src/Pure/drule.ML
author wenzelm
Thu Sep 21 19:04:55 2006 +0200 (2006-09-21)
changeset 20669 52ba40872033
parent 20579 4dc799edef89
child 20861 fd0e33caeb3b
permissions -rw-r--r--
added dest_equals_rhs;
moved dest_binop to thm.ML;
wenzelm@252
     1
(*  Title:      Pure/drule.ML
clasohm@0
     2
    ID:         $Id$
wenzelm@252
     3
    Author:     Lawrence C Paulson, Cambridge University Computer Laboratory
clasohm@0
     4
    Copyright   1993  University of Cambridge
clasohm@0
     5
wenzelm@3766
     6
Derived rules and other operations on theorems.
clasohm@0
     7
*)
clasohm@0
     8
berghofe@13606
     9
infix 0 RS RSN RL RLN MRS MRL OF COMP;
clasohm@0
    10
wenzelm@5903
    11
signature BASIC_DRULE =
wenzelm@3766
    12
sig
wenzelm@18179
    13
  val mk_implies: cterm * cterm -> cterm
wenzelm@18179
    14
  val list_implies: cterm list * cterm -> cterm
wenzelm@18179
    15
  val dest_implies: cterm -> cterm * cterm
wenzelm@18179
    16
  val dest_equals: cterm -> cterm * cterm
wenzelm@20669
    17
  val dest_equals_rhs: cterm -> cterm
wenzelm@18179
    18
  val strip_imp_prems: cterm -> cterm list
wenzelm@18179
    19
  val strip_imp_concl: cterm -> cterm
wenzelm@18179
    20
  val cprems_of: thm -> cterm list
wenzelm@18179
    21
  val cterm_fun: (term -> term) -> (cterm -> cterm)
wenzelm@18179
    22
  val ctyp_fun: (typ -> typ) -> (ctyp -> ctyp)
wenzelm@18206
    23
  val read_insts: theory -> (indexname -> typ option) * (indexname -> sort option) ->
wenzelm@18206
    24
    (indexname -> typ option) * (indexname -> sort option) -> string list ->
wenzelm@18206
    25
    (indexname * string) list -> (ctyp * ctyp) list * (cterm * cterm) list
wenzelm@4285
    26
  val types_sorts: thm -> (indexname-> typ option) * (indexname-> sort option)
wenzelm@18179
    27
  val strip_shyps_warning: thm -> thm
wenzelm@18179
    28
  val forall_intr_list: cterm list -> thm -> thm
wenzelm@18179
    29
  val forall_intr_frees: thm -> thm
wenzelm@18179
    30
  val forall_intr_vars: thm -> thm
wenzelm@18179
    31
  val forall_elim_list: cterm list -> thm -> thm
wenzelm@18179
    32
  val forall_elim_var: int -> thm -> thm
wenzelm@18179
    33
  val forall_elim_vars: int -> thm -> thm
wenzelm@18179
    34
  val gen_all: thm -> thm
wenzelm@18179
    35
  val lift_all: cterm -> thm -> thm
wenzelm@18179
    36
  val freeze_thaw: thm -> thm * (thm -> thm)
paulson@15495
    37
  val freeze_thaw_robust: thm -> thm * (int -> thm -> thm)
wenzelm@18179
    38
  val implies_elim_list: thm -> thm list -> thm
wenzelm@18179
    39
  val implies_intr_list: cterm list -> thm -> thm
wenzelm@18206
    40
  val instantiate: (ctyp * ctyp) list * (cterm * cterm) list -> thm -> thm
wenzelm@18179
    41
  val zero_var_indexes: thm -> thm
wenzelm@18179
    42
  val implies_intr_hyps: thm -> thm
wenzelm@18179
    43
  val standard: thm -> thm
wenzelm@18179
    44
  val standard': thm -> thm
wenzelm@18179
    45
  val rotate_prems: int -> thm -> thm
wenzelm@18179
    46
  val rearrange_prems: int list -> thm -> thm
wenzelm@18179
    47
  val RSN: thm * (int * thm) -> thm
wenzelm@18179
    48
  val RS: thm * thm -> thm
wenzelm@18179
    49
  val RLN: thm list * (int * thm list) -> thm list
wenzelm@18179
    50
  val RL: thm list * thm list -> thm list
wenzelm@18179
    51
  val MRS: thm list * thm -> thm
wenzelm@18179
    52
  val MRL: thm list list * thm list -> thm list
wenzelm@18179
    53
  val OF: thm * thm list -> thm
wenzelm@18179
    54
  val compose: thm * int * thm -> thm list
wenzelm@18179
    55
  val COMP: thm * thm -> thm
wenzelm@16425
    56
  val read_instantiate_sg: theory -> (string*string)list -> thm -> thm
wenzelm@18179
    57
  val read_instantiate: (string*string)list -> thm -> thm
wenzelm@18179
    58
  val cterm_instantiate: (cterm*cterm)list -> thm -> thm
wenzelm@18179
    59
  val eq_thm_thy: thm * thm -> bool
wenzelm@18179
    60
  val eq_thm_prop: thm * thm -> bool
wenzelm@19878
    61
  val equiv_thm: thm * thm -> bool
wenzelm@18179
    62
  val size_of_thm: thm -> int
wenzelm@18179
    63
  val reflexive_thm: thm
wenzelm@18179
    64
  val symmetric_thm: thm
wenzelm@18179
    65
  val transitive_thm: thm
wenzelm@18179
    66
  val symmetric_fun: thm -> thm
wenzelm@18179
    67
  val extensional: thm -> thm
wenzelm@18820
    68
  val equals_cong: thm
wenzelm@18179
    69
  val imp_cong: thm
wenzelm@18179
    70
  val swap_prems_eq: thm
wenzelm@18179
    71
  val asm_rl: thm
wenzelm@18179
    72
  val cut_rl: thm
wenzelm@18179
    73
  val revcut_rl: thm
wenzelm@18179
    74
  val thin_rl: thm
wenzelm@4285
    75
  val triv_forall_equality: thm
wenzelm@19051
    76
  val distinct_prems_rl: thm
wenzelm@18179
    77
  val swap_prems_rl: thm
wenzelm@18179
    78
  val equal_intr_rule: thm
wenzelm@18179
    79
  val equal_elim_rule1: thm
wenzelm@19421
    80
  val equal_elim_rule2: thm
wenzelm@18179
    81
  val inst: string -> string -> thm -> thm
wenzelm@18179
    82
  val instantiate': ctyp option list -> cterm option list -> thm -> thm
wenzelm@5903
    83
end;
wenzelm@5903
    84
wenzelm@5903
    85
signature DRULE =
wenzelm@5903
    86
sig
wenzelm@5903
    87
  include BASIC_DRULE
wenzelm@19999
    88
  val generalize: string list * string list -> thm -> thm
paulson@15949
    89
  val list_comb: cterm * cterm list -> cterm
berghofe@12908
    90
  val strip_comb: cterm -> cterm * cterm list
berghofe@15262
    91
  val strip_type: ctyp -> ctyp list * ctyp
paulson@15949
    92
  val beta_conv: cterm -> cterm -> cterm
wenzelm@15875
    93
  val plain_prop_of: thm -> term
wenzelm@20298
    94
  val fold_terms: (term -> 'a -> 'a) -> thm -> 'a -> 'a
wenzelm@15669
    95
  val add_used: thm -> string list -> string list
berghofe@17713
    96
  val flexflex_unique: thm -> thm
wenzelm@11975
    97
  val close_derivation: thm -> thm
wenzelm@12005
    98
  val local_standard: thm -> thm
wenzelm@19421
    99
  val store_thm: bstring -> thm -> thm
wenzelm@19421
   100
  val store_standard_thm: bstring -> thm -> thm
wenzelm@19421
   101
  val store_thm_open: bstring -> thm -> thm
wenzelm@19421
   102
  val store_standard_thm_open: bstring -> thm -> thm
wenzelm@11975
   103
  val compose_single: thm * int * thm -> thm
wenzelm@12373
   104
  val add_rule: thm -> thm list -> thm list
wenzelm@12373
   105
  val del_rule: thm -> thm list -> thm list
wenzelm@11975
   106
  val merge_rules: thm list * thm list -> thm list
wenzelm@18468
   107
  val imp_cong_rule: thm -> thm -> thm
skalberg@15001
   108
  val beta_eta_conversion: cterm -> thm
berghofe@15925
   109
  val eta_long_conversion: cterm -> thm
wenzelm@18468
   110
  val forall_conv: int -> (cterm -> thm) -> cterm -> thm
wenzelm@18468
   111
  val concl_conv: int -> (cterm -> thm) -> cterm -> thm
wenzelm@18468
   112
  val prems_conv: int -> (int -> cterm -> thm) -> cterm -> thm
wenzelm@18179
   113
  val goals_conv: (int -> bool) -> (cterm -> thm) -> cterm -> thm
wenzelm@18179
   114
  val fconv_rule: (cterm -> thm) -> thm -> thm
wenzelm@11975
   115
  val norm_hhf_eq: thm
wenzelm@12800
   116
  val is_norm_hhf: term -> bool
wenzelm@16425
   117
  val norm_hhf: theory -> term -> term
wenzelm@20298
   118
  val norm_hhf_cterm: cterm -> cterm
wenzelm@19878
   119
  val unvarify: thm -> thm
wenzelm@18025
   120
  val protect: cterm -> cterm
wenzelm@18025
   121
  val protectI: thm
wenzelm@18025
   122
  val protectD: thm
wenzelm@18179
   123
  val protect_cong: thm
wenzelm@18025
   124
  val implies_intr_protected: cterm list -> thm -> thm
wenzelm@19775
   125
  val termI: thm
wenzelm@19775
   126
  val mk_term: cterm -> thm
wenzelm@19775
   127
  val dest_term: thm -> cterm
wenzelm@19523
   128
  val sort_triv: theory -> typ * sort -> thm list
wenzelm@19504
   129
  val unconstrainTs: thm -> thm
berghofe@14081
   130
  val rename_bvars: (string * string) list -> thm -> thm
berghofe@14081
   131
  val rename_bvars': string option list -> thm -> thm
wenzelm@19124
   132
  val incr_indexes: thm -> thm -> thm
wenzelm@19124
   133
  val incr_indexes2: thm -> thm -> thm -> thm
wenzelm@12297
   134
  val remdups_rl: thm
wenzelm@18225
   135
  val multi_resolve: thm list -> thm -> thm Seq.seq
wenzelm@18225
   136
  val multi_resolves: thm list -> thm list -> thm Seq.seq
berghofe@13325
   137
  val abs_def: thm -> thm
wenzelm@16425
   138
  val read_instantiate_sg': theory -> (indexname * string) list -> thm -> thm
berghofe@15797
   139
  val read_instantiate': (indexname * string) list -> thm -> thm
wenzelm@3766
   140
end;
clasohm@0
   141
wenzelm@5903
   142
structure Drule: DRULE =
clasohm@0
   143
struct
clasohm@0
   144
wenzelm@3991
   145
wenzelm@16682
   146
(** some cterm->cterm operations: faster than calling cterm_of! **)
lcp@708
   147
paulson@2004
   148
fun dest_implies ct =
wenzelm@16682
   149
  (case Thm.term_of ct of
wenzelm@20669
   150
    Const ("==>", _) $ _ $ _ => Thm.dest_binop ct
wenzelm@20669
   151
  | _ => raise TERM ("dest_implies", [Thm.term_of ct]));
clasohm@1703
   152
berghofe@10414
   153
fun dest_equals ct =
wenzelm@16682
   154
  (case Thm.term_of ct of
wenzelm@20669
   155
    Const ("==", _) $ _ $ _ => Thm.dest_binop ct
wenzelm@20669
   156
  | _ => raise TERM ("dest_equals", [Thm.term_of ct]));
wenzelm@20669
   157
wenzelm@20669
   158
fun dest_equals_rhs ct =
wenzelm@20669
   159
  (case Thm.term_of ct of
wenzelm@20669
   160
    Const ("==", _) $ _ $ _ => Thm.dest_arg ct
wenzelm@20669
   161
  | _ => raise TERM ("dest_equals_rhs", [Thm.term_of ct]));
berghofe@10414
   162
lcp@708
   163
(* A1==>...An==>B  goes to  [A1,...,An], where B is not an implication *)
paulson@2004
   164
fun strip_imp_prems ct =
wenzelm@20579
   165
  let val (cA, cB) = dest_implies ct
wenzelm@20579
   166
  in cA :: strip_imp_prems cB end
wenzelm@20579
   167
  handle TERM _ => [];
lcp@708
   168
paulson@2004
   169
(* A1==>...An==>B  goes to B, where B is not an implication *)
paulson@2004
   170
fun strip_imp_concl ct =
wenzelm@20579
   171
  (case Thm.term_of ct of
wenzelm@20579
   172
    Const ("==>", _) $ _ $ _ => strip_imp_concl (Thm.dest_arg ct)
wenzelm@20579
   173
  | _ => ct);
paulson@2004
   174
lcp@708
   175
(*The premises of a theorem, as a cterm list*)
berghofe@13659
   176
val cprems_of = strip_imp_prems o cprop_of;
lcp@708
   177
berghofe@15797
   178
fun cterm_fun f ct =
wenzelm@16425
   179
  let val {t, thy, ...} = Thm.rep_cterm ct
wenzelm@16425
   180
  in Thm.cterm_of thy (f t) end;
berghofe@15797
   181
berghofe@15797
   182
fun ctyp_fun f cT =
wenzelm@16425
   183
  let val {T, thy, ...} = Thm.rep_ctyp cT
wenzelm@16425
   184
  in Thm.ctyp_of thy (f T) end;
berghofe@15797
   185
wenzelm@19421
   186
val cert = cterm_of ProtoPure.thy;
paulson@9547
   187
wenzelm@19421
   188
val implies = cert Term.implies;
wenzelm@19183
   189
fun mk_implies (A, B) = Thm.capply (Thm.capply implies A) B;
paulson@9547
   190
paulson@9547
   191
(*cterm version of list_implies: [A1,...,An], B  goes to [|A1;==>;An|]==>B *)
paulson@9547
   192
fun list_implies([], B) = B
paulson@9547
   193
  | list_implies(A::AS, B) = mk_implies (A, list_implies(AS,B));
paulson@9547
   194
paulson@15949
   195
(*cterm version of list_comb: maps  (f, [t1,...,tn])  to  f(t1,...,tn) *)
paulson@15949
   196
fun list_comb (f, []) = f
paulson@15949
   197
  | list_comb (f, t::ts) = list_comb (Thm.capply f t, ts);
paulson@15949
   198
berghofe@12908
   199
(*cterm version of strip_comb: maps  f(t1,...,tn)  to  (f, [t1,...,tn]) *)
wenzelm@18179
   200
fun strip_comb ct =
berghofe@12908
   201
  let
berghofe@12908
   202
    fun stripc (p as (ct, cts)) =
berghofe@12908
   203
      let val (ct1, ct2) = Thm.dest_comb ct
berghofe@12908
   204
      in stripc (ct1, ct2 :: cts) end handle CTERM _ => p
berghofe@12908
   205
  in stripc (ct, []) end;
berghofe@12908
   206
berghofe@15262
   207
(* cterm version of strip_type: maps  [T1,...,Tn]--->T  to   ([T1,T2,...,Tn], T) *)
berghofe@15262
   208
fun strip_type cT = (case Thm.typ_of cT of
berghofe@15262
   209
    Type ("fun", _) =>
berghofe@15262
   210
      let
berghofe@15262
   211
        val [cT1, cT2] = Thm.dest_ctyp cT;
berghofe@15262
   212
        val (cTs, cT') = strip_type cT2
berghofe@15262
   213
      in (cT1 :: cTs, cT') end
berghofe@15262
   214
  | _ => ([], cT));
berghofe@15262
   215
paulson@15949
   216
(*Beta-conversion for cterms, where x is an abstraction. Simply returns the rhs
paulson@15949
   217
  of the meta-equality returned by the beta_conversion rule.*)
wenzelm@18179
   218
fun beta_conv x y =
wenzelm@20579
   219
  Thm.dest_arg (cprop_of (Thm.beta_conversion false (Thm.capply x y)));
paulson@15949
   220
wenzelm@15875
   221
fun plain_prop_of raw_thm =
wenzelm@15875
   222
  let
wenzelm@15875
   223
    val thm = Thm.strip_shyps raw_thm;
wenzelm@15875
   224
    fun err msg = raise THM ("plain_prop_of: " ^ msg, 0, [thm]);
wenzelm@15875
   225
    val {hyps, prop, tpairs, ...} = Thm.rep_thm thm;
wenzelm@15875
   226
  in
wenzelm@15875
   227
    if not (null hyps) then
wenzelm@15875
   228
      err "theorem may not contain hypotheses"
wenzelm@15875
   229
    else if not (null (Thm.extra_shyps thm)) then
wenzelm@15875
   230
      err "theorem may not contain sort hypotheses"
wenzelm@15875
   231
    else if not (null tpairs) then
wenzelm@15875
   232
      err "theorem may not contain flex-flex pairs"
wenzelm@15875
   233
    else prop
wenzelm@15875
   234
  end;
wenzelm@15875
   235
wenzelm@20298
   236
fun fold_terms f th =
wenzelm@20298
   237
  let val {tpairs, prop, hyps, ...} = Thm.rep_thm th
wenzelm@20298
   238
  in fold (fn (t, u) => f t #> f u) tpairs #> f prop #> fold f hyps end;
wenzelm@20298
   239
wenzelm@15875
   240
lcp@708
   241
lcp@229
   242
(** reading of instantiations **)
lcp@229
   243
lcp@229
   244
fun absent ixn =
lcp@229
   245
  error("No such variable in term: " ^ Syntax.string_of_vname ixn);
lcp@229
   246
lcp@229
   247
fun inst_failure ixn =
lcp@229
   248
  error("Instantiation of " ^ Syntax.string_of_vname ixn ^ " fails");
lcp@229
   249
wenzelm@16425
   250
fun read_insts thy (rtypes,rsorts) (types,sorts) used insts =
wenzelm@10403
   251
let
berghofe@15442
   252
    fun is_tv ((a, _), _) =
berghofe@15442
   253
      (case Symbol.explode a of "'" :: _ => true | _ => false);
skalberg@15570
   254
    val (tvs, vs) = List.partition is_tv insts;
berghofe@15797
   255
    fun sort_of ixn = case rsorts ixn of SOME S => S | NONE => absent ixn;
berghofe@15442
   256
    fun readT (ixn, st) =
berghofe@15797
   257
        let val S = sort_of ixn;
wenzelm@16425
   258
            val T = Sign.read_typ (thy,sorts) st;
wenzelm@16425
   259
        in if Sign.typ_instance thy (T, TVar(ixn,S)) then (ixn,T)
nipkow@4281
   260
           else inst_failure ixn
nipkow@4281
   261
        end
nipkow@4281
   262
    val tye = map readT tvs;
nipkow@4281
   263
    fun mkty(ixn,st) = (case rtypes ixn of
skalberg@15531
   264
                          SOME T => (ixn,(st,typ_subst_TVars tye T))
skalberg@15531
   265
                        | NONE => absent ixn);
nipkow@4281
   266
    val ixnsTs = map mkty vs;
nipkow@4281
   267
    val ixns = map fst ixnsTs
nipkow@4281
   268
    and sTs  = map snd ixnsTs
wenzelm@16425
   269
    val (cts,tye2) = read_def_cterms(thy,types,sorts) used false sTs;
nipkow@4281
   270
    fun mkcVar(ixn,T) =
nipkow@4281
   271
        let val U = typ_subst_TVars tye2 T
wenzelm@16425
   272
        in cterm_of thy (Var(ixn,U)) end
nipkow@4281
   273
    val ixnTs = ListPair.zip(ixns, map snd sTs)
wenzelm@16425
   274
in (map (fn (ixn, T) => (ctyp_of thy (TVar (ixn, sort_of ixn)),
wenzelm@16425
   275
      ctyp_of thy T)) (tye2 @ tye),
nipkow@4281
   276
    ListPair.zip(map mkcVar ixnTs,cts))
nipkow@4281
   277
end;
lcp@229
   278
lcp@229
   279
wenzelm@252
   280
(*** Find the type (sort) associated with a (T)Var or (T)Free in a term
clasohm@0
   281
     Used for establishing default types (of variables) and sorts (of
clasohm@0
   282
     type variables) when reading another term.
clasohm@0
   283
     Index -1 indicates that a (T)Free rather than a (T)Var is wanted.
clasohm@0
   284
***)
clasohm@0
   285
clasohm@0
   286
fun types_sorts thm =
wenzelm@20329
   287
  let
wenzelm@20329
   288
    val vars = fold_terms Term.add_vars thm [];
wenzelm@20329
   289
    val frees = fold_terms Term.add_frees thm [];
wenzelm@20329
   290
    val tvars = fold_terms Term.add_tvars thm [];
wenzelm@20329
   291
    val tfrees = fold_terms Term.add_tfrees thm [];
wenzelm@20329
   292
    fun types (a, i) =
wenzelm@20329
   293
      if i < 0 then AList.lookup (op =) frees a else AList.lookup (op =) vars (a, i);
wenzelm@20329
   294
    fun sorts (a, i) =
wenzelm@20329
   295
      if i < 0 then AList.lookup (op =) tfrees a else AList.lookup (op =) tvars (a, i);
wenzelm@20329
   296
  in (types, sorts) end;
clasohm@0
   297
wenzelm@20329
   298
val add_used =
wenzelm@20329
   299
  (fold_terms o fold_types o fold_atyps)
wenzelm@20329
   300
    (fn TFree (a, _) => insert (op =) a
wenzelm@20329
   301
      | TVar ((a, _), _) => insert (op =) a
wenzelm@20329
   302
      | _ => I);
wenzelm@15669
   303
wenzelm@7636
   304
wenzelm@9455
   305
clasohm@0
   306
(** Standardization of rules **)
clasohm@0
   307
wenzelm@19523
   308
(* type classes and sorts *)
wenzelm@19523
   309
wenzelm@19523
   310
fun sort_triv thy (T, S) =
wenzelm@19523
   311
  let
wenzelm@19523
   312
    val certT = Thm.ctyp_of thy;
wenzelm@19523
   313
    val cT = certT T;
wenzelm@19523
   314
    fun class_triv c =
wenzelm@19523
   315
      Thm.class_triv thy c
wenzelm@19523
   316
      |> Thm.instantiate ([(certT (TVar (("'a", 0), [c])), cT)], []);
wenzelm@19523
   317
  in map class_triv S end;
wenzelm@19523
   318
wenzelm@19504
   319
fun unconstrainTs th =
wenzelm@20298
   320
  fold (Thm.unconstrainT o Thm.ctyp_of (Thm.theory_of_thm th) o TVar)
wenzelm@20298
   321
    (fold_terms Term.add_tvars th []) th;
wenzelm@19504
   322
wenzelm@7636
   323
fun strip_shyps_warning thm =
wenzelm@7636
   324
  let
wenzelm@16425
   325
    val str_of_sort = Pretty.str_of o Sign.pretty_sort (Thm.theory_of_thm thm);
wenzelm@7636
   326
    val thm' = Thm.strip_shyps thm;
wenzelm@7636
   327
    val xshyps = Thm.extra_shyps thm';
wenzelm@7636
   328
  in
wenzelm@7636
   329
    if null xshyps then ()
wenzelm@7636
   330
    else warning ("Pending sort hypotheses: " ^ commas (map str_of_sort xshyps));
wenzelm@7636
   331
    thm'
wenzelm@7636
   332
  end;
wenzelm@7636
   333
wenzelm@19730
   334
(*Generalization over a list of variables*)
wenzelm@19730
   335
val forall_intr_list = fold_rev forall_intr;
clasohm@0
   336
clasohm@0
   337
(*Generalization over all suitable Free variables*)
clasohm@0
   338
fun forall_intr_frees th =
wenzelm@19730
   339
    let
wenzelm@19730
   340
      val {prop, hyps, tpairs, thy,...} = rep_thm th;
wenzelm@19730
   341
      val fixed = fold Term.add_frees (Thm.terms_of_tpairs tpairs @ hyps) [];
wenzelm@19730
   342
      val frees = Term.fold_aterms (fn Free v =>
wenzelm@19730
   343
        if member (op =) fixed v then I else insert (op =) v | _ => I) prop [];
wenzelm@19730
   344
    in fold (forall_intr o cterm_of thy o Free) frees th end;
clasohm@0
   345
wenzelm@18535
   346
(*Generalization over Vars -- canonical order*)
wenzelm@18535
   347
fun forall_intr_vars th =
wenzelm@20298
   348
  fold forall_intr
wenzelm@20298
   349
    (map (Thm.cterm_of (Thm.theory_of_thm th) o Var) (fold_terms Term.add_vars th [])) th;
wenzelm@18535
   350
wenzelm@7898
   351
val forall_elim_var = PureThy.forall_elim_var;
wenzelm@7898
   352
val forall_elim_vars = PureThy.forall_elim_vars;
clasohm@0
   353
wenzelm@18025
   354
fun outer_params t =
wenzelm@20077
   355
  let val vs = Term.strip_all_vars t
wenzelm@20077
   356
  in Name.variant_list [] (map (Name.clean o #1) vs) ~~ map #2 vs end;
wenzelm@18025
   357
wenzelm@18025
   358
(*generalize outermost parameters*)
wenzelm@18025
   359
fun gen_all th =
wenzelm@12719
   360
  let
wenzelm@18025
   361
    val {thy, prop, maxidx, ...} = Thm.rep_thm th;
wenzelm@18025
   362
    val cert = Thm.cterm_of thy;
wenzelm@18025
   363
    fun elim (x, T) = Thm.forall_elim (cert (Var ((x, maxidx + 1), T)));
wenzelm@18025
   364
  in fold elim (outer_params prop) th end;
wenzelm@18025
   365
wenzelm@18025
   366
(*lift vars wrt. outermost goal parameters
wenzelm@18118
   367
  -- reverses the effect of gen_all modulo higher-order unification*)
wenzelm@18025
   368
fun lift_all goal th =
wenzelm@18025
   369
  let
wenzelm@18025
   370
    val thy = Theory.merge (Thm.theory_of_cterm goal, Thm.theory_of_thm th);
wenzelm@18025
   371
    val cert = Thm.cterm_of thy;
wenzelm@19421
   372
    val maxidx = Thm.maxidx_of th;
wenzelm@18025
   373
    val ps = outer_params (Thm.term_of goal)
wenzelm@18025
   374
      |> map (fn (x, T) => Var ((x, maxidx + 1), Logic.incr_tvar (maxidx + 1) T));
wenzelm@18025
   375
    val Ts = map Term.fastype_of ps;
wenzelm@20298
   376
    val inst = fold_terms Term.add_vars th [] |> map (fn (xi, T) =>
wenzelm@18025
   377
      (cert (Var (xi, T)), cert (Term.list_comb (Var (xi, Ts ---> T), ps))));
wenzelm@18025
   378
  in
wenzelm@18025
   379
    th |> Thm.instantiate ([], inst)
wenzelm@18025
   380
    |> fold_rev (Thm.forall_intr o cert) ps
wenzelm@18025
   381
  end;
wenzelm@18025
   382
wenzelm@19999
   383
(*direct generalization*)
wenzelm@19999
   384
fun generalize names th = Thm.generalize names (Thm.maxidx_of th + 1) th;
wenzelm@9554
   385
wenzelm@16949
   386
(*specialization over a list of cterms*)
wenzelm@16949
   387
val forall_elim_list = fold forall_elim;
clasohm@0
   388
wenzelm@16949
   389
(*maps A1,...,An |- B  to  [| A1;...;An |] ==> B*)
wenzelm@16949
   390
val implies_intr_list = fold_rev implies_intr;
clasohm@0
   391
wenzelm@16949
   392
(*maps [| A1;...;An |] ==> B and [A1,...,An]  to  B*)
skalberg@15570
   393
fun implies_elim_list impth ths = Library.foldl (uncurry implies_elim) (impth,ths);
clasohm@0
   394
clasohm@0
   395
(*Reset Var indexes to zero, renaming to preserve distinctness*)
wenzelm@252
   396
fun zero_var_indexes th =
wenzelm@16949
   397
  let
wenzelm@16949
   398
    val thy = Thm.theory_of_thm th;
wenzelm@16949
   399
    val certT = Thm.ctyp_of thy and cert = Thm.cterm_of thy;
wenzelm@20509
   400
    val (instT, inst) = TermSubst.zero_var_indexes_inst (Thm.full_prop_of th);
wenzelm@16949
   401
    val cinstT = map (fn (v, T) => (certT (TVar v), certT T)) instT;
wenzelm@16949
   402
    val cinst = map (fn (v, t) => (cert (Var v), cert t)) inst;
wenzelm@20260
   403
  in Thm.adjust_maxidx_thm ~1 (Thm.instantiate (cinstT, cinst) th) end;
clasohm@0
   404
clasohm@0
   405
paulson@14394
   406
(** Standard form of object-rule: no hypotheses, flexflex constraints,
paulson@14394
   407
    Frees, or outer quantifiers; all generality expressed by Vars of index 0.**)
wenzelm@10515
   408
wenzelm@16595
   409
(*Discharge all hypotheses.*)
wenzelm@16595
   410
fun implies_intr_hyps th =
wenzelm@16595
   411
  fold Thm.implies_intr (#hyps (Thm.crep_thm th)) th;
wenzelm@16595
   412
paulson@14394
   413
(*Squash a theorem's flexflex constraints provided it can be done uniquely.
paulson@14394
   414
  This step can lose information.*)
paulson@14387
   415
fun flexflex_unique th =
berghofe@17713
   416
  if null (tpairs_of th) then th else
wenzelm@19861
   417
    case Seq.chop 2 (flexflex_rule th) of
paulson@14387
   418
      ([th],_) => th
paulson@14387
   419
    | ([],_)   => raise THM("flexflex_unique: impossible constraints", 0, [th])
paulson@14387
   420
    |      _   => raise THM("flexflex_unique: multiple unifiers", 0, [th]);
paulson@14387
   421
wenzelm@10515
   422
fun close_derivation thm =
wenzelm@10515
   423
  if Thm.get_name_tags thm = ("", []) then Thm.name_thm ("", thm)
wenzelm@10515
   424
  else thm;
wenzelm@10515
   425
wenzelm@16949
   426
val standard' =
wenzelm@16949
   427
  implies_intr_hyps
wenzelm@16949
   428
  #> forall_intr_frees
wenzelm@19421
   429
  #> `Thm.maxidx_of
wenzelm@16949
   430
  #-> (fn maxidx =>
wenzelm@16949
   431
    forall_elim_vars (maxidx + 1)
wenzelm@16949
   432
    #> strip_shyps_warning
wenzelm@16949
   433
    #> zero_var_indexes
wenzelm@16949
   434
    #> Thm.varifyT
wenzelm@16949
   435
    #> Thm.compress);
wenzelm@1218
   436
wenzelm@16949
   437
val standard =
wenzelm@16949
   438
  flexflex_unique
wenzelm@16949
   439
  #> standard'
wenzelm@16949
   440
  #> close_derivation;
berghofe@11512
   441
wenzelm@16949
   442
val local_standard =
wenzelm@16949
   443
  strip_shyps
wenzelm@16949
   444
  #> zero_var_indexes
wenzelm@16949
   445
  #> Thm.compress
wenzelm@16949
   446
  #> close_derivation;
wenzelm@12005
   447
clasohm@0
   448
wenzelm@8328
   449
(*Convert all Vars in a theorem to Frees.  Also return a function for
paulson@4610
   450
  reversing that operation.  DOES NOT WORK FOR TYPE VARIABLES.
paulson@4610
   451
  Similar code in type/freeze_thaw*)
paulson@15495
   452
paulson@15495
   453
fun freeze_thaw_robust th =
wenzelm@19878
   454
 let val fth = Thm.freezeT th
wenzelm@16425
   455
     val {prop, tpairs, thy, ...} = rep_thm fth
paulson@15495
   456
 in
skalberg@15574
   457
   case foldr add_term_vars [] (prop :: Thm.terms_of_tpairs tpairs) of
paulson@15495
   458
       [] => (fth, fn i => fn x => x)   (*No vars: nothing to do!*)
paulson@15495
   459
     | vars =>
paulson@19753
   460
         let fun newName (Var(ix,_)) = (ix, gensym (string_of_indexname ix))
paulson@19753
   461
             val alist = map newName vars
paulson@15495
   462
             fun mk_inst (Var(v,T)) =
wenzelm@16425
   463
                 (cterm_of thy (Var(v,T)),
haftmann@17325
   464
                  cterm_of thy (Free(((the o AList.lookup (op =) alist) v), T)))
paulson@15495
   465
             val insts = map mk_inst vars
paulson@15495
   466
             fun thaw i th' = (*i is non-negative increment for Var indexes*)
paulson@15495
   467
                 th' |> forall_intr_list (map #2 insts)
paulson@15495
   468
                     |> forall_elim_list (map (Thm.cterm_incr_indexes i o #1) insts)
paulson@15495
   469
         in  (Thm.instantiate ([],insts) fth, thaw)  end
paulson@15495
   470
 end;
paulson@15495
   471
paulson@15495
   472
(*Basic version of the function above. No option to rename Vars apart in thaw.
wenzelm@19999
   473
  The Frees created from Vars have nice names. FIXME: does not check for
paulson@19753
   474
  clashes with variables in the assumptions, so delete and use freeze_thaw_robust instead?*)
paulson@4610
   475
fun freeze_thaw th =
wenzelm@19878
   476
 let val fth = Thm.freezeT th
wenzelm@16425
   477
     val {prop, tpairs, thy, ...} = rep_thm fth
paulson@7248
   478
 in
skalberg@15574
   479
   case foldr add_term_vars [] (prop :: Thm.terms_of_tpairs tpairs) of
paulson@7248
   480
       [] => (fth, fn x => x)
paulson@7248
   481
     | vars =>
wenzelm@8328
   482
         let fun newName (Var(ix,_), (pairs,used)) =
wenzelm@20077
   483
                   let val v = Name.variant used (string_of_indexname ix)
wenzelm@8328
   484
                   in  ((ix,v)::pairs, v::used)  end;
skalberg@15574
   485
             val (alist, _) = foldr newName ([], Library.foldr add_term_names
skalberg@15574
   486
               (prop :: Thm.terms_of_tpairs tpairs, [])) vars
wenzelm@8328
   487
             fun mk_inst (Var(v,T)) =
wenzelm@16425
   488
                 (cterm_of thy (Var(v,T)),
haftmann@17325
   489
                  cterm_of thy (Free(((the o AList.lookup (op =) alist) v), T)))
wenzelm@8328
   490
             val insts = map mk_inst vars
wenzelm@8328
   491
             fun thaw th' =
wenzelm@8328
   492
                 th' |> forall_intr_list (map #2 insts)
wenzelm@8328
   493
                     |> forall_elim_list (map #1 insts)
wenzelm@8328
   494
         in  (Thm.instantiate ([],insts) fth, thaw)  end
paulson@7248
   495
 end;
paulson@4610
   496
paulson@7248
   497
(*Rotates a rule's premises to the left by k*)
paulson@7248
   498
val rotate_prems = permute_prems 0;
paulson@4610
   499
oheimb@11163
   500
(* permute prems, where the i-th position in the argument list (counting from 0)
oheimb@11163
   501
   gives the position within the original thm to be transferred to position i.
oheimb@11163
   502
   Any remaining trailing positions are left unchanged. *)
oheimb@11163
   503
val rearrange_prems = let
oheimb@11163
   504
  fun rearr new []      thm = thm
wenzelm@11815
   505
  |   rearr new (p::ps) thm = rearr (new+1)
oheimb@11163
   506
     (map (fn q => if new<=q andalso q<p then q+1 else q) ps)
oheimb@11163
   507
     (permute_prems (new+1) (new-p) (permute_prems new (p-new) thm))
oheimb@11163
   508
  in rearr 0 end;
paulson@4610
   509
wenzelm@252
   510
(*Resolution: exactly one resolvent must be produced.*)
clasohm@0
   511
fun tha RSN (i,thb) =
wenzelm@19861
   512
  case Seq.chop 2 (biresolution false [(false,tha)] i thb) of
clasohm@0
   513
      ([th],_) => th
clasohm@0
   514
    | ([],_)   => raise THM("RSN: no unifiers", i, [tha,thb])
clasohm@0
   515
    |      _   => raise THM("RSN: multiple unifiers", i, [tha,thb]);
clasohm@0
   516
clasohm@0
   517
(*resolution: P==>Q, Q==>R gives P==>R. *)
clasohm@0
   518
fun tha RS thb = tha RSN (1,thb);
clasohm@0
   519
clasohm@0
   520
(*For joining lists of rules*)
wenzelm@252
   521
fun thas RLN (i,thbs) =
clasohm@0
   522
  let val resolve = biresolution false (map (pair false) thas) i
wenzelm@4270
   523
      fun resb thb = Seq.list_of (resolve thb) handle THM _ => []
wenzelm@19482
   524
  in maps resb thbs end;
clasohm@0
   525
clasohm@0
   526
fun thas RL thbs = thas RLN (1,thbs);
clasohm@0
   527
lcp@11
   528
(*Resolve a list of rules against bottom_rl from right to left;
lcp@11
   529
  makes proof trees*)
wenzelm@252
   530
fun rls MRS bottom_rl =
lcp@11
   531
  let fun rs_aux i [] = bottom_rl
wenzelm@252
   532
        | rs_aux i (rl::rls) = rl RSN (i, rs_aux (i+1) rls)
lcp@11
   533
  in  rs_aux 1 rls  end;
lcp@11
   534
lcp@11
   535
(*As above, but for rule lists*)
wenzelm@252
   536
fun rlss MRL bottom_rls =
lcp@11
   537
  let fun rs_aux i [] = bottom_rls
wenzelm@252
   538
        | rs_aux i (rls::rlss) = rls RLN (i, rs_aux (i+1) rlss)
lcp@11
   539
  in  rs_aux 1 rlss  end;
lcp@11
   540
wenzelm@9288
   541
(*A version of MRS with more appropriate argument order*)
wenzelm@9288
   542
fun bottom_rl OF rls = rls MRS bottom_rl;
wenzelm@9288
   543
wenzelm@252
   544
(*compose Q and [...,Qi,Q(i+1),...]==>R to [...,Q(i+1),...]==>R
clasohm@0
   545
  with no lifting or renaming!  Q may contain ==> or meta-quants
clasohm@0
   546
  ALWAYS deletes premise i *)
wenzelm@252
   547
fun compose(tha,i,thb) =
wenzelm@4270
   548
    Seq.list_of (bicompose false (false,tha,0) i thb);
clasohm@0
   549
wenzelm@6946
   550
fun compose_single (tha,i,thb) =
wenzelm@6946
   551
  (case compose (tha,i,thb) of
wenzelm@6946
   552
    [th] => th
wenzelm@6946
   553
  | _ => raise THM ("compose: unique result expected", i, [tha,thb]));
wenzelm@6946
   554
clasohm@0
   555
(*compose Q and [Q1,Q2,...,Qk]==>R to [Q2,...,Qk]==>R getting unique result*)
clasohm@0
   556
fun tha COMP thb =
clasohm@0
   557
    case compose(tha,1,thb) of
wenzelm@252
   558
        [th] => th
clasohm@0
   559
      | _ =>   raise THM("COMP", 1, [tha,thb]);
clasohm@0
   560
wenzelm@13105
   561
wenzelm@4016
   562
(** theorem equality **)
clasohm@0
   563
wenzelm@16425
   564
(*True if the two theorems have the same theory.*)
wenzelm@16425
   565
val eq_thm_thy = eq_thy o pairself Thm.theory_of_thm;
paulson@13650
   566
paulson@13650
   567
(*True if the two theorems have the same prop field, ignoring hyps, der, etc.*)
wenzelm@16720
   568
val eq_thm_prop = op aconv o pairself Thm.full_prop_of;
clasohm@0
   569
clasohm@0
   570
(*Useful "distance" function for BEST_FIRST*)
wenzelm@16720
   571
val size_of_thm = size_of_term o Thm.full_prop_of;
clasohm@0
   572
wenzelm@9829
   573
(*maintain lists of theorems --- preserving canonical order*)
wenzelm@18922
   574
val del_rule = remove eq_thm_prop;
wenzelm@18922
   575
fun add_rule th = cons th o del_rule th;
wenzelm@18922
   576
val merge_rules = Library.merge eq_thm_prop;
wenzelm@9829
   577
wenzelm@19878
   578
(*pattern equivalence*)
wenzelm@19878
   579
fun equiv_thm ths =
wenzelm@19878
   580
  Pattern.equiv (Theory.merge (pairself Thm.theory_of_thm ths)) (pairself Thm.full_prop_of ths);
lcp@1194
   581
lcp@1194
   582
clasohm@0
   583
(*** Meta-Rewriting Rules ***)
clasohm@0
   584
wenzelm@16425
   585
fun read_prop s = read_cterm ProtoPure.thy (s, propT);
paulson@4610
   586
wenzelm@9455
   587
fun store_thm name thm = hd (PureThy.smart_store_thms (name, [thm]));
wenzelm@9455
   588
fun store_standard_thm name thm = store_thm name (standard thm);
wenzelm@12135
   589
fun store_thm_open name thm = hd (PureThy.smart_store_thms_open (name, [thm]));
wenzelm@12135
   590
fun store_standard_thm_open name thm = store_thm_open name (standard' thm);
wenzelm@4016
   591
clasohm@0
   592
val reflexive_thm =
wenzelm@19421
   593
  let val cx = cert (Var(("x",0),TVar(("'a",0),[])))
wenzelm@12135
   594
  in store_standard_thm_open "reflexive" (Thm.reflexive cx) end;
clasohm@0
   595
clasohm@0
   596
val symmetric_thm =
wenzelm@14854
   597
  let val xy = read_prop "x == y"
wenzelm@16595
   598
  in store_standard_thm_open "symmetric" (Thm.implies_intr xy (Thm.symmetric (Thm.assume xy))) end;
clasohm@0
   599
clasohm@0
   600
val transitive_thm =
wenzelm@14854
   601
  let val xy = read_prop "x == y"
wenzelm@14854
   602
      val yz = read_prop "y == z"
clasohm@0
   603
      val xythm = Thm.assume xy and yzthm = Thm.assume yz
wenzelm@12135
   604
  in store_standard_thm_open "transitive" (Thm.implies_intr yz (Thm.transitive xythm yzthm)) end;
clasohm@0
   605
nipkow@4679
   606
fun symmetric_fun thm = thm RS symmetric_thm;
nipkow@4679
   607
berghofe@11512
   608
fun extensional eq =
berghofe@11512
   609
  let val eq' =
wenzelm@20579
   610
    abstract_rule "x" (Thm.dest_arg (fst (dest_equals (cprop_of eq)))) eq
berghofe@11512
   611
  in equal_elim (eta_conversion (cprop_of eq')) eq' end;
berghofe@11512
   612
wenzelm@18820
   613
val equals_cong =
wenzelm@18820
   614
  store_standard_thm_open "equals_cong" (Thm.reflexive (read_prop "x == y"));
wenzelm@18820
   615
berghofe@10414
   616
val imp_cong =
berghofe@10414
   617
  let
berghofe@10414
   618
    val ABC = read_prop "PROP A ==> PROP B == PROP C"
berghofe@10414
   619
    val AB = read_prop "PROP A ==> PROP B"
berghofe@10414
   620
    val AC = read_prop "PROP A ==> PROP C"
berghofe@10414
   621
    val A = read_prop "PROP A"
berghofe@10414
   622
  in
wenzelm@12135
   623
    store_standard_thm_open "imp_cong" (implies_intr ABC (equal_intr
berghofe@10414
   624
      (implies_intr AB (implies_intr A
berghofe@10414
   625
        (equal_elim (implies_elim (assume ABC) (assume A))
berghofe@10414
   626
          (implies_elim (assume AB) (assume A)))))
berghofe@10414
   627
      (implies_intr AC (implies_intr A
berghofe@10414
   628
        (equal_elim (symmetric (implies_elim (assume ABC) (assume A)))
berghofe@10414
   629
          (implies_elim (assume AC) (assume A)))))))
berghofe@10414
   630
  end;
berghofe@10414
   631
berghofe@10414
   632
val swap_prems_eq =
berghofe@10414
   633
  let
berghofe@10414
   634
    val ABC = read_prop "PROP A ==> PROP B ==> PROP C"
berghofe@10414
   635
    val BAC = read_prop "PROP B ==> PROP A ==> PROP C"
berghofe@10414
   636
    val A = read_prop "PROP A"
berghofe@10414
   637
    val B = read_prop "PROP B"
berghofe@10414
   638
  in
wenzelm@12135
   639
    store_standard_thm_open "swap_prems_eq" (equal_intr
berghofe@10414
   640
      (implies_intr ABC (implies_intr B (implies_intr A
berghofe@10414
   641
        (implies_elim (implies_elim (assume ABC) (assume A)) (assume B)))))
berghofe@10414
   642
      (implies_intr BAC (implies_intr A (implies_intr B
berghofe@10414
   643
        (implies_elim (implies_elim (assume BAC) (assume B)) (assume A))))))
berghofe@10414
   644
  end;
lcp@229
   645
wenzelm@18468
   646
val imp_cong_rule = combination o combination (reflexive implies);
clasohm@0
   647
skalberg@15001
   648
local
skalberg@15001
   649
  val dest_eq = dest_equals o cprop_of
skalberg@15001
   650
  val rhs_of = snd o dest_eq
skalberg@15001
   651
in
skalberg@15001
   652
fun beta_eta_conversion t =
skalberg@15001
   653
  let val thm = beta_conversion true t
skalberg@15001
   654
  in transitive thm (eta_conversion (rhs_of thm)) end
skalberg@15001
   655
end;
skalberg@15001
   656
berghofe@15925
   657
fun eta_long_conversion ct = transitive (beta_eta_conversion ct)
berghofe@15925
   658
  (symmetric (beta_eta_conversion (cterm_fun (Pattern.eta_long []) ct)));
berghofe@15925
   659
wenzelm@18337
   660
val abs_def =
wenzelm@18337
   661
  let
wenzelm@18337
   662
    fun contract_lhs th =
wenzelm@18337
   663
      Thm.transitive (Thm.symmetric (beta_eta_conversion (fst (dest_equals (cprop_of th))))) th;
wenzelm@18777
   664
    fun abstract cx th = Thm.abstract_rule
wenzelm@18777
   665
        (case Thm.term_of cx of Var ((x, _), _) => x | Free (x, _) => x | _ => "x") cx th
wenzelm@18777
   666
      handle THM _ => raise THM ("Malformed definitional equation", 0, [th]);
wenzelm@18337
   667
  in
wenzelm@18337
   668
    contract_lhs
wenzelm@18337
   669
    #> `(snd o strip_comb o fst o dest_equals o cprop_of)
wenzelm@18337
   670
    #-> fold_rev abstract
wenzelm@18337
   671
    #> contract_lhs
wenzelm@18337
   672
  end;
wenzelm@18337
   673
wenzelm@18468
   674
(*rewrite B in !!x1 ... xn. B*)
wenzelm@18251
   675
fun forall_conv 0 cv ct = cv ct
wenzelm@18251
   676
  | forall_conv n cv ct =
wenzelm@18468
   677
      (case try Thm.dest_comb ct of
wenzelm@18468
   678
        NONE => cv ct
wenzelm@18468
   679
      | SOME (A, B) =>
wenzelm@18468
   680
          (case (term_of A, term_of B) of
wenzelm@18468
   681
            (Const ("all", _), Abs (x, _, _)) =>
wenzelm@18468
   682
              let val (v, B') = Thm.dest_abs (SOME (gensym "all_")) B in
wenzelm@18468
   683
                Thm.combination (Thm.reflexive A)
wenzelm@18468
   684
                  (Thm.abstract_rule x v (forall_conv (n - 1) cv B'))
wenzelm@18468
   685
              end
wenzelm@18468
   686
          | _ => cv ct));
wenzelm@18468
   687
wenzelm@18468
   688
(*rewrite B in A1 ==> ... ==> An ==> B*)
wenzelm@18468
   689
fun concl_conv 0 cv ct = cv ct
wenzelm@18468
   690
  | concl_conv n cv ct =
wenzelm@18468
   691
      (case try dest_implies ct of
wenzelm@18468
   692
        NONE => cv ct
wenzelm@18468
   693
      | SOME (A, B) => imp_cong_rule (reflexive A) (concl_conv (n - 1) cv B));
skalberg@15001
   694
wenzelm@18468
   695
(*rewrite the A's in A1 ==> ... ==> An ==> B*)
wenzelm@18468
   696
fun prems_conv 0 _ = reflexive
wenzelm@18468
   697
  | prems_conv n cv =
wenzelm@18468
   698
      let
wenzelm@18468
   699
        fun conv i ct =
wenzelm@18468
   700
          if i = n + 1 then reflexive ct
wenzelm@18468
   701
          else
wenzelm@18468
   702
            (case try dest_implies ct of
wenzelm@18468
   703
              NONE => reflexive ct
wenzelm@18468
   704
            | SOME (A, B) => imp_cong_rule (cv i A) (conv (i + 1) B));
wenzelm@18468
   705
  in conv 1 end;
wenzelm@18468
   706
wenzelm@18468
   707
fun goals_conv pred cv = prems_conv ~1 (fn i => if pred i then cv else reflexive);
skalberg@15001
   708
fun fconv_rule cv th = equal_elim (cv (cprop_of th)) th;
skalberg@15001
   709
wenzelm@18468
   710
wenzelm@15669
   711
(*** Some useful meta-theorems ***)
clasohm@0
   712
clasohm@0
   713
(*The rule V/V, obtains assumption solving for eresolve_tac*)
wenzelm@12135
   714
val asm_rl = store_standard_thm_open "asm_rl" (Thm.trivial (read_prop "PROP ?psi"));
wenzelm@7380
   715
val _ = store_thm "_" asm_rl;
clasohm@0
   716
clasohm@0
   717
(*Meta-level cut rule: [| V==>W; V |] ==> W *)
wenzelm@4016
   718
val cut_rl =
wenzelm@12135
   719
  store_standard_thm_open "cut_rl"
wenzelm@9455
   720
    (Thm.trivial (read_prop "PROP ?psi ==> PROP ?theta"));
clasohm@0
   721
wenzelm@252
   722
(*Generalized elim rule for one conclusion; cut_rl with reversed premises:
clasohm@0
   723
     [| PROP V;  PROP V ==> PROP W |] ==> PROP W *)
clasohm@0
   724
val revcut_rl =
paulson@4610
   725
  let val V = read_prop "PROP V"
paulson@4610
   726
      and VW = read_prop "PROP V ==> PROP W";
wenzelm@4016
   727
  in
wenzelm@12135
   728
    store_standard_thm_open "revcut_rl"
wenzelm@4016
   729
      (implies_intr V (implies_intr VW (implies_elim (assume VW) (assume V))))
clasohm@0
   730
  end;
clasohm@0
   731
lcp@668
   732
(*for deleting an unwanted assumption*)
lcp@668
   733
val thin_rl =
paulson@4610
   734
  let val V = read_prop "PROP V"
paulson@4610
   735
      and W = read_prop "PROP W";
wenzelm@12135
   736
  in store_standard_thm_open "thin_rl" (implies_intr V (implies_intr W (assume W))) end;
lcp@668
   737
clasohm@0
   738
(* (!!x. PROP ?V) == PROP ?V       Allows removal of redundant parameters*)
clasohm@0
   739
val triv_forall_equality =
paulson@4610
   740
  let val V  = read_prop "PROP V"
paulson@4610
   741
      and QV = read_prop "!!x::'a. PROP V"
wenzelm@19421
   742
      and x  = cert (Free ("x", Term.aT []));
wenzelm@4016
   743
  in
wenzelm@12135
   744
    store_standard_thm_open "triv_forall_equality"
berghofe@11512
   745
      (equal_intr (implies_intr QV (forall_elim x (assume QV)))
berghofe@11512
   746
        (implies_intr V  (forall_intr x (assume V))))
clasohm@0
   747
  end;
clasohm@0
   748
wenzelm@19051
   749
(* (PROP ?Phi ==> PROP ?Phi ==> PROP ?Psi) ==>
wenzelm@19051
   750
   (PROP ?Phi ==> PROP ?Psi)
wenzelm@19051
   751
*)
wenzelm@19051
   752
val distinct_prems_rl =
wenzelm@19051
   753
  let
wenzelm@19051
   754
    val AAB = read_prop "PROP Phi ==> PROP Phi ==> PROP Psi"
wenzelm@19051
   755
    val A = read_prop "PROP Phi";
wenzelm@19051
   756
  in
wenzelm@19051
   757
    store_standard_thm_open "distinct_prems_rl"
wenzelm@19051
   758
      (implies_intr_list [AAB, A] (implies_elim_list (assume AAB) [assume A, assume A]))
wenzelm@19051
   759
  end;
wenzelm@19051
   760
nipkow@1756
   761
(* (PROP ?PhiA ==> PROP ?PhiB ==> PROP ?Psi) ==>
nipkow@1756
   762
   (PROP ?PhiB ==> PROP ?PhiA ==> PROP ?Psi)
nipkow@1756
   763
   `thm COMP swap_prems_rl' swaps the first two premises of `thm'
nipkow@1756
   764
*)
nipkow@1756
   765
val swap_prems_rl =
paulson@4610
   766
  let val cmajor = read_prop "PROP PhiA ==> PROP PhiB ==> PROP Psi";
nipkow@1756
   767
      val major = assume cmajor;
paulson@4610
   768
      val cminor1 = read_prop "PROP PhiA";
nipkow@1756
   769
      val minor1 = assume cminor1;
paulson@4610
   770
      val cminor2 = read_prop "PROP PhiB";
nipkow@1756
   771
      val minor2 = assume cminor2;
wenzelm@12135
   772
  in store_standard_thm_open "swap_prems_rl"
nipkow@1756
   773
       (implies_intr cmajor (implies_intr cminor2 (implies_intr cminor1
nipkow@1756
   774
         (implies_elim (implies_elim major minor1) minor2))))
nipkow@1756
   775
  end;
nipkow@1756
   776
nipkow@3653
   777
(* [| PROP ?phi ==> PROP ?psi; PROP ?psi ==> PROP ?phi |]
nipkow@3653
   778
   ==> PROP ?phi == PROP ?psi
wenzelm@8328
   779
   Introduction rule for == as a meta-theorem.
nipkow@3653
   780
*)
nipkow@3653
   781
val equal_intr_rule =
paulson@4610
   782
  let val PQ = read_prop "PROP phi ==> PROP psi"
paulson@4610
   783
      and QP = read_prop "PROP psi ==> PROP phi"
wenzelm@4016
   784
  in
wenzelm@12135
   785
    store_standard_thm_open "equal_intr_rule"
wenzelm@4016
   786
      (implies_intr PQ (implies_intr QP (equal_intr (assume PQ) (assume QP))))
nipkow@3653
   787
  end;
nipkow@3653
   788
wenzelm@19421
   789
(* PROP ?phi == PROP ?psi ==> PROP ?phi ==> PROP ?psi *)
wenzelm@13368
   790
val equal_elim_rule1 =
wenzelm@13368
   791
  let val eq = read_prop "PROP phi == PROP psi"
wenzelm@13368
   792
      and P = read_prop "PROP phi"
wenzelm@13368
   793
  in store_standard_thm_open "equal_elim_rule1"
wenzelm@13368
   794
    (Thm.equal_elim (assume eq) (assume P) |> implies_intr_list [eq, P])
wenzelm@13368
   795
  end;
wenzelm@4285
   796
wenzelm@19421
   797
(* PROP ?psi == PROP ?phi ==> PROP ?phi ==> PROP ?psi *)
wenzelm@19421
   798
val equal_elim_rule2 =
wenzelm@19421
   799
  store_standard_thm_open "equal_elim_rule2" (symmetric_thm RS equal_elim_rule1);
wenzelm@19421
   800
wenzelm@12297
   801
(* "[| PROP ?phi; PROP ?phi; PROP ?psi |] ==> PROP ?psi" *)
wenzelm@12297
   802
val remdups_rl =
wenzelm@12297
   803
  let val P = read_prop "PROP phi" and Q = read_prop "PROP psi";
wenzelm@12297
   804
  in store_standard_thm_open "remdups_rl" (implies_intr_list [P, P, Q] (Thm.assume Q)) end;
wenzelm@12297
   805
wenzelm@12297
   806
wenzelm@9554
   807
(*(PROP ?phi ==> (!!x. PROP ?psi(x))) == (!!x. PROP ?phi ==> PROP ?psi(x))
wenzelm@12297
   808
  Rewrite rule for HHF normalization.*)
wenzelm@9554
   809
wenzelm@9554
   810
val norm_hhf_eq =
wenzelm@9554
   811
  let
wenzelm@14854
   812
    val aT = TFree ("'a", []);
wenzelm@9554
   813
    val all = Term.all aT;
wenzelm@9554
   814
    val x = Free ("x", aT);
wenzelm@9554
   815
    val phi = Free ("phi", propT);
wenzelm@9554
   816
    val psi = Free ("psi", aT --> propT);
wenzelm@9554
   817
wenzelm@9554
   818
    val cx = cert x;
wenzelm@9554
   819
    val cphi = cert phi;
wenzelm@9554
   820
    val lhs = cert (Logic.mk_implies (phi, all $ Abs ("x", aT, psi $ Bound 0)));
wenzelm@9554
   821
    val rhs = cert (all $ Abs ("x", aT, Logic.mk_implies (phi, psi $ Bound 0)));
wenzelm@9554
   822
  in
wenzelm@9554
   823
    Thm.equal_intr
wenzelm@9554
   824
      (Thm.implies_elim (Thm.assume lhs) (Thm.assume cphi)
wenzelm@9554
   825
        |> Thm.forall_elim cx
wenzelm@9554
   826
        |> Thm.implies_intr cphi
wenzelm@9554
   827
        |> Thm.forall_intr cx
wenzelm@9554
   828
        |> Thm.implies_intr lhs)
wenzelm@9554
   829
      (Thm.implies_elim
wenzelm@9554
   830
          (Thm.assume rhs |> Thm.forall_elim cx) (Thm.assume cphi)
wenzelm@9554
   831
        |> Thm.forall_intr cx
wenzelm@9554
   832
        |> Thm.implies_intr cphi
wenzelm@9554
   833
        |> Thm.implies_intr rhs)
wenzelm@12135
   834
    |> store_standard_thm_open "norm_hhf_eq"
wenzelm@9554
   835
  end;
wenzelm@9554
   836
wenzelm@18179
   837
val norm_hhf_prop = Logic.dest_equals (Thm.prop_of norm_hhf_eq);
wenzelm@18179
   838
wenzelm@12800
   839
fun is_norm_hhf tm =
wenzelm@12800
   840
  let
wenzelm@12800
   841
    fun is_norm (Const ("==>", _) $ _ $ (Const ("all", _) $ _)) = false
wenzelm@12800
   842
      | is_norm (t $ u) = is_norm t andalso is_norm u
wenzelm@12800
   843
      | is_norm (Abs (_, _, t)) = is_norm t
wenzelm@12800
   844
      | is_norm _ = true;
wenzelm@18929
   845
  in is_norm (Envir.beta_eta_contract tm) end;
wenzelm@12800
   846
wenzelm@16425
   847
fun norm_hhf thy t =
wenzelm@12800
   848
  if is_norm_hhf t then t
wenzelm@18179
   849
  else Pattern.rewrite_term thy [norm_hhf_prop] [] t;
wenzelm@18179
   850
wenzelm@20298
   851
fun norm_hhf_cterm ct =
wenzelm@20298
   852
  if is_norm_hhf (Thm.term_of ct) then ct
wenzelm@20298
   853
  else cterm_fun (Pattern.rewrite_term (Thm.theory_of_cterm ct) [norm_hhf_prop] []) ct;
wenzelm@20298
   854
wenzelm@12800
   855
wenzelm@9554
   856
wenzelm@16425
   857
(*** Instantiate theorem th, reading instantiations in theory thy ****)
paulson@8129
   858
paulson@8129
   859
(*Version that normalizes the result: Thm.instantiate no longer does that*)
paulson@8129
   860
fun instantiate instpair th = Thm.instantiate instpair th  COMP   asm_rl;
paulson@8129
   861
wenzelm@16425
   862
fun read_instantiate_sg' thy sinsts th =
paulson@8129
   863
    let val ts = types_sorts th;
wenzelm@15669
   864
        val used = add_used th [];
wenzelm@16425
   865
    in  instantiate (read_insts thy ts ts used sinsts) th  end;
berghofe@15797
   866
wenzelm@16425
   867
fun read_instantiate_sg thy sinsts th =
wenzelm@20298
   868
  read_instantiate_sg' thy (map (apfst Syntax.read_indexname) sinsts) th;
paulson@8129
   869
paulson@8129
   870
(*Instantiate theorem th, reading instantiations under theory of th*)
paulson@8129
   871
fun read_instantiate sinsts th =
wenzelm@16425
   872
    read_instantiate_sg (Thm.theory_of_thm th) sinsts th;
paulson@8129
   873
berghofe@15797
   874
fun read_instantiate' sinsts th =
wenzelm@16425
   875
    read_instantiate_sg' (Thm.theory_of_thm th) sinsts th;
berghofe@15797
   876
paulson@8129
   877
paulson@8129
   878
(*Left-to-right replacements: tpairs = [...,(vi,ti),...].
paulson@8129
   879
  Instantiates distinct Vars by terms, inferring type instantiations. *)
paulson@8129
   880
local
wenzelm@16425
   881
  fun add_types ((ct,cu), (thy,tye,maxidx)) =
wenzelm@16425
   882
    let val {thy=thyt, t=t, T= T, maxidx=maxt,...} = rep_cterm ct
wenzelm@16425
   883
        and {thy=thyu, t=u, T= U, maxidx=maxu,...} = rep_cterm cu;
paulson@8129
   884
        val maxi = Int.max(maxidx, Int.max(maxt, maxu));
wenzelm@16425
   885
        val thy' = Theory.merge(thy, Theory.merge(thyt, thyu))
wenzelm@16949
   886
        val (tye',maxi') = Sign.typ_unify thy' (T, U) (tye, maxi)
wenzelm@10403
   887
          handle Type.TUNIFY => raise TYPE("Ill-typed instantiation", [T,U], [t,u])
wenzelm@16425
   888
    in  (thy', tye', maxi')  end;
paulson@8129
   889
in
paulson@8129
   890
fun cterm_instantiate ctpairs0 th =
wenzelm@16425
   891
  let val (thy,tye,_) = foldr add_types (Thm.theory_of_thm th, Vartab.empty, 0) ctpairs0
wenzelm@18179
   892
      fun instT(ct,cu) =
wenzelm@16425
   893
        let val inst = cterm_of thy o Envir.subst_TVars tye o term_of
paulson@14340
   894
        in (inst ct, inst cu) end
wenzelm@16425
   895
      fun ctyp2 (ixn, (S, T)) = (ctyp_of thy (TVar (ixn, S)), ctyp_of thy T)
berghofe@8406
   896
  in  instantiate (map ctyp2 (Vartab.dest tye), map instT ctpairs0) th  end
paulson@8129
   897
  handle TERM _ =>
wenzelm@16425
   898
           raise THM("cterm_instantiate: incompatible theories",0,[th])
paulson@8129
   899
       | TYPE (msg, _, _) => raise THM(msg, 0, [th])
paulson@8129
   900
end;
paulson@8129
   901
paulson@8129
   902
wenzelm@19878
   903
(* global schematic variables *)
wenzelm@19878
   904
wenzelm@19878
   905
fun unvarify th =
wenzelm@19878
   906
  let
wenzelm@19878
   907
    val thy = Thm.theory_of_thm th;
wenzelm@19878
   908
    val cert = Thm.cterm_of thy;
wenzelm@19878
   909
    val certT = Thm.ctyp_of thy;
wenzelm@19878
   910
wenzelm@19878
   911
    val prop = Thm.full_prop_of th;
wenzelm@19878
   912
    val _ = map Logic.unvarify (prop :: Thm.hyps_of th)
wenzelm@19878
   913
      handle TERM (msg, _) => raise THM (msg, 0, [th]);
wenzelm@19878
   914
wenzelm@19878
   915
    val instT0 = rev (Term.add_tvars prop []) |> map (fn v as ((a, _), S) => (v, TFree (a, S)));
wenzelm@19878
   916
    val instT = map (fn (v, T) => (certT (TVar v), certT T)) instT0;
wenzelm@19878
   917
    val inst = rev (Term.add_vars prop []) |> map (fn ((a, i), T) =>
wenzelm@20509
   918
      let val T' = TermSubst.instantiateT instT0 T
wenzelm@19878
   919
      in (cert (Var ((a, i), T')), cert (Free ((a, T')))) end);
wenzelm@19878
   920
  in Thm.instantiate (instT, inst) th end;
wenzelm@19878
   921
wenzelm@19878
   922
wenzelm@19775
   923
(** protected propositions and embedded terms **)
wenzelm@4789
   924
wenzelm@4789
   925
local
wenzelm@18025
   926
  val A = cert (Free ("A", propT));
wenzelm@19878
   927
  val prop_def = unvarify ProtoPure.prop_def;
wenzelm@19878
   928
  val term_def = unvarify ProtoPure.term_def;
wenzelm@4789
   929
in
wenzelm@18025
   930
  val protect = Thm.capply (cert Logic.protectC);
wenzelm@18799
   931
  val protectI = store_thm "protectI" (PureThy.kind_rule PureThy.internalK (standard
wenzelm@18025
   932
      (Thm.equal_elim (Thm.symmetric prop_def) (Thm.assume A))));
wenzelm@18799
   933
  val protectD = store_thm "protectD" (PureThy.kind_rule PureThy.internalK (standard
wenzelm@18025
   934
      (Thm.equal_elim prop_def (Thm.assume (protect A)))));
wenzelm@18179
   935
  val protect_cong = store_standard_thm_open "protect_cong" (Thm.reflexive (protect A));
wenzelm@19775
   936
wenzelm@19775
   937
  val termI = store_thm "termI" (PureThy.kind_rule PureThy.internalK (standard
wenzelm@19775
   938
      (Thm.equal_elim (Thm.symmetric term_def) (Thm.forall_intr A (Thm.trivial A)))));
wenzelm@4789
   939
end;
wenzelm@4789
   940
wenzelm@18025
   941
fun implies_intr_protected asms th =
wenzelm@18118
   942
  let val asms' = map protect asms in
wenzelm@18118
   943
    implies_elim_list
wenzelm@18118
   944
      (implies_intr_list asms th)
wenzelm@18118
   945
      (map (fn asm' => Thm.assume asm' RS protectD) asms')
wenzelm@18118
   946
    |> implies_intr_list asms'
wenzelm@18118
   947
  end;
wenzelm@11815
   948
wenzelm@19775
   949
fun mk_term ct =
wenzelm@19775
   950
  let
wenzelm@19775
   951
    val {thy, T, ...} = Thm.rep_cterm ct;
wenzelm@19775
   952
    val cert = Thm.cterm_of thy;
wenzelm@19775
   953
    val certT = Thm.ctyp_of thy;
wenzelm@19775
   954
    val a = certT (TVar (("'a", 0), []));
wenzelm@19775
   955
    val x = cert (Var (("x", 0), T));
wenzelm@19775
   956
  in Thm.instantiate ([(a, certT T)], [(x, ct)]) termI end;
wenzelm@19775
   957
wenzelm@19775
   958
fun dest_term th =
wenzelm@19775
   959
  let val cprop = Thm.cprop_of th in
wenzelm@19775
   960
    if can Logic.dest_term (Thm.term_of cprop) then
wenzelm@20579
   961
      Thm.dest_arg cprop
wenzelm@19775
   962
    else raise THM ("dest_term", 0, [th])
wenzelm@19775
   963
  end;
wenzelm@19775
   964
wenzelm@19775
   965
wenzelm@4789
   966
wenzelm@5688
   967
(** variations on instantiate **)
wenzelm@4285
   968
paulson@8550
   969
(*shorthand for instantiating just one variable in the current theory*)
wenzelm@16425
   970
fun inst x t = read_instantiate_sg (the_context()) [(x,t)];
paulson@8550
   971
paulson@8550
   972
wenzelm@4285
   973
(* instantiate by left-to-right occurrence of variables *)
wenzelm@4285
   974
wenzelm@4285
   975
fun instantiate' cTs cts thm =
wenzelm@4285
   976
  let
wenzelm@4285
   977
    fun err msg =
wenzelm@4285
   978
      raise TYPE ("instantiate': " ^ msg,
wenzelm@19482
   979
        map_filter (Option.map Thm.typ_of) cTs,
wenzelm@19482
   980
        map_filter (Option.map Thm.term_of) cts);
wenzelm@4285
   981
wenzelm@4285
   982
    fun inst_of (v, ct) =
wenzelm@16425
   983
      (Thm.cterm_of (Thm.theory_of_cterm ct) (Var v), ct)
wenzelm@4285
   984
        handle TYPE (msg, _, _) => err msg;
wenzelm@4285
   985
berghofe@15797
   986
    fun tyinst_of (v, cT) =
wenzelm@16425
   987
      (Thm.ctyp_of (Thm.theory_of_ctyp cT) (TVar v), cT)
berghofe@15797
   988
        handle TYPE (msg, _, _) => err msg;
berghofe@15797
   989
wenzelm@20298
   990
    fun zip_vars xs ys =
wenzelm@20298
   991
      zip_options xs ys handle Library.UnequalLengths =>
wenzelm@20298
   992
        err "more instantiations than variables in thm";
wenzelm@4285
   993
wenzelm@4285
   994
    (*instantiate types first!*)
wenzelm@4285
   995
    val thm' =
wenzelm@4285
   996
      if forall is_none cTs then thm
wenzelm@20298
   997
      else Thm.instantiate
wenzelm@20298
   998
        (map tyinst_of (zip_vars (rev (fold_terms Term.add_tvars thm [])) cTs), []) thm;
wenzelm@20579
   999
    val thm'' =
wenzelm@4285
  1000
      if forall is_none cts then thm'
wenzelm@20298
  1001
      else Thm.instantiate
wenzelm@20298
  1002
        ([], map inst_of (zip_vars (rev (fold_terms Term.add_vars thm' [])) cts)) thm';
wenzelm@20298
  1003
    in thm'' end;
wenzelm@4285
  1004
wenzelm@4285
  1005
berghofe@14081
  1006
berghofe@14081
  1007
(** renaming of bound variables **)
berghofe@14081
  1008
berghofe@14081
  1009
(* replace bound variables x_i in thm by y_i *)
berghofe@14081
  1010
(* where vs = [(x_1, y_1), ..., (x_n, y_n)]  *)
berghofe@14081
  1011
berghofe@14081
  1012
fun rename_bvars [] thm = thm
berghofe@14081
  1013
  | rename_bvars vs thm =
berghofe@14081
  1014
    let
wenzelm@16425
  1015
      val {thy, prop, ...} = rep_thm thm;
haftmann@17325
  1016
      fun ren (Abs (x, T, t)) = Abs (AList.lookup (op =) vs x |> the_default x, T, ren t)
berghofe@14081
  1017
        | ren (t $ u) = ren t $ ren u
berghofe@14081
  1018
        | ren t = t;
wenzelm@16425
  1019
    in equal_elim (reflexive (cterm_of thy (ren prop))) thm end;
berghofe@14081
  1020
berghofe@14081
  1021
berghofe@14081
  1022
(* renaming in left-to-right order *)
berghofe@14081
  1023
berghofe@14081
  1024
fun rename_bvars' xs thm =
berghofe@14081
  1025
  let
wenzelm@16425
  1026
    val {thy, prop, ...} = rep_thm thm;
berghofe@14081
  1027
    fun rename [] t = ([], t)
berghofe@14081
  1028
      | rename (x' :: xs) (Abs (x, T, t)) =
berghofe@14081
  1029
          let val (xs', t') = rename xs t
wenzelm@18929
  1030
          in (xs', Abs (the_default x x', T, t')) end
berghofe@14081
  1031
      | rename xs (t $ u) =
berghofe@14081
  1032
          let
berghofe@14081
  1033
            val (xs', t') = rename xs t;
berghofe@14081
  1034
            val (xs'', u') = rename xs' u
berghofe@14081
  1035
          in (xs'', t' $ u') end
berghofe@14081
  1036
      | rename xs t = (xs, t);
berghofe@14081
  1037
  in case rename xs prop of
wenzelm@16425
  1038
      ([], prop') => equal_elim (reflexive (cterm_of thy prop')) thm
berghofe@14081
  1039
    | _ => error "More names than abstractions in theorem"
berghofe@14081
  1040
  end;
berghofe@14081
  1041
berghofe@14081
  1042
wenzelm@19906
  1043
(* var indexes *)
wenzelm@6435
  1044
wenzelm@19421
  1045
fun incr_indexes th = Thm.incr_indexes (Thm.maxidx_of th + 1);
wenzelm@18025
  1046
wenzelm@19124
  1047
fun incr_indexes2 th1 th2 =
wenzelm@19421
  1048
  Thm.incr_indexes (Int.max (Thm.maxidx_of th1, Thm.maxidx_of th2) + 1);
wenzelm@6435
  1049
wenzelm@6435
  1050
wenzelm@11975
  1051
wenzelm@18225
  1052
(** multi_resolve **)
wenzelm@18225
  1053
wenzelm@18225
  1054
local
wenzelm@18225
  1055
wenzelm@18225
  1056
fun res th i rule =
wenzelm@18225
  1057
  Thm.biresolution false [(false, th)] i rule handle THM _ => Seq.empty;
wenzelm@18225
  1058
wenzelm@18225
  1059
fun multi_res _ [] rule = Seq.single rule
wenzelm@18225
  1060
  | multi_res i (th :: ths) rule = Seq.maps (res th i) (multi_res (i + 1) ths rule);
wenzelm@18225
  1061
wenzelm@18225
  1062
in
wenzelm@18225
  1063
wenzelm@18225
  1064
val multi_resolve = multi_res 1;
wenzelm@18225
  1065
fun multi_resolves facts rules = Seq.maps (multi_resolve facts) (Seq.of_list rules);
wenzelm@18225
  1066
wenzelm@18225
  1067
end;
wenzelm@18225
  1068
wenzelm@11975
  1069
end;
wenzelm@5903
  1070
wenzelm@5903
  1071
structure BasicDrule: BASIC_DRULE = Drule;
wenzelm@5903
  1072
open BasicDrule;