src/Pure/Isar/class.ML
author haftmann
Tue May 04 08:55:43 2010 +0200 (2010-05-04)
changeset 36635 080b755377c0
parent 36464 b789c1731fb7
child 36645 30bd207ec222
permissions -rw-r--r--
locale predicates of classes carry a mandatory "class" prefix
haftmann@35120
     1
(*  Title:      Pure/Isar/class.ML
haftmann@24218
     2
    Author:     Florian Haftmann, TU Muenchen
haftmann@24218
     3
haftmann@29575
     4
Type classes derived from primitive axclasses and locales - interfaces.
haftmann@24218
     5
*)
haftmann@24218
     6
haftmann@24218
     7
signature CLASS =
haftmann@24218
     8
sig
haftmann@29358
     9
  include CLASS_TARGET
haftmann@29439
    10
    (*FIXME the split into class_target.ML, theory_target.ML and
haftmann@29439
    11
      class.ML is artificial*)
haftmann@29358
    12
wenzelm@30344
    13
  val class: binding -> class list -> Element.context_i list
haftmann@29378
    14
    -> theory -> string * local_theory
wenzelm@30344
    15
  val class_cmd: binding -> xstring list -> Element.context list
haftmann@29378
    16
    -> theory -> string * local_theory
haftmann@29358
    17
  val prove_subclass: tactic -> class -> local_theory -> local_theory
haftmann@29358
    18
  val subclass: class -> local_theory -> Proof.state
haftmann@29358
    19
  val subclass_cmd: xstring -> local_theory -> Proof.state
haftmann@24218
    20
end;
haftmann@24218
    21
haftmann@24218
    22
structure Class : CLASS =
haftmann@24218
    23
struct
haftmann@24218
    24
haftmann@29358
    25
open Class_Target;
haftmann@28715
    26
haftmann@29665
    27
(** class definitions **)
haftmann@24218
    28
haftmann@24218
    29
local
haftmann@24218
    30
haftmann@29665
    31
(* calculating class-related rules including canonical interpretation *)
haftmann@29665
    32
haftmann@29547
    33
fun calculate thy class sups base_sort param_map assm_axiom =
haftmann@29547
    34
  let
haftmann@29547
    35
    val empty_ctxt = ProofContext.init thy;
haftmann@29547
    36
haftmann@29547
    37
    (* instantiation of canonical interpretation *)
haftmann@29575
    38
    val aT = TFree (Name.aT, base_sort);
haftmann@29627
    39
    val param_map_const = (map o apsnd) Const param_map;
haftmann@29627
    40
    val param_map_inst = (map o apsnd)
haftmann@29627
    41
      (Const o apsnd (map_atyps (K aT))) param_map;
haftmann@29627
    42
    val const_morph = Element.inst_morphism thy
haftmann@29627
    43
      (Symtab.empty, Symtab.make param_map_inst);
haftmann@29797
    44
    val typ_morph = Element.inst_morphism thy
haftmann@29797
    45
      (Symtab.empty |> Symtab.update (Name.aT, TFree (Name.aT, [class])), Symtab.empty);
haftmann@29797
    46
    val (([raw_props], [(_, raw_inst_morph)], export_morph), _) = empty_ctxt
haftmann@29547
    47
      |> Expression.cert_goal_expression ([(class, (("", false),
haftmann@29627
    48
           Expression.Named param_map_const))], []);
haftmann@29797
    49
    val (props, inst_morph) = if null param_map
haftmann@29797
    50
      then (raw_props |> map (Morphism.term typ_morph),
haftmann@29797
    51
        raw_inst_morph $> typ_morph)
haftmann@29797
    52
      else (raw_props, raw_inst_morph); (*FIXME proper handling in
haftmann@29797
    53
        locale.ML / expression.ML would be desirable*)
haftmann@29547
    54
haftmann@29547
    55
    (* witness for canonical interpretation *)
haftmann@29547
    56
    val prop = try the_single props;
haftmann@29547
    57
    val wit = Option.map (fn prop => let
haftmann@29547
    58
        val sup_axioms = map_filter (fst o rules thy) sups;
haftmann@29547
    59
        val loc_intro_tac = case Locale.intros_of thy class
haftmann@29547
    60
          of (_, NONE) => all_tac
haftmann@29547
    61
           | (_, SOME intro) => ALLGOALS (Tactic.rtac intro);
haftmann@29547
    62
        val tac = loc_intro_tac
haftmann@29547
    63
          THEN ALLGOALS (ProofContext.fact_tac (sup_axioms @ the_list assm_axiom))
haftmann@29547
    64
      in Element.prove_witness empty_ctxt prop tac end) prop;
haftmann@29547
    65
    val axiom = Option.map Element.conclude_witness wit;
haftmann@29547
    66
haftmann@29547
    67
    (* canonical interpretation *)
haftmann@29547
    68
    val base_morph = inst_morph
wenzelm@30335
    69
      $> Morphism.binding_morphism (Binding.prefix false (class_prefix class))
haftmann@29547
    70
      $> Element.satisfy_morphism (the_list wit);
haftmann@32886
    71
    val eq_morph = Element.eq_morphism thy (these_defs thy sups);
haftmann@29547
    72
haftmann@29547
    73
    (* assm_intro *)
wenzelm@30344
    74
    fun prove_assm_intro thm =
haftmann@29547
    75
      let
wenzelm@31794
    76
        val ((_, [thm']), _) = Variable.import true [thm] empty_ctxt;
haftmann@29627
    77
        val thm'' = Morphism.thm (const_morph $> eq_morph) thm';
haftmann@29627
    78
        val tac = ALLGOALS (ProofContext.fact_tac [thm'']);
wenzelm@32970
    79
      in Skip_Proof.prove_global thy [] [] (Thm.prop_of thm'') (K tac) end;
haftmann@29547
    80
    val assm_intro = Option.map prove_assm_intro
haftmann@29547
    81
      (fst (Locale.intros_of thy class));
haftmann@29547
    82
haftmann@29547
    83
    (* of_class *)
wenzelm@31943
    84
    val of_class_prop_concl = Logic.mk_of_class (aT, class);
haftmann@29547
    85
    val of_class_prop = case prop of NONE => of_class_prop_concl
haftmann@29627
    86
      | SOME prop => Logic.mk_implies (Morphism.term const_morph
haftmann@29627
    87
          ((map_types o map_atyps) (K aT) prop), of_class_prop_concl);
haftmann@29547
    88
    val sup_of_classes = map (snd o rules thy) sups;
wenzelm@35021
    89
    val loc_axiom_intros = map Drule.export_without_context_open (Locale.axioms_of thy class);
haftmann@29547
    90
    val axclass_intro = #intro (AxClass.get_info thy class);
wenzelm@31944
    91
    val base_sort_trivs = Thm.of_sort (Thm.ctyp_of thy aT, base_sort);
haftmann@29547
    92
    val tac = REPEAT (SOMEGOAL
haftmann@29547
    93
      (Tactic.match_tac (axclass_intro :: sup_of_classes
haftmann@29547
    94
         @ loc_axiom_intros @ base_sort_trivs)
haftmann@29547
    95
           ORELSE' Tactic.assume_tac));
wenzelm@32970
    96
    val of_class = Skip_Proof.prove_global thy [] [] of_class_prop (K tac);
haftmann@29547
    97
haftmann@32886
    98
  in (base_morph, eq_morph, export_morph, axiom, assm_intro, of_class) end;
haftmann@29547
    99
haftmann@29632
   100
haftmann@29665
   101
(* reading and processing class specifications *)
haftmann@29665
   102
haftmann@36460
   103
fun prep_class_elems prep_decl thy sups raw_elems =
haftmann@29632
   104
  let
haftmann@29665
   105
haftmann@29665
   106
    (* user space type system: only permits 'a type variable, improves towards 'a *)
haftmann@36460
   107
    val algebra = Sign.classes_of thy;
haftmann@36460
   108
    val inter_sort = curry (Sorts.inter_sort algebra);
haftmann@36460
   109
    val proto_base_sort = if null sups then Sign.defaultS thy
haftmann@36460
   110
      else fold inter_sort (map (base_sort thy) sups) [];
haftmann@29665
   111
    val base_constraints = (map o apsnd)
haftmann@29665
   112
      (map_type_tfree (K (TVar ((Name.aT, 0), proto_base_sort))) o fst o snd)
haftmann@29665
   113
        (these_operations thy sups);
haftmann@29665
   114
    val reject_bcd_etc = (map o map_atyps) (fn T as TFree (v, sort) =>
haftmann@29665
   115
          if v = Name.aT then T
haftmann@29665
   116
          else error ("No type variable other than " ^ Name.aT ^ " allowed in class specification")
haftmann@29665
   117
      | T => T);
haftmann@36460
   118
    fun singleton_fixate Ts =
haftmann@29665
   119
      let
haftmann@29665
   120
        fun extract f = (fold o fold_atyps) f Ts [];
haftmann@29665
   121
        val tfrees = extract
haftmann@29665
   122
          (fn TFree (v, sort) => insert (op =) (v, sort) | _ => I);
haftmann@29665
   123
        val inferred_sort = extract
haftmann@36460
   124
          (fn TVar (_, sort) => inter_sort sort | _ => I);
haftmann@29665
   125
        val fixate_sort = if null tfrees then inferred_sort
haftmann@29816
   126
          else case tfrees
haftmann@29816
   127
           of [(_, a_sort)] => if Sorts.sort_le algebra (a_sort, inferred_sort)
haftmann@36460
   128
                then inter_sort a_sort inferred_sort
haftmann@29816
   129
                else error ("Type inference imposes additional sort constraint "
haftmann@29816
   130
                  ^ Syntax.string_of_sort_global thy inferred_sort
haftmann@29816
   131
                  ^ " of type parameter " ^ Name.aT ^ " of sort "
haftmann@29816
   132
                  ^ Syntax.string_of_sort_global thy a_sort ^ ".")
haftmann@29816
   133
            | _ => error "Multiple type variables in class specification.";
haftmann@29665
   134
      in (map o map_atyps) (K (TFree (Name.aT, fixate_sort))) Ts end;
haftmann@32206
   135
    fun add_typ_check level name f = Context.proof_map
haftmann@32206
   136
      (Syntax.add_typ_check level name (fn xs => fn ctxt =>
haftmann@32206
   137
        let val xs' = f xs in if eq_list (op =) (xs, xs') then NONE else SOME (xs', ctxt) end));
haftmann@29632
   138
haftmann@35120
   139
    (* preprocessing elements, retrieving base sort from type-checked elements *)
haftmann@29702
   140
    val init_class_body = fold (ProofContext.add_const_constraint o apsnd SOME) base_constraints
haftmann@29702
   141
      #> redeclare_operations thy sups
haftmann@29702
   142
      #> add_typ_check 10 "reject_bcd_etc" reject_bcd_etc
haftmann@36460
   143
      #> add_typ_check ~10 "singleton_fixate" singleton_fixate;
haftmann@32206
   144
    val raw_supexpr = (map (fn sup => (sup, (("", false),
haftmann@32206
   145
      Expression.Positional []))) sups, []);
haftmann@32206
   146
    val ((raw_supparams, _, inferred_elems), _) = ProofContext.init thy
haftmann@32206
   147
      |> prep_decl raw_supexpr init_class_body raw_elems;
haftmann@29665
   148
    fun fold_element_types f (Element.Fixes fxs) = fold (fn (_, SOME T, _) => f T) fxs
haftmann@29665
   149
      | fold_element_types f (Element.Constrains cnstrs) = fold (f o snd) cnstrs
haftmann@29665
   150
      | fold_element_types f (Element.Assumes assms) = fold (fold (fn (t, ts) =>
haftmann@29665
   151
          fold_types f t #> (fold o fold_types) f ts) o snd) assms
haftmann@29665
   152
      | fold_element_types f (Element.Defines _) =
haftmann@29665
   153
          error ("\"defines\" element not allowed in class specification.")
haftmann@29665
   154
      | fold_element_types f (Element.Notes _) =
haftmann@29665
   155
          error ("\"notes\" element not allowed in class specification.");
haftmann@29665
   156
    val base_sort = if null inferred_elems then proto_base_sort else
haftmann@29665
   157
      case (fold o fold_element_types) Term.add_tfreesT inferred_elems []
haftmann@29665
   158
       of [] => error "No type variable in class specification"
haftmann@29665
   159
        | [(_, sort)] => sort
haftmann@32206
   160
        | _ => error "Multiple type variables in class specification";
haftmann@32206
   161
    val supparams = map (fn ((c, T), _) =>
haftmann@32206
   162
      (c, map_atyps (K (TFree (Name.aT, base_sort))) T)) raw_supparams;
haftmann@32206
   163
    val supparam_names = map fst supparams;
haftmann@32206
   164
    fun mk_param ((c, _), _) = Free (c, (the o AList.lookup (op =) supparams) c);
haftmann@32206
   165
    val supexpr = (map (fn sup => (sup, (("", false),
haftmann@32206
   166
      Expression.Positional (map (SOME o mk_param) (Locale.params_of thy sup))))) sups,
haftmann@32206
   167
        map (fn (c, T) => (Binding.name c, SOME T, NoSyn)) supparams);
haftmann@29575
   168
haftmann@32206
   169
  in (base_sort, supparam_names, supexpr, inferred_elems) end;
haftmann@29575
   170
haftmann@29665
   171
val cert_class_elems = prep_class_elems Expression.cert_declaration;
haftmann@29665
   172
val read_class_elems = prep_class_elems Expression.cert_read_declaration;
haftmann@29575
   173
haftmann@29665
   174
fun prep_class_spec prep_class prep_class_elems thy raw_supclasses raw_elems =
haftmann@29575
   175
  let
haftmann@29665
   176
haftmann@29575
   177
    (* prepare import *)
haftmann@29575
   178
    val inter_sort = curry (Sorts.inter_sort (Sign.classes_of thy));
haftmann@29608
   179
    val sups = map (prep_class thy) raw_supclasses
haftmann@29608
   180
      |> Sign.minimize_sort thy;
haftmann@29608
   181
    val _ = case filter_out (is_class thy) sups
haftmann@29608
   182
     of [] => ()
haftmann@29797
   183
      | no_classes => error ("No (proper) classes: " ^ commas (map quote no_classes));
haftmann@32206
   184
    val raw_supparams = (map o apsnd) (snd o snd) (these_params thy sups);
haftmann@32206
   185
    val raw_supparam_names = map fst raw_supparams;
haftmann@32206
   186
    val _ = if has_duplicates (op =) raw_supparam_names
haftmann@29575
   187
      then error ("Duplicate parameter(s) in superclasses: "
haftmann@32206
   188
        ^ (commas o map quote o duplicates (op =)) raw_supparam_names)
haftmann@29575
   189
      else ();
haftmann@29575
   190
haftmann@29575
   191
    (* infer types and base sort *)
haftmann@32206
   192
    val (base_sort, supparam_names, supexpr, inferred_elems) =
haftmann@36460
   193
      prep_class_elems thy sups raw_elems;
haftmann@32206
   194
    val sup_sort = inter_sort base_sort sups;
haftmann@29575
   195
haftmann@29575
   196
    (* process elements as class specification *)
haftmann@32206
   197
    val class_ctxt = begin sups base_sort (ProofContext.init thy);
haftmann@29665
   198
    val ((_, _, syntax_elems), _) = class_ctxt
haftmann@29702
   199
      |> Expression.cert_declaration supexpr I inferred_elems;
haftmann@29665
   200
    fun check_vars e vs = if null vs
haftmann@29665
   201
      then error ("No type variable in part of specification element "
haftmann@29665
   202
        ^ (Pretty.output o Pretty.chunks) (Element.pretty_ctxt class_ctxt e))
haftmann@29665
   203
      else ();
haftmann@29665
   204
    fun check_element (e as Element.Fixes fxs) =
haftmann@29665
   205
          map (fn (_, SOME T, _) => check_vars e (Term.add_tfreesT T [])) fxs
haftmann@29665
   206
      | check_element (e as Element.Assumes assms) =
haftmann@29665
   207
          maps (fn (_, ts_pss) => map
haftmann@29665
   208
            (fn (t, _) => check_vars e (Term.add_tfrees t [])) ts_pss) assms
haftmann@29665
   209
      | check_element e = [()];
haftmann@29665
   210
    val _ = map check_element syntax_elems;
haftmann@29665
   211
    fun fork_syn (Element.Fixes xs) =
wenzelm@30344
   212
          fold_map (fn (c, ty, syn) => cons (c, syn) #> pair (c, ty, NoSyn)) xs
haftmann@29665
   213
          #>> Element.Fixes
haftmann@29665
   214
      | fork_syn x = pair x;
haftmann@29575
   215
    val (elems, global_syntax) = fold_map fork_syn syntax_elems [];
haftmann@29665
   216
haftmann@32713
   217
  in (((sups, supparam_names), (sup_sort, base_sort, supexpr)), (elems, global_syntax)) end;
haftmann@29575
   218
haftmann@29665
   219
val cert_class_spec = prep_class_spec (K I) cert_class_elems;
haftmann@29665
   220
val read_class_spec = prep_class_spec Sign.intern_class read_class_elems;
haftmann@29665
   221
haftmann@29665
   222
haftmann@29665
   223
(* class establishment *)
haftmann@29575
   224
haftmann@32206
   225
fun add_consts class base_sort sups supparam_names global_syntax thy =
wenzelm@24968
   226
  let
haftmann@29816
   227
    (*FIXME simplify*)
haftmann@32206
   228
    val supconsts = supparam_names
haftmann@26518
   229
      |> AList.make (snd o the o AList.lookup (op =) (these_params thy sups))
haftmann@25683
   230
      |> (map o apsnd o apsnd o map_atyps o K o TFree) (Name.aT, [class]);
haftmann@29509
   231
    val all_params = Locale.params_of thy class;
haftmann@32206
   232
    val raw_params = (snd o chop (length supparam_names)) all_params;
wenzelm@30755
   233
    fun add_const ((raw_c, raw_ty), _) thy =
haftmann@25683
   234
      let
wenzelm@30755
   235
        val b = Binding.name raw_c;
wenzelm@30344
   236
        val c = Sign.full_name thy b;
haftmann@25683
   237
        val ty = map_atyps (K (TFree (Name.aT, base_sort))) raw_ty;
haftmann@25683
   238
        val ty0 = Type.strip_sorts ty;
haftmann@25683
   239
        val ty' = map_atyps (K (TFree (Name.aT, [class]))) ty0;
wenzelm@30344
   240
        val syn = (the_default NoSyn o AList.lookup Binding.eq_name global_syntax) b;
haftmann@25683
   241
      in
haftmann@25683
   242
        thy
wenzelm@33173
   243
        |> Sign.declare_const ((b, ty0), syn)
haftmann@25683
   244
        |> snd
wenzelm@30585
   245
        |> pair ((Name.of_binding b, ty), (c, ty'))
haftmann@25683
   246
      end;
haftmann@28715
   247
  in
haftmann@28715
   248
    thy
haftmann@29547
   249
    |> Sign.add_path (class_prefix class)
haftmann@28715
   250
    |> fold_map add_const raw_params
haftmann@28715
   251
    ||> Sign.restore_naming thy
haftmann@28715
   252
    |-> (fn params => pair (supconsts @ (map o apfst) fst params, params))
haftmann@28715
   253
  end;
haftmann@28715
   254
haftmann@32206
   255
fun adjungate_axclass bname class base_sort sups supsort supparam_names global_syntax thy =
haftmann@28715
   256
  let
haftmann@29816
   257
    (*FIXME simplify*)
haftmann@25683
   258
    fun globalize param_map = map_aterms
haftmann@25683
   259
      (fn Free (v, ty) => Const ((fst o the o AList.lookup (op =) param_map) v, ty)
haftmann@25683
   260
        | t => t);
haftmann@29509
   261
    val raw_pred = Locale.intros_of thy class
haftmann@25683
   262
      |> fst
wenzelm@35845
   263
      |> Option.map (Logic.unvarify_global o Logic.strip_imp_concl o Thm.prop_of);
haftmann@25683
   264
    fun get_axiom thy = case (#axioms o AxClass.get_info thy) class
haftmann@25683
   265
     of [] => NONE
haftmann@25683
   266
      | [thm] => SOME thm;
wenzelm@24968
   267
  in
wenzelm@24968
   268
    thy
haftmann@32206
   269
    |> add_consts class base_sort sups supparam_names global_syntax
haftmann@25683
   270
    |-> (fn (param_map, params) => AxClass.define_class (bname, supsort)
haftmann@26518
   271
          (map (fst o snd) params)
wenzelm@30211
   272
          [(Thm.empty_binding, Option.map (globalize param_map) raw_pred |> the_list)]
haftmann@25683
   273
    #> snd
haftmann@25683
   274
    #> `get_axiom
haftmann@25683
   275
    #-> (fn assm_axiom => fold (Sign.add_const_constraint o apsnd SOME o snd) params
haftmann@29526
   276
    #> pair (param_map, params, assm_axiom)))
wenzelm@24968
   277
  end;
wenzelm@24968
   278
haftmann@36635
   279
fun gen_class prep_class_spec b raw_supclasses raw_elems thy =
haftmann@24748
   280
  let
haftmann@36635
   281
    val class = Sign.full_name thy b;
haftmann@32206
   282
    val (((sups, supparam_names), (supsort, base_sort, supexpr)), (elems, global_syntax)) =
haftmann@32206
   283
      prep_class_spec thy raw_supclasses raw_elems;
haftmann@24218
   284
  in
haftmann@24218
   285
    thy
haftmann@36635
   286
    |> Expression.add_locale b (Binding.qualify true "class" b) supexpr elems
wenzelm@33671
   287
    |> snd |> Local_Theory.exit_global
haftmann@36635
   288
    |> adjungate_axclass b class base_sort sups supsort supparam_names global_syntax
haftmann@31696
   289
    ||> Theory.checkpoint
haftmann@29526
   290
    |-> (fn (param_map, params, assm_axiom) =>
haftmann@29547
   291
       `(fn thy => calculate thy class sups base_sort param_map assm_axiom)
haftmann@32886
   292
    #-> (fn (base_morph, eq_morph, export_morph, axiom, assm_intro, of_class) =>
haftmann@36463
   293
       Locale.add_registration (class, base_morph $> eq_morph (*FIXME duplication*)) (SOME (eq_morph, true)) export_morph
haftmann@32850
   294
    #> register class sups params base_sort base_morph export_morph axiom assm_intro of_class))
wenzelm@33553
   295
    |> Theory_Target.init (SOME class)
haftmann@25038
   296
    |> pair class
haftmann@24218
   297
  end;
haftmann@24218
   298
haftmann@24218
   299
in
haftmann@24218
   300
haftmann@29509
   301
val class = gen_class cert_class_spec;
haftmann@26518
   302
val class_cmd = gen_class read_class_spec;
haftmann@24218
   303
haftmann@24218
   304
end; (*local*)
haftmann@24218
   305
haftmann@24218
   306
haftmann@29358
   307
(** subclass relations **)
haftmann@25462
   308
haftmann@29358
   309
local
haftmann@25462
   310
haftmann@29358
   311
fun gen_subclass prep_class do_proof raw_sup lthy =
haftmann@25462
   312
  let
haftmann@29358
   313
    val thy = ProofContext.theory_of lthy;
haftmann@29558
   314
    val proto_sup = prep_class thy raw_sup;
wenzelm@33553
   315
    val proto_sub = case Theory_Target.peek lthy
haftmann@29558
   316
     of {is_class = false, ...} => error "Not in a class context"
haftmann@29358
   317
      | {target, ...} => target;
haftmann@31987
   318
    val (sub, sup) = AxClass.cert_classrel thy (proto_sub, proto_sup);
haftmann@29509
   319
haftmann@29509
   320
    val expr = ([(sup, (("", false), Expression.Positional []))], []);
haftmann@29558
   321
    val (([props], deps, export), goal_ctxt) =
haftmann@29509
   322
      Expression.cert_goal_expression expr lthy;
haftmann@29526
   323
    val some_prop = try the_single props;
haftmann@29558
   324
    val some_dep_morph = try the_single (map snd deps);
haftmann@29558
   325
    fun after_qed some_wit =
haftmann@29558
   326
      ProofContext.theory (register_subclass (sub, sup)
haftmann@29558
   327
        some_dep_morph some_wit export)
wenzelm@33553
   328
      #> ProofContext.theory_of #> Theory_Target.init (SOME sub);
haftmann@29558
   329
  in do_proof after_qed some_prop goal_ctxt end;
haftmann@25485
   330
haftmann@29575
   331
fun user_proof after_qed some_prop =
haftmann@29575
   332
  Element.witness_proof (after_qed o try the_single o the_single)
haftmann@29575
   333
    [the_list some_prop];
haftmann@25485
   334
haftmann@29575
   335
fun tactic_proof tac after_qed some_prop ctxt =
haftmann@29575
   336
  after_qed (Option.map
haftmann@29575
   337
    (fn prop => Element.prove_witness ctxt prop tac) some_prop) ctxt;
haftmann@28666
   338
haftmann@29358
   339
in
haftmann@28666
   340
haftmann@29358
   341
val subclass = gen_subclass (K I) user_proof;
haftmann@29358
   342
fun prove_subclass tac = gen_subclass (K I) (tactic_proof tac);
wenzelm@35669
   343
val subclass_cmd = gen_subclass (ProofContext.read_class o ProofContext.init) user_proof;
haftmann@25462
   344
haftmann@29358
   345
end; (*local*)
haftmann@29358
   346
haftmann@24218
   347
end;