun mk_case_names_exhausts descr new =
  map (RuleCases.case_names o exhaust_cases descr o #1)
    (List.filter (fn ((_, (name, _, _))) => name mem_string new) descr);

end;

(* theory data *)

type descr = (int * (string * dtyp list * (string * (dtyp list * dtyp) list) list)) list;

type nominal_datatype_info =
  {index : int,
   descr : descr,
   sorts : (string * sort) list,
   rec_names : string list,
   rec_rewrites : thm list,
   induction : thm,
   distinct : thm list,
   inject : thm list};

structure NominalDatatypesData = TheoryDataFun
(
  type T = nominal_datatype_info Symtab.table;
  val empty = Symtab.empty;
  val copy = I;
  val extend = I;
  fun merge _ tabs : T = Symtab.merge (K true) tabs;
);

val get_nominal_datatypes = NominalDatatypesData.get;
val put_nominal_datatypes = NominalDatatypesData.put;
val map_nominal_datatypes = NominalDatatypesData.map;
val get_nominal_datatype = Symtab.lookup o get_nominal_datatypes;


(**** make datatype info ****)

fun make_dt_info descr sorts induct reccomb_names rec_thms
    (((i, (_, (tname, _, _))), distinct), inject) =
  (tname,
   {index = i,
    descr = descr,
    sorts = sorts,
    rec_names = reccomb_names,
    rec_rewrites = rec_thms,
    induction = induct,
    distinct = distinct,
    inject = inject});

(*******************************)

val (_ $ (_ $ (_ $ (distinct_f $ _) $ _))) = hd (prems_of distinct_lemma);

fun read_typ sign ((Ts, sorts), str) =
  let
    val T = Type.no_tvars (Sign.read_def_typ (sign, (AList.lookup op =)
      (map (apfst (rpair ~1)) sorts)) str) handle TYPE (msg, _, _) => error msg
  in (Ts @ [T], add_typ_tfrees (T, sorts)) end;

(** simplification procedure for sorting permutations **)

val dj_cp = thm "dj_cp";

fun dest_permT (Type ("fun", [Type ("List.list", [Type ("*", [T, _])]),
      Type ("fun", [_, U])])) = (T, U);

fun permTs_of (Const ("Nominal.perm", T) $ t $ u) = fst (dest_permT T) :: permTs_of u
  | permTs_of _ = [];

fun perm_simproc' thy ss (Const ("Nominal.perm", T) $ t $ (u as Const ("Nominal.perm", U) $ r $ s)) =
      let
        val (aT as Type (a, []), S) = dest_permT T;
        val (bT as Type (b, []), _) = dest_permT U
      in if aT mem permTs_of u andalso aT <> bT then
          let
            val a' = Sign.base_name a;
            val b' = Sign.base_name b;
            val cp = PureThy.get_thm thy (Name ("cp_" ^ a' ^ "_" ^ b' ^ "_inst"));
            val dj = PureThy.get_thm thy (Name ("dj_" ^ b' ^ "_" ^ a'));
            val dj_cp' = [cp, dj] MRS dj_cp;
            val cert = SOME o cterm_of thy
          in
            SOME (mk_meta_eq (Drule.instantiate' [SOME (ctyp_of thy S)]
              [cert t, cert r, cert s] dj_cp'))
          end
        else NONE
      end
  | perm_simproc' thy ss _ = NONE;

val perm_simproc =
  Simplifier.simproc (the_context ()) "perm_simp" ["pi1 \\<bullet> (pi2 \\<bullet> x)"] perm_simproc';

val allE_Nil = read_instantiate_sg (the_context()) [("x", "[]")] allE;

val meta_spec = thm "meta_spec";

fun projections rule =
  ProjectRule.projections (ProofContext.init (Thm.theory_of_thm rule)) rule
  |> map (standard #> RuleCases.save rule);

val supp_prod = thm "supp_prod";
val fresh_prod = thm "fresh_prod";
val supports_fresh = thm "supports_fresh";
val supports_def = thm "Nominal.supports_def";
val fresh_def = thm "fresh_def";
val supp_def = thm "supp_def";
val rev_simps = thms "rev.simps";
val app_simps = thms "append.simps";
val at_fin_set_supp = thm "at_fin_set_supp";
val at_fin_set_fresh = thm "at_fin_set_fresh";
val abs_fun_eq1 = thm "abs_fun_eq1";

val collect_simp = rewrite_rule [mk_meta_eq mem_Collect_eq];

fun mk_perm Ts t u =
  let
    val T = fastype_of1 (Ts, t);
    val U = fastype_of1 (Ts, u)
  in Const ("Nominal.perm", T --> U --> U) $ t $ u end;

fun perm_of_pair (x, y) =
  let
    val T = fastype_of x;
    val pT = mk_permT T
  in Const ("List.list.Cons", HOLogic.mk_prodT (T, T) --> pT --> pT) $
    HOLogic.mk_prod (x, y) $ Const ("List.list.Nil", pT)
  end;

fun mk_not_sym ths = maps (fn th => case prop_of th of
    _ $ (Const ("Not", _) $ (Const ("op =", _) $ _ $ _)) => [th, th RS not_sym]
  | _ => [th]) ths;

fun fresh_const T U = Const ("Nominal.fresh", T --> U --> HOLogic.boolT);

fun gen_add_nominal_datatype prep_typ err flat_names new_type_names dts thy =
  let
    (* this theory is used just for parsing *)

    val tmp_thy = thy |>
      Theory.copy |>
      Sign.add_types (map (fn (tvs, tname, mx, _) =>
        (tname, length tvs, mx)) dts);

    val atoms = atoms_of thy;
    val classes = map (NameSpace.map_base (fn s => "pt_" ^ s)) atoms;
    val cp_classes = List.concat (map (fn atom1 => map (fn atom2 =>
      Sign.intern_class thy ("cp_" ^ Sign.base_name atom1 ^ "_" ^
        Sign.base_name atom2)) atoms) atoms);
    fun augment_sort S = S union classes;
    val augment_sort_typ = map_type_tfree (fn (s, S) => TFree (s, augment_sort S));

    fun prep_constr ((constrs, sorts), (cname, cargs, mx)) =
      let val (cargs', sorts') = Library.foldl (prep_typ tmp_thy) (([], sorts), cargs)
      in (constrs @ [(cname, cargs', mx)], sorts') end

    fun prep_dt_spec ((dts, sorts), (tvs, tname, mx, constrs)) =
      let val (constrs', sorts') = Library.foldl prep_constr (([], sorts), constrs)
      in (dts @ [(tvs, tname, mx, constrs')], sorts') end

    val (dts', sorts) = Library.foldl prep_dt_spec (([], []), dts);
    val sorts' = map (apsnd augment_sort) sorts;
    val tyvars = map #1 dts';

    val types_syntax = map (fn (tvs, tname, mx, constrs) => (tname, mx)) dts';
    val constr_syntax = map (fn (tvs, tname, mx, constrs) =>
      map (fn (cname, cargs, mx) => (cname, mx)) constrs) dts';

    val ps = map (fn (_, n, _, _) =>
      (Sign.full_name tmp_thy n, Sign.full_name tmp_thy (n ^ "_Rep"))) dts;
    val rps = map Library.swap ps;

    fun replace_types (Type ("Nominal.ABS", [T, U])) =
          Type ("fun", [T, Type ("Nominal.noption", [replace_types U])])
      | replace_types (Type (s, Ts)) =
          Type (getOpt (AList.lookup op = ps s, s), map replace_types Ts)
      | replace_types T = T;

    val dts'' = map (fn (tvs, tname, mx, constrs) => (tvs, tname ^ "_Rep", NoSyn,
      map (fn (cname, cargs, mx) => (cname ^ "_Rep",
        map (augment_sort_typ o replace_types) cargs, NoSyn)) constrs)) dts';

    val new_type_names' = map (fn n => n ^ "_Rep") new_type_names;
    val full_new_type_names' = map (Sign.full_name thy) new_type_names';

    val ({induction, ...},thy1) =
      DatatypePackage.add_datatype_i err flat_names new_type_names' dts'' thy;

    val SOME {descr, ...} = Symtab.lookup
      (DatatypePackage.get_datatypes thy1) (hd full_new_type_names');
    fun nth_dtyp i = typ_of_dtyp descr sorts' (DtRec i);

    (**** define permutation functions ****)

    val permT = mk_permT (TFree ("'x", HOLogic.typeS));
    val pi = Free ("pi", permT);
    val perm_types = map (fn (i, _) =>
      let val T = nth_dtyp i
      in permT --> T --> T end) descr;
    val perm_names = replicate (length new_type_names) "Nominal.perm" @
      DatatypeProp.indexify_names (map (fn i => Sign.full_name thy1
        ("perm_" ^ name_of_typ (nth_dtyp i)))
          (length new_type_names upto length descr - 1));
    val perm_names_types = perm_names ~~ perm_types;

    val perm_eqs = List.concat (map (fn (i, (_, _, constrs)) =>
      let val T = nth_dtyp i
      in map (fn (cname, dts) =>
        let
          val Ts = map (typ_of_dtyp descr sorts') dts;
          val names = DatatypeProp.make_tnames Ts;
          val args = map Free (names ~~ Ts);
          val c = Const (cname, Ts ---> T);
          fun perm_arg (dt, x) =
            let val T = type_of x
            in if is_rec_type dt then
                let val (Us, _) = strip_type T
                in list_abs (map (pair "x") Us,
                  Const (List.nth (perm_names_types, body_index dt)) $ pi $
                    list_comb (x, map (fn (i, U) =>
                      Const ("Nominal.perm", permT --> U --> U) $
                        (Const ("List.rev", permT --> permT) $ pi) $
                        Bound i) ((length Us - 1 downto 0) ~~ Us)))
                end
              else Const ("Nominal.perm", permT --> T --> T) $ pi $ x
            end;
        in
          (("", HOLogic.mk_Trueprop (HOLogic.mk_eq
            (Const (List.nth (perm_names_types, i)) $
               Free ("pi", mk_permT (TFree ("'x", HOLogic.typeS))) $
               list_comb (c, args),
             list_comb (c, map perm_arg (dts ~~ args))))), [])
        end) constrs
      end) descr);

    val (perm_simps, thy2) = thy1 |>
      Sign.add_consts_i (map (fn (s, T) => (Sign.base_name s, T, NoSyn))
        (List.drop (perm_names_types, length new_type_names))) |>
      OldPrimrecPackage.add_primrec_unchecked_i "" perm_eqs;

    (**** prove that permutation functions introduced by unfolding are ****)
    (**** equivalent to already existing permutation functions         ****)

    val _ = warning ("length descr: " ^ string_of_int (length descr));
    val _ = warning ("length new_type_names: " ^ string_of_int (length new_type_names));

    val perm_indnames = DatatypeProp.make_tnames (map body_type perm_types);
    val perm_fun_def = PureThy.get_thm thy2 (Name "perm_fun_def");

    val unfolded_perm_eq_thms =
      if length descr = length new_type_names then []
      else map standard (List.drop (split_conj_thm
        (Goal.prove_global thy2 [] []
          (HOLogic.mk_Trueprop (foldr1 HOLogic.mk_conj
            (map (fn (c as (s, T), x) =>
               let val [T1, T2] = binder_types T
               in HOLogic.mk_eq (Const c $ pi $ Free (x, T2),
                 Const ("Nominal.perm", T) $ pi $ Free (x, T2))
               end)
             (perm_names_types ~~ perm_indnames))))
          (fn _ => EVERY [indtac induction perm_indnames 1,
            ALLGOALS (asm_full_simp_tac
              (simpset_of thy2 addsimps [perm_fun_def]))])),
        length new_type_names));

    (**** prove [] \<bullet> t = t ****)

    val _ = warning "perm_empty_thms";

    val perm_empty_thms = List.concat (map (fn a =>
      let val permT = mk_permT (Type (a, []))
      in map standard (List.take (split_conj_thm
        (Goal.prove_global thy2 [] []
          (HOLogic.mk_Trueprop (foldr1 HOLogic.mk_conj
            (map (fn ((s, T), x) => HOLogic.mk_eq
                (Const (s, permT --> T --> T) $
                   Const ("List.list.Nil", permT) $ Free (x, T),
                 Free (x, T)))
             (perm_names ~~
              map body_type perm_types ~~ perm_indnames))))
          (fn _ => EVERY [indtac induction perm_indnames 1,
            ALLGOALS (asm_full_simp_tac (simpset_of thy2))])),
        length new_type_names))
      end)
      atoms);

    (**** prove (pi1 @ pi2) \<bullet> t = pi1 \<bullet> (pi2 \<bullet> t) ****)

    val _ = warning "perm_append_thms";

    (*FIXME: these should be looked up statically*)
    val at_pt_inst = PureThy.get_thm thy2 (Name "at_pt_inst");
    val pt2 = PureThy.get_thm thy2 (Name "pt2");

    val perm_append_thms = List.concat (map (fn a =>
      let
        val permT = mk_permT (Type (a, []));
        val pi1 = Free ("pi1", permT);
        val pi2 = Free ("pi2", permT);
        val pt_inst = PureThy.get_thm thy2 (Name ("pt_" ^ Sign.base_name a ^ "_inst"));
        val pt2' = pt_inst RS pt2;
        val pt2_ax = PureThy.get_thm thy2
          (Name (NameSpace.map_base (fn s => "pt_" ^ s ^ "2") a));
      in List.take (map standard (split_conj_thm
        (Goal.prove_global thy2 [] []
             (HOLogic.mk_Trueprop (foldr1 HOLogic.mk_conj
                (map (fn ((s, T), x) =>
                    let val perm = Const (s, permT --> T --> T)
                    in HOLogic.mk_eq
                      (perm $ (Const ("List.append", permT --> permT --> permT) $
                         pi1 $ pi2) $ Free (x, T),
                       perm $ pi1 $ (perm $ pi2 $ Free (x, T)))
                    end)
                  (perm_names ~~
                   map body_type perm_types ~~ perm_indnames))))
           (fn _ => EVERY [indtac induction perm_indnames 1,
              ALLGOALS (asm_full_simp_tac (simpset_of thy2 addsimps [pt2', pt2_ax]))]))),
         length new_type_names)
      end) atoms);

    (**** prove pi1 ~ pi2 ==> pi1 \<bullet> t = pi2 \<bullet> t ****)

    val _ = warning "perm_eq_thms";

    val pt3 = PureThy.get_thm thy2 (Name "pt3");
    val pt3_rev = PureThy.get_thm thy2 (Name "pt3_rev");

    val perm_eq_thms = List.concat (map (fn a =>
      let
        val permT = mk_permT (Type (a, []));
        val pi1 = Free ("pi1", permT);
        val pi2 = Free ("pi2", permT);
        (*FIXME: not robust - better access these theorems using NominalData?*)
        val at_inst = PureThy.get_thm thy2 (Name ("at_" ^ Sign.base_name a ^ "_inst"));
        val pt_inst = PureThy.get_thm thy2 (Name ("pt_" ^ Sign.base_name a ^ "_inst"));
        val pt3' = pt_inst RS pt3;
        val pt3_rev' = at_inst RS (pt_inst RS pt3_rev);
        val pt3_ax = PureThy.get_thm thy2
          (Name (NameSpace.map_base (fn s => "pt_" ^ s ^ "3") a));
      in List.take (map standard (split_conj_thm
        (Goal.prove_global thy2 [] [] (Logic.mk_implies
             (HOLogic.mk_Trueprop (Const ("Nominal.prm_eq",
                permT --> permT --> HOLogic.boolT) $ pi1 $ pi2),
              HOLogic.mk_Trueprop (foldr1 HOLogic.mk_conj
                (map (fn ((s, T), x) =>
                    let val perm = Const (s, permT --> T --> T)
                    in HOLogic.mk_eq
                      (perm $ pi1 $ Free (x, T),
                       perm $ pi2 $ Free (x, T))
                    end)
                  (perm_names ~~
                   map body_type perm_types ~~ perm_indnames)))))
           (fn _ => EVERY [indtac induction perm_indnames 1,
              ALLGOALS (asm_full_simp_tac (simpset_of thy2 addsimps [pt3', pt3_rev', pt3_ax]))]))),
         length new_type_names)
      end) atoms);

    (**** prove pi1 \<bullet> (pi2 \<bullet> t) = (pi1 \<bullet> pi2) \<bullet> (pi1 \<bullet> t) ****)

    val cp1 = PureThy.get_thm thy2 (Name "cp1");
    val dj_cp = PureThy.get_thm thy2 (Name "dj_cp");
    val pt_perm_compose = PureThy.get_thm thy2 (Name "pt_perm_compose");
    val pt_perm_compose_rev = PureThy.get_thm thy2 (Name "pt_perm_compose_rev");
    val dj_perm_perm_forget = PureThy.get_thm thy2 (Name "dj_perm_perm_forget");

    fun composition_instance name1 name2 thy =
      let
        val name1' = Sign.base_name name1;
        val name2' = Sign.base_name name2;
        val cp_class = Sign.intern_class thy ("cp_" ^ name1' ^ "_" ^ name2');
        val permT1 = mk_permT (Type (name1, []));
        val permT2 = mk_permT (Type (name2, []));
        val augment = map_type_tfree
          (fn (x, S) => TFree (x, cp_class :: S));
        val Ts = map (augment o body_type) perm_types;
        val cp_inst = PureThy.get_thm thy
          (Name ("cp_" ^ name1' ^ "_" ^ name2' ^ "_inst"));
        val simps = simpset_of thy addsimps (perm_fun_def ::
          (if name1 <> name2 then
             let val dj = PureThy.get_thm thy (Name ("dj_" ^ name2' ^ "_" ^ name1'))
             in [dj RS (cp_inst RS dj_cp), dj RS dj_perm_perm_forget] end
           else
             let
               val at_inst = PureThy.get_thm thy (Name ("at_" ^ name1' ^ "_inst"));
               val pt_inst = PureThy.get_thm thy (Name ("pt_" ^ name1' ^ "_inst"))
             in
               [cp_inst RS cp1 RS sym,
                at_inst RS (pt_inst RS pt_perm_compose) RS sym,
                at_inst RS (pt_inst RS pt_perm_compose_rev) RS sym]
            end))
        val thms = split_conj_thm (Goal.prove_global thy [] []
            (HOLogic.mk_Trueprop (foldr1 HOLogic.mk_conj
              (map (fn ((s, T), x) =>
                  let
                    val pi1 = Free ("pi1", permT1);
                    val pi2 = Free ("pi2", permT2);
                    val perm1 = Const (s, permT1 --> T --> T);
                    val perm2 = Const (s, permT2 --> T --> T);
                    val perm3 = Const ("Nominal.perm", permT1 --> permT2 --> permT2)
                  in HOLogic.mk_eq
                    (perm1 $ pi1 $ (perm2 $ pi2 $ Free (x, T)),
                     perm2 $ (perm3 $ pi1 $ pi2) $ (perm1 $ pi1 $ Free (x, T)))
                  end)
                (perm_names ~~ Ts ~~ perm_indnames))))
          (fn _ => EVERY [indtac induction perm_indnames 1,
             ALLGOALS (asm_full_simp_tac simps)]))
      in
        foldl (fn ((s, tvs), thy) => AxClass.prove_arity
            (s, replicate (length tvs) (cp_class :: classes), [cp_class])
            (Class.intro_classes_tac [] THEN ALLGOALS (resolve_tac thms)) thy)
          thy (full_new_type_names' ~~ tyvars)
      end;

    val (perm_thmss,thy3) = thy2 |>
      fold (fn name1 => fold (composition_instance name1) atoms) atoms |>
      curry (Library.foldr (fn ((i, (tyname, args, _)), thy) =>
        AxClass.prove_arity (tyname, replicate (length args) classes, classes)
        (Class.intro_classes_tac [] THEN REPEAT (EVERY
           [resolve_tac perm_empty_thms 1,
            resolve_tac perm_append_thms 1,
            resolve_tac perm_eq_thms 1, assume_tac 1])) thy))
        (List.take (descr, length new_type_names)) |>
      PureThy.add_thmss
        [((space_implode "_" new_type_names ^ "_unfolded_perm_eq",
          unfolded_perm_eq_thms), [Simplifier.simp_add]),
         ((space_implode "_" new_type_names ^ "_perm_empty",
          perm_empty_thms), [Simplifier.simp_add]),
         ((space_implode "_" new_type_names ^ "_perm_append",
          perm_append_thms), [Simplifier.simp_add]),
         ((space_implode "_" new_type_names ^ "_perm_eq",
          perm_eq_thms), [Simplifier.simp_add])];

    (**** Define representing sets ****)

    val _ = warning "representing sets";

    val rep_set_names = DatatypeProp.indexify_names
      (map (fn (i, _) => name_of_typ (nth_dtyp i) ^ "_set") descr);
    val big_rep_name =
      space_implode "_" (DatatypeProp.indexify_names (List.mapPartial
        (fn (i, ("Nominal.noption", _, _)) => NONE
          | (i, _) => SOME (name_of_typ (nth_dtyp i))) descr)) ^ "_set";
    val _ = warning ("big_rep_name: " ^ big_rep_name);

    fun strip_option (dtf as DtType ("fun", [dt, DtRec i])) =
          (case AList.lookup op = descr i of
             SOME ("Nominal.noption", _, [(_, [dt']), _]) =>
               apfst (cons dt) (strip_option dt')
           | _ => ([], dtf))
      | strip_option (DtType ("fun", [dt, DtType ("Nominal.noption", [dt'])])) =
          apfst (cons dt) (strip_option dt')
      | strip_option dt = ([], dt);

    val dt_atomTs = distinct op = (map (typ_of_dtyp descr sorts')
      (List.concat (map (fn (_, (_, _, cs)) => List.concat
        (map (List.concat o map (fst o strip_option) o snd) cs)) descr)));

    fun make_intr s T (cname, cargs) =
      let
        fun mk_prem (dt, (j, j', prems, ts)) =
          let
            val (dts, dt') = strip_option dt;
            val (dts', dt'') = strip_dtyp dt';
            val Ts = map (typ_of_dtyp descr sorts') dts;
            val Us = map (typ_of_dtyp descr sorts') dts';
            val T = typ_of_dtyp descr sorts' dt'';
            val free = mk_Free "x" (Us ---> T) j;
            val free' = app_bnds free (length Us);
            fun mk_abs_fun (T, (i, t)) =
              let val U = fastype_of t
              in (i + 1, Const ("Nominal.abs_fun", [T, U, T] --->
                Type ("Nominal.noption", [U])) $ mk_Free "y" T i $ t)
              end
          in (j + 1, j' + length Ts,
            case dt'' of
                DtRec k => list_all (map (pair "x") Us,
                  HOLogic.mk_Trueprop (Free (List.nth (rep_set_names, k),
                    T --> HOLogic.boolT) $ free')) :: prems
              | _ => prems,
            snd (foldr mk_abs_fun (j', free) Ts) :: ts)
          end;

        val (_, _, prems, ts) = foldr mk_prem (1, 1, [], []) cargs;
        val concl = HOLogic.mk_Trueprop (Free (s, T --> HOLogic.boolT) $
          list_comb (Const (cname, map fastype_of ts ---> T), ts))
      in Logic.list_implies (prems, concl)
      end;

    val (intr_ts, (rep_set_names', recTs')) =
      apfst List.concat (apsnd ListPair.unzip (ListPair.unzip (List.mapPartial
        (fn ((_, ("Nominal.noption", _, _)), _) => NONE
          | ((i, (_, _, constrs)), rep_set_name) =>
              let val T = nth_dtyp i
              in SOME (map (make_intr rep_set_name T) constrs,
                (rep_set_name, T))
              end)
                (descr ~~ rep_set_names))));
    val rep_set_names'' = map (Sign.full_name thy3) rep_set_names';

    val ({raw_induct = rep_induct, intrs = rep_intrs, ...}, thy4) =
      setmp InductivePackage.quiet_mode false
        (InductivePackage.add_inductive_global {verbose = false, kind = Thm.internalK,
            group = serial_string (),  (* FIXME pass proper group (!?) *)
            alt_name = big_rep_name, coind = false, no_elim = true, no_ind = false}
           (map (fn (s, T) => ((s, T --> HOLogic.boolT), NoSyn))
              (rep_set_names' ~~ recTs'))
           [] (map (fn x => (("", []), x)) intr_ts) []) thy3;

    (**** Prove that representing set is closed under permutation ****)

    val _ = warning "proving closure under permutation...";

    val abs_perm = PureThy.get_thms thy4 (Name "abs_perm");

    val perm_indnames' = List.mapPartial
      (fn (x, (_, ("Nominal.noption", _, _))) => NONE | (x, _) => SOME x)
      (perm_indnames ~~ descr);

    fun mk_perm_closed name = map (fn th => standard (th RS mp))
      (List.take (split_conj_thm (Goal.prove_global thy4 [] []
        (HOLogic.mk_Trueprop (foldr1 HOLogic.mk_conj (map
           (fn ((s, T), x) =>
              let
                val T = map_type_tfree
                  (fn (s, cs) => TFree (s, cs union cp_classes)) T;
                val S = Const (s, T --> HOLogic.boolT);
                val permT = mk_permT (Type (name, []))
              in HOLogic.mk_imp (S $ Free (x, T),
                S $ (Const ("Nominal.perm", permT --> T --> T) $
                  Free ("pi", permT) $ Free (x, T)))
              end) (rep_set_names'' ~~ recTs' ~~ perm_indnames'))))
        (fn _ => EVERY (* CU: added perm_fun_def in the final tactic in order to deal with funs *)
           [indtac rep_induct [] 1,
            ALLGOALS (simp_tac (simpset_of thy4 addsimps
              (symmetric perm_fun_def :: abs_perm))),
            ALLGOALS (resolve_tac rep_intrs
               THEN_ALL_NEW (asm_full_simp_tac (simpset_of thy4 addsimps [perm_fun_def])))])),
        length new_type_names));

    (* FIXME: theorems are stored in database for testing only *)
    val perm_closed_thmss = map mk_perm_closed atoms;
    val (_, thy5) = PureThy.add_thmss [(("perm_closed", List.concat perm_closed_thmss), [])] thy4;

    (**** typedef ****)

    val _ = warning "defining type...";

    val (typedefs, thy6) =
      thy5
      |> fold_map (fn ((((name, mx), tvs), (cname, U)), name') => fn thy =>
        setmp TypedefPackage.quiet_mode true
          (TypedefPackage.add_typedef_i false (SOME name') (name, tvs, mx)
            (Const ("Collect", (U --> HOLogic.boolT) --> HOLogic.mk_setT U) $
               Const (cname, U --> HOLogic.boolT)) NONE
            (rtac exI 1 THEN rtac CollectI 1 THEN
              QUIET_BREADTH_FIRST (has_fewer_prems 1)
              (resolve_tac rep_intrs 1))) thy |> (fn ((_, r), thy) =>
        let
          val permT = mk_permT (TFree (Name.variant tvs "'a", HOLogic.typeS));
          val pi = Free ("pi", permT);
          val tvs' = map (fn s => TFree (s, the (AList.lookup op = sorts' s))) tvs;
          val T = Type (Sign.intern_type thy name, tvs');
        in apfst (pair r o hd)
          (PureThy.add_defs_unchecked_i true [(("prm_" ^ name ^ "_def", Logic.mk_equals
            (Const ("Nominal.perm", permT --> T --> T) $ pi $ Free ("x", T),
             Const (Sign.intern_const thy ("Abs_" ^ name), U --> T) $
               (Const ("Nominal.perm", permT --> U --> U) $ pi $
                 (Const (Sign.intern_const thy ("Rep_" ^ name), T --> U) $
                   Free ("x", T))))), [])] thy)
        end))
          (types_syntax ~~ tyvars ~~
            List.take (rep_set_names'' ~~ recTs', length new_type_names) ~~
            new_type_names);

    val perm_defs = map snd typedefs;
    val Abs_inverse_thms = map (collect_simp o #Abs_inverse o fst) typedefs;
    val Rep_inverse_thms = map (#Rep_inverse o fst) typedefs;
    val Rep_thms = map (collect_simp o #Rep o fst) typedefs;

    val big_name = space_implode "_" new_type_names;


    (** prove that new types are in class pt_<name> **)

    val _ = warning "prove that new types are in class pt_<name> ...";

    fun pt_instance ((class, atom), perm_closed_thms) =
      fold (fn ((((((Abs_inverse, Rep_inverse), Rep),
        perm_def), name), tvs), perm_closed) => fn thy =>
          AxClass.prove_arity
            (Sign.intern_type thy name,
              replicate (length tvs) (classes @ cp_classes), [class])
            (EVERY [Class.intro_classes_tac [],
              rewrite_goals_tac [perm_def],
              asm_full_simp_tac (simpset_of thy addsimps [Rep_inverse]) 1,
              asm_full_simp_tac (simpset_of thy addsimps
                [Rep RS perm_closed RS Abs_inverse]) 1,
              asm_full_simp_tac (HOL_basic_ss addsimps [PureThy.get_thm thy
                (Name ("pt_" ^ Sign.base_name atom ^ "3"))]) 1]) thy)
        (Abs_inverse_thms ~~ Rep_inverse_thms ~~ Rep_thms ~~ perm_defs ~~
           new_type_names ~~ tyvars ~~ perm_closed_thms);


    (** prove that new types are in class cp_<name1>_<name2> **)

    val _ = warning "prove that new types are in class cp_<name1>_<name2> ...";

    fun cp_instance (atom1, perm_closed_thms1) (atom2, perm_closed_thms2) thy =
      let
        val name = "cp_" ^ Sign.base_name atom1 ^ "_" ^ Sign.base_name atom2;
        val class = Sign.intern_class thy name;
        val cp1' = PureThy.get_thm thy (Name (name ^ "_inst")) RS cp1
      in fold (fn ((((((Abs_inverse, Rep),
        perm_def), name), tvs), perm_closed1), perm_closed2) => fn thy =>
          AxClass.prove_arity
            (Sign.intern_type thy name,
              replicate (length tvs) (classes @ cp_classes), [class])
            (EVERY [Class.intro_classes_tac [],
              rewrite_goals_tac [perm_def],
              asm_full_simp_tac (simpset_of thy addsimps
                ((Rep RS perm_closed1 RS Abs_inverse) ::
                 (if atom1 = atom2 then []
                  else [Rep RS perm_closed2 RS Abs_inverse]))) 1,
              cong_tac 1,
              rtac refl 1,
              rtac cp1' 1]) thy)
        (Abs_inverse_thms ~~ Rep_thms ~~ perm_defs ~~ new_type_names ~~
           tyvars ~~ perm_closed_thms1 ~~ perm_closed_thms2) thy
      end;

    val thy7 = fold (fn x => fn thy => thy |>
      pt_instance x |>
      fold (cp_instance (apfst snd x)) (atoms ~~ perm_closed_thmss))
        (classes ~~ atoms ~~ perm_closed_thmss) thy6;

    (**** constructors ****)

    fun mk_abs_fun (x, t) =
      let
        val T = fastype_of x;
        val U = fastype_of t
      in
        Const ("Nominal.abs_fun", T --> U --> T -->
          Type ("Nominal.noption", [U])) $ x $ t
      end;

    val (ty_idxs, _) = foldl
      (fn ((i, ("Nominal.noption", _, _)), p) => p
        | ((i, _), (ty_idxs, j)) => (ty_idxs @ [(i, j)], j + 1)) ([], 0) descr;

    fun reindex (DtType (s, dts)) = DtType (s, map reindex dts)
      | reindex (DtRec i) = DtRec (the (AList.lookup op = ty_idxs i))
      | reindex dt = dt;

    fun strip_suffix i s = implode (List.take (explode s, size s - i));

    (** strips the "_Rep" in type names *)
    fun strip_nth_name i s =
      let val xs = NameSpace.explode s;
      in NameSpace.implode (Library.nth_map (length xs - i) (strip_suffix 4) xs) end;

    val (descr'', ndescr) = ListPair.unzip (List.mapPartial
      (fn (i, ("Nominal.noption", _, _)) => NONE
        | (i, (s, dts, constrs)) =>
             let
               val SOME index = AList.lookup op = ty_idxs i;
               val (constrs1, constrs2) = ListPair.unzip
                 (map (fn (cname, cargs) => apfst (pair (strip_nth_name 2 (strip_nth_name 1 cname)))
                   (foldl_map (fn (dts, dt) =>
                     let val (dts', dt') = strip_option dt
                     in (dts @ dts' @ [reindex dt'], (length dts, length dts')) end)
                       ([], cargs))) constrs)
             in SOME ((index, (strip_nth_name 1 s,  map reindex dts, constrs1)),
               (index, constrs2))
             end) descr);

    val (descr1, descr2) = chop (length new_type_names) descr'';
    val descr' = [descr1, descr2];

    fun partition_cargs idxs xs = map (fn (i, j) =>
      (List.take (List.drop (xs, i), j), List.nth (xs, i + j))) idxs;

    val pdescr = map (fn ((i, (s, dts, constrs)), (_, idxss)) => (i, (s, dts,
      map (fn ((cname, cargs), idxs) => (cname, partition_cargs idxs cargs))
        (constrs ~~ idxss)))) (descr'' ~~ ndescr);

    fun nth_dtyp' i = typ_of_dtyp descr'' sorts' (DtRec i);

    val rep_names = map (fn s =>
      Sign.intern_const thy7 ("Rep_" ^ s)) new_type_names;
    val abs_names = map (fn s =>
      Sign.intern_const thy7 ("Abs_" ^ s)) new_type_names;

    val recTs = get_rec_types descr'' sorts';
    val newTs' = Library.take (length new_type_names, recTs');
    val newTs = Library.take (length new_type_names, recTs);

    val full_new_type_names = map (Sign.full_name thy) new_type_names;

    fun make_constr_def tname T T' ((thy, defs, eqns),
        (((cname_rep, _), (cname, cargs)), (cname', mx))) =
      let
        fun constr_arg ((dts, dt), (j, l_args, r_args)) =
          let
            val xs = map (fn (dt, i) => mk_Free "x" (typ_of_dtyp descr'' sorts' dt) i)
              (dts ~~ (j upto j + length dts - 1))
            val x = mk_Free "x" (typ_of_dtyp descr'' sorts' dt) (j + length dts)
          in
            (j + length dts + 1,
             xs @ x :: l_args,
             foldr mk_abs_fun
               (case dt of
                  DtRec k => if k < length new_type_names then
                      Const (List.nth (rep_names, k), typ_of_dtyp descr'' sorts' dt -->
                        typ_of_dtyp descr sorts' dt) $ x
                    else error "nested recursion not (yet) supported"
                | _ => x) xs :: r_args)
          end

        val (_, l_args, r_args) = foldr constr_arg (1, [], []) cargs;
        val abs_name = Sign.intern_const thy ("Abs_" ^ tname);
        val rep_name = Sign.intern_const thy ("Rep_" ^ tname);
        val constrT = map fastype_of l_args ---> T;
        val lhs = list_comb (Const (cname, constrT), l_args);
        val rhs = list_comb (Const (cname_rep, map fastype_of r_args ---> T'), r_args);
        val def = Logic.mk_equals (lhs, Const (abs_name, T' --> T) $ rhs);
        val eqn = HOLogic.mk_Trueprop (HOLogic.mk_eq
          (Const (rep_name, T --> T') $ lhs, rhs));
        val def_name = (Sign.base_name cname) ^ "_def";
        val ([def_thm], thy') = thy |>
          Sign.add_consts_i [(cname', constrT, mx)] |>
          (PureThy.add_defs_i false o map Thm.no_attributes) [(def_name, def)]
      in (thy', defs @ [def_thm], eqns @ [eqn]) end;

    fun dt_constr_defs ((thy, defs, eqns, dist_lemmas), ((((((_, (_, _, constrs)),
        (_, (_, _, constrs'))), tname), T), T'), constr_syntax)) =
      let
        val rep_const = cterm_of thy
          (Const (Sign.intern_const thy ("Rep_" ^ tname), T --> T'));
        val dist = standard (cterm_instantiate [(cterm_of thy distinct_f, rep_const)] distinct_lemma);
        val (thy', defs', eqns') = Library.foldl (make_constr_def tname T T')
          ((Sign.add_path tname thy, defs, []), constrs ~~ constrs' ~~ constr_syntax)
      in
        (parent_path flat_names thy', defs', eqns @ [eqns'], dist_lemmas @ [dist])
      end;

    val (thy8, constr_defs, constr_rep_eqns, dist_lemmas) = Library.foldl dt_constr_defs
      ((thy7, [], [], []), List.take (descr, length new_type_names) ~~
        List.take (pdescr, length new_type_names) ~~
        new_type_names ~~ newTs ~~ newTs' ~~ constr_syntax);

    val abs_inject_thms = map (collect_simp o #Abs_inject o fst) typedefs
    val rep_inject_thms = map (#Rep_inject o fst) typedefs

    (* prove theorem  Rep_i (Constr_j ...) = Constr'_j ...  *)

    fun prove_constr_rep_thm eqn =
      let
        val inj_thms = map (fn r => r RS iffD1) abs_inject_thms;
        val rewrites = constr_defs @ map mk_meta_eq Rep_inverse_thms
      in Goal.prove_global thy8 [] [] eqn (fn _ => EVERY
        [resolve_tac inj_thms 1,
         rewrite_goals_tac rewrites,
         rtac refl 3,
         resolve_tac rep_intrs 2,
         REPEAT (resolve_tac Rep_thms 1)])
      end;

    val constr_rep_thmss = map (map prove_constr_rep_thm) constr_rep_eqns;

    (* prove theorem  pi \<bullet> Rep_i x = Rep_i (pi \<bullet> x) *)

    fun prove_perm_rep_perm (atom, perm_closed_thms) = map (fn th =>
      let
        val _ $ (_ $ (Rep $ x)) = Logic.unvarify (prop_of th);
        val Type ("fun", [T, U]) = fastype_of Rep;
        val permT = mk_permT (Type (atom, []));
        val pi = Free ("pi", permT);
      in
        Goal.prove_global thy8 [] [] (HOLogic.mk_Trueprop (HOLogic.mk_eq
            (Const ("Nominal.perm", permT --> U --> U) $ pi $ (Rep $ x),
             Rep $ (Const ("Nominal.perm", permT --> T --> T) $ pi $ x))))
          (fn _ => simp_tac (HOL_basic_ss addsimps (perm_defs @ Abs_inverse_thms @
            perm_closed_thms @ Rep_thms)) 1)
      end) Rep_thms;

    val perm_rep_perm_thms = List.concat (map prove_perm_rep_perm
      (atoms ~~ perm_closed_thmss));

    (* prove distinctness theorems *)

    val distinctness_limit = Config.get_thy thy8 DatatypeProp.distinctness_limit;
    val thy8' = Config.put_thy DatatypeProp.distinctness_limit 1000 thy8;
    val distinct_props = DatatypeProp.make_distincts new_type_names descr' sorts' thy8';
    val thy8 = Config.put_thy DatatypeProp.distinctness_limit distinctness_limit thy8';

    val dist_rewrites = map (fn (rep_thms, dist_lemma) =>
      dist_lemma::(rep_thms @ [In0_eq, In1_eq, In0_not_In1, In1_not_In0]))
        (constr_rep_thmss ~~ dist_lemmas);

    fun prove_distinct_thms (_, []) = []
      | prove_distinct_thms (p as (rep_thms, dist_lemma), t::ts) =
          let
            val dist_thm = Goal.prove_global thy8 [] [] t (fn _ =>
              simp_tac (simpset_of thy8 addsimps (dist_lemma :: rep_thms)) 1)
          in dist_thm::(standard (dist_thm RS not_sym))::
            (prove_distinct_thms (p, ts))
          end;

    val distinct_thms = map prove_distinct_thms
      (constr_rep_thmss ~~ dist_lemmas ~~ distinct_props);

    (** prove equations for permutation functions **)

    val perm_simps' = map (fn (((i, (_, _, constrs)), tname), constr_rep_thms) =>
      let val T = nth_dtyp' i
      in List.concat (map (fn (atom, perm_closed_thms) =>
          map (fn ((cname, dts), constr_rep_thm) =>
        let
          val cname = Sign.intern_const thy8
            (NameSpace.append tname (Sign.base_name cname));
          val permT = mk_permT (Type (atom, []));
          val pi = Free ("pi", permT);

          fun perm t =
            let val T = fastype_of t
            in Const ("Nominal.perm", permT --> T --> T) $ pi $ t end;

          fun constr_arg ((dts, dt), (j, l_args, r_args)) =
            let
              val Ts = map (typ_of_dtyp descr'' sorts') dts;
              val xs = map (fn (T, i) => mk_Free "x" T i)
                (Ts ~~ (j upto j + length dts - 1))
              val x = mk_Free "x" (typ_of_dtyp descr'' sorts' dt) (j + length dts)
            in
              (j + length dts + 1,
               xs @ x :: l_args,
               map perm (xs @ [x]) @ r_args)
            end

          val (_, l_args, r_args) = foldr constr_arg (1, [], []) dts;
          val c = Const (cname, map fastype_of l_args ---> T)
        in
          Goal.prove_global thy8 [] []
            (HOLogic.mk_Trueprop (HOLogic.mk_eq
              (perm (list_comb (c, l_args)), list_comb (c, r_args))))
            (fn _ => EVERY
              [simp_tac (simpset_of thy8 addsimps (constr_rep_thm :: perm_defs)) 1,
               simp_tac (HOL_basic_ss addsimps (Rep_thms @ Abs_inverse_thms @
                 constr_defs @ perm_closed_thms)) 1,
               TRY (simp_tac (HOL_basic_ss addsimps
                 (symmetric perm_fun_def :: abs_perm)) 1),
               TRY (simp_tac (HOL_basic_ss addsimps
                 (perm_fun_def :: perm_defs @ Rep_thms @ Abs_inverse_thms @
                    perm_closed_thms)) 1)])
        end) (constrs ~~ constr_rep_thms)) (atoms ~~ perm_closed_thmss))
      end) (List.take (pdescr, length new_type_names) ~~ new_type_names ~~ constr_rep_thmss);

    (** prove injectivity of constructors **)

    val rep_inject_thms' = map (fn th => th RS sym) rep_inject_thms;
    val alpha = PureThy.get_thms thy8 (Name "alpha");
    val abs_fresh = PureThy.get_thms thy8 (Name "abs_fresh");

    val inject_thms = map (fn (((i, (_, _, constrs)), tname), constr_rep_thms) =>
      let val T = nth_dtyp' i
      in List.mapPartial (fn ((cname, dts), constr_rep_thm) =>
        if null dts then NONE else SOME
        let
          val cname = Sign.intern_const thy8
            (NameSpace.append tname (Sign.base_name cname));

          fun make_inj ((dts, dt), (j, args1, args2, eqs)) =
            let
              val Ts_idx = map (typ_of_dtyp descr'' sorts') dts ~~ (j upto j + length dts - 1);
              val xs = map (fn (T, i) => mk_Free "x" T i) Ts_idx;
              val ys = map (fn (T, i) => mk_Free "y" T i) Ts_idx;
              val x = mk_Free "x" (typ_of_dtyp descr'' sorts' dt) (j + length dts);
              val y = mk_Free "y" (typ_of_dtyp descr'' sorts' dt) (j + length dts)
            in
              (j + length dts + 1,
               xs @ (x :: args1), ys @ (y :: args2),
               HOLogic.mk_eq
                 (foldr mk_abs_fun x xs, foldr mk_abs_fun y ys) :: eqs)
            end;

          val (_, args1, args2, eqs) = foldr make_inj (1, [], [], []) dts;
          val Ts = map fastype_of args1;
          val c = Const (cname, Ts ---> T)
        in
          Goal.prove_global thy8 [] [] (HOLogic.mk_Trueprop (HOLogic.mk_eq
              (HOLogic.mk_eq (list_comb (c, args1), list_comb (c, args2)),
               foldr1 HOLogic.mk_conj eqs)))
            (fn _ => EVERY
               [asm_full_simp_tac (simpset_of thy8 addsimps (constr_rep_thm ::
                  rep_inject_thms')) 1,
                TRY (asm_full_simp_tac (HOL_basic_ss addsimps (fresh_def :: supp_def ::
                  alpha @ abs_perm @ abs_fresh @ rep_inject_thms @
                  perm_rep_perm_thms)) 1),
                TRY (asm_full_simp_tac (HOL_basic_ss addsimps (perm_fun_def ::
                  expand_fun_eq :: rep_inject_thms @ perm_rep_perm_thms)) 1)])
        end) (constrs ~~ constr_rep_thms)
      end) (List.take (pdescr, length new_type_names) ~~ new_type_names ~~ constr_rep_thmss);

    (** equations for support and freshness **)

    val (supp_thms, fresh_thms) = ListPair.unzip (map ListPair.unzip
      (map (fn ((((i, (_, _, constrs)), tname), inject_thms'), perm_thms') =>
      let val T = nth_dtyp' i
      in List.concat (map (fn (cname, dts) => map (fn atom =>
        let
          val cname = Sign.intern_const thy8
            (NameSpace.append tname (Sign.base_name cname));
          val atomT = Type (atom, []);

          fun process_constr ((dts, dt), (j, args1, args2)) =
            let
              val Ts_idx = map (typ_of_dtyp descr'' sorts') dts ~~ (j upto j + length dts - 1);
              val xs = map (fn (T, i) => mk_Free "x" T i) Ts_idx;
              val x = mk_Free "x" (typ_of_dtyp descr'' sorts' dt) (j + length dts)
            in
              (j + length dts + 1,
               xs @ (x :: args1), foldr mk_abs_fun x xs :: args2)
            end;

          val (_, args1, args2) = foldr process_constr (1, [], []) dts;
          val Ts = map fastype_of args1;
          val c = list_comb (Const (cname, Ts ---> T), args1);
          fun supp t =
            Const ("Nominal.supp", fastype_of t --> HOLogic.mk_setT atomT) $ t;
          fun fresh t = fresh_const atomT (fastype_of t) $ Free ("a", atomT) $ t;
          val supp_thm = Goal.prove_global thy8 [] []
              (HOLogic.mk_Trueprop (HOLogic.mk_eq
                (supp c,
                 if null dts then Const ("{}", HOLogic.mk_setT atomT)
                 else foldr1 (HOLogic.mk_binop "op Un") (map supp args2))))
            (fn _ =>
              simp_tac (HOL_basic_ss addsimps (supp_def ::
                 Un_assoc :: de_Morgan_conj :: Collect_disj_eq :: finite_Un ::
                 symmetric empty_def :: finite_emptyI :: simp_thms @
                 abs_perm @ abs_fresh @ inject_thms' @ perm_thms')) 1)
        in
          (supp_thm,
           Goal.prove_global thy8 [] [] (HOLogic.mk_Trueprop (HOLogic.mk_eq
              (fresh c,
               if null dts then HOLogic.true_const
               else foldr1 HOLogic.mk_conj (map fresh args2))))
             (fn _ =>
               simp_tac (HOL_ss addsimps [Un_iff, empty_iff, fresh_def, supp_thm]) 1))
        end) atoms) constrs)
      end) (List.take (pdescr, length new_type_names) ~~ new_type_names ~~ inject_thms ~~ perm_simps')));

    (**** weak induction theorem ****)

    fun mk_indrule_lemma ((prems, concls), (((i, _), T), U)) =
      let
        val Rep_t = Const (List.nth (rep_names, i), T --> U) $
          mk_Free "x" T i;

        val Abs_t =  Const (List.nth (abs_names, i), U --> T)

      in (prems @ [HOLogic.imp $
            (Const (List.nth (rep_set_names'', i), U --> HOLogic.boolT) $ Rep_t) $
              (mk_Free "P" (T --> HOLogic.boolT) (i + 1) $ (Abs_t $ Rep_t))],
          concls @ [mk_Free "P" (T --> HOLogic.boolT) (i + 1) $ mk_Free "x" T i])
      end;

    val (indrule_lemma_prems, indrule_lemma_concls) =
      Library.foldl mk_indrule_lemma (([], []), (descr'' ~~ recTs ~~ recTs'));

    val indrule_lemma = Goal.prove_global thy8 [] []
      (Logic.mk_implies
        (HOLogic.mk_Trueprop (mk_conj indrule_lemma_prems),
         HOLogic.mk_Trueprop (mk_conj indrule_lemma_concls))) (fn _ => EVERY
           [REPEAT (etac conjE 1),
            REPEAT (EVERY
              [TRY (rtac conjI 1), full_simp_tac (HOL_basic_ss addsimps Rep_inverse_thms) 1,
               etac mp 1, resolve_tac Rep_thms 1])]);

    val Ps = map head_of (HOLogic.dest_conj (HOLogic.dest_Trueprop (concl_of indrule_lemma)));
    val frees = if length Ps = 1 then [Free ("P", snd (dest_Var (hd Ps)))] else
      map (Free o apfst fst o dest_Var) Ps;
    val indrule_lemma' = cterm_instantiate
      (map (cterm_of thy8) Ps ~~ map (cterm_of thy8) frees) indrule_lemma;

    val Abs_inverse_thms' = map (fn r => r RS subst) Abs_inverse_thms;

    val dt_induct_prop = DatatypeProp.make_ind descr' sorts';
    val dt_induct = Goal.prove_global thy8 []
      (Logic.strip_imp_prems dt_induct_prop) (Logic.strip_imp_concl dt_induct_prop)
      (fn prems => EVERY
        [rtac indrule_lemma' 1,
         (indtac rep_induct [] THEN_ALL_NEW ObjectLogic.atomize_prems_tac) 1,
         EVERY (map (fn (prem, r) => (EVERY
           [REPEAT (eresolve_tac Abs_inverse_thms' 1),
            simp_tac (HOL_basic_ss addsimps [symmetric r]) 1,
            DEPTH_SOLVE_1 (ares_tac [prem] 1 ORELSE etac allE 1)]))
                (prems ~~ constr_defs))]);

    val case_names_induct = mk_case_names_induct descr'';

    (**** prove that new datatypes have finite support ****)

    val _ = warning "proving finite support for the new datatype";

    val indnames = DatatypeProp.make_tnames recTs;

    val abs_supp = PureThy.get_thms thy8 (Name "abs_supp");
    val supp_atm = PureThy.get_thms thy8 (Name "supp_atm");

    val finite_supp_thms = map (fn atom =>
      let val atomT = Type (atom, [])
      in map standard (List.take
        (split_conj_thm (Goal.prove_global thy8 [] [] (HOLogic.mk_Trueprop
           (foldr1 HOLogic.mk_conj (map (fn (s, T) =>
             Const ("Finite_Set.finite", HOLogic.mk_setT atomT --> HOLogic.boolT) $
               (Const ("Nominal.supp", T --> HOLogic.mk_setT atomT) $ Free (s, T)))
               (indnames ~~ recTs))))
           (fn _ => indtac dt_induct indnames 1 THEN
            ALLGOALS (asm_full_simp_tac (simpset_of thy8 addsimps
              (abs_supp @ supp_atm @
               PureThy.get_thms thy8 (Name ("fs_" ^ Sign.base_name atom ^ "1")) @
               List.concat supp_thms))))),
         length new_type_names))
      end) atoms;

    val simp_atts = replicate (length new_type_names) [Simplifier.simp_add];

	(* Function to add both the simp and eqvt attributes *)
        (* These two attributes are duplicated on all the types in the mutual nominal datatypes *)

    val simp_eqvt_atts = replicate (length new_type_names) [Simplifier.simp_add, NominalThmDecls.eqvt_add];
 
    val (_, thy9) = thy8 |>
      Sign.add_path big_name |>
      PureThy.add_thms [(("weak_induct", dt_induct), [case_names_induct])] ||>>
      PureThy.add_thmss [(("weak_inducts", projections dt_induct), [case_names_induct])] ||>
      Sign.parent_path ||>>
      DatatypeAux.store_thmss_atts "distinct" new_type_names simp_atts distinct_thms ||>>
      DatatypeAux.store_thmss "constr_rep" new_type_names constr_rep_thmss ||>>
      DatatypeAux.store_thmss_atts "perm" new_type_names simp_eqvt_atts perm_simps' ||>>
      DatatypeAux.store_thmss "inject" new_type_names inject_thms ||>>
      DatatypeAux.store_thmss "supp" new_type_names supp_thms ||>>
      DatatypeAux.store_thmss_atts "fresh" new_type_names simp_atts fresh_thms ||>
      fold (fn (atom, ths) => fn thy =>
        let val class = Sign.intern_class thy ("fs_" ^ Sign.base_name atom)
        in fold (fn T => AxClass.prove_arity
            (fst (dest_Type T),
              replicate (length sorts) [class], [class])
            (Class.intro_classes_tac [] THEN resolve_tac ths 1)) newTs thy
        end) (atoms ~~ finite_supp_thms);

    (**** strong induction theorem ****)

    val pnames = if length descr'' = 1 then ["P"]
      else map (fn i => "P" ^ string_of_int i) (1 upto length descr'');
    val ind_sort = if null dt_atomTs then HOLogic.typeS
      else Sign.certify_sort thy9 (map (fn T => Sign.intern_class thy9 ("fs_" ^
        Sign.base_name (fst (dest_Type T)))) dt_atomTs);
    val fsT = TFree ("'n", ind_sort);
    val fsT' = TFree ("'n", HOLogic.typeS);

    val fresh_fs = map (fn (s, T) => (T, Free (s, fsT' --> HOLogic.mk_setT T)))
      (DatatypeProp.indexify_names (replicate (length dt_atomTs) "f") ~~ dt_atomTs);

    fun make_pred fsT i T =
      Free (List.nth (pnames, i), fsT --> T --> HOLogic.boolT);

    fun mk_fresh1 xs [] = []
      | mk_fresh1 xs ((y as (_, T)) :: ys) = map (fn x => HOLogic.mk_Trueprop
            (HOLogic.mk_not (HOLogic.mk_eq (Free y, Free x))))
              (filter (fn (_, U) => T = U) (rev xs)) @
          mk_fresh1 (y :: xs) ys;

    fun mk_fresh2 xss [] = []
      | mk_fresh2 xss ((p as (ys, _)) :: yss) = List.concat (map (fn y as (_, T) =>
            map (fn (_, x as (_, U)) => HOLogic.mk_Trueprop
              (fresh_const T U $ Free y $ Free x)) (rev xss @ yss)) ys) @
          mk_fresh2 (p :: xss) yss;

    fun make_ind_prem fsT f k T ((cname, cargs), idxs) =
      let
        val recs = List.filter is_rec_type cargs;
        val Ts = map (typ_of_dtyp descr'' sorts') cargs;
        val recTs' = map (typ_of_dtyp descr'' sorts') recs;
        val tnames = Name.variant_list pnames (DatatypeProp.make_tnames Ts);
        val rec_tnames = map fst (List.filter (is_rec_type o snd) (tnames ~~ cargs));
        val frees = tnames ~~ Ts;
        val frees' = partition_cargs idxs frees;
        val z = (Name.variant tnames "z", fsT);

        fun mk_prem ((dt, s), T) =
          let
            val (Us, U) = strip_type T;
            val l = length Us
          in list_all (z :: map (pair "x") Us, HOLogic.mk_Trueprop
            (make_pred fsT (body_index dt) U $ Bound l $ app_bnds (Free (s, T)) l))
          end;

        val prems = map mk_prem (recs ~~ rec_tnames ~~ recTs');
        val prems' = map (fn p as (_, T) => HOLogic.mk_Trueprop
            (f T (Free p) (Free z))) (List.concat (map fst frees')) @
          mk_fresh1 [] (List.concat (map fst frees')) @
          mk_fresh2 [] frees'

      in list_all_free (frees @ [z], Logic.list_implies (prems' @ prems,
        HOLogic.mk_Trueprop (make_pred fsT k T $ Free z $
          list_comb (Const (cname, Ts ---> T), map Free frees))))
      end;

    val ind_prems = List.concat (map (fn (((i, (_, _, constrs)), (_, idxss)), T) =>
      map (make_ind_prem fsT (fn T => fn t => fn u =>
        fresh_const T fsT $ t $ u) i T)
          (constrs ~~ idxss)) (descr'' ~~ ndescr ~~ recTs));
    val tnames = DatatypeProp.make_tnames recTs;
    val zs = Name.variant_list tnames (replicate (length descr'') "z");
    val ind_concl = HOLogic.mk_Trueprop (foldr1 (HOLogic.mk_binop "op &")
      (map (fn ((((i, _), T), tname), z) =>
        make_pred fsT i T $ Free (z, fsT) $ Free (tname, T))
        (descr'' ~~ recTs ~~ tnames ~~ zs)));
    val induct = Logic.list_implies (ind_prems, ind_concl);

    val ind_prems' =
      map (fn (_, f as Free (_, T)) => list_all_free ([("x", fsT')],
        HOLogic.mk_Trueprop (Const ("Finite_Set.finite", body_type T -->
          HOLogic.boolT) $ (f $ Free ("x", fsT'))))) fresh_fs @
      List.concat (map (fn (((i, (_, _, constrs)), (_, idxss)), T) =>
        map (make_ind_prem fsT' (fn T => fn t => fn u => HOLogic.Not $
          HOLogic.mk_mem (t, the (AList.lookup op = fresh_fs T) $ u)) i T)
            (constrs ~~ idxss)) (descr'' ~~ ndescr ~~ recTs));
    val ind_concl' = HOLogic.mk_Trueprop (foldr1 (HOLogic.mk_binop "op &")
      (map (fn ((((i, _), T), tname), z) =>
        make_pred fsT' i T $ Free (z, fsT') $ Free (tname, T))
        (descr'' ~~ recTs ~~ tnames ~~ zs)));
    val induct' = Logic.list_implies (ind_prems', ind_concl');

    val aux_ind_vars =
      (DatatypeProp.indexify_names (replicate (length dt_atomTs) "pi") ~~
       map mk_permT dt_atomTs) @ [("z", fsT')];
    val aux_ind_Ts = rev (map snd aux_ind_vars);
    val aux_ind_concl = HOLogic.mk_Trueprop (foldr1 (HOLogic.mk_binop "op &")
      (map (fn (((i, _), T), tname) =>
        HOLogic.list_all (aux_ind_vars, make_pred fsT' i T $ Bound 0 $
          fold_rev (mk_perm aux_ind_Ts) (map Bound (length dt_atomTs downto 1))
            (Free (tname, T))))
        (descr'' ~~ recTs ~~ tnames)));

    val fin_set_supp = map (fn Type (s, _) =>
      PureThy.get_thm thy9 (Name ("at_" ^ Sign.base_name s ^ "_inst")) RS
        at_fin_set_supp) dt_atomTs;
    val fin_set_fresh = map (fn Type (s, _) =>
      PureThy.get_thm thy9 (Name ("at_" ^ Sign.base_name s ^ "_inst")) RS
        at_fin_set_fresh) dt_atomTs;
    val pt1_atoms = map (fn Type (s, _) =>
      PureThy.get_thm thy9 (Name ("pt_" ^ Sign.base_name s ^ "1"))) dt_atomTs;
    val pt2_atoms = map (fn Type (s, _) =>
      PureThy.get_thm thy9 (Name ("pt_" ^ Sign.base_name s ^ "2")) RS sym) dt_atomTs;
    val exists_fresh' = PureThy.get_thms thy9 (Name "exists_fresh'");
    val fs_atoms = PureThy.get_thms thy9 (Name "fin_supp");
    val abs_supp = PureThy.get_thms thy9 (Name "abs_supp");
    val perm_fresh_fresh = PureThy.get_thms thy9 (Name "perm_fresh_fresh");
    val calc_atm = PureThy.get_thms thy9 (Name "calc_atm");
    val fresh_atm = PureThy.get_thms thy9 (Name "fresh_atm");
    val fresh_left = PureThy.get_thms thy9 (Name "fresh_left");
    val perm_swap = PureThy.get_thms thy9 (Name "perm_swap");

    fun obtain_fresh_name' ths ts T (freshs1, freshs2, ctxt) =
      let
        val p = foldr1 HOLogic.mk_prod (ts @ freshs1);
        val ex = Goal.prove ctxt [] [] (HOLogic.mk_Trueprop
            (HOLogic.exists_const T $ Abs ("x", T,
              fresh_const T (fastype_of p) $
                Bound 0 $ p)))
          (fn _ => EVERY
            [resolve_tac exists_fresh' 1,
             simp_tac (HOL_ss addsimps (supp_prod :: finite_Un :: fs_atoms @
               fin_set_supp @ ths)) 1]);
        val (([cx], ths), ctxt') = Obtain.result
          (fn _ => EVERY
            [etac exE 1,
             full_simp_tac (HOL_ss addsimps (fresh_prod :: fresh_atm)) 1,
             REPEAT (etac conjE 1)])
          [ex] ctxt
      in (freshs1 @ [term_of cx], freshs2 @ ths, ctxt') end;

    fun fresh_fresh_inst thy a b =
      let
        val T = fastype_of a;
        val SOME th = find_first (fn th => case prop_of th of
            _ $ (_ $ (Const (_, Type (_, [U, _])) $ _ $ _)) $ _ => U = T
          | _ => false) perm_fresh_fresh
      in
        Drule.instantiate' []
          [SOME (cterm_of thy a), NONE, SOME (cterm_of thy b)] th
      end;

    (**********************************************************************
      The subgoals occurring in the proof of induct_aux have the
      following parameters:

        x_1 ... x_k p_1 ... p_m z

      where

        x_i : constructor arguments (introduced by weak induction rule)
        p_i : permutations (one for each atom type in the data type)
        z   : freshness context
    ***********************************************************************)

    val _ = warning "proving strong induction theorem ...";

    val induct_aux = Goal.prove_global thy9 [] ind_prems' ind_concl' (fn prems =>
      let
        val (prems1, prems2) = chop (length dt_atomTs) prems;
        val ind_ss2 = HOL_ss addsimps
          finite_Diff :: abs_fresh @ abs_supp @ fs_atoms;
        val ind_ss1 = ind_ss2 addsimps fresh_left @ calc_atm @
          fresh_atm @ rev_simps @ app_simps;
        val ind_ss3 = HOL_ss addsimps abs_fun_eq1 ::
          abs_perm @ calc_atm @ perm_swap;
        val ind_ss4 = HOL_basic_ss addsimps fresh_left @ prems1 @
          fin_set_fresh @ calc_atm;
        val ind_ss5 = HOL_basic_ss addsimps pt1_atoms;
        val ind_ss6 = HOL_basic_ss addsimps flat perm_simps';
        val th = Goal.prove (ProofContext.init thy9) [] [] aux_ind_concl
          (fn {context = context1, ...} =>
             EVERY (indtac dt_induct tnames 1 ::
               maps (fn ((_, (_, _, constrs)), (_, constrs')) =>
                 map (fn ((cname, cargs), is) =>
                   REPEAT (rtac allI 1) THEN
                   SUBPROOF (fn {prems = iprems, params, concl,
                       context = context2, ...} =>
                     let
                       val concl' = term_of concl;
                       val _ $ (_ $ _ $ u) = concl';
                       val U = fastype_of u;
                       val (xs, params') =
                         chop (length cargs) (map term_of params);
                       val Ts = map fastype_of xs;
                       val cnstr = Const (cname, Ts ---> U);
                       val (pis, z) = split_last params';
                       val mk_pi = fold_rev (mk_perm []) pis;
                       val xs' = partition_cargs is xs;
                       val xs'' = map (fn (ts, u) => (map mk_pi ts, mk_pi u)) xs';
                       val ts = maps (fn (ts, u) => ts @ [u]) xs'';
                       val (freshs1, freshs2, context3) = fold (fn t =>
                         let val T = fastype_of t
                         in obtain_fresh_name' prems1
                           (the (AList.lookup op = fresh_fs T) $ z :: ts) T
                         end) (maps fst xs') ([], [], context2);
                       val freshs1' = unflat (map fst xs') freshs1;
                       val freshs2' = map (Simplifier.simplify ind_ss4)
                         (mk_not_sym freshs2);
                       val ind_ss1' = ind_ss1 addsimps freshs2';
                       val ind_ss3' = ind_ss3 addsimps freshs2';
                       val rename_eq =
                         if forall (null o fst) xs' then []
                         else [Goal.prove context3 [] []
                           (HOLogic.mk_Trueprop (HOLogic.mk_eq
                             (list_comb (cnstr, ts),
                              list_comb (cnstr, maps (fn ((bs, t), cs) =>
                                cs @ [fold_rev (mk_perm []) (map perm_of_pair
                                  (bs ~~ cs)) t]) (xs'' ~~ freshs1')))))
                           (fn _ => EVERY
                              (simp_tac (HOL_ss addsimps flat inject_thms) 1 ::
                               REPEAT (FIRSTGOAL (rtac conjI)) ::
                               maps (fn ((bs, t), cs) =>
                                 if null bs then []
                                 else rtac sym 1 :: maps (fn (b, c) =>
                                   [rtac trans 1, rtac sym 1,
                                    rtac (fresh_fresh_inst thy9 b c) 1,
                                    simp_tac ind_ss1' 1,
                                    simp_tac ind_ss2 1,
                                    simp_tac ind_ss3' 1]) (bs ~~ cs))
                                 (xs'' ~~ freshs1')))];
                       val th = Goal.prove context3 [] [] concl' (fn _ => EVERY
                         [simp_tac (ind_ss6 addsimps rename_eq) 1,
                          cut_facts_tac iprems 1,
                          (resolve_tac prems THEN_ALL_NEW
                            SUBGOAL (fn (t, i) => case Logic.strip_assums_concl t of
                                _ $ (Const ("Nominal.fresh", _) $ _ $ _) =>
                                  simp_tac ind_ss1' i
                              | _ $ (Const ("Not", _) $ _) =>
                                  resolve_tac freshs2' i
                              | _ => asm_simp_tac (HOL_basic_ss addsimps
                                  pt2_atoms addsimprocs [perm_simproc]) i)) 1])
                       val final = ProofContext.export context3 context2 [th]
                     in
                       resolve_tac final 1
                     end) context1 1) (constrs ~~ constrs')) (descr'' ~~ ndescr)))
      in
        EVERY
          [cut_facts_tac [th] 1,
           REPEAT (eresolve_tac [conjE, allE_Nil] 1),
           REPEAT (etac allE 1),
           REPEAT (TRY (rtac conjI 1) THEN asm_full_simp_tac ind_ss5 1)]
      end);

    val induct_aux' = Thm.instantiate ([],
      map (fn (s, T) =>
        let val pT = TVar (("'n", 0), HOLogic.typeS) --> T --> HOLogic.boolT
        in (cterm_of thy9 (Var ((s, 0), pT)), cterm_of thy9 (Free (s, pT))) end)
          (pnames ~~ recTs) @
      map (fn (_, f) =>
        let val f' = Logic.varify f
        in (cterm_of thy9 f',
          cterm_of thy9 (Const ("Nominal.supp", fastype_of f')))
        end) fresh_fs) induct_aux;

    val induct = Goal.prove_global thy9 [] ind_prems ind_concl
      (fn prems => EVERY
         [rtac induct_aux' 1,
          REPEAT (resolve_tac fs_atoms 1),
          REPEAT ((resolve_tac prems THEN_ALL_NEW
            (etac meta_spec ORELSE' full_simp_tac (HOL_basic_ss addsimps [fresh_def]))) 1)])

    val (_, thy10) = thy9 |>
      Sign.add_path big_name |>
      PureThy.add_thms [(("induct'", induct_aux), [])] ||>>
      PureThy.add_thms [(("induct", induct), [case_names_induct])] ||>>
      PureThy.add_thmss [(("inducts", projections induct), [case_names_induct])];

    (**** recursion combinator ****)

    val _ = warning "defining recursion combinator ...";

    val used = foldr add_typ_tfree_names [] recTs;

    val (rec_result_Ts', rec_fn_Ts') = DatatypeProp.make_primrec_Ts descr' sorts' used;

    val rec_sort = if null dt_atomTs then HOLogic.typeS else
      let val names = map (Sign.base_name o fst o dest_Type) dt_atomTs
      in Sign.certify_sort thy10 (map (Sign.intern_class thy10)
        (map (fn s => "pt_" ^ s) names @
         List.concat (map (fn s => List.mapPartial (fn s' =>
           if s = s' then NONE
           else SOME ("cp_" ^ s ^ "_" ^ s')) names) names)))
      end;

    val rec_result_Ts = map (fn TFree (s, _) => TFree (s, rec_sort)) rec_result_Ts';
    val rec_fn_Ts = map (typ_subst_atomic (rec_result_Ts' ~~ rec_result_Ts)) rec_fn_Ts';

    val rec_set_Ts = map (fn (T1, T2) =>
      rec_fn_Ts @ [T1, T2] ---> HOLogic.boolT) (recTs ~~ rec_result_Ts);

    val big_rec_name = big_name ^ "_rec_set";
    val rec_set_names' =
      if length descr'' = 1 then [big_rec_name] else
        map ((curry (op ^) (big_rec_name ^ "_")) o string_of_int)
          (1 upto (length descr''));
    val rec_set_names =  map (Sign.full_name thy10) rec_set_names';

    val rec_fns = map (uncurry (mk_Free "f"))
      (rec_fn_Ts ~~ (1 upto (length rec_fn_Ts)));
    val rec_sets' = map (fn c => list_comb (Free c, rec_fns))
      (rec_set_names' ~~ rec_set_Ts);
    val rec_sets = map (fn c => list_comb (Const c, rec_fns))
      (rec_set_names ~~ rec_set_Ts);

    (* introduction rules for graph of recursion function *)

    val rec_preds = map (fn (a, T) =>
      Free (a, T --> HOLogic.boolT)) (pnames ~~ rec_result_Ts);

    fun mk_fresh3 rs [] = []
      | mk_fresh3 rs ((p as (ys, z)) :: yss) = List.concat (map (fn y as (_, T) =>
            List.mapPartial (fn ((_, (_, x)), r as (_, U)) => if z = x then NONE
              else SOME (HOLogic.mk_Trueprop
                (fresh_const T U $ Free y $ Free r))) rs) ys) @
          mk_fresh3 rs yss;

    (* FIXME: avoid collisions with other variable names? *)
    val rec_ctxt = Free ("z", fsT');

    fun make_rec_intr T p rec_set ((rec_intr_ts, rec_prems, rec_prems',
          rec_eq_prems, l), ((cname, cargs), idxs)) =
      let
        val Ts = map (typ_of_dtyp descr'' sorts') cargs;
        val frees = map (fn i => "x" ^ string_of_int i) (1 upto length Ts) ~~ Ts;
        val frees' = partition_cargs idxs frees;
        val binders = List.concat (map fst frees');
        val atomTs = distinct op = (maps (map snd o fst) frees');
        val recs = List.mapPartial
          (fn ((_, DtRec i), p) => SOME (i, p) | _ => NONE)
          (partition_cargs idxs cargs ~~ frees');
        val frees'' = map (fn i => "y" ^ string_of_int i) (1 upto length recs) ~~
          map (fn (i, _) => List.nth (rec_result_Ts, i)) recs;
        val prems1 = map (fn ((i, (_, x)), y) => HOLogic.mk_Trueprop
          (List.nth (rec_sets', i) $ Free x $ Free y)) (recs ~~ frees'');
        val prems2 =
          map (fn f => map (fn p as (_, T) => HOLogic.mk_Trueprop
            (fresh_const T (fastype_of f) $ Free p $ f)) binders) rec_fns;
        val prems3 = mk_fresh1 [] binders @ mk_fresh2 [] frees';
        val prems4 = map (fn ((i, _), y) =>
          HOLogic.mk_Trueprop (List.nth (rec_preds, i) $ Free y)) (recs ~~ frees'');
        val prems5 = mk_fresh3 (recs ~~ frees'') frees';
        val prems6 = maps (fn aT => map (fn y as (_, T) => HOLogic.mk_Trueprop
          (Const ("Finite_Set.finite", HOLogic.mk_setT aT --> HOLogic.boolT) $
             (Const ("Nominal.supp", T --> HOLogic.mk_setT aT) $ Free y)))
               frees'') atomTs;
        val prems7 = map (fn x as (_, T) => HOLogic.mk_Trueprop
          (fresh_const T fsT' $ Free x $ rec_ctxt)) binders;
        val result = list_comb (List.nth (rec_fns, l), map Free (frees @ frees''));
        val result_freshs = map (fn p as (_, T) =>
          fresh_const T (fastype_of result) $ Free p $ result) binders;
        val P = HOLogic.mk_Trueprop (p $ result)
      in
        (rec_intr_ts @ [Logic.list_implies (List.concat prems2 @ prems3 @ prems1,
           HOLogic.mk_Trueprop (rec_set $
             list_comb (Const (cname, Ts ---> T), map Free frees) $ result))],
         rec_prems @ [list_all_free (frees @ frees'', Logic.list_implies (prems4, P))],
         rec_prems' @ map (fn fr => list_all_free (frees @ frees'',
           Logic.list_implies (List.nth (prems2, l) @ prems3 @ prems5 @ prems7 @ prems6 @ [P],
             HOLogic.mk_Trueprop fr))) result_freshs,
         rec_eq_prems @ [List.concat prems2 @ prems3],
         l + 1)
      end;

    val (rec_intr_ts, rec_prems, rec_prems', rec_eq_prems, _) =
      Library.foldl (fn (x, ((((d, d'), T), p), rec_set)) =>
        Library.foldl (make_rec_intr T p rec_set) (x, #3 (snd d) ~~ snd d'))
          (([], [], [], [], 0), descr'' ~~ ndescr ~~ recTs ~~ rec_preds ~~ rec_sets');

    val ({intrs = rec_intrs, elims = rec_elims, raw_induct = rec_induct, ...}, thy11) =
      thy10 |>
      setmp InductivePackage.quiet_mode (!quiet_mode)
        (InductivePackage.add_inductive_global {verbose = false, kind = Thm.internalK,
            group = serial_string (),  (* FIXME pass proper group (!?) *)
            alt_name = big_rec_name, coind = false, no_elim = false, no_ind = false}
           (map (fn (s, T) => ((s, T), NoSyn)) (rec_set_names' ~~ rec_set_Ts))
           (map dest_Free rec_fns)
           (map (fn x => (("", []), x)) rec_intr_ts) []) ||>
      PureThy.hide_thms true [NameSpace.append
        (Sign.full_name thy10 big_rec_name) "induct"];

    (** equivariance **)

    val fresh_bij = PureThy.get_thms thy11 (Name "fresh_bij");
    val perm_bij = PureThy.get_thms thy11 (Name "perm_bij");

    val (rec_equiv_thms, rec_equiv_thms') = ListPair.unzip (map (fn aT =>
      let
        val permT = mk_permT aT;
        val pi = Free ("pi", permT);
        val rec_fns_pi = map (mk_perm [] pi o uncurry (mk_Free "f"))
          (rec_fn_Ts ~~ (1 upto (length rec_fn_Ts)));
        val rec_sets_pi = map (fn c => list_comb (Const c, rec_fns_pi))
          (rec_set_names ~~ rec_set_Ts);
        val ps = map (fn ((((T, U), R), R'), i) =>
          let
            val x = Free ("x" ^ string_of_int i, T);
            val y = Free ("y" ^ string_of_int i, U)
          in
            (R $ x $ y, R' $ mk_perm [] pi x $ mk_perm [] pi y)
          end) (recTs ~~ rec_result_Ts ~~ rec_sets ~~ rec_sets_pi ~~ (1 upto length recTs));
        val ths = map (fn th => standard (th RS mp)) (split_conj_thm
          (Goal.prove_global thy11 [] []
            (HOLogic.mk_Trueprop (foldr1 HOLogic.mk_conj (map HOLogic.mk_imp ps)))
            (fn _ => rtac rec_induct 1 THEN REPEAT
               (NominalPermeq.perm_simp_tac (HOL_basic_ss addsimps flat perm_simps') 1 THEN
                (resolve_tac rec_intrs THEN_ALL_NEW
                 asm_simp_tac (HOL_ss addsimps (fresh_bij @ perm_bij))) 1))))
        val ths' = map (fn ((P, Q), th) =>
          Goal.prove_global thy11 [] []
            (Logic.mk_implies (HOLogic.mk_Trueprop Q, HOLogic.mk_Trueprop P))
            (fn _ => dtac (Thm.instantiate ([],
                 [(cterm_of thy11 (Var (("pi", 0), permT)),
                   cterm_of thy11 (Const ("List.rev", permT --> permT) $ pi))]) th) 1 THEN
               NominalPermeq.perm_simp_tac HOL_ss 1)) (ps ~~ ths)
      in (ths, ths') end) dt_atomTs);

    (** finite support **)

    val rec_fin_supp_thms = map (fn aT =>
      let
        val name = Sign.base_name (fst (dest_Type aT));
        val fs_name = PureThy.get_thm thy11 (Name ("fs_" ^ name ^ "1"));
        val aset = HOLogic.mk_setT aT;
        val finite = Const ("Finite_Set.finite", aset --> HOLogic.boolT);
        val fins = map (fn (f, T) => HOLogic.mk_Trueprop
          (finite $ (Const ("Nominal.supp", T --> aset) $ f)))
            (rec_fns ~~ rec_fn_Ts)
      in
        map (fn th => standard (th RS mp)) (split_conj_thm
          (Goal.prove_global thy11 [] fins
            (HOLogic.mk_Trueprop (foldr1 HOLogic.mk_conj
              (map (fn (((T, U), R), i) =>
                 let
                   val x = Free ("x" ^ string_of_int i, T);
                   val y = Free ("y" ^ string_of_int i, U)
                 in
                   HOLogic.mk_imp (R $ x $ y,
                     finite $ (Const ("Nominal.supp", U --> aset) $ y))
                 end) (recTs ~~ rec_result_Ts ~~ rec_sets ~~ (1 upto length recTs)))))
            (fn fins => (rtac rec_induct THEN_ALL_NEW cut_facts_tac fins) 1 THEN REPEAT
               (NominalPermeq.finite_guess_tac (HOL_ss addsimps [fs_name]) 1))))
      end) dt_atomTs;

    (** freshness **)

    val finite_premss = map (fn aT =>
      map (fn (f, T) => HOLogic.mk_Trueprop
        (Const ("Finite_Set.finite", HOLogic.mk_setT aT --> HOLogic.boolT) $
           (Const ("Nominal.supp", T --> HOLogic.mk_setT aT) $ f)))
           (rec_fns ~~ rec_fn_Ts)) dt_atomTs;

    val rec_fresh_thms = map (fn ((aT, eqvt_ths), finite_prems) =>
      let
        val name = Sign.base_name (fst (dest_Type aT));
        val fs_name = PureThy.get_thm thy11 (Name ("fs_" ^ name ^ "1"));
        val a = Free ("a", aT);
        val freshs = map (fn (f, fT) => HOLogic.mk_Trueprop
          (fresh_const aT fT $ a $ f)) (rec_fns ~~ rec_fn_Ts)
      in
        map (fn (((T, U), R), eqvt_th) =>
          let
            val x = Free ("x", T);
            val y = Free ("y", U);
            val y' = Free ("y'", U)
          in
            standard (Goal.prove (ProofContext.init thy11) [] (finite_prems @
                [HOLogic.mk_Trueprop (R $ x $ y),
                 HOLogic.mk_Trueprop (HOLogic.mk_all ("y'", U,
                   HOLogic.mk_imp (R $ x $ y', HOLogic.mk_eq (y', y)))),
                 HOLogic.mk_Trueprop (fresh_const aT T $ a $ x)] @
              freshs)
              (HOLogic.mk_Trueprop (fresh_const aT U $ a $ y))
              (fn {prems, context} =>
                 let
                   val (finite_prems, rec_prem :: unique_prem ::
                     fresh_prems) = chop (length finite_prems) prems;
                   val unique_prem' = unique_prem RS spec RS mp;
                   val unique = [unique_prem', unique_prem' RS sym] MRS trans;
                   val _ $ (_ $ (_ $ S $ _)) $ _ = prop_of supports_fresh;
                   val tuple = foldr1 HOLogic.mk_prod (x :: rec_fns)
                 in EVERY
                   [rtac (Drule.cterm_instantiate
                      [(cterm_of thy11 S,
                        cterm_of thy11 (Const ("Nominal.supp",
                          fastype_of tuple --> HOLogic.mk_setT aT) $ tuple))]
                      supports_fresh) 1,
                    simp_tac (HOL_basic_ss addsimps
                      [supports_def, symmetric fresh_def, fresh_prod]) 1,
                    REPEAT_DETERM (resolve_tac [allI, impI] 1),
                    REPEAT_DETERM (etac conjE 1),
                    rtac unique 1,
                    SUBPROOF (fn {prems = prems', params = [a, b], ...} => EVERY
                      [cut_facts_tac [rec_prem] 1,
                       rtac (Thm.instantiate ([],
                         [(cterm_of thy11 (Var (("pi", 0), mk_permT aT)),
                           cterm_of thy11 (perm_of_pair (term_of a, term_of b)))]) eqvt_th) 1,
                       asm_simp_tac (HOL_ss addsimps
                         (prems' @ perm_swap @ perm_fresh_fresh)) 1]) context 1,
                    rtac rec_prem 1,
                    simp_tac (HOL_ss addsimps (fs_name ::
                      supp_prod :: finite_Un :: finite_prems)) 1,
                    simp_tac (HOL_ss addsimps (symmetric fresh_def ::
                      fresh_prod :: fresh_prems)) 1]
                 end))
          end) (recTs ~~ rec_result_Ts ~~ rec_sets ~~ eqvt_ths)
      end) (dt_atomTs ~~ rec_equiv_thms' ~~ finite_premss);

    (** uniqueness **)

    val fun_tuple = foldr1 HOLogic.mk_prod (rec_ctxt :: rec_fns);
    val fun_tupleT = fastype_of fun_tuple;
    val rec_unique_frees =
      DatatypeProp.indexify_names (replicate (length recTs) "x") ~~ recTs;
    val rec_unique_frees'' = map (fn (s, T) => (s ^ "'", T)) rec_unique_frees;
    val rec_unique_frees' =
      DatatypeProp.indexify_names (replicate (length recTs) "y") ~~ rec_result_Ts;
    val rec_unique_concls = map (fn ((x, U), R) =>
        Const ("Ex1", (U --> HOLogic.boolT) --> HOLogic.boolT) $
          Abs ("y", U, R $ Free x $ Bound 0))
      (rec_unique_frees ~~ rec_result_Ts ~~ rec_sets);

    val induct_aux_rec = Drule.cterm_instantiate
      (map (pairself (cterm_of thy11))
         (map (fn (aT, f) => (Logic.varify f, Abs ("z", HOLogic.unitT,
            Const ("Nominal.supp", fun_tupleT --> HOLogic.mk_setT aT) $ fun_tuple)))
              fresh_fs @
          map (fn (((P, T), (x, U)), Q) =>
           (Var ((P, 0), HOLogic.unitT --> Logic.varifyT T --> HOLogic.boolT),
            Abs ("z", HOLogic.unitT, absfree (x, U, Q))))
              (pnames ~~ recTs ~~ rec_unique_frees ~~ rec_unique_concls) @
          map (fn (s, T) => (Var ((s, 0), Logic.varifyT T), Free (s, T)))
            rec_unique_frees)) induct_aux;

    fun obtain_fresh_name vs ths rec_fin_supp T (freshs1, freshs2, ctxt) =
      let
        val p = foldr1 HOLogic.mk_prod (vs @ freshs1);
        val ex = Goal.prove ctxt [] [] (HOLogic.mk_Trueprop
            (HOLogic.exists_const T $ Abs ("x", T,
              fresh_const T (fastype_of p) $ Bound 0 $ p)))
          (fn _ => EVERY
            [cut_facts_tac ths 1,
             REPEAT_DETERM (dresolve_tac (the (AList.lookup op = rec_fin_supp T)) 1),
             resolve_tac exists_fresh' 1,
             asm_simp_tac (HOL_ss addsimps (supp_prod :: finite_Un :: fs_atoms)) 1]);
        val (([cx], ths), ctxt') = Obtain.result
          (fn _ => EVERY
            [etac exE 1,
             full_simp_tac (HOL_ss addsimps (fresh_prod :: fresh_atm)) 1,
             REPEAT (etac conjE 1)])
          [ex] ctxt
      in (freshs1 @ [term_of cx], freshs2 @ ths, ctxt') end;

    val finite_ctxt_prems = map (fn aT =>
      HOLogic.mk_Trueprop
        (Const ("Finite_Set.finite", HOLogic.mk_setT aT --> HOLogic.boolT) $
           (Const ("Nominal.supp", fsT' --> HOLogic.mk_setT aT) $ rec_ctxt))) dt_atomTs;

    val rec_unique_thms = split_conj_thm (Goal.prove
      (ProofContext.init thy11) (map fst rec_unique_frees)
      (List.concat finite_premss @ finite_ctxt_prems @ rec_prems @ rec_prems')
      (HOLogic.mk_Trueprop (foldr1 HOLogic.mk_conj rec_unique_concls))
      (fn {prems, context} =>
         let
           val k = length rec_fns;
           val (finite_thss, ths1) = fold_map (fn T => fn xs =>
             apfst (pair T) (chop k xs)) dt_atomTs prems;
           val (finite_ctxt_ths, ths2) = chop (length dt_atomTs) ths1;
           val (P_ind_ths, fcbs) = chop k ths2;
           val P_ths = map (fn th => th RS mp) (split_conj_thm
             (Goal.prove context
               (map fst (rec_unique_frees'' @ rec_unique_frees')) []
               (HOLogic.mk_Trueprop (foldr1 HOLogic.mk_conj
                  (map (fn (((x, y), S), P) => HOLogic.mk_imp
                    (S $ Free x $ Free y, P $ (Free y)))
                      (rec_unique_frees'' ~~ rec_unique_frees' ~~ rec_sets ~~ rec_preds))))
               (fn _ =>
                  rtac rec_induct 1 THEN
                  REPEAT ((resolve_tac P_ind_ths THEN_ALL_NEW assume_tac) 1))));
           val rec_fin_supp_thms' = map
             (fn (ths, (T, fin_ths)) => (T, map (curry op MRS fin_ths) ths))
             (rec_fin_supp_thms ~~ finite_thss);
         in EVERY
           ([rtac induct_aux_rec 1] @
            maps (fn ((_, finite_ths), finite_th) =>
              [cut_facts_tac (finite_th :: finite_ths) 1,
               asm_simp_tac (HOL_ss addsimps [supp_prod, finite_Un]) 1])
                (finite_thss ~~ finite_ctxt_ths) @
            maps (fn ((_, idxss), elim) => maps (fn idxs =>
              [full_simp_tac (HOL_ss addsimps [symmetric fresh_def, supp_prod, Un_iff]) 1,
               REPEAT_DETERM (eresolve_tac [conjE, ex1E] 1),
               rtac ex1I 1,
               (resolve_tac rec_intrs THEN_ALL_NEW atac) 1,
               rotate_tac ~1 1,
               ((DETERM o etac elim) THEN_ALL_NEW full_simp_tac
                  (HOL_ss addsimps List.concat distinct_thms)) 1] @
               (if null idxs then [] else [hyp_subst_tac 1,
                SUBPROOF (fn {asms, concl, prems = prems', params, context = context', ...} =>
                  let
                    val SOME prem = find_first (can (HOLogic.dest_eq o
                      HOLogic.dest_Trueprop o prop_of)) prems';
                    val _ $ (_ $ lhs $ rhs) = prop_of prem;
                    val _ $ (_ $ lhs' $ rhs') = term_of concl;
                    val rT = fastype_of lhs';
                    val (c, cargsl) = strip_comb lhs;
                    val cargsl' = partition_cargs idxs cargsl;
                    val boundsl = List.concat (map fst cargsl');
                    val (_, cargsr) = strip_comb rhs;
                    val cargsr' = partition_cargs idxs cargsr;
                    val boundsr = List.concat (map fst cargsr');
                    val (params1, _ :: params2) =
                      chop (length params div 2) (map term_of params);
                    val params' = params1 @ params2;
                    val rec_prems = filter (fn th => case prop_of th of
                      _ $ (S $ _ $ _) => S mem rec_sets | _ => false) prems';
                    val fresh_prems = filter (fn th => case prop_of th of
                        _ $ (Const ("Nominal.fresh", _) $ _ $ _) => true
                      | _ $ (Const ("Not", _) $ _) => true
                      | _ => false) prems';
                    val Ts = map fastype_of boundsl;

                    val _ = warning "step 1: obtaining fresh names";
                    val (freshs1, freshs2, context'') = fold
                      (obtain_fresh_name (rec_ctxt :: rec_fns @ params')
                         (List.concat (map snd finite_thss) @
                            finite_ctxt_ths @ rec_prems)
                         rec_fin_supp_thms')
                      Ts ([], [], context');
                    val pi1 = map perm_of_pair (boundsl ~~ freshs1);
                    val rpi1 = rev pi1;
                    val pi2 = map perm_of_pair (boundsr ~~ freshs1);
                    val rpi2 = rev pi2;

                    val fresh_prems' = mk_not_sym fresh_prems;
                    val freshs2' = mk_not_sym freshs2;

                    (** as, bs, cs # K as ts, K bs us **)
                    val _ = warning "step 2: as, bs, cs # K as ts, K bs us";
                    val prove_fresh_ss = HOL_ss addsimps
                      (finite_Diff :: List.concat fresh_thms @
                       fs_atoms @ abs_fresh @ abs_supp @ fresh_atm);
                    (* FIXME: avoid asm_full_simp_tac ? *)
                    fun prove_fresh ths y x = Goal.prove context'' [] []
                      (HOLogic.mk_Trueprop (fresh_const
                         (fastype_of x) (fastype_of y) $ x $ y))
                      (fn _ => cut_facts_tac ths 1 THEN asm_full_simp_tac prove_fresh_ss 1);
                    val constr_fresh_thms =
                      map (prove_fresh fresh_prems lhs) boundsl @
                      map (prove_fresh fresh_prems rhs) boundsr @
                      map (prove_fresh freshs2 lhs) freshs1 @
                      map (prove_fresh freshs2 rhs) freshs1;

                    (** pi1 o (K as ts) = pi2 o (K bs us) **)
                    val _ = warning "step 3: pi1 o (K as ts) = pi2 o (K bs us)";
                    val pi1_pi2_eq = Goal.prove context'' [] []
                      (HOLogic.mk_Trueprop (HOLogic.mk_eq
                        (fold_rev (mk_perm []) pi1 lhs, fold_rev (mk_perm []) pi2 rhs)))
                      (fn _ => EVERY
                         [cut_facts_tac constr_fresh_thms 1,
                          asm_simp_tac (HOL_basic_ss addsimps perm_fresh_fresh) 1,
                          rtac prem 1]);

                    (** pi1 o ts = pi2 o us **)
                    val _ = warning "step 4: pi1 o ts = pi2 o us";
                    val pi1_pi2_eqs = map (fn (t, u) =>
                      Goal.prove context'' [] []
                        (HOLogic.mk_Trueprop (HOLogic.mk_eq
                          (fold_rev (mk_perm []) pi1 t, fold_rev (mk_perm []) pi2 u)))
                        (fn _ => EVERY
                           [cut_facts_tac [pi1_pi2_eq] 1,
                            asm_full_simp_tac (HOL_ss addsimps
                              (calc_atm @ List.concat perm_simps' @
                               fresh_prems' @ freshs2' @ abs_perm @
                               alpha @ List.concat inject_thms)) 1]))
                        (map snd cargsl' ~~ map snd cargsr');

                    (** pi1^-1 o pi2 o us = ts **)
                    val _ = warning "step 5: pi1^-1 o pi2 o us = ts";
                    val rpi1_pi2_eqs = map (fn ((t, u), eq) =>
                      Goal.prove context'' [] []
                        (HOLogic.mk_Trueprop (HOLogic.mk_eq
                          (fold_rev (mk_perm []) (rpi1 @ pi2) u, t)))
                        (fn _ => simp_tac (HOL_ss addsimps
                           ((eq RS sym) :: perm_swap)) 1))
                        (map snd cargsl' ~~ map snd cargsr' ~~ pi1_pi2_eqs);

                    val (rec_prems1, rec_prems2) =
                      chop (length rec_prems div 2) rec_prems;

                    (** (ts, pi1^-1 o pi2 o vs) in rec_set **)
                    val _ = warning "step 6: (ts, pi1^-1 o pi2 o vs) in rec_set";
                    val rec_prems' = map (fn th =>
                      let
                        val _ $ (S $ x $ y) = prop_of th;
                        val k = find_index (equal S) rec_sets;
                        val pi = rpi1 @ pi2;
                        fun mk_pi z = fold_rev (mk_perm []) pi z;
                        fun eqvt_tac p =
                          let
                            val U as Type (_, [Type (_, [T, _])]) = fastype_of p;
                            val l = find_index (equal T) dt_atomTs;
                            val th = List.nth (List.nth (rec_equiv_thms', l), k);
                            val th' = Thm.instantiate ([],
                              [(cterm_of thy11 (Var (("pi", 0), U)),
                                cterm_of thy11 p)]) th;
                          in rtac th' 1 end;
                        val th' = Goal.prove context'' [] []
                          (HOLogic.mk_Trueprop (S $ mk_pi x $ mk_pi y))
                          (fn _ => EVERY
                             (map eqvt_tac pi @
                              [simp_tac (HOL_ss addsimps (fresh_prems' @ freshs2' @
                                 perm_swap @ perm_fresh_fresh)) 1,
                               rtac th 1]))
                      in
                        Simplifier.simplify
                          (HOL_basic_ss addsimps rpi1_pi2_eqs) th'
                      end) rec_prems2;

                    val ihs = filter (fn th => case prop_of th of
                      _ $ (Const ("All", _) $ _) => true | _ => false) prems';

                    (** pi1 o rs = pi2 o vs , rs = pi1^-1 o pi2 o vs **)
                    val _ = warning "step 7: pi1 o rs = pi2 o vs , rs = pi1^-1 o pi2 o vs";
                    val rec_eqns = map (fn (th, ih) =>
                      let
                        val th' = th RS (ih RS spec RS mp) RS sym;
                        val _ $ (_ $ lhs $ rhs) = prop_of th';
                        fun strip_perm (_ $ _ $ t) = strip_perm t
                          | strip_perm t = t;
                      in
                        Goal.prove context'' [] []
                           (HOLogic.mk_Trueprop (HOLogic.mk_eq
                              (fold_rev (mk_perm []) pi1 lhs,
                               fold_rev (mk_perm []) pi2 (strip_perm rhs))))
                           (fn _ => simp_tac (HOL_basic_ss addsimps
                              (th' :: perm_swap)) 1)
                      end) (rec_prems' ~~ ihs);

                    (** as # rs **)
                    val _ = warning "step 8: as # rs";
                    val rec_freshs = List.concat
                      (map (fn (rec_prem, ih) =>
                        let
                          val _ $ (S $ x $ (y as Free (_, T))) =
                            prop_of rec_prem;
                          val k = find_index (equal S) rec_sets;
                          val atoms = List.concat (List.mapPartial (fn (bs, z) =>
                            if z = x then NONE else SOME bs) cargsl')
                        in
                          map (fn a as Free (_, aT) =>
                            let val l = find_index (equal aT) dt_atomTs;
                            in
                              Goal.prove context'' [] []
                                (HOLogic.mk_Trueprop (fresh_const aT T $ a $ y))
                                (fn _ => EVERY
                                   (rtac (List.nth (List.nth (rec_fresh_thms, l), k)) 1 ::
                                    map (fn th => rtac th 1)
                                      (snd (List.nth (finite_thss, l))) @
                                    [rtac rec_prem 1, rtac ih 1,
                                     REPEAT_DETERM (resolve_tac fresh_prems 1)]))
                            end) atoms
                        end) (rec_prems1 ~~ ihs));

                    (** as # fK as ts rs , bs # fK bs us vs **)
                    val _ = warning "step 9: as # fK as ts rs , bs # fK bs us vs";
                    fun prove_fresh_result (a as Free (_, aT)) =
                      Goal.prove context'' [] []
                        (HOLogic.mk_Trueprop (fresh_const aT rT $ a $ rhs'))
                        (fn _ => EVERY
                           [resolve_tac fcbs 1,
                            REPEAT_DETERM (resolve_tac
                              (fresh_prems @ rec_freshs) 1),
                            REPEAT_DETERM (resolve_tac (maps snd rec_fin_supp_thms') 1
                              THEN resolve_tac rec_prems 1),
                            resolve_tac P_ind_ths 1,
                            REPEAT_DETERM (resolve_tac (P_ths @ rec_prems) 1)]);

                    val fresh_results'' = map prove_fresh_result boundsl;

                    fun prove_fresh_result'' ((a as Free (_, aT), b), th) =
                      let val th' = Goal.prove context'' [] []
                        (HOLogic.mk_Trueprop (fresh_const aT rT $
                            fold_rev (mk_perm []) (rpi2 @ pi1) a $
                            fold_rev (mk_perm []) (rpi2 @ pi1) rhs'))
                        (fn _ => simp_tac (HOL_ss addsimps fresh_bij) 1 THEN
                           rtac th 1)
                      in
                        Goal.prove context'' [] []
                          (HOLogic.mk_Trueprop (fresh_const aT rT $ b $ lhs'))
                          (fn _ => EVERY
                             [cut_facts_tac [th'] 1,
                              NominalPermeq.perm_simp_tac (HOL_ss addsimps
                                (rec_eqns @ pi1_pi2_eqs @ perm_swap)) 1,
                              full_simp_tac (HOL_ss addsimps (calc_atm @
                                fresh_prems' @ freshs2' @ perm_fresh_fresh)) 1])
                      end;

                    val fresh_results = fresh_results'' @ map prove_fresh_result''
                      (boundsl ~~ boundsr ~~ fresh_results'');

                    (** cs # fK as ts rs , cs # fK bs us vs **)
                    val _ = warning "step 10: cs # fK as ts rs , cs # fK bs us vs";
                    fun prove_fresh_result' recs t (a as Free (_, aT)) =
                      Goal.prove context'' [] []
                        (HOLogic.mk_Trueprop (fresh_const aT rT $ a $ t))
                        (fn _ => EVERY
                          [cut_facts_tac recs 1,
                           REPEAT_DETERM (dresolve_tac
                             (the (AList.lookup op = rec_fin_supp_thms' aT)) 1),
                           NominalPermeq.fresh_guess_tac
                             (HOL_ss addsimps (freshs2 @
                                fs_atoms @ fresh_atm @
                                List.concat (map snd finite_thss))) 1]);

                    val fresh_results' =
                      map (prove_fresh_result' rec_prems1 rhs') freshs1 @
                      map (prove_fresh_result' rec_prems2 lhs') freshs1;

                    (** pi1 o (fK as ts rs) = pi2 o (fK bs us vs) **)
                    val _ = warning "step 11: pi1 o (fK as ts rs) = pi2 o (fK bs us vs)";
                    val pi1_pi2_result = Goal.prove context'' [] []
                      (HOLogic.mk_Trueprop (HOLogic.mk_eq
                        (fold_rev (mk_perm []) pi1 rhs', fold_rev (mk_perm []) pi2 lhs')))
                      (fn _ => NominalPermeq.perm_simp_tac (HOL_ss addsimps
                           pi1_pi2_eqs @ rec_eqns) 1 THEN
                         TRY (simp_tac (HOL_ss addsimps
                           (fresh_prems' @ freshs2' @ calc_atm @ perm_fresh_fresh)) 1));

                    val _ = warning "final result";
                    val final = Goal.prove context'' [] [] (term_of concl)
                      (fn _ => cut_facts_tac [pi1_pi2_result RS sym] 1 THEN
                        full_simp_tac (HOL_basic_ss addsimps perm_fresh_fresh @
                          fresh_results @ fresh_results') 1);
                    val final' = ProofContext.export context'' context' [final];
                    val _ = warning "finished!"
                  in
                    resolve_tac final' 1
                  end) context 1])) idxss) (ndescr ~~ rec_elims))
         end));

    val rec_total_thms = map (fn r => r RS theI') rec_unique_thms;

    (* define primrec combinators *)

    val big_reccomb_name = (space_implode "_" new_type_names) ^ "_rec";
    val reccomb_names = map (Sign.full_name thy11)
      (if length descr'' = 1 then [big_reccomb_name] else
        (map ((curry (op ^) (big_reccomb_name ^ "_")) o string_of_int)
          (1 upto (length descr''))));
    val reccombs = map (fn ((name, T), T') => list_comb
      (Const (name, rec_fn_Ts @ [T] ---> T'), rec_fns))
        (reccomb_names ~~ recTs ~~ rec_result_Ts);

    val (reccomb_defs, thy12) =
      thy11
      |> Sign.add_consts_i (map (fn ((name, T), T') =>
          (Sign.base_name name, rec_fn_Ts @ [T] ---> T', NoSyn))
          (reccomb_names ~~ recTs ~~ rec_result_Ts))
      |> (PureThy.add_defs_i false o map Thm.no_attributes) (map (fn ((((name, comb), set), T), T') =>
          ((Sign.base_name name) ^ "_def", Logic.mk_equals (comb, absfree ("x", T,
           Const ("The", (T' --> HOLogic.boolT) --> T') $ absfree ("y", T',
             set $ Free ("x", T) $ Free ("y", T'))))))
               (reccomb_names ~~ reccombs ~~ rec_sets ~~ recTs ~~ rec_result_Ts));

    (* prove characteristic equations for primrec combinators *)

    val rec_thms = map (fn (prems, concl) =>
      let
        val _ $ (_ $ (_ $ x) $ _) = concl;
        val (_, cargs) = strip_comb x;
        val ps = map (fn (x as Free (_, T), i) =>
          (Free ("x" ^ string_of_int i, T), x)) (cargs ~~ (1 upto length cargs));
        val concl' = subst_atomic_types (rec_result_Ts' ~~ rec_result_Ts) concl;
        val prems' = List.concat finite_premss @ finite_ctxt_prems @
          rec_prems @ rec_prems' @ map (subst_atomic ps) prems;
        fun solve rules prems = resolve_tac rules THEN_ALL_NEW
          (resolve_tac prems THEN_ALL_NEW atac)
      in
        Goal.prove_global thy12 [] prems' concl'
          (fn prems => EVERY
            [rewrite_goals_tac reccomb_defs,
             rtac the1_equality 1,
             solve rec_unique_thms prems 1,
             resolve_tac rec_intrs 1,
             REPEAT (solve (prems @ rec_total_thms) prems 1)])
      end) (rec_eq_prems ~~
        DatatypeProp.make_primrecs new_type_names descr' sorts' thy12);

    val dt_infos = map (make_dt_info pdescr sorts induct reccomb_names rec_thms)
      ((0 upto length descr1 - 1) ~~ descr1 ~~ distinct_thms ~~ inject_thms);

    (* FIXME: theorems are stored in database for testing only *)
    val (_, thy13) = thy12 |>
      PureThy.add_thmss
        [(("rec_equiv", List.concat rec_equiv_thms), []),
         (("rec_equiv'", List.concat rec_equiv_thms'), []),
         (("rec_fin_supp", List.concat rec_fin_supp_thms), []),
         (("rec_fresh", List.concat rec_fresh_thms), []),
         (("rec_unique", map standard rec_unique_thms), []),
         (("recs", rec_thms), [])] ||>
      Sign.parent_path ||>
      map_nominal_datatypes (fold Symtab.update dt_infos);

  in
    thy13
  end;

val add_nominal_datatype = gen_add_nominal_datatype read_typ true;


(* FIXME: The following stuff should be exported by DatatypePackage *)

local structure P = OuterParse and K = OuterKeyword in

val datatype_decl =
  Scan.option (P.$$$ "(" |-- P.name --| P.$$$ ")") -- P.type_args -- P.name -- P.opt_infix --
    (P.$$$ "=" |-- P.enum1 "|" (P.name -- Scan.repeat P.typ -- P.opt_mixfix));

fun mk_datatype args =
  let
    val names = map (fn ((((NONE, _), t), _), _) => t | ((((SOME t, _), _), _), _) => t) args;
    val specs = map (fn ((((_, vs), t), mx), cons) =>
      (vs, t, mx, map (fn ((x, y), z) => (x, y, z)) cons)) args;
  in add_nominal_datatype false names specs end;

val _ =
  OuterSyntax.command "nominal_datatype" "define inductive datatypes" K.thy_decl
    (P.and_list1 datatype_decl >> (Toplevel.theory o mk_datatype));

end;

end