src/HOL/Tools/datatype_rep_proofs.ML
author wenzelm
Thu Mar 27 14:41:09 2008 +0100 (2008-03-27)
changeset 26424 a6cad32a27b0
parent 26359 6d437bde2f1d
child 26475 3cc1e48d0ce1
permissions -rw-r--r--
eliminated theory ProtoPure;
     1 (*  Title:      HOL/Tools/datatype_rep_proofs.ML
     2     ID:         $Id$
     3     Author:     Stefan Berghofer, TU Muenchen
     4 
     5 Definitional introduction of datatypes
     6 Proof of characteristic theorems:
     7 
     8  - injectivity of constructors
     9  - distinctness of constructors
    10  - induction theorem
    11 
    12 *)
    13 
    14 signature DATATYPE_REP_PROOFS =
    15 sig
    16   val representation_proofs : bool -> DatatypeAux.datatype_info Symtab.table ->
    17     string list -> DatatypeAux.descr list -> (string * sort) list ->
    18       (string * mixfix) list -> (string * mixfix) list list -> attribute
    19         -> theory -> (thm list list * thm list list * thm list list *
    20           DatatypeAux.simproc_dist list * thm) * theory
    21 end;
    22 
    23 structure DatatypeRepProofs : DATATYPE_REP_PROOFS =
    24 struct
    25 
    26 open DatatypeAux;
    27 
    28 val (_ $ (_ $ (_ $ (distinct_f $ _) $ _))) = hd (prems_of distinct_lemma);
    29 
    30 val collect_simp = rewrite_rule [mk_meta_eq mem_Collect_eq];
    31 
    32 
    33 (** theory context references **)
    34 
    35 val f_myinv_f = thm "f_myinv_f";
    36 val myinv_f_f = thm "myinv_f_f";
    37 
    38 
    39 fun exh_thm_of (dt_info : datatype_info Symtab.table) tname =
    40   #exhaustion (the (Symtab.lookup dt_info tname));
    41 
    42 (******************************************************************************)
    43 
    44 fun representation_proofs flat_names (dt_info : datatype_info Symtab.table)
    45       new_type_names descr sorts types_syntax constr_syntax case_names_induct thy =
    46   let
    47     val Datatype_thy = ThyInfo.the_theory "Datatype" thy;
    48     val node_name = "Datatype.node";
    49     val In0_name = "Datatype.In0";
    50     val In1_name = "Datatype.In1";
    51     val Scons_name = "Datatype.Scons";
    52     val Leaf_name = "Datatype.Leaf";
    53     val Numb_name = "Datatype.Numb";
    54     val Lim_name = "Datatype.Lim";
    55     val Suml_name = "Datatype.Suml";
    56     val Sumr_name = "Datatype.Sumr";
    57 
    58     val [In0_inject, In1_inject, Scons_inject, Leaf_inject,
    59          In0_eq, In1_eq, In0_not_In1, In1_not_In0,
    60          Lim_inject, Suml_inject, Sumr_inject] = map (PureThy.get_thm Datatype_thy)
    61           ["In0_inject", "In1_inject", "Scons_inject", "Leaf_inject",
    62            "In0_eq", "In1_eq", "In0_not_In1", "In1_not_In0",
    63            "Lim_inject", "Suml_inject", "Sumr_inject"];
    64 
    65     val descr' = List.concat descr;
    66 
    67     val big_name = space_implode "_" new_type_names;
    68     val thy1 = add_path flat_names big_name thy;
    69     val big_rec_name = big_name ^ "_rep_set";
    70     val rep_set_names' =
    71       (if length descr' = 1 then [big_rec_name] else
    72         (map ((curry (op ^) (big_rec_name ^ "_")) o string_of_int)
    73           (1 upto (length descr'))));
    74     val rep_set_names = map (Sign.full_name thy1) rep_set_names';
    75 
    76     val tyvars = map (fn (_, (_, Ts, _)) => map dest_DtTFree Ts) (hd descr);
    77     val leafTs' = get_nonrec_types descr' sorts;
    78     val branchTs = get_branching_types descr' sorts;
    79     val branchT = if null branchTs then HOLogic.unitT
    80       else BalancedTree.make (fn (T, U) => Type ("+", [T, U])) branchTs;
    81     val arities = get_arities descr' \ 0;
    82     val unneeded_vars = hd tyvars \\ foldr add_typ_tfree_names [] (leafTs' @ branchTs);
    83     val leafTs = leafTs' @ (map (fn n => TFree (n, (the o AList.lookup (op =) sorts) n)) unneeded_vars);
    84     val recTs = get_rec_types descr' sorts;
    85     val newTs = Library.take (length (hd descr), recTs);
    86     val oldTs = Library.drop (length (hd descr), recTs);
    87     val sumT = if null leafTs then HOLogic.unitT
    88       else BalancedTree.make (fn (T, U) => Type ("+", [T, U])) leafTs;
    89     val Univ_elT = HOLogic.mk_setT (Type (node_name, [sumT, branchT]));
    90     val UnivT = HOLogic.mk_setT Univ_elT;
    91     val UnivT' = Univ_elT --> HOLogic.boolT;
    92     val Collect = Const ("Collect", UnivT' --> UnivT);
    93 
    94     val In0 = Const (In0_name, Univ_elT --> Univ_elT);
    95     val In1 = Const (In1_name, Univ_elT --> Univ_elT);
    96     val Leaf = Const (Leaf_name, sumT --> Univ_elT);
    97     val Lim = Const (Lim_name, (branchT --> Univ_elT) --> Univ_elT);
    98 
    99     (* make injections needed for embedding types in leaves *)
   100 
   101     fun mk_inj T' x =
   102       let
   103         fun mk_inj' T n i =
   104           if n = 1 then x else
   105           let val n2 = n div 2;
   106               val Type (_, [T1, T2]) = T
   107           in
   108             if i <= n2 then
   109               Const ("Sum_Type.Inl", T1 --> T) $ (mk_inj' T1 n2 i)
   110             else
   111               Const ("Sum_Type.Inr", T2 --> T) $ (mk_inj' T2 (n - n2) (i - n2))
   112           end
   113       in mk_inj' sumT (length leafTs) (1 + find_index_eq T' leafTs)
   114       end;
   115 
   116     (* make injections for constructors *)
   117 
   118     fun mk_univ_inj ts = BalancedTree.access
   119       {left = fn t => In0 $ t,
   120         right = fn t => In1 $ t,
   121         init =
   122           if ts = [] then Const ("arbitrary", Univ_elT)
   123           else foldr1 (HOLogic.mk_binop Scons_name) ts};
   124 
   125     (* function spaces *)
   126 
   127     fun mk_fun_inj T' x =
   128       let
   129         fun mk_inj T n i =
   130           if n = 1 then x else
   131           let
   132             val n2 = n div 2;
   133             val Type (_, [T1, T2]) = T;
   134             fun mkT U = (U --> Univ_elT) --> T --> Univ_elT
   135           in
   136             if i <= n2 then Const (Suml_name, mkT T1) $ mk_inj T1 n2 i
   137             else Const (Sumr_name, mkT T2) $ mk_inj T2 (n - n2) (i - n2)
   138           end
   139       in mk_inj branchT (length branchTs) (1 + find_index_eq T' branchTs)
   140       end;
   141 
   142     val mk_lim = foldr (fn (T, t) => Lim $ mk_fun_inj T (Abs ("x", T, t)));
   143 
   144     (************** generate introduction rules for representing set **********)
   145 
   146     val _ = message "Constructing representing sets ...";
   147 
   148     (* make introduction rule for a single constructor *)
   149 
   150     fun make_intr s n (i, (_, cargs)) =
   151       let
   152         fun mk_prem (dt, (j, prems, ts)) = (case strip_dtyp dt of
   153             (dts, DtRec k) =>
   154               let
   155                 val Ts = map (typ_of_dtyp descr' sorts) dts;
   156                 val free_t =
   157                   app_bnds (mk_Free "x" (Ts ---> Univ_elT) j) (length Ts)
   158               in (j + 1, list_all (map (pair "x") Ts,
   159                   HOLogic.mk_Trueprop
   160                     (Free (List.nth (rep_set_names', k), UnivT') $ free_t)) :: prems,
   161                 mk_lim free_t Ts :: ts)
   162               end
   163           | _ =>
   164               let val T = typ_of_dtyp descr' sorts dt
   165               in (j + 1, prems, (Leaf $ mk_inj T (mk_Free "x" T j))::ts)
   166               end);
   167 
   168         val (_, prems, ts) = foldr mk_prem (1, [], []) cargs;
   169         val concl = HOLogic.mk_Trueprop
   170           (Free (s, UnivT') $ mk_univ_inj ts n i)
   171       in Logic.list_implies (prems, concl)
   172       end;
   173 
   174     val intr_ts = List.concat (map (fn ((_, (_, _, constrs)), rep_set_name) =>
   175       map (make_intr rep_set_name (length constrs))
   176         ((1 upto (length constrs)) ~~ constrs)) (descr' ~~ rep_set_names'));
   177 
   178     val ({raw_induct = rep_induct, intrs = rep_intrs, ...}, thy2) =
   179       setmp InductivePackage.quiet_mode (! quiet_mode)
   180         (InductivePackage.add_inductive_global (serial_string ())
   181           {verbose = false, kind = Thm.internalK, alt_name = big_rec_name,
   182             coind = false, no_elim = true, no_ind = false}
   183           (map (fn s => ((s, UnivT'), NoSyn)) rep_set_names') []
   184           (map (fn x => (("", []), x)) intr_ts) []) thy1;
   185 
   186     (********************************* typedef ********************************)
   187 
   188     val (typedefs, thy3) = thy2 |>
   189       parent_path flat_names |>
   190       fold_map (fn ((((name, mx), tvs), c), name') =>
   191         setmp TypedefPackage.quiet_mode true
   192           (TypedefPackage.add_typedef_i false (SOME name') (name, tvs, mx)
   193             (Collect $ Const (c, UnivT')) NONE
   194             (rtac exI 1 THEN rtac CollectI 1 THEN
   195               QUIET_BREADTH_FIRST (has_fewer_prems 1)
   196               (resolve_tac rep_intrs 1))))
   197                 (types_syntax ~~ tyvars ~~
   198                   (Library.take (length newTs, rep_set_names)) ~~ new_type_names) ||>
   199       add_path flat_names big_name;
   200 
   201     (*********************** definition of constructors ***********************)
   202 
   203     val big_rep_name = (space_implode "_" new_type_names) ^ "_Rep_";
   204     val rep_names = map (curry op ^ "Rep_") new_type_names;
   205     val rep_names' = map (fn i => big_rep_name ^ (string_of_int i))
   206       (1 upto (length (List.concat (tl descr))));
   207     val all_rep_names = map (Sign.intern_const thy3) rep_names @
   208       map (Sign.full_name thy3) rep_names';
   209 
   210     (* isomorphism declarations *)
   211 
   212     val iso_decls = map (fn (T, s) => (s, T --> Univ_elT, NoSyn))
   213       (oldTs ~~ rep_names');
   214 
   215     (* constructor definitions *)
   216 
   217     fun make_constr_def tname T n ((thy, defs, eqns, i), ((cname, cargs), (cname', mx))) =
   218       let
   219         fun constr_arg (dt, (j, l_args, r_args)) =
   220           let val T = typ_of_dtyp descr' sorts dt;
   221               val free_t = mk_Free "x" T j
   222           in (case (strip_dtyp dt, strip_type T) of
   223               ((_, DtRec m), (Us, U)) => (j + 1, free_t :: l_args, mk_lim
   224                 (Const (List.nth (all_rep_names, m), U --> Univ_elT) $
   225                    app_bnds free_t (length Us)) Us :: r_args)
   226             | _ => (j + 1, free_t::l_args, (Leaf $ mk_inj T free_t)::r_args))
   227           end;
   228 
   229         val (_, l_args, r_args) = foldr constr_arg (1, [], []) cargs;
   230         val constrT = (map (typ_of_dtyp descr' sorts) cargs) ---> T;
   231         val abs_name = Sign.intern_const thy ("Abs_" ^ tname);
   232         val rep_name = Sign.intern_const thy ("Rep_" ^ tname);
   233         val lhs = list_comb (Const (cname, constrT), l_args);
   234         val rhs = mk_univ_inj r_args n i;
   235         val def = equals T $ lhs $ (Const (abs_name, Univ_elT --> T) $ rhs);
   236         val def_name = (Sign.base_name cname) ^ "_def";
   237         val eqn = HOLogic.mk_Trueprop (HOLogic.mk_eq
   238           (Const (rep_name, T --> Univ_elT) $ lhs, rhs));
   239         val ([def_thm], thy') =
   240           thy
   241           |> Sign.add_consts_i [(cname', constrT, mx)]
   242           |> (PureThy.add_defs_i false o map Thm.no_attributes) [(def_name, def)];
   243 
   244       in (thy', defs @ [def_thm], eqns @ [eqn], i + 1) end;
   245 
   246     (* constructor definitions for datatype *)
   247 
   248     fun dt_constr_defs ((thy, defs, eqns, rep_congs, dist_lemmas),
   249         ((((_, (_, _, constrs)), tname), T), constr_syntax)) =
   250       let
   251         val _ $ (_ $ (cong_f $ _) $ _) = concl_of arg_cong;
   252         val rep_const = cterm_of thy
   253           (Const (Sign.intern_const thy ("Rep_" ^ tname), T --> Univ_elT));
   254         val cong' = standard (cterm_instantiate [(cterm_of thy cong_f, rep_const)] arg_cong);
   255         val dist = standard (cterm_instantiate [(cterm_of thy distinct_f, rep_const)] distinct_lemma);
   256         val (thy', defs', eqns', _) = Library.foldl ((make_constr_def tname T) (length constrs))
   257           ((add_path flat_names tname thy, defs, [], 1), constrs ~~ constr_syntax)
   258       in
   259         (parent_path flat_names thy', defs', eqns @ [eqns'],
   260           rep_congs @ [cong'], dist_lemmas @ [dist])
   261       end;
   262 
   263     val (thy4, constr_defs, constr_rep_eqns, rep_congs, dist_lemmas) = Library.foldl dt_constr_defs
   264       ((thy3 |> Sign.add_consts_i iso_decls |> parent_path flat_names, [], [], [], []),
   265         hd descr ~~ new_type_names ~~ newTs ~~ constr_syntax);
   266 
   267     (*********** isomorphisms for new types (introduced by typedef) ***********)
   268 
   269     val _ = message "Proving isomorphism properties ...";
   270 
   271     val newT_iso_axms = map (fn (_, td) =>
   272       (collect_simp (#Abs_inverse td), #Rep_inverse td,
   273        collect_simp (#Rep td))) typedefs;
   274 
   275     val newT_iso_inj_thms = map (fn (_, td) =>
   276       (collect_simp (#Abs_inject td) RS iffD1, #Rep_inject td RS iffD1)) typedefs;
   277 
   278     (********* isomorphisms between existing types and "unfolded" types *******)
   279 
   280     (*---------------------------------------------------------------------*)
   281     (* isomorphisms are defined using primrec-combinators:                 *)
   282     (* generate appropriate functions for instantiating primrec-combinator *)
   283     (*                                                                     *)
   284     (*   e.g.  dt_Rep_i = list_rec ... (%h t y. In1 (Scons (Leaf h) y))    *)
   285     (*                                                                     *)
   286     (* also generate characteristic equations for isomorphisms             *)
   287     (*                                                                     *)
   288     (*   e.g.  dt_Rep_i (cons h t) = In1 (Scons (dt_Rep_j h) (dt_Rep_i t)) *)
   289     (*---------------------------------------------------------------------*)
   290 
   291     fun make_iso_def k ks n ((fs, eqns, i), (cname, cargs)) =
   292       let
   293         val argTs = map (typ_of_dtyp descr' sorts) cargs;
   294         val T = List.nth (recTs, k);
   295         val rep_name = List.nth (all_rep_names, k);
   296         val rep_const = Const (rep_name, T --> Univ_elT);
   297         val constr = Const (cname, argTs ---> T);
   298 
   299         fun process_arg ks' ((i2, i2', ts, Ts), dt) =
   300           let
   301             val T' = typ_of_dtyp descr' sorts dt;
   302             val (Us, U) = strip_type T'
   303           in (case strip_dtyp dt of
   304               (_, DtRec j) => if j mem ks' then
   305                   (i2 + 1, i2' + 1, ts @ [mk_lim (app_bnds
   306                      (mk_Free "y" (Us ---> Univ_elT) i2') (length Us)) Us],
   307                    Ts @ [Us ---> Univ_elT])
   308                 else
   309                   (i2 + 1, i2', ts @ [mk_lim
   310                      (Const (List.nth (all_rep_names, j), U --> Univ_elT) $
   311                         app_bnds (mk_Free "x" T' i2) (length Us)) Us], Ts)
   312             | _ => (i2 + 1, i2', ts @ [Leaf $ mk_inj T' (mk_Free "x" T' i2)], Ts))
   313           end;
   314 
   315         val (i2, i2', ts, Ts) = Library.foldl (process_arg ks) ((1, 1, [], []), cargs);
   316         val xs = map (uncurry (mk_Free "x")) (argTs ~~ (1 upto (i2 - 1)));
   317         val ys = map (uncurry (mk_Free "y")) (Ts ~~ (1 upto (i2' - 1)));
   318         val f = list_abs_free (map dest_Free (xs @ ys), mk_univ_inj ts n i);
   319 
   320         val (_, _, ts', _) = Library.foldl (process_arg []) ((1, 1, [], []), cargs);
   321         val eqn = HOLogic.mk_Trueprop (HOLogic.mk_eq
   322           (rep_const $ list_comb (constr, xs), mk_univ_inj ts' n i))
   323 
   324       in (fs @ [f], eqns @ [eqn], i + 1) end;
   325 
   326     (* define isomorphisms for all mutually recursive datatypes in list ds *)
   327 
   328     fun make_iso_defs (ds, (thy, char_thms)) =
   329       let
   330         val ks = map fst ds;
   331         val (_, (tname, _, _)) = hd ds;
   332         val {rec_rewrites, rec_names, ...} = the (Symtab.lookup dt_info tname);
   333 
   334         fun process_dt ((fs, eqns, isos), (k, (tname, _, constrs))) =
   335           let
   336             val (fs', eqns', _) = Library.foldl (make_iso_def k ks (length constrs))
   337               ((fs, eqns, 1), constrs);
   338             val iso = (List.nth (recTs, k), List.nth (all_rep_names, k))
   339           in (fs', eqns', isos @ [iso]) end;
   340         
   341         val (fs, eqns, isos) = Library.foldl process_dt (([], [], []), ds);
   342         val fTs = map fastype_of fs;
   343         val defs = map (fn (rec_name, (T, iso_name)) => ((Sign.base_name iso_name) ^ "_def",
   344           equals (T --> Univ_elT) $ Const (iso_name, T --> Univ_elT) $
   345             list_comb (Const (rec_name, fTs @ [T] ---> Univ_elT), fs))) (rec_names ~~ isos);
   346         val (def_thms, thy') = (PureThy.add_defs_i false o map Thm.no_attributes) defs thy;
   347 
   348         (* prove characteristic equations *)
   349 
   350         val rewrites = def_thms @ (map mk_meta_eq rec_rewrites);
   351         val char_thms' = map (fn eqn => Goal.prove_global thy' [] [] eqn
   352           (fn _ => EVERY [rewrite_goals_tac rewrites, rtac refl 1])) eqns;
   353 
   354       in (thy', char_thms' @ char_thms) end;
   355 
   356     val (thy5, iso_char_thms) = foldr make_iso_defs
   357       (add_path flat_names big_name thy4, []) (tl descr);
   358 
   359     (* prove isomorphism properties *)
   360 
   361     fun mk_funs_inv thm =
   362       let
   363         val {thy, prop, ...} = rep_thm thm;
   364         val _ $ (_ $ ((S as Const (_, Type (_, [U, _]))) $ _ )) $
   365           (_ $ (_ $ (r $ (a $ _)) $ _)) = Type.freeze prop;
   366         val used = add_term_tfree_names (a, []);
   367 
   368         fun mk_thm i =
   369           let
   370             val Ts = map (TFree o rpair HOLogic.typeS)
   371               (Name.variant_list used (replicate i "'t"));
   372             val f = Free ("f", Ts ---> U)
   373           in Goal.prove_global thy [] [] (Logic.mk_implies
   374             (HOLogic.mk_Trueprop (HOLogic.list_all
   375                (map (pair "x") Ts, S $ app_bnds f i)),
   376              HOLogic.mk_Trueprop (HOLogic.mk_eq (list_abs (map (pair "x") Ts,
   377                r $ (a $ app_bnds f i)), f))))
   378             (fn _ => EVERY [REPEAT (rtac ext 1), REPEAT (etac allE 1), rtac thm 1, atac 1])
   379           end
   380       in map (fn r => r RS subst) (thm :: map mk_thm arities) end;
   381 
   382     (* prove  inj dt_Rep_i  and  dt_Rep_i x : dt_rep_set_i *)
   383 
   384     fun prove_iso_thms (ds, (inj_thms, elem_thms)) =
   385       let
   386         val (_, (tname, _, _)) = hd ds;
   387         val {induction, ...} = the (Symtab.lookup dt_info tname);
   388 
   389         fun mk_ind_concl (i, _) =
   390           let
   391             val T = List.nth (recTs, i);
   392             val Rep_t = Const (List.nth (all_rep_names, i), T --> Univ_elT);
   393             val rep_set_name = List.nth (rep_set_names, i)
   394           in (HOLogic.all_const T $ Abs ("y", T, HOLogic.imp $
   395                 HOLogic.mk_eq (Rep_t $ mk_Free "x" T i, Rep_t $ Bound 0) $
   396                   HOLogic.mk_eq (mk_Free "x" T i, Bound 0)),
   397               Const (rep_set_name, UnivT') $ (Rep_t $ mk_Free "x" T i))
   398           end;
   399 
   400         val (ind_concl1, ind_concl2) = ListPair.unzip (map mk_ind_concl ds);
   401 
   402         val rewrites = map mk_meta_eq iso_char_thms;
   403         val inj_thms' = map snd newT_iso_inj_thms @
   404           map (fn r => r RS @{thm injD}) inj_thms;
   405 
   406         val inj_thm = Goal.prove_global thy5 [] []
   407           (HOLogic.mk_Trueprop (mk_conj ind_concl1)) (fn _ => EVERY
   408             [(indtac induction [] THEN_ALL_NEW ObjectLogic.atomize_prems_tac) 1,
   409              REPEAT (EVERY
   410                [rtac allI 1, rtac impI 1,
   411                 exh_tac (exh_thm_of dt_info) 1,
   412                 REPEAT (EVERY
   413                   [hyp_subst_tac 1,
   414                    rewrite_goals_tac rewrites,
   415                    REPEAT (dresolve_tac [In0_inject, In1_inject] 1),
   416                    (eresolve_tac [In0_not_In1 RS notE, In1_not_In0 RS notE] 1)
   417                    ORELSE (EVERY
   418                      [REPEAT (eresolve_tac (Scons_inject ::
   419                         map make_elim [Leaf_inject, Inl_inject, Inr_inject]) 1),
   420                       REPEAT (cong_tac 1), rtac refl 1,
   421                       REPEAT (atac 1 ORELSE (EVERY
   422                         [REPEAT (rtac ext 1),
   423                          REPEAT (eresolve_tac (mp :: allE ::
   424                            map make_elim (Suml_inject :: Sumr_inject ::
   425                              Lim_inject :: fun_cong :: inj_thms')) 1),
   426                          atac 1]))])])])]);
   427 
   428         val inj_thms'' = map (fn r => r RS @{thm datatype_injI})
   429                              (split_conj_thm inj_thm);
   430 
   431         val elem_thm = 
   432             Goal.prove_global thy5 [] [] (HOLogic.mk_Trueprop (mk_conj ind_concl2))
   433               (fn _ =>
   434                EVERY [(indtac induction [] THEN_ALL_NEW ObjectLogic.atomize_prems_tac) 1,
   435                 rewrite_goals_tac rewrites,
   436                 REPEAT ((resolve_tac rep_intrs THEN_ALL_NEW
   437                   ((REPEAT o etac allE) THEN' ares_tac elem_thms)) 1)]);
   438 
   439       in (inj_thms'' @ inj_thms, elem_thms @ (split_conj_thm elem_thm))
   440       end;
   441 
   442     val (iso_inj_thms_unfolded, iso_elem_thms) = foldr prove_iso_thms
   443       ([], map #3 newT_iso_axms) (tl descr);
   444     val iso_inj_thms = map snd newT_iso_inj_thms @
   445       map (fn r => r RS @{thm injD}) iso_inj_thms_unfolded;
   446 
   447     (* prove  dt_rep_set_i x --> x : range dt_Rep_i *)
   448 
   449     fun mk_iso_t (((set_name, iso_name), i), T) =
   450       let val isoT = T --> Univ_elT
   451       in HOLogic.imp $ 
   452         (Const (set_name, UnivT') $ mk_Free "x" Univ_elT i) $
   453           (if i < length newTs then Const ("True", HOLogic.boolT)
   454            else HOLogic.mk_mem (mk_Free "x" Univ_elT i,
   455              Const ("image", [isoT, HOLogic.mk_setT T] ---> UnivT) $
   456                Const (iso_name, isoT) $ Const ("UNIV", HOLogic.mk_setT T)))
   457       end;
   458 
   459     val iso_t = HOLogic.mk_Trueprop (mk_conj (map mk_iso_t
   460       (rep_set_names ~~ all_rep_names ~~ (0 upto (length descr' - 1)) ~~ recTs)));
   461 
   462     (* all the theorems are proved by one single simultaneous induction *)
   463 
   464     val range_eqs = map (fn r => mk_meta_eq (r RS @{thm range_ex1_eq}))
   465       iso_inj_thms_unfolded;
   466 
   467     val iso_thms = if length descr = 1 then [] else
   468       Library.drop (length newTs, split_conj_thm
   469         (Goal.prove_global thy5 [] [] iso_t (fn _ => EVERY
   470            [(indtac rep_induct [] THEN_ALL_NEW ObjectLogic.atomize_prems_tac) 1,
   471             REPEAT (rtac TrueI 1),
   472             rewrite_goals_tac (mk_meta_eq choice_eq ::
   473               symmetric (mk_meta_eq @{thm expand_fun_eq}) :: range_eqs),
   474             rewrite_goals_tac (map symmetric range_eqs),
   475             REPEAT (EVERY
   476               [REPEAT (eresolve_tac ([rangeE, ex1_implies_ex RS exE] @
   477                  List.concat (map (mk_funs_inv o #1) newT_iso_axms)) 1),
   478                TRY (hyp_subst_tac 1),
   479                rtac (sym RS range_eqI) 1,
   480                resolve_tac iso_char_thms 1])])));
   481 
   482     val Abs_inverse_thms' =
   483       map #1 newT_iso_axms @
   484       map2 (fn r_inj => fn r => f_myinv_f OF [r_inj, r RS mp])
   485         iso_inj_thms_unfolded iso_thms;
   486 
   487     val Abs_inverse_thms = List.concat (map mk_funs_inv Abs_inverse_thms');
   488 
   489     (******************* freeness theorems for constructors *******************)
   490 
   491     val _ = message "Proving freeness of constructors ...";
   492 
   493     (* prove theorem  Rep_i (Constr_j ...) = Inj_j ...  *)
   494     
   495     fun prove_constr_rep_thm eqn =
   496       let
   497         val inj_thms = map fst newT_iso_inj_thms;
   498         val rewrites = @{thm o_def} :: constr_defs @ (map (mk_meta_eq o #2) newT_iso_axms)
   499       in Goal.prove_global thy5 [] [] eqn (fn _ => EVERY
   500         [resolve_tac inj_thms 1,
   501          rewrite_goals_tac rewrites,
   502          rtac refl 3,
   503          resolve_tac rep_intrs 2,
   504          REPEAT (resolve_tac iso_elem_thms 1)])
   505       end;
   506 
   507     (*--------------------------------------------------------------*)
   508     (* constr_rep_thms and rep_congs are used to prove distinctness *)
   509     (* of constructors.                                             *)
   510     (*--------------------------------------------------------------*)
   511 
   512     val constr_rep_thms = map (map prove_constr_rep_thm) constr_rep_eqns;
   513 
   514     val dist_rewrites = map (fn (rep_thms, dist_lemma) =>
   515       dist_lemma::(rep_thms @ [In0_eq, In1_eq, In0_not_In1, In1_not_In0]))
   516         (constr_rep_thms ~~ dist_lemmas);
   517 
   518     fun prove_distinct_thms (_, []) = []
   519       | prove_distinct_thms (dist_rewrites', t::_::ts) =
   520           let
   521             val dist_thm = Goal.prove_global thy5 [] [] t (fn _ =>
   522               EVERY [simp_tac (HOL_ss addsimps dist_rewrites') 1])
   523           in dist_thm::(standard (dist_thm RS not_sym))::
   524             (prove_distinct_thms (dist_rewrites', ts))
   525           end;
   526 
   527     val distinct_thms = map prove_distinct_thms (dist_rewrites ~~
   528       DatatypeProp.make_distincts new_type_names descr sorts thy5);
   529 
   530     val simproc_dists = map (fn ((((_, (_, _, constrs)), rep_thms), congr), dists) =>
   531       if length constrs < Config.get_thy thy5 DatatypeProp.distinctness_limit
   532       then FewConstrs dists
   533       else ManyConstrs (congr, HOL_basic_ss addsimps rep_thms)) (hd descr ~~
   534         constr_rep_thms ~~ rep_congs ~~ distinct_thms);
   535 
   536     (* prove injectivity of constructors *)
   537 
   538     fun prove_constr_inj_thm rep_thms t =
   539       let val inj_thms = Scons_inject :: (map make_elim
   540         (iso_inj_thms @
   541           [In0_inject, In1_inject, Leaf_inject, Inl_inject, Inr_inject,
   542            Lim_inject, Suml_inject, Sumr_inject]))
   543       in Goal.prove_global thy5 [] [] t (fn _ => EVERY
   544         [rtac iffI 1,
   545          REPEAT (etac conjE 2), hyp_subst_tac 2, rtac refl 2,
   546          dresolve_tac rep_congs 1, dtac box_equals 1,
   547          REPEAT (resolve_tac rep_thms 1),
   548          REPEAT (eresolve_tac inj_thms 1),
   549          REPEAT (ares_tac [conjI] 1 ORELSE (EVERY [REPEAT (rtac ext 1),
   550            REPEAT (eresolve_tac (make_elim fun_cong :: inj_thms) 1),
   551            atac 1]))])
   552       end;
   553 
   554     val constr_inject = map (fn (ts, thms) => map (prove_constr_inj_thm thms) ts)
   555       ((DatatypeProp.make_injs descr sorts) ~~ constr_rep_thms);
   556 
   557     val ((constr_inject', distinct_thms'), thy6) =
   558       thy5
   559       |> parent_path flat_names
   560       |> store_thmss "inject" new_type_names constr_inject
   561       ||>> store_thmss "distinct" new_type_names distinct_thms;
   562 
   563     (*************************** induction theorem ****************************)
   564 
   565     val _ = message "Proving induction rule for datatypes ...";
   566 
   567     val Rep_inverse_thms = (map (fn (_, iso, _) => iso RS subst) newT_iso_axms) @
   568       (map (fn r => r RS myinv_f_f RS subst) iso_inj_thms_unfolded);
   569     val Rep_inverse_thms' = map (fn r => r RS myinv_f_f) iso_inj_thms_unfolded;
   570 
   571     fun mk_indrule_lemma ((prems, concls), ((i, _), T)) =
   572       let
   573         val Rep_t = Const (List.nth (all_rep_names, i), T --> Univ_elT) $
   574           mk_Free "x" T i;
   575 
   576         val Abs_t = if i < length newTs then
   577             Const (Sign.intern_const thy6
   578               ("Abs_" ^ (List.nth (new_type_names, i))), Univ_elT --> T)
   579           else Const ("Inductive.myinv", [T --> Univ_elT, Univ_elT] ---> T) $
   580             Const (List.nth (all_rep_names, i), T --> Univ_elT)
   581 
   582       in (prems @ [HOLogic.imp $
   583             (Const (List.nth (rep_set_names, i), UnivT') $ Rep_t) $
   584               (mk_Free "P" (T --> HOLogic.boolT) (i + 1) $ (Abs_t $ Rep_t))],
   585           concls @ [mk_Free "P" (T --> HOLogic.boolT) (i + 1) $ mk_Free "x" T i])
   586       end;
   587 
   588     val (indrule_lemma_prems, indrule_lemma_concls) =
   589       Library.foldl mk_indrule_lemma (([], []), (descr' ~~ recTs));
   590 
   591     val cert = cterm_of thy6;
   592 
   593     val indrule_lemma = Goal.prove_global thy6 [] []
   594       (Logic.mk_implies
   595         (HOLogic.mk_Trueprop (mk_conj indrule_lemma_prems),
   596          HOLogic.mk_Trueprop (mk_conj indrule_lemma_concls))) (fn _ => EVERY
   597            [REPEAT (etac conjE 1),
   598             REPEAT (EVERY
   599               [TRY (rtac conjI 1), resolve_tac Rep_inverse_thms 1,
   600                etac mp 1, resolve_tac iso_elem_thms 1])]);
   601 
   602     val Ps = map head_of (HOLogic.dest_conj (HOLogic.dest_Trueprop (concl_of indrule_lemma)));
   603     val frees = if length Ps = 1 then [Free ("P", snd (dest_Var (hd Ps)))] else
   604       map (Free o apfst fst o dest_Var) Ps;
   605     val indrule_lemma' = cterm_instantiate (map cert Ps ~~ map cert frees) indrule_lemma;
   606 
   607     val dt_induct_prop = DatatypeProp.make_ind descr sorts;
   608     val dt_induct = Goal.prove_global thy6 []
   609       (Logic.strip_imp_prems dt_induct_prop) (Logic.strip_imp_concl dt_induct_prop)
   610       (fn prems => EVERY
   611         [rtac indrule_lemma' 1,
   612          (indtac rep_induct [] THEN_ALL_NEW ObjectLogic.atomize_prems_tac) 1,
   613          EVERY (map (fn (prem, r) => (EVERY
   614            [REPEAT (eresolve_tac Abs_inverse_thms 1),
   615             simp_tac (HOL_basic_ss addsimps ((symmetric r)::Rep_inverse_thms')) 1,
   616             DEPTH_SOLVE_1 (ares_tac [prem] 1 ORELSE etac allE 1)]))
   617                 (prems ~~ (constr_defs @ (map mk_meta_eq iso_char_thms))))]);
   618 
   619     val ([dt_induct'], thy7) =
   620       thy6
   621       |> Sign.add_path big_name
   622       |> PureThy.add_thms [(("induct", dt_induct), [case_names_induct])]
   623       ||> Sign.parent_path;
   624 
   625   in
   626     ((constr_inject', distinct_thms', dist_rewrites, simproc_dists, dt_induct'), thy7)
   627   end;
   628 
   629 end;