src/HOL/Tools/Datatype/datatype.ML
changeset 33968 f94fb13ecbb3
parent 33963 977b94b64905
child 33969 1e7ca47c6c3d
--- a/src/HOL/Tools/Datatype/datatype.ML	Mon Nov 30 11:42:48 2009 +0100
+++ b/src/HOL/Tools/Datatype/datatype.ML	Mon Nov 30 11:42:49 2009 +0100
@@ -1,19 +1,748 @@
-(*  Title:      HOL/Tools/datatype.ML
+(*  Title:      HOL/Tools/Datatype/datatype.ML
     Author:     Stefan Berghofer, TU Muenchen
 
-Datatype package interface for Isabelle/HOL.
+Datatype package: definitional introduction of datatypes
+with proof of characteristic theorems: injectivity / distinctness
+of constructors and induction.  Main interface to datatypes
+after full bootstrap of datatype package.
 *)
 
 signature DATATYPE =
 sig
   include DATATYPE_DATA
-  include DATATYPE_REP_PROOFS
+  val add_datatype : config -> string list -> (string list * binding * mixfix *
+    (binding * typ list * mixfix) list) list -> theory -> string list * theory
+  val datatype_cmd : string list -> (string list * binding * mixfix *
+    (binding * string list * mixfix) list) list -> theory -> theory
 end;
 
-structure Datatype =
+structure Datatype : DATATYPE =
 struct
 
+(** auxiliary **)
+
+open Datatype_Aux;
 open Datatype_Data;
-open DatatypeRepProofs;
+
+val (_ $ (_ $ (_ $ (distinct_f $ _) $ _))) = hd (prems_of distinct_lemma);
+
+val collect_simp = rewrite_rule [mk_meta_eq mem_Collect_eq];
+
+fun exh_thm_of (dt_info : info Symtab.table) tname =
+  #exhaust (the (Symtab.lookup dt_info tname));
+
+val node_name = @{type_name "Datatype.node"};
+val In0_name = @{const_name "Datatype.In0"};
+val In1_name = @{const_name "Datatype.In1"};
+val Scons_name = @{const_name "Datatype.Scons"};
+val Leaf_name = @{const_name "Datatype.Leaf"};
+val Numb_name = @{const_name "Datatype.Numb"};
+val Lim_name = @{const_name "Datatype.Lim"};
+val Suml_name = @{const_name "Sum_Type.Suml"};
+val Sumr_name = @{const_name "Sum_Type.Sumr"};
+
+val In0_inject = @{thm In0_inject};
+val In1_inject = @{thm In1_inject};
+val Scons_inject = @{thm Scons_inject};
+val Leaf_inject = @{thm Leaf_inject};
+val In0_eq = @{thm In0_eq};
+val In1_eq = @{thm In1_eq};
+val In0_not_In1 = @{thm In0_not_In1};
+val In1_not_In0 = @{thm In1_not_In0};
+val Lim_inject = @{thm Lim_inject};
+val Inl_inject = @{thm Inl_inject};
+val Inr_inject = @{thm Inr_inject};
+val Suml_inject = @{thm Suml_inject};
+val Sumr_inject = @{thm Sumr_inject};
+
+
+
+(** proof of characteristic theorems **)
+
+fun representation_proofs (config : config) (dt_info : info Symtab.table)
+      new_type_names descr sorts types_syntax constr_syntax case_names_induct thy =
+  let
+    val descr' = flat descr;
+    val big_name = space_implode "_" new_type_names;
+    val thy1 = Sign.add_path big_name thy;
+    val big_rec_name = big_name ^ "_rep_set";
+    val rep_set_names' =
+      (if length descr' = 1 then [big_rec_name] else
+        (map ((curry (op ^) (big_rec_name ^ "_")) o string_of_int)
+          (1 upto (length descr'))));
+    val rep_set_names = map (Sign.full_bname thy1) rep_set_names';
+
+    val tyvars = map (fn (_, (_, Ts, _)) => map dest_DtTFree Ts) (hd descr);
+    val leafTs' = get_nonrec_types descr' sorts;
+    val branchTs = get_branching_types descr' sorts;
+    val branchT = if null branchTs then HOLogic.unitT
+      else Balanced_Tree.make (fn (T, U) => Type ("+", [T, U])) branchTs;
+    val arities = remove (op =) 0 (get_arities descr');
+    val unneeded_vars =
+      subtract (op =) (List.foldr OldTerm.add_typ_tfree_names [] (leafTs' @ branchTs)) (hd tyvars);
+    val leafTs = leafTs' @ map (fn n => TFree (n, (the o AList.lookup (op =) sorts) n)) unneeded_vars;
+    val recTs = get_rec_types descr' sorts;
+    val (newTs, oldTs) = chop (length (hd descr)) recTs;
+    val sumT = if null leafTs then HOLogic.unitT
+      else Balanced_Tree.make (fn (T, U) => Type ("+", [T, U])) leafTs;
+    val Univ_elT = HOLogic.mk_setT (Type (node_name, [sumT, branchT]));
+    val UnivT = HOLogic.mk_setT Univ_elT;
+    val UnivT' = Univ_elT --> HOLogic.boolT;
+    val Collect = Const (@{const_name Collect}, UnivT' --> UnivT);
+
+    val In0 = Const (In0_name, Univ_elT --> Univ_elT);
+    val In1 = Const (In1_name, Univ_elT --> Univ_elT);
+    val Leaf = Const (Leaf_name, sumT --> Univ_elT);
+    val Lim = Const (Lim_name, (branchT --> Univ_elT) --> Univ_elT);
+
+    (* make injections needed for embedding types in leaves *)
+
+    fun mk_inj T' x =
+      let
+        fun mk_inj' T n i =
+          if n = 1 then x else
+          let val n2 = n div 2;
+              val Type (_, [T1, T2]) = T
+          in
+            if i <= n2 then
+              Const (@{const_name "Sum_Type.Inl"}, T1 --> T) $ (mk_inj' T1 n2 i)
+            else
+              Const (@{const_name "Sum_Type.Inr"}, T2 --> T) $ (mk_inj' T2 (n - n2) (i - n2))
+          end
+      in mk_inj' sumT (length leafTs) (1 + find_index (fn T'' => T'' = T') leafTs)
+      end;
+
+    (* make injections for constructors *)
+
+    fun mk_univ_inj ts = Balanced_Tree.access
+      {left = fn t => In0 $ t,
+        right = fn t => In1 $ t,
+        init =
+          if ts = [] then Const (@{const_name undefined}, Univ_elT)
+          else foldr1 (HOLogic.mk_binop Scons_name) ts};
+
+    (* function spaces *)
+
+    fun mk_fun_inj T' x =
+      let
+        fun mk_inj T n i =
+          if n = 1 then x else
+          let
+            val n2 = n div 2;
+            val Type (_, [T1, T2]) = T;
+            fun mkT U = (U --> Univ_elT) --> T --> Univ_elT
+          in
+            if i <= n2 then Const (Suml_name, mkT T1) $ mk_inj T1 n2 i
+            else Const (Sumr_name, mkT T2) $ mk_inj T2 (n - n2) (i - n2)
+          end
+      in mk_inj branchT (length branchTs) (1 + find_index (fn T'' => T'' = T') branchTs)
+      end;
+
+    fun mk_lim t Ts = fold_rev (fn T => fn t => Lim $ mk_fun_inj T (Abs ("x", T, t))) Ts t;
+
+    (************** generate introduction rules for representing set **********)
+
+    val _ = message config "Constructing representing sets ...";
+
+    (* make introduction rule for a single constructor *)
+
+    fun make_intr s n (i, (_, cargs)) =
+      let
+        fun mk_prem dt (j, prems, ts) =
+          (case strip_dtyp dt of
+            (dts, DtRec k) =>
+              let
+                val Ts = map (typ_of_dtyp descr' sorts) dts;
+                val free_t =
+                  app_bnds (mk_Free "x" (Ts ---> Univ_elT) j) (length Ts)
+              in (j + 1, list_all (map (pair "x") Ts,
+                  HOLogic.mk_Trueprop
+                    (Free (nth rep_set_names' k, UnivT') $ free_t)) :: prems,
+                mk_lim free_t Ts :: ts)
+              end
+          | _ =>
+              let val T = typ_of_dtyp descr' sorts dt
+              in (j + 1, prems, (Leaf $ mk_inj T (mk_Free "x" T j))::ts)
+              end);
+
+        val (_, prems, ts) = fold_rev mk_prem cargs (1, [], []);
+        val concl = HOLogic.mk_Trueprop
+          (Free (s, UnivT') $ mk_univ_inj ts n i)
+      in Logic.list_implies (prems, concl)
+      end;
+
+    val intr_ts = maps (fn ((_, (_, _, constrs)), rep_set_name) =>
+      map (make_intr rep_set_name (length constrs))
+        ((1 upto (length constrs)) ~~ constrs)) (descr' ~~ rep_set_names');
+
+    val ({raw_induct = rep_induct, intrs = rep_intrs, ...}, thy2) =
+      thy1
+      |> Sign.map_naming Name_Space.conceal
+      |> Inductive.add_inductive_global
+          {quiet_mode = #quiet config, verbose = false, alt_name = Binding.name big_rec_name,
+           coind = false, no_elim = true, no_ind = false, skip_mono = true, fork_mono = false}
+          (map (fn s => ((Binding.name s, UnivT'), NoSyn)) rep_set_names') []
+          (map (fn x => (Attrib.empty_binding, x)) intr_ts) []
+      ||> Sign.restore_naming thy1
+      ||> Theory.checkpoint;
+
+    (********************************* typedef ********************************)
+
+    val (typedefs, thy3) = thy2 |>
+      Sign.parent_path |>
+      fold_map (fn ((((name, mx), tvs), c), name') =>
+          Typedef.add_typedef false (SOME (Binding.name name')) (name, tvs, mx)
+            (Collect $ Const (c, UnivT')) NONE
+            (rtac exI 1 THEN rtac CollectI 1 THEN
+              QUIET_BREADTH_FIRST (has_fewer_prems 1)
+              (resolve_tac rep_intrs 1)))
+                (types_syntax ~~ tyvars ~~
+                  (take (length newTs) rep_set_names) ~~ new_type_names) ||>
+      Sign.add_path big_name;
+
+    (*********************** definition of constructors ***********************)
+
+    val big_rep_name = (space_implode "_" new_type_names) ^ "_Rep_";
+    val rep_names = map (curry op ^ "Rep_") new_type_names;
+    val rep_names' = map (fn i => big_rep_name ^ (string_of_int i))
+      (1 upto (length (flat (tl descr))));
+    val all_rep_names = map (Sign.intern_const thy3) rep_names @
+      map (Sign.full_bname thy3) rep_names';
+
+    (* isomorphism declarations *)
+
+    val iso_decls = map (fn (T, s) => (Binding.name s, T --> Univ_elT, NoSyn))
+      (oldTs ~~ rep_names');
+
+    (* constructor definitions *)
+
+    fun make_constr_def tname T n ((cname, cargs), (cname', mx)) (thy, defs, eqns, i) =
+      let
+        fun constr_arg dt (j, l_args, r_args) =
+          let val T = typ_of_dtyp descr' sorts dt;
+              val free_t = mk_Free "x" T j
+          in (case (strip_dtyp dt, strip_type T) of
+              ((_, DtRec m), (Us, U)) => (j + 1, free_t :: l_args, mk_lim
+                (Const (nth all_rep_names m, U --> Univ_elT) $
+                   app_bnds free_t (length Us)) Us :: r_args)
+            | _ => (j + 1, free_t::l_args, (Leaf $ mk_inj T free_t)::r_args))
+          end;
+
+        val (_, l_args, r_args) = fold_rev constr_arg cargs (1, [], []);
+        val constrT = (map (typ_of_dtyp descr' sorts) cargs) ---> T;
+        val abs_name = Sign.intern_const thy ("Abs_" ^ tname);
+        val rep_name = Sign.intern_const thy ("Rep_" ^ tname);
+        val lhs = list_comb (Const (cname, constrT), l_args);
+        val rhs = mk_univ_inj r_args n i;
+        val def = Logic.mk_equals (lhs, Const (abs_name, Univ_elT --> T) $ rhs);
+        val def_name = Long_Name.base_name cname ^ "_def";
+        val eqn = HOLogic.mk_Trueprop (HOLogic.mk_eq
+          (Const (rep_name, T --> Univ_elT) $ lhs, rhs));
+        val ([def_thm], thy') =
+          thy
+          |> Sign.add_consts_i [(cname', constrT, mx)]
+          |> (PureThy.add_defs false o map Thm.no_attributes) [(Binding.name def_name, def)];
+
+      in (thy', defs @ [def_thm], eqns @ [eqn], i + 1) end;
+
+    (* constructor definitions for datatype *)
+
+    fun dt_constr_defs ((((_, (_, _, constrs)), tname), T), constr_syntax)
+        (thy, defs, eqns, rep_congs, dist_lemmas) =
+      let
+        val _ $ (_ $ (cong_f $ _) $ _) = concl_of arg_cong;
+        val rep_const = cterm_of thy
+          (Const (Sign.intern_const thy ("Rep_" ^ tname), T --> Univ_elT));
+        val cong' =
+          Drule.standard (cterm_instantiate [(cterm_of thy cong_f, rep_const)] arg_cong);
+        val dist =
+          Drule.standard (cterm_instantiate [(cterm_of thy distinct_f, rep_const)] distinct_lemma);
+        val (thy', defs', eqns', _) = fold ((make_constr_def tname T) (length constrs))
+          (constrs ~~ constr_syntax) (Sign.add_path tname thy, defs, [], 1);
+      in
+        (Sign.parent_path thy', defs', eqns @ [eqns'],
+          rep_congs @ [cong'], dist_lemmas @ [dist])
+      end;
+
+    val (thy4, constr_defs, constr_rep_eqns, rep_congs, dist_lemmas) =
+      fold dt_constr_defs
+        (hd descr ~~ new_type_names ~~ newTs ~~ constr_syntax)
+        (thy3 |> Sign.add_consts_i iso_decls |> Sign.parent_path, [], [], [], []);
+
+
+    (*********** isomorphisms for new types (introduced by typedef) ***********)
+
+    val _ = message config "Proving isomorphism properties ...";
+
+    val newT_iso_axms = map (fn (_, td) =>
+      (collect_simp (#Abs_inverse td), #Rep_inverse td,
+       collect_simp (#Rep td))) typedefs;
+
+    val newT_iso_inj_thms = map (fn (_, td) =>
+      (collect_simp (#Abs_inject td) RS iffD1, #Rep_inject td RS iffD1)) typedefs;
+
+    (********* isomorphisms between existing types and "unfolded" types *******)
+
+    (*---------------------------------------------------------------------*)
+    (* isomorphisms are defined using primrec-combinators:                 *)
+    (* generate appropriate functions for instantiating primrec-combinator *)
+    (*                                                                     *)
+    (*   e.g.  dt_Rep_i = list_rec ... (%h t y. In1 (Scons (Leaf h) y))    *)
+    (*                                                                     *)
+    (* also generate characteristic equations for isomorphisms             *)
+    (*                                                                     *)
+    (*   e.g.  dt_Rep_i (cons h t) = In1 (Scons (dt_Rep_j h) (dt_Rep_i t)) *)
+    (*---------------------------------------------------------------------*)
+
+    fun make_iso_def k ks n (cname, cargs) (fs, eqns, i) =
+      let
+        val argTs = map (typ_of_dtyp descr' sorts) cargs;
+        val T = nth recTs k;
+        val rep_name = nth all_rep_names k;
+        val rep_const = Const (rep_name, T --> Univ_elT);
+        val constr = Const (cname, argTs ---> T);
+
+        fun process_arg ks' dt (i2, i2', ts, Ts) =
+          let
+            val T' = typ_of_dtyp descr' sorts dt;
+            val (Us, U) = strip_type T'
+          in (case strip_dtyp dt of
+              (_, DtRec j) => if j mem ks' then
+                  (i2 + 1, i2' + 1, ts @ [mk_lim (app_bnds
+                     (mk_Free "y" (Us ---> Univ_elT) i2') (length Us)) Us],
+                   Ts @ [Us ---> Univ_elT])
+                else
+                  (i2 + 1, i2', ts @ [mk_lim
+                     (Const (nth all_rep_names j, U --> Univ_elT) $
+                        app_bnds (mk_Free "x" T' i2) (length Us)) Us], Ts)
+            | _ => (i2 + 1, i2', ts @ [Leaf $ mk_inj T' (mk_Free "x" T' i2)], Ts))
+          end;
+
+        val (i2, i2', ts, Ts) = fold (process_arg ks) cargs (1, 1, [], []);
+        val xs = map (uncurry (mk_Free "x")) (argTs ~~ (1 upto (i2 - 1)));
+        val ys = map (uncurry (mk_Free "y")) (Ts ~~ (1 upto (i2' - 1)));
+        val f = list_abs_free (map dest_Free (xs @ ys), mk_univ_inj ts n i);
+
+        val (_, _, ts', _) = fold (process_arg []) cargs (1, 1, [], []);
+        val eqn = HOLogic.mk_Trueprop (HOLogic.mk_eq
+          (rep_const $ list_comb (constr, xs), mk_univ_inj ts' n i))
+
+      in (fs @ [f], eqns @ [eqn], i + 1) end;
+
+    (* define isomorphisms for all mutually recursive datatypes in list ds *)
+
+    fun make_iso_defs ds (thy, char_thms) =
+      let
+        val ks = map fst ds;
+        val (_, (tname, _, _)) = hd ds;
+        val {rec_rewrites, rec_names, ...} = the (Symtab.lookup dt_info tname);
+
+        fun process_dt (k, (tname, _, constrs)) (fs, eqns, isos) =
+          let
+            val (fs', eqns', _) =
+              fold (make_iso_def k ks (length constrs)) constrs (fs, eqns, 1);
+            val iso = (nth recTs k, nth all_rep_names k)
+          in (fs', eqns', isos @ [iso]) end;
+        
+        val (fs, eqns, isos) = fold process_dt ds ([], [], []);
+        val fTs = map fastype_of fs;
+        val defs = map (fn (rec_name, (T, iso_name)) => (Binding.name (Long_Name.base_name iso_name ^ "_def"),
+          Logic.mk_equals (Const (iso_name, T --> Univ_elT),
+            list_comb (Const (rec_name, fTs @ [T] ---> Univ_elT), fs)))) (rec_names ~~ isos);
+        val (def_thms, thy') =
+          apsnd Theory.checkpoint ((PureThy.add_defs false o map Thm.no_attributes) defs thy);
+
+        (* prove characteristic equations *)
+
+        val rewrites = def_thms @ (map mk_meta_eq rec_rewrites);
+        val char_thms' = map (fn eqn => Skip_Proof.prove_global thy' [] [] eqn
+          (fn _ => EVERY [rewrite_goals_tac rewrites, rtac refl 1])) eqns;
+
+      in (thy', char_thms' @ char_thms) end;
+
+    val (thy5, iso_char_thms) = apfst Theory.checkpoint (fold_rev make_iso_defs
+        (tl descr) (Sign.add_path big_name thy4, []));
+
+    (* prove isomorphism properties *)
+
+    fun mk_funs_inv thy thm =
+      let
+        val prop = Thm.prop_of thm;
+        val _ $ (_ $ ((S as Const (_, Type (_, [U, _]))) $ _ )) $
+          (_ $ (_ $ (r $ (a $ _)) $ _)) = Type.legacy_freeze prop;
+        val used = OldTerm.add_term_tfree_names (a, []);
+
+        fun mk_thm i =
+          let
+            val Ts = map (TFree o rpair HOLogic.typeS)
+              (Name.variant_list used (replicate i "'t"));
+            val f = Free ("f", Ts ---> U)
+          in Skip_Proof.prove_global thy [] [] (Logic.mk_implies
+            (HOLogic.mk_Trueprop (HOLogic.list_all
+               (map (pair "x") Ts, S $ app_bnds f i)),
+             HOLogic.mk_Trueprop (HOLogic.mk_eq (list_abs (map (pair "x") Ts,
+               r $ (a $ app_bnds f i)), f))))
+            (fn _ => EVERY [REPEAT_DETERM_N i (rtac ext 1),
+               REPEAT (etac allE 1), rtac thm 1, atac 1])
+          end
+      in map (fn r => r RS subst) (thm :: map mk_thm arities) end;
+
+    (* prove  inj dt_Rep_i  and  dt_Rep_i x : dt_rep_set_i *)
+
+    val fun_congs = map (fn T => make_elim (Drule.instantiate'
+      [SOME (ctyp_of thy5 T)] [] fun_cong)) branchTs;
+
+    fun prove_iso_thms ds (inj_thms, elem_thms) =
+      let
+        val (_, (tname, _, _)) = hd ds;
+        val induct = (#induct o the o Symtab.lookup dt_info) tname;
+
+        fun mk_ind_concl (i, _) =
+          let
+            val T = nth recTs i;
+            val Rep_t = Const (nth all_rep_names i, T --> Univ_elT);
+            val rep_set_name = nth rep_set_names i
+          in (HOLogic.all_const T $ Abs ("y", T, HOLogic.imp $
+                HOLogic.mk_eq (Rep_t $ mk_Free "x" T i, Rep_t $ Bound 0) $
+                  HOLogic.mk_eq (mk_Free "x" T i, Bound 0)),
+              Const (rep_set_name, UnivT') $ (Rep_t $ mk_Free "x" T i))
+          end;
+
+        val (ind_concl1, ind_concl2) = ListPair.unzip (map mk_ind_concl ds);
+
+        val rewrites = map mk_meta_eq iso_char_thms;
+        val inj_thms' = map snd newT_iso_inj_thms @
+          map (fn r => r RS @{thm injD}) inj_thms;
+
+        val inj_thm = Skip_Proof.prove_global thy5 [] []
+          (HOLogic.mk_Trueprop (mk_conj ind_concl1)) (fn _ => EVERY
+            [(indtac induct [] THEN_ALL_NEW ObjectLogic.atomize_prems_tac) 1,
+             REPEAT (EVERY
+               [rtac allI 1, rtac impI 1,
+                exh_tac (exh_thm_of dt_info) 1,
+                REPEAT (EVERY
+                  [hyp_subst_tac 1,
+                   rewrite_goals_tac rewrites,
+                   REPEAT (dresolve_tac [In0_inject, In1_inject] 1),
+                   (eresolve_tac [In0_not_In1 RS notE, In1_not_In0 RS notE] 1)
+                   ORELSE (EVERY
+                     [REPEAT (eresolve_tac (Scons_inject ::
+                        map make_elim [Leaf_inject, Inl_inject, Inr_inject]) 1),
+                      REPEAT (cong_tac 1), rtac refl 1,
+                      REPEAT (atac 1 ORELSE (EVERY
+                        [REPEAT (rtac ext 1),
+                         REPEAT (eresolve_tac (mp :: allE ::
+                           map make_elim (Suml_inject :: Sumr_inject ::
+                             Lim_inject :: inj_thms') @ fun_congs) 1),
+                         atac 1]))])])])]);
+
+        val inj_thms'' = map (fn r => r RS @{thm datatype_injI})
+                             (split_conj_thm inj_thm);
+
+        val elem_thm = 
+            Skip_Proof.prove_global thy5 [] [] (HOLogic.mk_Trueprop (mk_conj ind_concl2))
+              (fn _ =>
+               EVERY [(indtac induct [] THEN_ALL_NEW ObjectLogic.atomize_prems_tac) 1,
+                rewrite_goals_tac rewrites,
+                REPEAT ((resolve_tac rep_intrs THEN_ALL_NEW
+                  ((REPEAT o etac allE) THEN' ares_tac elem_thms)) 1)]);
+
+      in (inj_thms'' @ inj_thms, elem_thms @ (split_conj_thm elem_thm))
+      end;
+
+    val (iso_inj_thms_unfolded, iso_elem_thms) =
+      fold_rev prove_iso_thms (tl descr) ([], map #3 newT_iso_axms);
+    val iso_inj_thms = map snd newT_iso_inj_thms @
+      map (fn r => r RS @{thm injD}) iso_inj_thms_unfolded;
+
+    (* prove  dt_rep_set_i x --> x : range dt_Rep_i *)
+
+    fun mk_iso_t (((set_name, iso_name), i), T) =
+      let val isoT = T --> Univ_elT
+      in HOLogic.imp $ 
+        (Const (set_name, UnivT') $ mk_Free "x" Univ_elT i) $
+          (if i < length newTs then HOLogic.true_const
+           else HOLogic.mk_mem (mk_Free "x" Univ_elT i,
+             Const (@{const_name image}, isoT --> HOLogic.mk_setT T --> UnivT) $
+               Const (iso_name, isoT) $ Const (@{const_name UNIV}, HOLogic.mk_setT T)))
+      end;
+
+    val iso_t = HOLogic.mk_Trueprop (mk_conj (map mk_iso_t
+      (rep_set_names ~~ all_rep_names ~~ (0 upto (length descr' - 1)) ~~ recTs)));
+
+    (* all the theorems are proved by one single simultaneous induction *)
+
+    val range_eqs = map (fn r => mk_meta_eq (r RS @{thm range_ex1_eq}))
+      iso_inj_thms_unfolded;
+
+    val iso_thms = if length descr = 1 then [] else
+      drop (length newTs) (split_conj_thm
+        (Skip_Proof.prove_global thy5 [] [] iso_t (fn _ => EVERY
+           [(indtac rep_induct [] THEN_ALL_NEW ObjectLogic.atomize_prems_tac) 1,
+            REPEAT (rtac TrueI 1),
+            rewrite_goals_tac (mk_meta_eq choice_eq ::
+              symmetric (mk_meta_eq @{thm expand_fun_eq}) :: range_eqs),
+            rewrite_goals_tac (map symmetric range_eqs),
+            REPEAT (EVERY
+              [REPEAT (eresolve_tac ([rangeE, ex1_implies_ex RS exE] @
+                 maps (mk_funs_inv thy5 o #1) newT_iso_axms) 1),
+               TRY (hyp_subst_tac 1),
+               rtac (sym RS range_eqI) 1,
+               resolve_tac iso_char_thms 1])])));
+
+    val Abs_inverse_thms' =
+      map #1 newT_iso_axms @
+      map2 (fn r_inj => fn r => @{thm f_the_inv_into_f} OF [r_inj, r RS mp])
+        iso_inj_thms_unfolded iso_thms;
+
+    val Abs_inverse_thms = maps (mk_funs_inv thy5) Abs_inverse_thms';
+
+    (******************* freeness theorems for constructors *******************)
+
+    val _ = message config "Proving freeness of constructors ...";
+
+    (* prove theorem  Rep_i (Constr_j ...) = Inj_j ...  *)
+    
+    fun prove_constr_rep_thm eqn =
+      let
+        val inj_thms = map fst newT_iso_inj_thms;
+        val rewrites = @{thm o_def} :: constr_defs @ (map (mk_meta_eq o #2) newT_iso_axms)
+      in Skip_Proof.prove_global thy5 [] [] eqn (fn _ => EVERY
+        [resolve_tac inj_thms 1,
+         rewrite_goals_tac rewrites,
+         rtac refl 3,
+         resolve_tac rep_intrs 2,
+         REPEAT (resolve_tac iso_elem_thms 1)])
+      end;
+
+    (*--------------------------------------------------------------*)
+    (* constr_rep_thms and rep_congs are used to prove distinctness *)
+    (* of constructors.                                             *)
+    (*--------------------------------------------------------------*)
+
+    val constr_rep_thms = map (map prove_constr_rep_thm) constr_rep_eqns;
+
+    val dist_rewrites = map (fn (rep_thms, dist_lemma) =>
+      dist_lemma::(rep_thms @ [In0_eq, In1_eq, In0_not_In1, In1_not_In0]))
+        (constr_rep_thms ~~ dist_lemmas);
+
+    fun prove_distinct_thms dist_rewrites' (k, ts) =
+      let
+        fun prove [] = []
+          | prove (t :: ts) =
+              let
+                val dist_thm = Skip_Proof.prove_global thy5 [] [] t (fn _ =>
+                  EVERY [simp_tac (HOL_ss addsimps dist_rewrites') 1])
+              in dist_thm :: Drule.standard (dist_thm RS not_sym) :: prove ts end;
+      in prove ts end;
+
+    val distinct_thms = map2 (prove_distinct_thms)
+      dist_rewrites (Datatype_Prop.make_distincts descr sorts);
+
+    (* prove injectivity of constructors *)
+
+    fun prove_constr_inj_thm rep_thms t =
+      let val inj_thms = Scons_inject :: (map make_elim
+        (iso_inj_thms @
+          [In0_inject, In1_inject, Leaf_inject, Inl_inject, Inr_inject,
+           Lim_inject, Suml_inject, Sumr_inject]))
+      in Skip_Proof.prove_global thy5 [] [] t (fn _ => EVERY
+        [rtac iffI 1,
+         REPEAT (etac conjE 2), hyp_subst_tac 2, rtac refl 2,
+         dresolve_tac rep_congs 1, dtac box_equals 1,
+         REPEAT (resolve_tac rep_thms 1),
+         REPEAT (eresolve_tac inj_thms 1),
+         REPEAT (ares_tac [conjI] 1 ORELSE (EVERY [REPEAT (rtac ext 1),
+           REPEAT (eresolve_tac (make_elim fun_cong :: inj_thms) 1),
+           atac 1]))])
+      end;
+
+    val constr_inject = map (fn (ts, thms) => map (prove_constr_inj_thm thms) ts)
+      ((Datatype_Prop.make_injs descr sorts) ~~ constr_rep_thms);
+
+    val ((constr_inject', distinct_thms'), thy6) =
+      thy5
+      |> Sign.parent_path
+      |> store_thmss "inject" new_type_names constr_inject
+      ||>> store_thmss "distinct" new_type_names distinct_thms;
+
+    (*************************** induction theorem ****************************)
+
+    val _ = message config "Proving induction rule for datatypes ...";
+
+    val Rep_inverse_thms = (map (fn (_, iso, _) => iso RS subst) newT_iso_axms) @
+      (map (fn r => r RS @{thm the_inv_f_f} RS subst) iso_inj_thms_unfolded);
+    val Rep_inverse_thms' = map (fn r => r RS @{thm the_inv_f_f}) iso_inj_thms_unfolded;
+
+    fun mk_indrule_lemma ((i, _), T) (prems, concls) =
+      let
+        val Rep_t = Const (nth all_rep_names i, T --> Univ_elT) $
+          mk_Free "x" T i;
+
+        val Abs_t = if i < length newTs then
+            Const (Sign.intern_const thy6
+              ("Abs_" ^ (nth new_type_names i)), Univ_elT --> T)
+          else Const (@{const_name the_inv_into},
+              [HOLogic.mk_setT T, T --> Univ_elT, Univ_elT] ---> T) $
+            HOLogic.mk_UNIV T $ Const (nth all_rep_names i, T --> Univ_elT)
+
+      in (prems @ [HOLogic.imp $
+            (Const (nth rep_set_names i, UnivT') $ Rep_t) $
+              (mk_Free "P" (T --> HOLogic.boolT) (i + 1) $ (Abs_t $ Rep_t))],
+          concls @ [mk_Free "P" (T --> HOLogic.boolT) (i + 1) $ mk_Free "x" T i])
+      end;
+
+    val (indrule_lemma_prems, indrule_lemma_concls) =
+      fold mk_indrule_lemma (descr' ~~ recTs) ([], []);
+
+    val cert = cterm_of thy6;
+
+    val indrule_lemma = Skip_Proof.prove_global thy6 [] []
+      (Logic.mk_implies
+        (HOLogic.mk_Trueprop (mk_conj indrule_lemma_prems),
+         HOLogic.mk_Trueprop (mk_conj indrule_lemma_concls))) (fn _ => EVERY
+           [REPEAT (etac conjE 1),
+            REPEAT (EVERY
+              [TRY (rtac conjI 1), resolve_tac Rep_inverse_thms 1,
+               etac mp 1, resolve_tac iso_elem_thms 1])]);
+
+    val Ps = map head_of (HOLogic.dest_conj (HOLogic.dest_Trueprop (concl_of indrule_lemma)));
+    val frees = if length Ps = 1 then [Free ("P", snd (dest_Var (hd Ps)))] else
+      map (Free o apfst fst o dest_Var) Ps;
+    val indrule_lemma' = cterm_instantiate (map cert Ps ~~ map cert frees) indrule_lemma;
+
+    val dt_induct_prop = Datatype_Prop.make_ind descr sorts;
+    val dt_induct = Skip_Proof.prove_global thy6 []
+      (Logic.strip_imp_prems dt_induct_prop) (Logic.strip_imp_concl dt_induct_prop)
+      (fn {prems, ...} => EVERY
+        [rtac indrule_lemma' 1,
+         (indtac rep_induct [] THEN_ALL_NEW ObjectLogic.atomize_prems_tac) 1,
+         EVERY (map (fn (prem, r) => (EVERY
+           [REPEAT (eresolve_tac Abs_inverse_thms 1),
+            simp_tac (HOL_basic_ss addsimps ((symmetric r)::Rep_inverse_thms')) 1,
+            DEPTH_SOLVE_1 (ares_tac [prem] 1 ORELSE etac allE 1)]))
+                (prems ~~ (constr_defs @ (map mk_meta_eq iso_char_thms))))]);
+
+    val ([dt_induct'], thy7) =
+      thy6
+      |> Sign.add_path big_name
+      |> PureThy.add_thms [((Binding.name "induct", dt_induct), [case_names_induct])]
+      ||> Sign.parent_path
+      ||> Theory.checkpoint;
+
+  in
+    ((constr_inject', distinct_thms', dt_induct'), thy7)
+  end;
+
+
+
+(** definitional introduction of datatypes **)
+
+fun gen_add_datatype prep_typ config new_type_names dts thy =
+  let
+    val _ = Theory.requires thy "Datatype" "datatype definitions";
+
+    (* this theory is used just for parsing *)
+    val tmp_thy = thy |>
+      Theory.copy |>
+      Sign.add_types (map (fn (tvs, tname, mx, _) =>
+        (tname, length tvs, mx)) dts);
+
+    val (tyvars, _, _, _)::_ = dts;
+    val (new_dts, types_syntax) = ListPair.unzip (map (fn (tvs, tname, mx, _) =>
+      let val full_tname = Sign.full_name tmp_thy (Binding.map_name (Syntax.type_name mx) tname)
+      in
+        (case duplicates (op =) tvs of
+          [] =>
+            if eq_set (op =) (tyvars, tvs) then ((full_tname, tvs), (tname, mx))
+            else error ("Mutually recursive datatypes must have same type parameters")
+        | dups => error ("Duplicate parameter(s) for datatype " ^ quote (Binding.str_of tname) ^
+            " : " ^ commas dups))
+      end) dts);
+    val dt_names = map fst new_dts;
+
+    val _ =
+      (case duplicates (op =) (map fst new_dts) @ duplicates (op =) new_type_names of
+        [] => ()
+      | dups => error ("Duplicate datatypes: " ^ commas dups));
+
+    fun prep_dt_spec (tvs, tname, mx, constrs) tname' (dts', constr_syntax, sorts, i) =
+      let
+        fun prep_constr (cname, cargs, mx') (constrs, constr_syntax', sorts') =
+          let
+            val (cargs', sorts'') = fold_map (prep_typ tmp_thy) cargs sorts';
+            val _ =
+              (case subtract (op =) tvs (fold (curry OldTerm.add_typ_tfree_names) cargs' []) of
+                [] => ()
+              | vs => error ("Extra type variables on rhs: " ^ commas vs))
+          in (constrs @ [(Sign.full_name_path tmp_thy tname'
+                  (Binding.map_name (Syntax.const_name mx') cname),
+                   map (dtyp_of_typ new_dts) cargs')],
+              constr_syntax' @ [(cname, mx')], sorts'')
+          end handle ERROR msg => cat_error msg
+           ("The error above occured in constructor " ^ quote (Binding.str_of cname) ^
+            " of datatype " ^ quote (Binding.str_of tname));
+
+        val (constrs', constr_syntax', sorts') =
+          fold prep_constr constrs ([], [], sorts)
+
+      in
+        case duplicates (op =) (map fst constrs') of
+           [] =>
+             (dts' @ [(i, (Sign.full_name tmp_thy (Binding.map_name (Syntax.type_name mx) tname),
+                map DtTFree tvs, constrs'))],
+              constr_syntax @ [constr_syntax'], sorts', i + 1)
+         | dups => error ("Duplicate constructors " ^ commas dups ^
+             " in datatype " ^ quote (Binding.str_of tname))
+      end;
+
+    val (dts', constr_syntax, sorts', i) =
+      fold2 prep_dt_spec dts new_type_names ([], [], [], 0);
+    val sorts = sorts' @ map (rpair (Sign.defaultS tmp_thy)) (subtract (op =) (map fst sorts') tyvars);
+    val dt_info = Datatype_Data.get_all thy;
+    val (descr, _) = unfold_datatypes tmp_thy dts' sorts dt_info dts' i;
+    val _ = check_nonempty descr handle (exn as Datatype_Empty s) =>
+      if #strict config then error ("Nonemptiness check failed for datatype " ^ s)
+      else raise exn;
+
+    val _ = message config ("Constructing datatype(s) " ^ commas_quote new_type_names);
+
+  in
+    thy
+    |> representation_proofs config dt_info new_type_names descr sorts
+        types_syntax constr_syntax (Datatype_Data.mk_case_names_induct (flat descr))
+    |-> (fn (inject, distinct, induct) => Datatype_Data.derive_datatype_props
+        config dt_names (SOME new_type_names) descr sorts
+        induct inject distinct)
+  end;
+
+val add_datatype = gen_add_datatype Datatype_Data.cert_typ;
+val datatype_cmd = snd ooo gen_add_datatype Datatype_Data.read_typ default_config;
+
+local
+
+structure P = OuterParse and K = OuterKeyword
+
+fun prep_datatype_decls args =
+  let
+    val names = map
+      (fn ((((NONE, _), t), _), _) => Binding.name_of t | ((((SOME t, _), _), _), _) => t) args;
+    val specs = map (fn ((((_, vs), t), mx), cons) =>
+      (vs, t, mx, map (fn ((x, y), z) => (x, y, z)) cons)) args;
+  in (names, specs) end;
+
+val parse_datatype_decl =
+  (Scan.option (P.$$$ "(" |-- P.name --| P.$$$ ")") -- P.type_args -- P.binding -- P.opt_infix --
+    (P.$$$ "=" |-- P.enum1 "|" (P.binding -- Scan.repeat P.typ -- P.opt_mixfix)));
+
+val parse_datatype_decls = P.and_list1 parse_datatype_decl >> prep_datatype_decls;
+
+in
+
+val _ =
+  OuterSyntax.command "datatype" "define inductive datatypes" K.thy_decl
+    (parse_datatype_decls >> (fn (names, specs) => Toplevel.theory (datatype_cmd names specs)));
 
 end;
+
+end;