src/HOLCF/Tools/Domain/domain_take_proofs.ML
author huffman
Mon Mar 08 07:22:30 2010 -0800 (2010-03-08)
changeset 35650 64fff18d7f08
parent 35594 47d68e33ca29
child 35651 5dd352a85464
permissions -rw-r--r--
add function add_qualified_def
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(*  Title:      HOLCF/Tools/domain/domain_take_proofs.ML
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    Author:     Brian Huffman
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Defines take functions for the given domain equation
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and proves related theorems.
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*)
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signature DOMAIN_TAKE_PROOFS =
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sig
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  type iso_info =
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    {
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      absT : typ,
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      repT : typ,
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      abs_const : term,
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      rep_const : term,
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      abs_inverse : thm,
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      rep_inverse : thm
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    }
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  val define_take_functions :
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    (binding * iso_info) list -> theory ->
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    { take_consts : term list,
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      take_defs : thm list,
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      chain_take_thms : thm list,
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      take_0_thms : thm list,
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      take_Suc_thms : thm list,
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      deflation_take_thms : thm list,
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      finite_consts : term list,
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      finite_defs : thm list
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    } * theory
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  val map_of_typ :
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    theory -> (typ * term) list -> typ -> term
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  val add_map_function :
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    (string * string * thm) -> theory -> theory
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  val get_map_tab : theory -> string Symtab.table
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  val get_deflation_thms : theory -> thm list
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end;
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structure Domain_Take_Proofs : DOMAIN_TAKE_PROOFS =
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struct
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type iso_info =
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  {
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    absT : typ,
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    repT : typ,
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    abs_const : term,
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    rep_const : term,
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    abs_inverse : thm,
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    rep_inverse : thm
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  };
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val beta_ss =
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  HOL_basic_ss
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    addsimps simp_thms
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    addsimps [@{thm beta_cfun}]
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    addsimprocs [@{simproc cont_proc}];
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val beta_tac = simp_tac beta_ss;
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(******************************************************************************)
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(******************************** theory data *********************************)
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(******************************************************************************)
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structure MapData = Theory_Data
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(
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  (* constant names like "foo_map" *)
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  type T = string Symtab.table;
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  val empty = Symtab.empty;
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  val extend = I;
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  fun merge data = Symtab.merge (K true) data;
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);
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structure DeflMapData = Theory_Data
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(
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  (* theorems like "deflation a ==> deflation (foo_map$a)" *)
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  type T = thm list;
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  val empty = [];
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  val extend = I;
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  val merge = Thm.merge_thms;
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);
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fun add_map_function (tname, map_name, deflation_map_thm) =
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    MapData.map (Symtab.insert (K true) (tname, map_name))
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    #> DeflMapData.map (Thm.add_thm deflation_map_thm);
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val get_map_tab = MapData.get;
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val get_deflation_thms = DeflMapData.get;
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(******************************************************************************)
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(************************** building types and terms **************************)
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(******************************************************************************)
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open HOLCF_Library;
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infixr 6 ->>;
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infix -->>;
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infix 9 `;
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fun mapT (T as Type (_, Ts)) =
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    (map (fn T => T ->> T) Ts) -->> (T ->> T)
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  | mapT T = T ->> T;
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fun mk_deflation t =
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  Const (@{const_name deflation}, Term.fastype_of t --> boolT) $ t;
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fun mk_eqs (t, u) = HOLogic.mk_Trueprop (HOLogic.mk_eq (t, u));
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(******************************************************************************)
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(****************************** isomorphism info ******************************)
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(******************************************************************************)
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fun deflation_abs_rep (info : iso_info) : thm =
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  let
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    val abs_iso = #abs_inverse info;
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    val rep_iso = #rep_inverse info;
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    val thm = @{thm deflation_abs_rep} OF [abs_iso, rep_iso];
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  in
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    Drule.export_without_context thm
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  end
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(******************************************************************************)
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(********************* building map functions over types **********************)
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(******************************************************************************)
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fun map_of_typ (thy : theory) (sub : (typ * term) list) (T : typ) : term =
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  let
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    val map_tab = get_map_tab thy;
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    fun auto T = T ->> T;
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    fun map_of T =
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        case AList.lookup (op =) sub T of
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          SOME m => (m, true) | NONE => map_of' T
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    and map_of' (T as (Type (c, Ts))) =
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        (case Symtab.lookup map_tab c of
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          SOME map_name =>
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          let
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            val map_type = map auto Ts -->> auto T;
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            val (ms, bs) = map_split map_of Ts;
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          in
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            if exists I bs
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            then (list_ccomb (Const (map_name, map_type), ms), true)
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            else (mk_ID T, false)
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          end
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        | NONE => (mk_ID T, false))
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      | map_of' T = (mk_ID T, false);
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  in
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    fst (map_of T)
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  end;
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(******************************************************************************)
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(********************* declaring definitions and theorems *********************)
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(******************************************************************************)
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fun define_const
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    (bind : binding, rhs : term)
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    (thy : theory)
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    : (term * thm) * theory =
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  let
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    val typ = Term.fastype_of rhs;
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    val (const, thy) = Sign.declare_const ((bind, typ), NoSyn) thy;
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    val eqn = Logic.mk_equals (const, rhs);
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    val def = Thm.no_attributes (Binding.suffix_name "_def" bind, eqn);
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    val (def_thm, thy) = yield_singleton (PureThy.add_defs false) def thy;
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  in
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    ((const, def_thm), thy)
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  end;
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fun add_qualified_def name (path, eqn) thy =
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    thy
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    |> Sign.add_path path
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    |> yield_singleton (PureThy.add_defs false)
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        (Thm.no_attributes (Binding.name name, eqn))
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    ||> Sign.parent_path;
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fun add_qualified_thm name (path, thm) thy =
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    thy
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    |> Sign.add_path path
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    |> yield_singleton PureThy.add_thms
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        (Thm.no_attributes (Binding.name name, thm))
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    ||> Sign.parent_path;
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fun add_qualified_simp_thm name (path, thm) thy =
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    thy
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    |> Sign.add_path path
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    |> yield_singleton PureThy.add_thms
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        ((Binding.name name, thm), [Simplifier.simp_add])
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    ||> Sign.parent_path;
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(******************************************************************************)
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(************************** defining take functions ***************************)
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(******************************************************************************)
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fun define_take_functions
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    (spec : (binding * iso_info) list)
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    (thy : theory) =
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  let
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    (* retrieve components of spec *)
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    val dom_binds = map fst spec;
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    val iso_infos = map snd spec;
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    val dom_eqns = map (fn x => (#absT x, #repT x)) iso_infos;
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    val rep_abs_consts = map (fn x => (#rep_const x, #abs_const x)) iso_infos;
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    val dnames = map Binding.name_of dom_binds;
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    (* get table of map functions *)
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    val map_tab = MapData.get thy;
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    fun mk_projs []      t = []
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      | mk_projs (x::[]) t = [(x, t)]
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      | mk_projs (x::xs) t = (x, mk_fst t) :: mk_projs xs (mk_snd t);
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    fun mk_cfcomp2 ((rep_const, abs_const), f) =
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        mk_cfcomp (abs_const, mk_cfcomp (f, rep_const));
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    (* define take functional *)
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    val newTs : typ list = map fst dom_eqns;
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    val copy_arg_type = mk_tupleT (map (fn T => T ->> T) newTs);
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    val copy_arg = Free ("f", copy_arg_type);
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    val copy_args = map snd (mk_projs dom_binds copy_arg);
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    fun one_copy_rhs (rep_abs, (lhsT, rhsT)) =
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      let
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        val body = map_of_typ thy (newTs ~~ copy_args) rhsT;
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      in
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        mk_cfcomp2 (rep_abs, body)
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      end;
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    val take_functional =
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        big_lambda copy_arg
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          (mk_tuple (map one_copy_rhs (rep_abs_consts ~~ dom_eqns)));
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    val take_rhss =
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      let
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        val n = Free ("n", HOLogic.natT);
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        val rhs = mk_iterate (n, take_functional);
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      in
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        map (lambda n o snd) (mk_projs dom_binds rhs)
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      end;
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    (* define take constants *)
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    fun define_take_const ((tbind, take_rhs), (lhsT, rhsT)) thy =
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      let
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        val take_type = HOLogic.natT --> lhsT ->> lhsT;
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        val take_bind = Binding.suffix_name "_take" tbind;
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        val (take_const, thy) =
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          Sign.declare_const ((take_bind, take_type), NoSyn) thy;
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        val take_eqn = Logic.mk_equals (take_const, take_rhs);
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        val (take_def_thm, thy) =
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            add_qualified_def "take_def"
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             (Binding.name_of tbind, take_eqn) thy;
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      in ((take_const, take_def_thm), thy) end;
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    val ((take_consts, take_defs), thy) = thy
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      |> fold_map define_take_const (dom_binds ~~ take_rhss ~~ dom_eqns)
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      |>> ListPair.unzip;
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    (* prove chain_take lemmas *)
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    fun prove_chain_take (take_const, dname) thy =
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      let
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        val goal = mk_trp (mk_chain take_const);
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        val rules = take_defs @ @{thms chain_iterate ch2ch_fst ch2ch_snd};
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        val tac = simp_tac (HOL_basic_ss addsimps rules) 1;
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        val thm = Goal.prove_global thy [] [] goal (K tac);
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      in
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        add_qualified_simp_thm "chain_take" (dname, thm) thy
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      end;
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    val (chain_take_thms, thy) =
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      fold_map prove_chain_take (take_consts ~~ dnames) thy;
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    (* prove take_0 lemmas *)
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    fun prove_take_0 ((take_const, dname), (lhsT, rhsT)) thy =
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      let
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        val lhs = take_const $ @{term "0::nat"};
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        val goal = mk_eqs (lhs, mk_bottom (lhsT ->> lhsT));
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        val rules = take_defs @ @{thms iterate_0 fst_strict snd_strict};
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        val tac = simp_tac (HOL_basic_ss addsimps rules) 1;
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        val take_0_thm = Goal.prove_global thy [] [] goal (K tac);
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      in
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        add_qualified_thm "take_0" (dname, take_0_thm) thy
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      end;
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    val (take_0_thms, thy) =
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      fold_map prove_take_0 (take_consts ~~ dnames ~~ dom_eqns) thy;
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    (* prove take_Suc lemmas *)
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    val n = Free ("n", natT);
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    val take_is = map (fn t => t $ n) take_consts;
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    fun prove_take_Suc
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          (((take_const, rep_abs), dname), (lhsT, rhsT)) thy =
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      let
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        val lhs = take_const $ (@{term Suc} $ n);
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        val body = map_of_typ thy (newTs ~~ take_is) rhsT;
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        val rhs = mk_cfcomp2 (rep_abs, body);
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        val goal = mk_eqs (lhs, rhs);
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        val simps = @{thms iterate_Suc fst_conv snd_conv}
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        val rules = take_defs @ simps;
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        val tac = simp_tac (beta_ss addsimps rules) 1;
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        val take_Suc_thm = Goal.prove_global thy [] [] goal (K tac);
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      in
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        add_qualified_thm "take_Suc" (dname, take_Suc_thm) thy
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      end;
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    val (take_Suc_thms, thy) =
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      fold_map prove_take_Suc
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        (take_consts ~~ rep_abs_consts ~~ dnames ~~ dom_eqns) thy;
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    (* prove deflation theorems for take functions *)
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    val deflation_abs_rep_thms = map deflation_abs_rep iso_infos;
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    val deflation_take_thm =
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      let
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        val n = Free ("n", natT);
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        fun mk_goal take_const = mk_deflation (take_const $ n);
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        val goal = mk_trp (foldr1 mk_conj (map mk_goal take_consts));
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        val adm_rules =
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          @{thms adm_conj adm_subst [OF _ adm_deflation]
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                 cont2cont_fst cont2cont_snd cont_id};
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        val bottom_rules =
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          take_0_thms @ @{thms deflation_UU simp_thms};
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        val deflation_rules =
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          @{thms conjI deflation_ID}
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          @ deflation_abs_rep_thms
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          @ DeflMapData.get thy;
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      in
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        Goal.prove_global thy [] [] goal (fn _ =>
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         EVERY
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          [rtac @{thm nat.induct} 1,
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           simp_tac (HOL_basic_ss addsimps bottom_rules) 1,
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           asm_simp_tac (HOL_basic_ss addsimps take_Suc_thms) 1,
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           REPEAT (etac @{thm conjE} 1
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                   ORELSE resolve_tac deflation_rules 1
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                   ORELSE atac 1)])
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      end;
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    fun conjuncts [] thm = []
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      | conjuncts (n::[]) thm = [(n, thm)]
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      | conjuncts (n::ns) thm = let
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          val thmL = thm RS @{thm conjunct1};
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          val thmR = thm RS @{thm conjunct2};
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        in (n, thmL):: conjuncts ns thmR end;
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    val (deflation_take_thms, thy) =
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      fold_map (add_qualified_thm "deflation_take")
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        (map (apsnd Drule.export_without_context)
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          (conjuncts dnames deflation_take_thm)) thy;
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    (* prove strictness of take functions *)
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    fun prove_take_strict (deflation_take, dname) thy =
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      let
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        val take_strict_thm =
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            Drule.export_without_context
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            (@{thm deflation_strict} OF [deflation_take]);
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      in
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        add_qualified_thm "take_strict" (dname, take_strict_thm) thy
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      end;
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    val (take_strict_thms, thy) =
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      fold_map prove_take_strict
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        (deflation_take_thms ~~ dnames) thy;
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    (* prove take/take rules *)
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    fun prove_take_take ((chain_take, deflation_take), dname) thy =
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      let
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        val take_take_thm =
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            Drule.export_without_context
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            (@{thm deflation_chain_min} OF [chain_take, deflation_take]);
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      in
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        add_qualified_thm "take_take" (dname, take_take_thm) thy
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      end;
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    val (take_take_thms, thy) =
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      fold_map prove_take_take
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        (chain_take_thms ~~ deflation_take_thms ~~ dnames) thy;
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    (* prove take_below rules *)
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    fun prove_take_below (deflation_take, dname) thy =
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      let
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        val take_below_thm =
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            Drule.export_without_context
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            (@{thm deflation.below} OF [deflation_take]);
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      in
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        add_qualified_thm "take_below" (dname, take_below_thm) thy
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      end;
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    val (take_below_thms, thy) =
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      fold_map prove_take_below
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        (deflation_take_thms ~~ dnames) thy;
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    (* define finiteness predicates *)
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    fun define_finite_const ((tbind, take_const), (lhsT, rhsT)) thy =
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      let
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        val finite_type = lhsT --> boolT;
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        val finite_bind = Binding.suffix_name "_finite" tbind;
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        val (finite_const, thy) =
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          Sign.declare_const ((finite_bind, finite_type), NoSyn) thy;
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        val x = Free ("x", lhsT);
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        val n = Free ("n", natT);
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        val finite_rhs =
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          lambda x (HOLogic.exists_const natT $
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            (lambda n (mk_eq (mk_capply (take_const $ n, x), x))));
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        val finite_eqn = Logic.mk_equals (finite_const, finite_rhs);
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        val (finite_def_thm, thy) =
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            add_qualified_def "finite_def"
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             (Binding.name_of tbind, finite_eqn) thy;
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      in ((finite_const, finite_def_thm), thy) end;
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    val ((finite_consts, finite_defs), thy) = thy
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      |> fold_map define_finite_const (dom_binds ~~ take_consts ~~ dom_eqns)
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      |>> ListPair.unzip;
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   400
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   401
    val result =
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   402
      {
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   403
        take_consts = take_consts,
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        take_defs = take_defs,
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        chain_take_thms = chain_take_thms,
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        take_0_thms = take_0_thms,
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        take_Suc_thms = take_Suc_thms,
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        deflation_take_thms = deflation_take_thms,
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        finite_consts = finite_consts,
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        finite_defs = finite_defs
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      };
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   412
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   413
  in
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    (result, thy)
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  end;
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end;