src/HOL/Codatatype/Tools/bnf_fp_sugar.ML
author blanchet
Fri, 14 Sep 2012 12:09:27 +0200
changeset 50376 cc1d39529dd1
parent 50357 8ea4bad49ed5
child 50377 1271aca16aed
permissions -rw-r--r--
derive induction via backward proof, to ensure that the premises are in the right order for constructors like "X x y x" where x and y are mutually recursive
     1 (*  Title:      HOL/Codatatype/Tools/bnf_fp_sugar.ML
     2     Author:     Jasmin Blanchette, TU Muenchen
     3     Copyright   2012
     4 
     5 Sugar for constructing LFPs and GFPs.
     6 *)
     7 
     8 signature BNF_FP_SUGAR =
     9 sig
    10   val datatyp: bool ->
    11     (mixfix list -> (string * sort) list option -> binding list -> typ list * typ list list ->
    12       BNF_Def.BNF list -> local_theory ->
    13       (term list * term list * term list * term list * thm * thm list * thm list * thm list *
    14          thm list * thm list) * local_theory) ->
    15     bool * ((((typ * sort) list * binding) * mixfix) * ((((binding * binding) *
    16       (binding * typ) list) * (binding * term) list) * mixfix) list) list ->
    17     local_theory -> local_theory
    18   val parse_datatype_cmd: bool ->
    19     (mixfix list -> (string * sort) list option -> binding list -> typ list * typ list list ->
    20       BNF_Def.BNF list -> local_theory ->
    21       (term list * term list * term list * term list * thm * thm list * thm list * thm list *
    22          thm list * thm list) * local_theory) ->
    23     (local_theory -> local_theory) parser
    24 end;
    25 
    26 structure BNF_FP_Sugar : BNF_FP_SUGAR =
    27 struct
    28 
    29 open BNF_Util
    30 open BNF_Wrap
    31 open BNF_Def
    32 open BNF_FP_Util
    33 open BNF_FP_Sugar_Tactics
    34 
    35 val simp_attrs = @{attributes [simp]};
    36 
    37 fun split_list11 xs =
    38   (map #1 xs, map #2 xs, map #3 xs, map #4 xs, map #5 xs, map #6 xs, map #7 xs, map #8 xs,
    39    map #9 xs, map #10 xs, map #11 xs);
    40 
    41 fun strip_map_type (Type (@{type_name fun}, [T as Type _, T'])) = strip_map_type T' |>> cons T
    42   | strip_map_type T = ([], T);
    43 
    44 fun resort_tfree S (TFree (s, _)) = TFree (s, S);
    45 
    46 fun typ_subst inst (T as Type (s, Ts)) =
    47     (case AList.lookup (op =) inst T of
    48       NONE => Type (s, map (typ_subst inst) Ts)
    49     | SOME T' => T')
    50   | typ_subst inst T = the_default T (AList.lookup (op =) inst T);
    51 
    52 val lists_bmoc = fold (fn xs => fn t => Term.list_comb (t, xs));
    53 
    54 fun mk_id T = Const (@{const_name id}, T --> T);
    55 fun mk_id_fun T = Abs (Name.uu, T, Bound 0);
    56 
    57 fun mk_tupled_fun x f xs = HOLogic.tupled_lambda x (Term.list_comb (f, xs));
    58 fun mk_uncurried_fun f xs = mk_tupled_fun (HOLogic.mk_tuple xs) f xs;
    59 fun mk_uncurried2_fun f xss =
    60   mk_tupled_fun (HOLogic.mk_tuple (map HOLogic.mk_tuple xss)) f (flat xss);
    61 
    62 fun tick v f = Term.lambda v (HOLogic.mk_prod (v, f $ v));
    63 
    64 fun tack z_name (c, v) f =
    65   let val z = Free (z_name, mk_sumT (fastype_of v, fastype_of c)) in
    66     Term.lambda z (mk_sum_case (Term.lambda v v, Term.lambda c (f $ c)) $ z)
    67   end;
    68 
    69 fun fold_def_rule n thm = funpow n (fn thm => thm RS fun_cong) (thm RS meta_eq_to_obj_eq) RS sym;
    70 
    71 fun cannot_merge_types () = error "Mutually recursive types must have the same type parameters";
    72 
    73 fun merge_type_arg T T' = if T = T' then T else cannot_merge_types ();
    74 
    75 fun merge_type_args (As, As') =
    76   if length As = length As' then map2 merge_type_arg As As' else cannot_merge_types ();
    77 
    78 fun type_args_constrained_of (((cAs, _), _), _) = cAs;
    79 fun type_binding_of (((_, b), _), _) = b;
    80 fun mixfix_of ((_, mx), _) = mx;
    81 fun ctr_specs_of (_, ctr_specs) = ctr_specs;
    82 
    83 fun disc_of ((((disc, _), _), _), _) = disc;
    84 fun ctr_of ((((_, ctr), _), _), _) = ctr;
    85 fun args_of (((_, args), _), _) = args;
    86 fun defaults_of ((_, ds), _) = ds;
    87 fun ctr_mixfix_of (_, mx) = mx;
    88 
    89 fun define_datatype prepare_constraint prepare_typ prepare_term lfp construct (no_dests, specs)
    90     no_defs_lthy0 =
    91   let
    92     (* TODO: sanity checks on arguments *)
    93 
    94     val _ = if not lfp andalso no_dests then error "Cannot define destructor-less codatatypes"
    95       else ();
    96 
    97     val N = length specs;
    98     val fp_bs = map type_binding_of specs;
    99     val fp_common_name = mk_common_name fp_bs;
   100 
   101     fun prepare_type_arg (ty, c) =
   102       let val TFree (s, _) = prepare_typ no_defs_lthy0 ty in
   103         TFree (s, prepare_constraint no_defs_lthy0 c)
   104       end;
   105 
   106     val Ass0 = map (map prepare_type_arg o type_args_constrained_of) specs;
   107     val unsorted_Ass0 = map (map (resort_tfree HOLogic.typeS)) Ass0;
   108     val unsorted_As = Library.foldr1 merge_type_args unsorted_Ass0;
   109 
   110     val (((Bs, Cs), vs'), no_defs_lthy) =
   111       no_defs_lthy0
   112       |> fold (Variable.declare_typ o resort_tfree dummyS) unsorted_As
   113       |> mk_TFrees N
   114       ||>> mk_TFrees N
   115       ||>> Variable.variant_fixes (map Binding.name_of fp_bs);
   116 
   117     (* TODO: cleaner handling of fake contexts, without "background_theory" *)
   118     (*the "perhaps o try" below helps gracefully handles the case where the new type is defined in a
   119       locale and shadows an existing global type*)
   120     val fake_thy =
   121       Theory.copy #> fold (fn spec => perhaps (try (Sign.add_type no_defs_lthy
   122         (type_binding_of spec, length (type_args_constrained_of spec), mixfix_of spec)))) specs;
   123     val fake_lthy = Proof_Context.background_theory fake_thy no_defs_lthy;
   124 
   125     fun mk_fake_T b =
   126       Type (fst (Term.dest_Type (Proof_Context.read_type_name fake_lthy true (Binding.name_of b))),
   127         unsorted_As);
   128 
   129     val fake_Ts = map mk_fake_T fp_bs;
   130 
   131     val mixfixes = map mixfix_of specs;
   132 
   133     val _ = (case duplicates Binding.eq_name fp_bs of [] => ()
   134       | b :: _ => error ("Duplicate type name declaration " ^ quote (Binding.name_of b)));
   135 
   136     val ctr_specss = map ctr_specs_of specs;
   137 
   138     val disc_bindingss = map (map disc_of) ctr_specss;
   139     val ctr_bindingss =
   140       map2 (fn fp_b => map (Binding.qualify false (Binding.name_of fp_b) o ctr_of))
   141         fp_bs ctr_specss;
   142     val ctr_argsss = map (map args_of) ctr_specss;
   143     val ctr_mixfixess = map (map ctr_mixfix_of) ctr_specss;
   144 
   145     val sel_bindingsss = map (map (map fst)) ctr_argsss;
   146     val fake_ctr_Tsss0 = map (map (map (prepare_typ fake_lthy o snd))) ctr_argsss;
   147     val raw_sel_defaultsss = map (map defaults_of) ctr_specss;
   148 
   149     val (As :: _) :: fake_ctr_Tsss =
   150       burrow (burrow (Syntax.check_typs fake_lthy)) (Ass0 :: fake_ctr_Tsss0);
   151 
   152     val _ = (case duplicates (op =) unsorted_As of [] => ()
   153       | A :: _ => error ("Duplicate type parameter " ^
   154           quote (Syntax.string_of_typ no_defs_lthy A)));
   155 
   156     val rhs_As' = fold (fold (fold Term.add_tfreesT)) fake_ctr_Tsss [];
   157     val _ = (case subtract (op =) (map dest_TFree As) rhs_As' of
   158         [] => ()
   159       | A' :: _ => error ("Extra type variable on right-hand side: " ^
   160           quote (Syntax.string_of_typ no_defs_lthy (TFree A'))));
   161 
   162     fun eq_fpT (T as Type (s, Us)) (Type (s', Us')) =
   163         s = s' andalso (Us = Us' orelse error ("Illegal occurrence of recursive type " ^
   164           quote (Syntax.string_of_typ fake_lthy T)))
   165       | eq_fpT _ _ = false;
   166 
   167     fun freeze_fp (T as Type (s, Us)) =
   168         (case find_index (eq_fpT T) fake_Ts of ~1 => Type (s, map freeze_fp Us) | j => nth Bs j)
   169       | freeze_fp T = T;
   170 
   171     val ctr_TsssBs = map (map (map freeze_fp)) fake_ctr_Tsss;
   172     val ctr_sum_prod_TsBs = map (mk_sumTN_balanced o map HOLogic.mk_tupleT) ctr_TsssBs;
   173 
   174     val fp_eqs =
   175       map dest_TFree Bs ~~ map (Term.typ_subst_atomic (As ~~ unsorted_As)) ctr_sum_prod_TsBs;
   176 
   177     val (pre_bnfs, ((unfs0, flds0, fp_iters0, fp_recs0, fp_induct, unf_flds, fld_unfs, fld_injects,
   178         fp_iter_thms, fp_rec_thms), lthy)) =
   179       fp_bnf construct fp_bs mixfixes (map dest_TFree unsorted_As) fp_eqs no_defs_lthy0;
   180 
   181     val add_nested_bnf_names =
   182       let
   183         fun add (Type (s, Ts)) ss =
   184             let val (needs, ss') = fold_map add Ts ss in
   185               if exists I needs then (true, insert (op =) s ss') else (false, ss')
   186             end
   187           | add T ss = (member (op =) As T, ss);
   188       in snd oo add end;
   189 
   190     val nested_bnfs =
   191       map_filter (bnf_of lthy) (fold (fold (fold add_nested_bnf_names)) ctr_TsssBs []);
   192 
   193     val timer = time (Timer.startRealTimer ());
   194 
   195     fun mk_unf_or_fld get_T Ts t =
   196       let val Type (_, Ts0) = get_T (fastype_of t) in
   197         Term.subst_atomic_types (Ts0 ~~ Ts) t
   198       end;
   199 
   200     val mk_unf = mk_unf_or_fld domain_type;
   201     val mk_fld = mk_unf_or_fld range_type;
   202 
   203     val unfs = map (mk_unf As) unfs0;
   204     val flds = map (mk_fld As) flds0;
   205 
   206     val fpTs = map (domain_type o fastype_of) unfs;
   207     val vs = map2 (curry Free) vs' fpTs;
   208 
   209     val ctr_Tsss = map (map (map (Term.typ_subst_atomic (Bs ~~ fpTs)))) ctr_TsssBs;
   210     val ns = map length ctr_Tsss;
   211     val kss = map (fn n => 1 upto n) ns;
   212     val mss = map (map length) ctr_Tsss;
   213     val Css = map2 replicate ns Cs;
   214 
   215     fun mk_iter_like Ts Us t =
   216       let
   217         val (bindings, body) = strip_type (fastype_of t);
   218         val (f_Us, prebody) = split_last bindings;
   219         val Type (_, Ts0) = if lfp then prebody else body;
   220         val Us0 = distinct (op =) (map (if lfp then body_type else domain_type) f_Us);
   221       in
   222         Term.subst_atomic_types (Ts0 @ Us0 ~~ Ts @ Us) t
   223       end;
   224 
   225     val fp_iters as fp_iter1 :: _ = map (mk_iter_like As Cs) fp_iters0;
   226     val fp_recs as fp_rec1 :: _ = map (mk_iter_like As Cs) fp_recs0;
   227 
   228     val fp_iter_fun_Ts = fst (split_last (binder_types (fastype_of fp_iter1)));
   229     val fp_rec_fun_Ts = fst (split_last (binder_types (fastype_of fp_rec1)));
   230 
   231     val ((iter_only as (gss, _, _), rec_only as (hss, _, _)),
   232          (zs, cs, cpss, coiter_only as ((pgss, crgsss), _), corec_only as ((phss, cshsss), _))) =
   233       if lfp then
   234         let
   235           val y_Tsss =
   236             map3 (fn n => fn ms => map2 dest_tupleT ms o dest_sumTN_balanced n o domain_type)
   237               ns mss fp_iter_fun_Ts;
   238           val g_Tss = map2 (map2 (curry (op --->))) y_Tsss Css;
   239 
   240           val ((gss, ysss), _) =
   241             lthy
   242             |> mk_Freess "f" g_Tss
   243             ||>> mk_Freesss "x" y_Tsss;
   244           val yssss = map (map (map single)) ysss;
   245 
   246           fun dest_rec_prodT (T as Type (@{type_name prod}, Us as [_, U])) =
   247               if member (op =) Cs U then Us else [T]
   248             | dest_rec_prodT T = [T];
   249 
   250           val z_Tssss =
   251             map3 (fn n => fn ms => map2 (map dest_rec_prodT oo dest_tupleT) ms o
   252               dest_sumTN_balanced n o domain_type) ns mss fp_rec_fun_Ts;
   253           val h_Tss = map2 (map2 (fold_rev (curry (op --->)))) z_Tssss Css;
   254 
   255           val hss = map2 (map2 retype_free) h_Tss gss;
   256           val zssss_hd = map2 (map2 (map2 (retype_free o hd))) z_Tssss ysss;
   257           val (zssss_tl, _) =
   258             lthy
   259             |> mk_Freessss "y" (map (map (map tl)) z_Tssss);
   260           val zssss = map2 (map2 (map2 cons)) zssss_hd zssss_tl;
   261         in
   262           (((gss, g_Tss, yssss), (hss, h_Tss, zssss)),
   263            ([], [], [], (([], []), ([], [])), (([], []), ([], []))))
   264         end
   265       else
   266         let
   267           (*avoid "'a itself" arguments in coiterators and corecursors*)
   268           val mss' =  map (fn [0] => [1] | ms => ms) mss;
   269 
   270           val p_Tss = map2 (fn n => replicate (Int.max (0, n - 1)) o mk_predT) ns Cs;
   271 
   272           fun zip_predss_getterss qss fss = maps (op @) (qss ~~ fss);
   273 
   274           fun zip_preds_predsss_gettersss [] [qss] [fss] = zip_predss_getterss qss fss
   275             | zip_preds_predsss_gettersss (p :: ps) (qss :: qsss) (fss :: fsss) =
   276               p :: zip_predss_getterss qss fss @ zip_preds_predsss_gettersss ps qsss fsss;
   277 
   278           fun mk_types maybe_dest_sumT fun_Ts =
   279             let
   280               val f_sum_prod_Ts = map range_type fun_Ts;
   281               val f_prod_Tss = map2 dest_sumTN_balanced ns f_sum_prod_Ts;
   282               val f_Tssss =
   283                 map3 (fn C => map2 (map (map (curry (op -->) C) o maybe_dest_sumT) oo dest_tupleT))
   284                   Cs mss' f_prod_Tss;
   285               val q_Tssss =
   286                 map (map (map (fn [_] => [] | [_, C] => [mk_predT (domain_type C)]))) f_Tssss;
   287               val pf_Tss = map3 zip_preds_predsss_gettersss p_Tss q_Tssss f_Tssss;
   288             in (q_Tssss, f_sum_prod_Ts, f_Tssss, pf_Tss) end;
   289 
   290           val (r_Tssss, g_sum_prod_Ts, g_Tssss, pg_Tss) = mk_types single fp_iter_fun_Ts;
   291 
   292           val ((((Free (z, _), cs), pss), gssss), _) =
   293             lthy
   294             |> yield_singleton (mk_Frees "z") dummyT
   295             ||>> mk_Frees "a" Cs
   296             ||>> mk_Freess "p" p_Tss
   297             ||>> mk_Freessss "g" g_Tssss;
   298           val rssss = map (map (map (fn [] => []))) r_Tssss;
   299 
   300           fun dest_corec_sumT (T as Type (@{type_name sum}, Us as [_, U])) =
   301               if member (op =) Cs U then Us else [T]
   302             | dest_corec_sumT T = [T];
   303 
   304           val (s_Tssss, h_sum_prod_Ts, h_Tssss, ph_Tss) = mk_types dest_corec_sumT fp_rec_fun_Ts;
   305 
   306           val hssss_hd = map2 (map2 (map2 (fn T :: _ => fn [g] => retype_free T g))) h_Tssss gssss;
   307           val ((sssss, hssss_tl), _) =
   308             lthy
   309             |> mk_Freessss "q" s_Tssss
   310             ||>> mk_Freessss "h" (map (map (map tl)) h_Tssss);
   311           val hssss = map2 (map2 (map2 cons)) hssss_hd hssss_tl;
   312 
   313           val cpss = map2 (fn c => map (fn p => p $ c)) cs pss;
   314 
   315           fun mk_preds_getters_join [] [cf] = cf
   316             | mk_preds_getters_join [cq] [cf, cf'] =
   317               mk_If cq (mk_Inl (fastype_of cf') cf) (mk_Inr (fastype_of cf) cf');
   318 
   319           fun mk_terms qssss fssss =
   320             let
   321               val pfss = map3 zip_preds_predsss_gettersss pss qssss fssss;
   322               val cqssss = map2 (fn c => map (map (map (fn f => f $ c)))) cs qssss;
   323               val cfssss = map2 (fn c => map (map (map (fn f => f $ c)))) cs fssss;
   324               val cqfsss = map2 (map2 (map2 mk_preds_getters_join)) cqssss cfssss;
   325             in (pfss, cqfsss) end;
   326         in
   327           ((([], [], []), ([], [], [])),
   328            ([z], cs, cpss, (mk_terms rssss gssss, (g_sum_prod_Ts, pg_Tss)),
   329             (mk_terms sssss hssss, (h_sum_prod_Ts, ph_Tss))))
   330         end;
   331 
   332     fun define_ctrs_case_for_type (((((((((((((((((((fp_b, fpT), C), v), fld), unf), fp_iter),
   333           fp_rec), fld_unf), unf_fld), fld_inject), n), ks), ms), ctr_bindings), ctr_mixfixes),
   334         ctr_Tss), disc_bindings), sel_bindingss), raw_sel_defaultss) no_defs_lthy =
   335       let
   336         val unfT = domain_type (fastype_of fld);
   337         val ctr_prod_Ts = map HOLogic.mk_tupleT ctr_Tss;
   338         val ctr_sum_prod_T = mk_sumTN_balanced ctr_prod_Ts;
   339         val case_Ts = map (fn Ts => Ts ---> C) ctr_Tss;
   340 
   341         val (((u, fs), xss), _) =
   342           no_defs_lthy
   343           |> yield_singleton (mk_Frees "u") unfT
   344           ||>> mk_Frees "f" case_Ts
   345           ||>> mk_Freess "x" ctr_Tss;
   346 
   347         val ctr_rhss =
   348           map2 (fn k => fn xs => fold_rev Term.lambda xs (fld $
   349             mk_InN_balanced ctr_sum_prod_T n (HOLogic.mk_tuple xs) k)) ks xss;
   350 
   351         val case_binding = Binding.suffix_name ("_" ^ caseN) fp_b;
   352 
   353         val case_rhs =
   354           fold_rev Term.lambda (fs @ [v])
   355             (mk_sum_caseN_balanced (map2 mk_uncurried_fun fs xss) $ (unf $ v));
   356 
   357         val ((raw_case :: raw_ctrs, raw_case_def :: raw_ctr_defs), (lthy', lthy)) = no_defs_lthy
   358           |> apfst split_list o fold_map3 (fn b => fn mx => fn rhs =>
   359               Local_Theory.define ((b, mx), ((Thm.def_binding b, []), rhs)) #>> apsnd snd)
   360             (case_binding :: ctr_bindings) (NoSyn :: ctr_mixfixes) (case_rhs :: ctr_rhss)
   361           ||> `Local_Theory.restore;
   362 
   363         val phi = Proof_Context.export_morphism lthy lthy';
   364 
   365         val ctr_defs = map (Morphism.thm phi) raw_ctr_defs;
   366         val case_def = Morphism.thm phi raw_case_def;
   367 
   368         val ctrs0 = map (Morphism.term phi) raw_ctrs;
   369         val casex0 = Morphism.term phi raw_case;
   370 
   371         val ctrs = map (mk_ctr As) ctrs0;
   372 
   373         fun exhaust_tac {context = ctxt, ...} =
   374           let
   375             val fld_iff_unf_thm =
   376               let
   377                 val goal =
   378                   fold_rev Logic.all [u, v]
   379                     (mk_Trueprop_eq (HOLogic.mk_eq (v, fld $ u), HOLogic.mk_eq (unf $ v, u)));
   380               in
   381                 Skip_Proof.prove lthy [] [] goal (fn {context = ctxt, ...} =>
   382                   mk_fld_iff_unf_tac ctxt (map (SOME o certifyT lthy) [unfT, fpT])
   383                     (certify lthy fld) (certify lthy unf) fld_unf unf_fld)
   384                 |> Thm.close_derivation
   385                 |> Morphism.thm phi
   386               end;
   387 
   388             val sumEN_thm' =
   389               Local_Defs.unfold lthy @{thms all_unit_eq}
   390                 (Drule.instantiate' (map (SOME o certifyT lthy) ctr_prod_Ts) []
   391                    (mk_sumEN_balanced n))
   392               |> Morphism.thm phi;
   393           in
   394             mk_exhaust_tac ctxt n ctr_defs fld_iff_unf_thm sumEN_thm'
   395           end;
   396 
   397         val inject_tacss =
   398           map2 (fn 0 => K [] | _ => fn ctr_def => [fn {context = ctxt, ...} =>
   399               mk_inject_tac ctxt ctr_def fld_inject]) ms ctr_defs;
   400 
   401         val half_distinct_tacss =
   402           map (map (fn (def, def') => fn {context = ctxt, ...} =>
   403             mk_half_distinct_tac ctxt fld_inject [def, def'])) (mk_half_pairss ctr_defs);
   404 
   405         val case_tacs =
   406           map3 (fn k => fn m => fn ctr_def => fn {context = ctxt, ...} =>
   407             mk_case_tac ctxt n k m case_def ctr_def unf_fld) ks ms ctr_defs;
   408 
   409         val tacss = [exhaust_tac] :: inject_tacss @ half_distinct_tacss @ [case_tacs];
   410 
   411         fun define_iter_rec ((selss0, discIs, sel_thmss), no_defs_lthy) =
   412           let
   413             val fpT_to_C = fpT --> C;
   414 
   415             fun generate_iter_like (suf, fp_iter_like, (fss, f_Tss, xssss)) =
   416               let
   417                 val res_T = fold_rev (curry (op --->)) f_Tss fpT_to_C;
   418                 val binding = Binding.suffix_name ("_" ^ suf) fp_b;
   419                 val spec =
   420                   mk_Trueprop_eq (lists_bmoc fss (Free (Binding.name_of binding, res_T)),
   421                     Term.list_comb (fp_iter_like,
   422                       map2 (mk_sum_caseN_balanced oo map2 mk_uncurried2_fun) fss xssss));
   423               in (binding, spec) end;
   424 
   425             val iter_like_infos =
   426               [(iterN, fp_iter, iter_only),
   427                (recN, fp_rec, rec_only)];
   428 
   429             val (bindings, specs) = map generate_iter_like iter_like_infos |> split_list;
   430 
   431             val ((csts, defs), (lthy', lthy)) = no_defs_lthy
   432               |> apfst split_list o fold_map2 (fn b => fn spec =>
   433                 Specification.definition (SOME (b, NONE, NoSyn), ((Thm.def_binding b, []), spec))
   434                 #>> apsnd snd) bindings specs
   435               ||> `Local_Theory.restore;
   436 
   437             val phi = Proof_Context.export_morphism lthy lthy';
   438 
   439             val [iter_def, rec_def] = map (Morphism.thm phi) defs;
   440 
   441             val [iter, recx] = map (mk_iter_like As Cs o Morphism.term phi) csts;
   442           in
   443             ((ctrs, selss0, iter, recx, v, xss, ctr_defs, discIs, sel_thmss, iter_def, rec_def),
   444              lthy)
   445           end;
   446 
   447         fun define_coiter_corec ((selss0, discIs, sel_thmss), no_defs_lthy) =
   448           let
   449             val B_to_fpT = C --> fpT;
   450 
   451             fun mk_preds_getterss_join c n cps sum_prod_T cqfss =
   452               Term.lambda c (mk_IfN sum_prod_T cps
   453                 (map2 (mk_InN_balanced sum_prod_T n) (map HOLogic.mk_tuple cqfss) (1 upto n)));
   454 
   455             fun generate_coiter_like (suf, fp_iter_like, ((pfss, cqfsss), (f_sum_prod_Ts,
   456                 pf_Tss))) =
   457               let
   458                 val res_T = fold_rev (curry (op --->)) pf_Tss B_to_fpT;
   459                 val binding = Binding.suffix_name ("_" ^ suf) fp_b;
   460                 val spec =
   461                   mk_Trueprop_eq (lists_bmoc pfss (Free (Binding.name_of binding, res_T)),
   462                     Term.list_comb (fp_iter_like,
   463                       map5 mk_preds_getterss_join cs ns cpss f_sum_prod_Ts cqfsss));
   464               in (binding, spec) end;
   465 
   466             val coiter_like_infos =
   467               [(coiterN, fp_iter, coiter_only),
   468                (corecN, fp_rec, corec_only)];
   469 
   470             val (bindings, specs) = map generate_coiter_like coiter_like_infos |> split_list;
   471 
   472             val ((csts, defs), (lthy', lthy)) = no_defs_lthy
   473               |> apfst split_list o fold_map2 (fn b => fn spec =>
   474                 Specification.definition (SOME (b, NONE, NoSyn), ((Thm.def_binding b, []), spec))
   475                 #>> apsnd snd) bindings specs
   476               ||> `Local_Theory.restore;
   477 
   478             val phi = Proof_Context.export_morphism lthy lthy';
   479 
   480             val [coiter_def, corec_def] = map (Morphism.thm phi) defs;
   481 
   482             val [coiter, corec] = map (mk_iter_like As Cs o Morphism.term phi) csts;
   483           in
   484             ((ctrs, selss0, coiter, corec, v, xss, ctr_defs, discIs, sel_thmss, coiter_def,
   485               corec_def), lthy)
   486           end;
   487 
   488         fun wrap lthy =
   489           let val sel_defaultss = map (map (apsnd (prepare_term lthy))) raw_sel_defaultss in
   490             wrap_datatype tacss (((no_dests, ctrs0), casex0), (disc_bindings, (sel_bindingss,
   491               sel_defaultss))) lthy
   492           end;
   493 
   494         val define_iter_likes = if lfp then define_iter_rec else define_coiter_corec;
   495       in
   496         ((wrap, define_iter_likes), lthy')
   497       end;
   498 
   499     val pre_map_defs = map map_def_of_bnf pre_bnfs;
   500     val pre_set_defss = map set_defs_of_bnf pre_bnfs;
   501     val map_ids = map map_id_of_bnf nested_bnfs;
   502 
   503     fun mk_map Ts Us t =
   504       let val (Type (_, Ts0), Type (_, Us0)) = strip_map_type (fastype_of t) |>> List.last in
   505         Term.subst_atomic_types (Ts0 @ Us0 ~~ Ts @ Us) t
   506       end;
   507 
   508     fun build_map build_arg (Type (s, Ts)) (Type (_, Us)) =
   509       let
   510         val map0 = map_of_bnf (the (bnf_of lthy s));
   511         val mapx = mk_map Ts Us map0;
   512         val TUs = map dest_funT (fst (split_last (fst (strip_map_type (fastype_of mapx)))));
   513         val args = map build_arg TUs;
   514       in Term.list_comb (mapx, args) end;
   515 
   516     fun derive_induct_iter_rec_thms_for_types ((ctrss, _, iters, recs, vs, xsss, ctr_defss, _, _,
   517         iter_defs, rec_defs), lthy) =
   518       let
   519         val (induct_thms, induct_thm) =
   520           let
   521             val (ps, names_lthy) =
   522               lthy
   523               |> mk_Frees "P" (map mk_predT fpTs);
   524 
   525             fun mk_prem_prem (x as Free (_, T)) =
   526               map HOLogic.mk_Trueprop
   527                 (case find_index (curry (op =) T) fpTs of
   528                   ~1 => []
   529                 | i => [nth ps i $ x]);
   530 
   531             fun mk_prem p ctr ctr_Ts =
   532               let val (xs, _) = names_lthy |> mk_Frees "x" ctr_Ts in
   533                 fold_rev Logic.all xs
   534                   (Logic.list_implies (maps mk_prem_prem xs,
   535                      HOLogic.mk_Trueprop (p $ Term.list_comb (ctr, xs))))
   536               end;
   537 
   538             val goal =
   539               fold_rev (fold_rev Logic.all) [ps, vs]
   540                 (Library.foldr Logic.list_implies (map3 (map2 o mk_prem) ps ctrss ctr_Tsss,
   541                    HOLogic.mk_Trueprop (Library.foldr1 HOLogic.mk_conj
   542                      (map2 (curry (op $)) ps vs))));
   543 
   544             val induct_thm =
   545               Skip_Proof.prove lthy [] [] goal (fn {context = ctxt, ...} =>
   546                 Skip_Proof.cheat_tac (Proof_Context.theory_of ctxt));
   547           in
   548             `(conj_dests N) induct_thm
   549           end;
   550 
   551         val (iter_thmss, rec_thmss) =
   552           let
   553             val xctrss = map2 (map2 (curry Term.list_comb)) ctrss xsss;
   554             val giters = map (lists_bmoc gss) iters;
   555             val hrecs = map (lists_bmoc hss) recs;
   556 
   557             fun mk_goal_iter_like fss fiter_like xctr f xs fxs =
   558               fold_rev (fold_rev Logic.all) (xs :: fss)
   559                 (mk_Trueprop_eq (fiter_like $ xctr, Term.list_comb (f, fxs)));
   560 
   561             fun build_call fiter_likes maybe_tick (T, U) =
   562               if T = U then
   563                 mk_id T
   564               else
   565                 (case find_index (curry (op =) T) fpTs of
   566                   ~1 => build_map (build_call fiter_likes maybe_tick) T U
   567                 | j => maybe_tick (nth vs j) (nth fiter_likes j));
   568 
   569             fun mk_U maybe_mk_prodT =
   570               typ_subst (map2 (fn fpT => fn C => (fpT, maybe_mk_prodT fpT C)) fpTs Cs);
   571 
   572             fun intr_calls fiter_likes maybe_cons maybe_tick maybe_mk_prodT (x as Free (_, T)) =
   573               if member (op =) fpTs T then
   574                 maybe_cons x [build_call fiter_likes (K I) (T, mk_U (K I) T) $ x]
   575               else if exists_subtype (member (op =) fpTs) T then
   576                 [build_call fiter_likes maybe_tick (T, mk_U maybe_mk_prodT T) $ x]
   577               else
   578                 [x];
   579 
   580             val gxsss = map (map (maps (intr_calls giters (K I) (K I) (K I)))) xsss;
   581             val hxsss = map (map (maps (intr_calls hrecs cons tick (curry HOLogic.mk_prodT)))) xsss;
   582 
   583             val goal_iterss = map5 (map4 o mk_goal_iter_like gss) giters xctrss gss xsss gxsss;
   584             val goal_recss = map5 (map4 o mk_goal_iter_like hss) hrecs xctrss hss xsss hxsss;
   585 
   586             val iter_tacss =
   587               map2 (map o mk_iter_like_tac pre_map_defs map_ids iter_defs) fp_iter_thms ctr_defss;
   588             val rec_tacss =
   589               map2 (map o mk_iter_like_tac pre_map_defs map_ids rec_defs) fp_rec_thms ctr_defss;
   590           in
   591             (map2 (map2 (fn goal => fn tac => Skip_Proof.prove lthy [] [] goal (tac o #context)))
   592                goal_iterss iter_tacss,
   593              map2 (map2 (fn goal => fn tac => Skip_Proof.prove lthy [] [] goal (tac o #context)))
   594                goal_recss rec_tacss)
   595           end;
   596 
   597         val common_notes =
   598           (if N > 1 then [(inductN, [induct_thm], [])] (* FIXME: attribs *) else [])
   599           |> map (fn (thmN, thms, attrs) =>
   600               ((Binding.qualify true fp_common_name (Binding.name thmN), attrs), [(thms, [])]));
   601 
   602         val notes =
   603           [(inductN, map single induct_thms, []), (* FIXME: attribs *)
   604            (itersN, iter_thmss, simp_attrs),
   605            (recsN, rec_thmss, Code.add_default_eqn_attrib :: simp_attrs)]
   606           |> maps (fn (thmN, thmss, attrs) =>
   607             map2 (fn b => fn thms =>
   608               ((Binding.qualify true (Binding.name_of b) (Binding.name thmN), attrs),
   609                 [(thms, [])])) fp_bs thmss);
   610       in
   611         lthy |> Local_Theory.notes (common_notes @ notes) |> snd
   612       end;
   613 
   614     fun derive_coinduct_coiter_corec_thms_for_types ((ctrss, selsss, coiters, corecs, vs, _,
   615         ctr_defss, discIss, sel_thmsss, coiter_defs, corec_defs), lthy) =
   616       let
   617         val (coinduct_thms, coinduct_thm) =
   618           let
   619             val coinduct_thm = fp_induct;
   620           in
   621             `(conj_dests N) coinduct_thm
   622           end;
   623 
   624         val (coiter_thmss, corec_thmss) =
   625           let
   626             val z = the_single zs;
   627             val gcoiters = map (lists_bmoc pgss) coiters;
   628             val hcorecs = map (lists_bmoc phss) corecs;
   629 
   630             fun mk_goal_cond pos = HOLogic.mk_Trueprop o (not pos ? HOLogic.mk_not);
   631 
   632             fun mk_goal_coiter_like pfss c cps fcoiter_like n k ctr m cfs' =
   633               fold_rev (fold_rev Logic.all) ([c] :: pfss)
   634                 (Logic.list_implies (seq_conds mk_goal_cond n k cps,
   635                    mk_Trueprop_eq (fcoiter_like $ c, Term.list_comb (ctr, take m cfs'))));
   636 
   637             fun build_call fiter_likes maybe_tack (T, U) =
   638               if T = U then
   639                 mk_id T
   640               else
   641                 (case find_index (curry (op =) U) fpTs of
   642                   ~1 => build_map (build_call fiter_likes maybe_tack) T U
   643                 | j => maybe_tack (nth cs j, nth vs j) (nth fiter_likes j));
   644 
   645             fun mk_U maybe_mk_sumT =
   646               typ_subst (map2 (fn C => fn fpT => (maybe_mk_sumT fpT C, fpT)) Cs fpTs);
   647 
   648             fun intr_calls fiter_likes maybe_mk_sumT maybe_tack cqf =
   649               let val T = fastype_of cqf in
   650                 if exists_subtype (member (op =) Cs) T then
   651                   build_call fiter_likes maybe_tack (T, mk_U maybe_mk_sumT T) $ cqf
   652                 else
   653                   cqf
   654               end;
   655 
   656             val crgsss' = map (map (map (intr_calls gcoiters (K I) (K I)))) crgsss;
   657             val cshsss' = map (map (map (intr_calls hcorecs (curry mk_sumT) (tack z)))) cshsss;
   658 
   659             val goal_coiterss =
   660               map8 (map4 oooo mk_goal_coiter_like pgss) cs cpss gcoiters ns kss ctrss mss crgsss';
   661             val goal_corecss =
   662               map8 (map4 oooo mk_goal_coiter_like phss) cs cpss hcorecs ns kss ctrss mss cshsss';
   663 
   664             val coiter_tacss =
   665               map3 (map oo mk_coiter_like_tac coiter_defs map_ids) fp_iter_thms pre_map_defs
   666                 ctr_defss;
   667             val corec_tacss =
   668               map3 (map oo mk_coiter_like_tac corec_defs map_ids) fp_rec_thms pre_map_defs
   669                 ctr_defss;
   670           in
   671             (map2 (map2 (fn goal => fn tac =>
   672                  Skip_Proof.prove lthy [] [] goal (tac o #context) |> Thm.close_derivation))
   673                goal_coiterss coiter_tacss,
   674              map2 (map2 (fn goal => fn tac =>
   675                  Skip_Proof.prove lthy [] [] goal (tac o #context)
   676                  |> Local_Defs.unfold lthy @{thms sum_case_if} |> Thm.close_derivation))
   677                goal_corecss corec_tacss)
   678           end;
   679 
   680         fun mk_disc_coiter_like_thms [_] = K []
   681           | mk_disc_coiter_like_thms thms = map2 (curry (op RS)) thms;
   682 
   683         val disc_coiter_thmss = map2 mk_disc_coiter_like_thms coiter_thmss discIss;
   684         val disc_corec_thmss = map2 mk_disc_coiter_like_thms corec_thmss discIss;
   685 
   686         fun mk_sel_coiter_like_thm coiter_like_thm sel0 sel_thm =
   687           let
   688             val (domT, ranT) = dest_funT (fastype_of sel0);
   689             val arg_cong' =
   690               Drule.instantiate' (map (SOME o certifyT lthy) [domT, ranT])
   691                 [NONE, NONE, SOME (certify lthy sel0)] arg_cong
   692               |> Thm.varifyT_global;
   693             val sel_thm' = sel_thm RSN (2, trans);
   694           in
   695             coiter_like_thm RS arg_cong' RS sel_thm'
   696           end;
   697 
   698         val sel_coiter_thmsss =
   699           map3 (map3 (map2 o mk_sel_coiter_like_thm)) coiter_thmss selsss sel_thmsss;
   700         val sel_corec_thmsss =
   701           map3 (map3 (map2 o mk_sel_coiter_like_thm)) corec_thmss selsss sel_thmsss;
   702 
   703         val common_notes =
   704           (if N > 1 then [(coinductN, [coinduct_thm], [])] (* FIXME: attribs *) else [])
   705           |> map (fn (thmN, thms, attrs) =>
   706               ((Binding.qualify true fp_common_name (Binding.name thmN), attrs), [(thms, [])]));
   707 
   708         val notes =
   709           [(coinductN, map single coinduct_thms, []), (* FIXME: attribs *)
   710            (coitersN, coiter_thmss, []),
   711            (disc_coitersN, disc_coiter_thmss, []),
   712            (sel_coitersN, map flat sel_coiter_thmsss, []),
   713            (corecsN, corec_thmss, []),
   714            (disc_corecsN, disc_corec_thmss, []),
   715            (sel_corecsN, map flat sel_corec_thmsss, [])]
   716           |> maps (fn (thmN, thmss, attrs) =>
   717             map_filter (fn (_, []) => NONE | (b, thms) =>
   718               SOME ((Binding.qualify true (Binding.name_of b) (Binding.name thmN), attrs),
   719                 [(thms, [])])) (fp_bs ~~ thmss));
   720       in
   721         lthy |> Local_Theory.notes (common_notes @ notes) |> snd
   722       end;
   723 
   724     fun wrap_types_and_define_iter_likes ((wraps, define_iter_likess), lthy) =
   725       fold_map2 (curry (op o)) define_iter_likess wraps lthy |>> split_list11
   726 
   727     val lthy' = lthy
   728       |> fold_map define_ctrs_case_for_type (fp_bs ~~ fpTs ~~ Cs ~~ vs ~~ flds ~~ unfs ~~
   729         fp_iters ~~ fp_recs ~~ fld_unfs ~~ unf_flds ~~ fld_injects ~~ ns ~~ kss ~~ mss ~~
   730         ctr_bindingss ~~ ctr_mixfixess ~~ ctr_Tsss ~~ disc_bindingss ~~ sel_bindingsss ~~
   731         raw_sel_defaultsss)
   732       |>> split_list |> wrap_types_and_define_iter_likes
   733       |> (if lfp then derive_induct_iter_rec_thms_for_types
   734           else derive_coinduct_coiter_corec_thms_for_types);
   735 
   736     val timer = time (timer ("Constructors, discriminators, selectors, etc., for the new " ^
   737       (if lfp then "" else "co") ^ "datatype"));
   738   in
   739     timer; lthy'
   740   end;
   741 
   742 val datatyp = define_datatype (K I) (K I) (K I);
   743 
   744 val datatype_cmd = define_datatype Typedecl.read_constraint Syntax.parse_typ Syntax.read_term;
   745 
   746 val parse_binding_colon = Parse.binding --| @{keyword ":"};
   747 val parse_opt_binding_colon = Scan.optional parse_binding_colon no_binding;
   748 
   749 val parse_ctr_arg =
   750   @{keyword "("} |-- parse_binding_colon -- Parse.typ --| @{keyword ")"} ||
   751   (Parse.typ >> pair no_binding);
   752 
   753 val parse_defaults =
   754   @{keyword "("} |-- @{keyword "defaults"} |-- Scan.repeat parse_bound_term --| @{keyword ")"};
   755 
   756 val parse_single_spec =
   757   Parse.type_args_constrained -- Parse.binding -- Parse.opt_mixfix --
   758   (@{keyword "="} |-- Parse.enum1 "|" (parse_opt_binding_colon -- Parse.binding --
   759     Scan.repeat parse_ctr_arg -- Scan.optional parse_defaults [] -- Parse.opt_mixfix));
   760 
   761 val parse_datatype = parse_wrap_options -- Parse.and_list1 parse_single_spec;
   762 
   763 fun parse_datatype_cmd lfp construct = parse_datatype >> datatype_cmd lfp construct;
   764 
   765 end;