src/Pure/Isar/class_declaration.ML
author haftmann
Tue Oct 26 14:06:22 2010 +0200 (2010-10-26)
changeset 40188 eddda8e38360
parent 38875 c7a66b584147
child 41585 45d7da4e4ccf
permissions -rw-r--r--
consider base sorts of superclasses simultaneously during processing of class specification -- avoids clash of different base sorts
haftmann@38379
     1
(*  Title:      Pure/Isar/class_declaration.ML
haftmann@24218
     2
    Author:     Florian Haftmann, TU Muenchen
haftmann@24218
     3
haftmann@38379
     4
Declaring classes and subclass relations.
haftmann@24218
     5
*)
haftmann@24218
     6
haftmann@38379
     7
signature CLASS_DECLARATION =
haftmann@24218
     8
sig
wenzelm@30344
     9
  val class: binding -> class list -> Element.context_i list
haftmann@29378
    10
    -> theory -> string * local_theory
wenzelm@30344
    11
  val class_cmd: binding -> xstring list -> Element.context list
haftmann@29378
    12
    -> theory -> string * local_theory
haftmann@29358
    13
  val prove_subclass: tactic -> class -> local_theory -> local_theory
haftmann@29358
    14
  val subclass: class -> local_theory -> Proof.state
haftmann@29358
    15
  val subclass_cmd: xstring -> local_theory -> Proof.state
haftmann@24218
    16
end;
haftmann@24218
    17
haftmann@38379
    18
structure Class_Declaration: CLASS_DECLARATION =
haftmann@24218
    19
struct
haftmann@24218
    20
haftmann@29665
    21
(** class definitions **)
haftmann@24218
    22
haftmann@24218
    23
local
haftmann@24218
    24
haftmann@29665
    25
(* calculating class-related rules including canonical interpretation *)
haftmann@29665
    26
haftmann@29547
    27
fun calculate thy class sups base_sort param_map assm_axiom =
haftmann@29547
    28
  let
wenzelm@36610
    29
    val empty_ctxt = ProofContext.init_global thy;
haftmann@29547
    30
haftmann@29547
    31
    (* instantiation of canonical interpretation *)
haftmann@29575
    32
    val aT = TFree (Name.aT, base_sort);
haftmann@29627
    33
    val param_map_const = (map o apsnd) Const param_map;
haftmann@29627
    34
    val param_map_inst = (map o apsnd)
haftmann@29627
    35
      (Const o apsnd (map_atyps (K aT))) param_map;
haftmann@29627
    36
    val const_morph = Element.inst_morphism thy
haftmann@29627
    37
      (Symtab.empty, Symtab.make param_map_inst);
haftmann@29797
    38
    val typ_morph = Element.inst_morphism thy
haftmann@29797
    39
      (Symtab.empty |> Symtab.update (Name.aT, TFree (Name.aT, [class])), Symtab.empty);
haftmann@29797
    40
    val (([raw_props], [(_, raw_inst_morph)], export_morph), _) = empty_ctxt
haftmann@29547
    41
      |> Expression.cert_goal_expression ([(class, (("", false),
haftmann@29627
    42
           Expression.Named param_map_const))], []);
haftmann@29797
    43
    val (props, inst_morph) = if null param_map
haftmann@29797
    44
      then (raw_props |> map (Morphism.term typ_morph),
haftmann@29797
    45
        raw_inst_morph $> typ_morph)
haftmann@29797
    46
      else (raw_props, raw_inst_morph); (*FIXME proper handling in
haftmann@29797
    47
        locale.ML / expression.ML would be desirable*)
haftmann@29547
    48
haftmann@29547
    49
    (* witness for canonical interpretation *)
haftmann@29547
    50
    val prop = try the_single props;
haftmann@29547
    51
    val wit = Option.map (fn prop => let
haftmann@38379
    52
        val sup_axioms = map_filter (fst o Class.rules thy) sups;
haftmann@29547
    53
        val loc_intro_tac = case Locale.intros_of thy class
haftmann@29547
    54
          of (_, NONE) => all_tac
haftmann@29547
    55
           | (_, SOME intro) => ALLGOALS (Tactic.rtac intro);
haftmann@29547
    56
        val tac = loc_intro_tac
haftmann@29547
    57
          THEN ALLGOALS (ProofContext.fact_tac (sup_axioms @ the_list assm_axiom))
haftmann@29547
    58
      in Element.prove_witness empty_ctxt prop tac end) prop;
haftmann@29547
    59
    val axiom = Option.map Element.conclude_witness wit;
haftmann@29547
    60
haftmann@29547
    61
    (* canonical interpretation *)
haftmann@29547
    62
    val base_morph = inst_morph
haftmann@38379
    63
      $> Morphism.binding_morphism (Binding.prefix false (Class.class_prefix class))
haftmann@29547
    64
      $> Element.satisfy_morphism (the_list wit);
haftmann@38379
    65
    val eq_morph = Element.eq_morphism thy (Class.these_defs thy sups);
haftmann@29547
    66
haftmann@29547
    67
    (* assm_intro *)
wenzelm@30344
    68
    fun prove_assm_intro thm =
haftmann@29547
    69
      let
wenzelm@31794
    70
        val ((_, [thm']), _) = Variable.import true [thm] empty_ctxt;
haftmann@36674
    71
        val const_eq_morph = case eq_morph
haftmann@36674
    72
         of SOME eq_morph => const_morph $> eq_morph
haftmann@36674
    73
          | NONE => const_morph
haftmann@36674
    74
        val thm'' = Morphism.thm const_eq_morph thm';
haftmann@29627
    75
        val tac = ALLGOALS (ProofContext.fact_tac [thm'']);
wenzelm@32970
    76
      in Skip_Proof.prove_global thy [] [] (Thm.prop_of thm'') (K tac) end;
haftmann@29547
    77
    val assm_intro = Option.map prove_assm_intro
haftmann@29547
    78
      (fst (Locale.intros_of thy class));
haftmann@29547
    79
haftmann@29547
    80
    (* of_class *)
wenzelm@31943
    81
    val of_class_prop_concl = Logic.mk_of_class (aT, class);
haftmann@29547
    82
    val of_class_prop = case prop of NONE => of_class_prop_concl
haftmann@29627
    83
      | SOME prop => Logic.mk_implies (Morphism.term const_morph
haftmann@29627
    84
          ((map_types o map_atyps) (K aT) prop), of_class_prop_concl);
haftmann@38379
    85
    val sup_of_classes = map (snd o Class.rules thy) sups;
wenzelm@35021
    86
    val loc_axiom_intros = map Drule.export_without_context_open (Locale.axioms_of thy class);
haftmann@29547
    87
    val axclass_intro = #intro (AxClass.get_info thy class);
wenzelm@31944
    88
    val base_sort_trivs = Thm.of_sort (Thm.ctyp_of thy aT, base_sort);
haftmann@29547
    89
    val tac = REPEAT (SOMEGOAL
haftmann@29547
    90
      (Tactic.match_tac (axclass_intro :: sup_of_classes
haftmann@29547
    91
         @ loc_axiom_intros @ base_sort_trivs)
haftmann@29547
    92
           ORELSE' Tactic.assume_tac));
wenzelm@32970
    93
    val of_class = Skip_Proof.prove_global thy [] [] of_class_prop (K tac);
haftmann@29547
    94
haftmann@32886
    95
  in (base_morph, eq_morph, export_morph, axiom, assm_intro, of_class) end;
haftmann@29547
    96
haftmann@29632
    97
haftmann@29665
    98
(* reading and processing class specifications *)
haftmann@29665
    99
haftmann@36460
   100
fun prep_class_elems prep_decl thy sups raw_elems =
haftmann@29632
   101
  let
haftmann@29665
   102
haftmann@29665
   103
    (* user space type system: only permits 'a type variable, improves towards 'a *)
haftmann@36460
   104
    val algebra = Sign.classes_of thy;
haftmann@36460
   105
    val inter_sort = curry (Sorts.inter_sort algebra);
haftmann@36460
   106
    val proto_base_sort = if null sups then Sign.defaultS thy
haftmann@38379
   107
      else fold inter_sort (map (Class.base_sort thy) sups) [];
haftmann@29665
   108
    val base_constraints = (map o apsnd)
haftmann@29665
   109
      (map_type_tfree (K (TVar ((Name.aT, 0), proto_base_sort))) o fst o snd)
haftmann@38379
   110
        (Class.these_operations thy sups);
haftmann@29665
   111
    val reject_bcd_etc = (map o map_atyps) (fn T as TFree (v, sort) =>
haftmann@29665
   112
          if v = Name.aT then T
haftmann@29665
   113
          else error ("No type variable other than " ^ Name.aT ^ " allowed in class specification")
haftmann@29665
   114
      | T => T);
haftmann@36460
   115
    fun singleton_fixate Ts =
haftmann@29665
   116
      let
haftmann@29665
   117
        fun extract f = (fold o fold_atyps) f Ts [];
haftmann@29665
   118
        val tfrees = extract
haftmann@29665
   119
          (fn TFree (v, sort) => insert (op =) (v, sort) | _ => I);
haftmann@29665
   120
        val inferred_sort = extract
haftmann@36460
   121
          (fn TVar (_, sort) => inter_sort sort | _ => I);
haftmann@29665
   122
        val fixate_sort = if null tfrees then inferred_sort
haftmann@29816
   123
          else case tfrees
haftmann@29816
   124
           of [(_, a_sort)] => if Sorts.sort_le algebra (a_sort, inferred_sort)
haftmann@36460
   125
                then inter_sort a_sort inferred_sort
haftmann@29816
   126
                else error ("Type inference imposes additional sort constraint "
haftmann@29816
   127
                  ^ Syntax.string_of_sort_global thy inferred_sort
haftmann@29816
   128
                  ^ " of type parameter " ^ Name.aT ^ " of sort "
wenzelm@38875
   129
                  ^ Syntax.string_of_sort_global thy a_sort)
wenzelm@38875
   130
            | _ => error "Multiple type variables in class specification";
haftmann@29665
   131
      in (map o map_atyps) (K (TFree (Name.aT, fixate_sort))) Ts end;
haftmann@40188
   132
    fun after_infer_fixate Ts =
haftmann@40188
   133
      let
haftmann@40188
   134
        val sort' = (fold o fold_atyps) (fn T as TFree _ => I | T as TVar (vi, sort) =>
haftmann@40188
   135
          if Type_Infer.is_param vi then inter_sort sort else I) Ts [];
haftmann@40188
   136
      in
haftmann@40188
   137
        (map o map_atyps)
haftmann@40188
   138
          (fn T as TFree _ => T | T as TVar (vi, _) =>
haftmann@40188
   139
            if Type_Infer.is_param vi then Type_Infer.param 0 (Name.aT, sort') else T) Ts
haftmann@40188
   140
      end;
haftmann@32206
   141
    fun add_typ_check level name f = Context.proof_map
haftmann@38435
   142
      (Syntax.add_typ_check level name (fn Ts => fn ctxt =>
haftmann@38435
   143
        let val Ts' = f Ts in if eq_list (op =) (Ts, Ts') then NONE else SOME (Ts', ctxt) end));
haftmann@29632
   144
haftmann@35120
   145
    (* preprocessing elements, retrieving base sort from type-checked elements *)
haftmann@38493
   146
    val raw_supexpr = (map (fn sup => (sup, (("", false),
haftmann@38493
   147
      Expression.Positional []))) sups, []);
haftmann@29702
   148
    val init_class_body = fold (ProofContext.add_const_constraint o apsnd SOME) base_constraints
haftmann@38379
   149
      #> Class.redeclare_operations thy sups
haftmann@29702
   150
      #> add_typ_check 10 "reject_bcd_etc" reject_bcd_etc
haftmann@36460
   151
      #> add_typ_check ~10 "singleton_fixate" singleton_fixate;
haftmann@38435
   152
    val ((raw_supparams, _, raw_inferred_elems), _) = ProofContext.init_global thy
haftmann@38493
   153
      |> add_typ_check 5 "after_infer_fixate" after_infer_fixate
haftmann@32206
   154
      |> prep_decl raw_supexpr init_class_body raw_elems;
haftmann@38435
   155
    fun filter_element (Element.Fixes []) = NONE
haftmann@38435
   156
      | filter_element (e as Element.Fixes _) = SOME e
haftmann@38435
   157
      | filter_element (Element.Constrains []) = NONE
haftmann@38435
   158
      | filter_element (e as Element.Constrains _) = SOME e
haftmann@38435
   159
      | filter_element (Element.Assumes []) = NONE
haftmann@38435
   160
      | filter_element (e as Element.Assumes _) = SOME e
haftmann@38435
   161
      | filter_element (Element.Defines _) = error ("\"defines\" element not allowed in class specification.")
haftmann@38435
   162
      | filter_element (Element.Notes _) = error ("\"notes\" element not allowed in class specification.");
haftmann@38435
   163
    val inferred_elems = map_filter filter_element raw_inferred_elems;
haftmann@29665
   164
    fun fold_element_types f (Element.Fixes fxs) = fold (fn (_, SOME T, _) => f T) fxs
haftmann@29665
   165
      | fold_element_types f (Element.Constrains cnstrs) = fold (f o snd) cnstrs
haftmann@29665
   166
      | fold_element_types f (Element.Assumes assms) = fold (fold (fn (t, ts) =>
haftmann@29665
   167
          fold_types f t #> (fold o fold_types) f ts) o snd) assms
haftmann@29665
   168
    val base_sort = if null inferred_elems then proto_base_sort else
haftmann@29665
   169
      case (fold o fold_element_types) Term.add_tfreesT inferred_elems []
haftmann@29665
   170
       of [] => error "No type variable in class specification"
haftmann@29665
   171
        | [(_, sort)] => sort
haftmann@32206
   172
        | _ => error "Multiple type variables in class specification";
haftmann@32206
   173
    val supparams = map (fn ((c, T), _) =>
haftmann@32206
   174
      (c, map_atyps (K (TFree (Name.aT, base_sort))) T)) raw_supparams;
haftmann@32206
   175
    val supparam_names = map fst supparams;
haftmann@32206
   176
    fun mk_param ((c, _), _) = Free (c, (the o AList.lookup (op =) supparams) c);
haftmann@32206
   177
    val supexpr = (map (fn sup => (sup, (("", false),
haftmann@32206
   178
      Expression.Positional (map (SOME o mk_param) (Locale.params_of thy sup))))) sups,
haftmann@32206
   179
        map (fn (c, T) => (Binding.name c, SOME T, NoSyn)) supparams);
haftmann@29575
   180
haftmann@32206
   181
  in (base_sort, supparam_names, supexpr, inferred_elems) end;
haftmann@29575
   182
haftmann@29665
   183
val cert_class_elems = prep_class_elems Expression.cert_declaration;
haftmann@29665
   184
val read_class_elems = prep_class_elems Expression.cert_read_declaration;
haftmann@29575
   185
haftmann@29665
   186
fun prep_class_spec prep_class prep_class_elems thy raw_supclasses raw_elems =
haftmann@29575
   187
  let
haftmann@29665
   188
haftmann@29575
   189
    (* prepare import *)
haftmann@29575
   190
    val inter_sort = curry (Sorts.inter_sort (Sign.classes_of thy));
haftmann@29608
   191
    val sups = map (prep_class thy) raw_supclasses
haftmann@29608
   192
      |> Sign.minimize_sort thy;
haftmann@38379
   193
    val _ = case filter_out (Class.is_class thy) sups
haftmann@29608
   194
     of [] => ()
haftmann@29797
   195
      | no_classes => error ("No (proper) classes: " ^ commas (map quote no_classes));
haftmann@38379
   196
    val raw_supparams = (map o apsnd) (snd o snd) (Class.these_params thy sups);
haftmann@32206
   197
    val raw_supparam_names = map fst raw_supparams;
haftmann@32206
   198
    val _ = if has_duplicates (op =) raw_supparam_names
haftmann@29575
   199
      then error ("Duplicate parameter(s) in superclasses: "
haftmann@32206
   200
        ^ (commas o map quote o duplicates (op =)) raw_supparam_names)
haftmann@29575
   201
      else ();
haftmann@29575
   202
haftmann@29575
   203
    (* infer types and base sort *)
haftmann@32206
   204
    val (base_sort, supparam_names, supexpr, inferred_elems) =
haftmann@36460
   205
      prep_class_elems thy sups raw_elems;
haftmann@32206
   206
    val sup_sort = inter_sort base_sort sups;
haftmann@29575
   207
haftmann@29575
   208
    (* process elements as class specification *)
haftmann@38379
   209
    val class_ctxt = Class.begin sups base_sort (ProofContext.init_global thy);
haftmann@29665
   210
    val ((_, _, syntax_elems), _) = class_ctxt
haftmann@29702
   211
      |> Expression.cert_declaration supexpr I inferred_elems;
haftmann@29665
   212
    fun check_vars e vs = if null vs
haftmann@29665
   213
      then error ("No type variable in part of specification element "
wenzelm@36746
   214
        ^ (Pretty.string_of o Pretty.chunks) (Element.pretty_ctxt class_ctxt e))
haftmann@29665
   215
      else ();
haftmann@29665
   216
    fun check_element (e as Element.Fixes fxs) =
haftmann@29665
   217
          map (fn (_, SOME T, _) => check_vars e (Term.add_tfreesT T [])) fxs
haftmann@29665
   218
      | check_element (e as Element.Assumes assms) =
haftmann@29665
   219
          maps (fn (_, ts_pss) => map
haftmann@29665
   220
            (fn (t, _) => check_vars e (Term.add_tfrees t [])) ts_pss) assms
haftmann@29665
   221
      | check_element e = [()];
haftmann@29665
   222
    val _ = map check_element syntax_elems;
haftmann@29665
   223
    fun fork_syn (Element.Fixes xs) =
wenzelm@30344
   224
          fold_map (fn (c, ty, syn) => cons (c, syn) #> pair (c, ty, NoSyn)) xs
haftmann@29665
   225
          #>> Element.Fixes
haftmann@29665
   226
      | fork_syn x = pair x;
haftmann@29575
   227
    val (elems, global_syntax) = fold_map fork_syn syntax_elems [];
haftmann@29665
   228
haftmann@32713
   229
  in (((sups, supparam_names), (sup_sort, base_sort, supexpr)), (elems, global_syntax)) end;
haftmann@29575
   230
haftmann@29665
   231
val cert_class_spec = prep_class_spec (K I) cert_class_elems;
haftmann@29665
   232
val read_class_spec = prep_class_spec Sign.intern_class read_class_elems;
haftmann@29665
   233
haftmann@29665
   234
haftmann@29665
   235
(* class establishment *)
haftmann@29575
   236
haftmann@32206
   237
fun add_consts class base_sort sups supparam_names global_syntax thy =
wenzelm@24968
   238
  let
haftmann@29816
   239
    (*FIXME simplify*)
haftmann@32206
   240
    val supconsts = supparam_names
haftmann@38379
   241
      |> AList.make (snd o the o AList.lookup (op =) (Class.these_params thy sups))
haftmann@25683
   242
      |> (map o apsnd o apsnd o map_atyps o K o TFree) (Name.aT, [class]);
haftmann@29509
   243
    val all_params = Locale.params_of thy class;
haftmann@32206
   244
    val raw_params = (snd o chop (length supparam_names)) all_params;
wenzelm@30755
   245
    fun add_const ((raw_c, raw_ty), _) thy =
haftmann@25683
   246
      let
wenzelm@30755
   247
        val b = Binding.name raw_c;
wenzelm@30344
   248
        val c = Sign.full_name thy b;
haftmann@25683
   249
        val ty = map_atyps (K (TFree (Name.aT, base_sort))) raw_ty;
haftmann@25683
   250
        val ty0 = Type.strip_sorts ty;
haftmann@25683
   251
        val ty' = map_atyps (K (TFree (Name.aT, [class]))) ty0;
wenzelm@30344
   252
        val syn = (the_default NoSyn o AList.lookup Binding.eq_name global_syntax) b;
haftmann@25683
   253
      in
haftmann@25683
   254
        thy
wenzelm@33173
   255
        |> Sign.declare_const ((b, ty0), syn)
haftmann@25683
   256
        |> snd
wenzelm@30585
   257
        |> pair ((Name.of_binding b, ty), (c, ty'))
haftmann@25683
   258
      end;
haftmann@28715
   259
  in
haftmann@28715
   260
    thy
haftmann@38379
   261
    |> Sign.add_path (Class.class_prefix class)
haftmann@28715
   262
    |> fold_map add_const raw_params
haftmann@28715
   263
    ||> Sign.restore_naming thy
haftmann@28715
   264
    |-> (fn params => pair (supconsts @ (map o apfst) fst params, params))
haftmann@28715
   265
  end;
haftmann@28715
   266
haftmann@32206
   267
fun adjungate_axclass bname class base_sort sups supsort supparam_names global_syntax thy =
haftmann@28715
   268
  let
haftmann@29816
   269
    (*FIXME simplify*)
haftmann@25683
   270
    fun globalize param_map = map_aterms
haftmann@25683
   271
      (fn Free (v, ty) => Const ((fst o the o AList.lookup (op =) param_map) v, ty)
haftmann@25683
   272
        | t => t);
haftmann@29509
   273
    val raw_pred = Locale.intros_of thy class
haftmann@25683
   274
      |> fst
wenzelm@35845
   275
      |> Option.map (Logic.unvarify_global o Logic.strip_imp_concl o Thm.prop_of);
haftmann@25683
   276
    fun get_axiom thy = case (#axioms o AxClass.get_info thy) class
haftmann@25683
   277
     of [] => NONE
haftmann@25683
   278
      | [thm] => SOME thm;
wenzelm@24968
   279
  in
wenzelm@24968
   280
    thy
haftmann@32206
   281
    |> add_consts class base_sort sups supparam_names global_syntax
haftmann@25683
   282
    |-> (fn (param_map, params) => AxClass.define_class (bname, supsort)
haftmann@26518
   283
          (map (fst o snd) params)
wenzelm@30211
   284
          [(Thm.empty_binding, Option.map (globalize param_map) raw_pred |> the_list)]
haftmann@25683
   285
    #> snd
haftmann@25683
   286
    #> `get_axiom
haftmann@25683
   287
    #-> (fn assm_axiom => fold (Sign.add_const_constraint o apsnd SOME o snd) params
haftmann@29526
   288
    #> pair (param_map, params, assm_axiom)))
wenzelm@24968
   289
  end;
wenzelm@24968
   290
haftmann@36635
   291
fun gen_class prep_class_spec b raw_supclasses raw_elems thy =
haftmann@24748
   292
  let
haftmann@36635
   293
    val class = Sign.full_name thy b;
haftmann@32206
   294
    val (((sups, supparam_names), (supsort, base_sort, supexpr)), (elems, global_syntax)) =
haftmann@32206
   295
      prep_class_spec thy raw_supclasses raw_elems;
haftmann@24218
   296
  in
haftmann@24218
   297
    thy
haftmann@36635
   298
    |> Expression.add_locale b (Binding.qualify true "class" b) supexpr elems
wenzelm@33671
   299
    |> snd |> Local_Theory.exit_global
haftmann@36635
   300
    |> adjungate_axclass b class base_sort sups supsort supparam_names global_syntax
haftmann@31696
   301
    ||> Theory.checkpoint
haftmann@29526
   302
    |-> (fn (param_map, params, assm_axiom) =>
haftmann@29547
   303
       `(fn thy => calculate thy class sups base_sort param_map assm_axiom)
haftmann@32886
   304
    #-> (fn (base_morph, eq_morph, export_morph, axiom, assm_intro, of_class) =>
ballarin@38107
   305
       Context.theory_map (Locale.add_registration (class, base_morph)
ballarin@38107
   306
         (Option.map (rpair true) eq_morph) export_morph)
haftmann@38379
   307
    #> Class.register class sups params base_sort base_morph export_morph axiom assm_intro of_class))
haftmann@38389
   308
    |> Named_Target.init class
haftmann@25038
   309
    |> pair class
haftmann@24218
   310
  end;
haftmann@24218
   311
haftmann@24218
   312
in
haftmann@24218
   313
haftmann@29509
   314
val class = gen_class cert_class_spec;
haftmann@26518
   315
val class_cmd = gen_class read_class_spec;
haftmann@24218
   316
haftmann@24218
   317
end; (*local*)
haftmann@24218
   318
haftmann@24218
   319
haftmann@29358
   320
(** subclass relations **)
haftmann@25462
   321
haftmann@29358
   322
local
haftmann@25462
   323
haftmann@29358
   324
fun gen_subclass prep_class do_proof raw_sup lthy =
haftmann@25462
   325
  let
haftmann@29358
   326
    val thy = ProofContext.theory_of lthy;
haftmann@29558
   327
    val proto_sup = prep_class thy raw_sup;
haftmann@38350
   328
    val proto_sub = case Named_Target.peek lthy
haftmann@38390
   329
     of SOME {target, is_class = true, ...} => target
haftmann@38390
   330
      | _ => error "Not in a class target";
haftmann@31987
   331
    val (sub, sup) = AxClass.cert_classrel thy (proto_sub, proto_sup);
haftmann@29509
   332
haftmann@29509
   333
    val expr = ([(sup, (("", false), Expression.Positional []))], []);
haftmann@29558
   334
    val (([props], deps, export), goal_ctxt) =
haftmann@29509
   335
      Expression.cert_goal_expression expr lthy;
haftmann@29526
   336
    val some_prop = try the_single props;
haftmann@29558
   337
    val some_dep_morph = try the_single (map snd deps);
haftmann@29558
   338
    fun after_qed some_wit =
wenzelm@38756
   339
      ProofContext.background_theory (Class.register_subclass (sub, sup)
haftmann@29558
   340
        some_dep_morph some_wit export)
haftmann@38389
   341
      #> ProofContext.theory_of #> Named_Target.init sub;
haftmann@29558
   342
  in do_proof after_qed some_prop goal_ctxt end;
haftmann@25485
   343
haftmann@29575
   344
fun user_proof after_qed some_prop =
haftmann@29575
   345
  Element.witness_proof (after_qed o try the_single o the_single)
haftmann@29575
   346
    [the_list some_prop];
haftmann@25485
   347
haftmann@29575
   348
fun tactic_proof tac after_qed some_prop ctxt =
haftmann@29575
   349
  after_qed (Option.map
haftmann@29575
   350
    (fn prop => Element.prove_witness ctxt prop tac) some_prop) ctxt;
haftmann@28666
   351
haftmann@29358
   352
in
haftmann@28666
   353
haftmann@29358
   354
val subclass = gen_subclass (K I) user_proof;
haftmann@29358
   355
fun prove_subclass tac = gen_subclass (K I) (tactic_proof tac);
wenzelm@36610
   356
val subclass_cmd = gen_subclass (ProofContext.read_class o ProofContext.init_global) user_proof;
haftmann@25462
   357
haftmann@29358
   358
end; (*local*)
haftmann@29358
   359
haftmann@24218
   360
end;