src/Pure/thm.ML
author nipkow
Mon Oct 07 19:01:51 2002 +0200 (2002-10-07)
changeset 13629 a46362d2b19b
parent 13528 d14fb18343cb
child 13642 a3d97348ceb6
permissions -rw-r--r--
take/drop -> splitAt
wenzelm@250
     1
(*  Title:      Pure/thm.ML
clasohm@0
     2
    ID:         $Id$
wenzelm@250
     3
    Author:     Lawrence C Paulson, Cambridge University Computer Laboratory
lcp@229
     4
    Copyright   1994  University of Cambridge
lcp@229
     5
wenzelm@1160
     6
The core of Isabelle's Meta Logic: certified types and terms, meta
wenzelm@10486
     7
theorems, meta rules (including lifting and resolution).
clasohm@0
     8
*)
clasohm@0
     9
wenzelm@6089
    10
signature BASIC_THM =
paulson@1503
    11
  sig
wenzelm@1160
    12
  (*certified types*)
wenzelm@387
    13
  type ctyp
wenzelm@1238
    14
  val rep_ctyp          : ctyp -> {sign: Sign.sg, T: typ}
wenzelm@1238
    15
  val typ_of            : ctyp -> typ
wenzelm@1238
    16
  val ctyp_of           : Sign.sg -> typ -> ctyp
wenzelm@1238
    17
  val read_ctyp         : Sign.sg -> string -> ctyp
wenzelm@1160
    18
wenzelm@1160
    19
  (*certified terms*)
wenzelm@1160
    20
  type cterm
clasohm@1493
    21
  exception CTERM of string
wenzelm@4270
    22
  val rep_cterm         : cterm -> {sign: Sign.sg, t: term, T: typ, maxidx: int}
wenzelm@4288
    23
  val crep_cterm        : cterm -> {sign: Sign.sg, t: term, T: ctyp, maxidx: int}
wenzelm@9461
    24
  val sign_of_cterm	: cterm -> Sign.sg
wenzelm@1238
    25
  val term_of           : cterm -> term
wenzelm@1238
    26
  val cterm_of          : Sign.sg -> term -> cterm
paulson@2671
    27
  val ctyp_of_term      : cterm -> ctyp
wenzelm@1238
    28
  val read_cterm        : Sign.sg -> string * typ -> cterm
wenzelm@1238
    29
  val cterm_fun         : (term -> term) -> (cterm -> cterm)
clasohm@1703
    30
  val adjust_maxidx     : cterm -> cterm
wenzelm@1238
    31
  val read_def_cterm    :
wenzelm@1160
    32
    Sign.sg * (indexname -> typ option) * (indexname -> sort option) ->
wenzelm@1160
    33
    string list -> bool -> string * typ -> cterm * (indexname * typ) list
nipkow@4281
    34
  val read_def_cterms   :
nipkow@4281
    35
    Sign.sg * (indexname -> typ option) * (indexname -> sort option) ->
nipkow@4281
    36
    string list -> bool -> (string * typ)list
nipkow@4281
    37
    -> cterm list * (indexname * typ)list
wenzelm@1160
    38
wenzelm@6089
    39
  type tag		(* = string * string list *)
paulson@1529
    40
wenzelm@1160
    41
  (*meta theorems*)
wenzelm@1160
    42
  type thm
berghofe@11518
    43
  val rep_thm           : thm -> {sign: Sign.sg, der: bool * Proofterm.proof, maxidx: int,
wenzelm@2386
    44
                                  shyps: sort list, hyps: term list, 
wenzelm@2386
    45
                                  prop: term}
berghofe@11518
    46
  val crep_thm          : thm -> {sign: Sign.sg, der: bool * Proofterm.proof, maxidx: int,
wenzelm@2386
    47
                                  shyps: sort list, hyps: cterm list, 
wenzelm@2386
    48
                                  prop: cterm}
wenzelm@6089
    49
  exception THM of string * int * thm list
wenzelm@6089
    50
  type 'a attribute 	(* = 'a * thm -> 'a * thm *)
wenzelm@3994
    51
  val eq_thm		: thm * thm -> bool
wenzelm@3967
    52
  val sign_of_thm       : thm -> Sign.sg
wenzelm@12803
    53
  val prop_of           : thm -> term
wenzelm@13528
    54
  val proof_of		: thm -> Proofterm.proof
wenzelm@4254
    55
  val transfer_sg	: Sign.sg -> thm -> thm
wenzelm@3895
    56
  val transfer		: theory -> thm -> thm
wenzelm@1238
    57
  val tpairs_of         : thm -> (term * term) list
wenzelm@1238
    58
  val prems_of          : thm -> term list
wenzelm@1238
    59
  val nprems_of         : thm -> int
wenzelm@1238
    60
  val concl_of          : thm -> term
wenzelm@1238
    61
  val cprop_of          : thm -> cterm
wenzelm@1238
    62
  val extra_shyps       : thm -> sort list
wenzelm@1238
    63
  val strip_shyps       : thm -> thm
wenzelm@3812
    64
  val get_axiom         : theory -> xstring -> thm
wenzelm@6368
    65
  val def_name		: string -> string
wenzelm@4847
    66
  val get_def           : theory -> xstring -> thm
wenzelm@1238
    67
  val axioms_of         : theory -> (string * thm) list
wenzelm@1160
    68
wenzelm@1160
    69
  (*meta rules*)
wenzelm@1238
    70
  val assume            : cterm -> thm
paulson@1416
    71
  val compress          : thm -> thm
wenzelm@1238
    72
  val implies_intr      : cterm -> thm -> thm
wenzelm@1238
    73
  val implies_elim      : thm -> thm -> thm
wenzelm@1238
    74
  val forall_intr       : cterm -> thm -> thm
wenzelm@1238
    75
  val forall_elim       : cterm -> thm -> thm
wenzelm@1238
    76
  val reflexive         : cterm -> thm
wenzelm@1238
    77
  val symmetric         : thm -> thm
wenzelm@1238
    78
  val transitive        : thm -> thm -> thm
berghofe@10416
    79
  val beta_conversion   : bool -> cterm -> thm
berghofe@10416
    80
  val eta_conversion    : cterm -> thm
wenzelm@1238
    81
  val abstract_rule     : string -> cterm -> thm -> thm
wenzelm@1238
    82
  val combination       : thm -> thm -> thm
wenzelm@1238
    83
  val equal_intr        : thm -> thm -> thm
wenzelm@1238
    84
  val equal_elim        : thm -> thm -> thm
wenzelm@1238
    85
  val implies_intr_hyps : thm -> thm
wenzelm@4270
    86
  val flexflex_rule     : thm -> thm Seq.seq
wenzelm@1238
    87
  val instantiate       :
wenzelm@1160
    88
    (indexname * ctyp) list * (cterm * cterm) list -> thm -> thm
wenzelm@1238
    89
  val trivial           : cterm -> thm
wenzelm@6368
    90
  val class_triv        : Sign.sg -> class -> thm
wenzelm@1238
    91
  val varifyT           : thm -> thm
wenzelm@12500
    92
  val varifyT'          : string list -> thm -> thm * (string * indexname) list
wenzelm@1238
    93
  val freezeT           : thm -> thm
wenzelm@1238
    94
  val dest_state        : thm * int ->
wenzelm@1160
    95
    (term * term) list * term list * term * term
wenzelm@1238
    96
  val lift_rule         : (thm * int) -> thm -> thm
berghofe@10416
    97
  val incr_indexes      : int -> thm -> thm
wenzelm@4270
    98
  val assumption        : int -> thm -> thm Seq.seq
wenzelm@1238
    99
  val eq_assumption     : int -> thm -> thm
paulson@2671
   100
  val rotate_rule       : int -> int -> thm -> thm
paulson@7248
   101
  val permute_prems     : int -> int -> thm -> thm
wenzelm@1160
   102
  val rename_params_rule: string list * int -> thm -> thm
wenzelm@1238
   103
  val bicompose         : bool -> bool * thm * int ->
wenzelm@4270
   104
    int -> thm -> thm Seq.seq
wenzelm@1238
   105
  val biresolution      : bool -> (bool * thm) list ->
wenzelm@4270
   106
    int -> thm -> thm Seq.seq
wenzelm@4999
   107
  val invoke_oracle     : theory -> xstring -> Sign.sg * Object.T -> thm
wenzelm@250
   108
end;
clasohm@0
   109
wenzelm@6089
   110
signature THM =
wenzelm@6089
   111
sig
wenzelm@6089
   112
  include BASIC_THM
wenzelm@10767
   113
  val dest_comb         : cterm -> cterm * cterm
wenzelm@10767
   114
  val dest_abs          : string option -> cterm -> cterm * cterm
wenzelm@10767
   115
  val capply            : cterm -> cterm -> cterm
wenzelm@10767
   116
  val cabs              : cterm -> cterm -> cterm
wenzelm@8299
   117
  val major_prem_of	: thm -> term
wenzelm@7534
   118
  val no_prems		: thm -> bool
wenzelm@6089
   119
  val no_attributes	: 'a -> 'a * 'b attribute list
wenzelm@6089
   120
  val apply_attributes	: ('a * thm) * 'a attribute list -> ('a * thm)
wenzelm@6089
   121
  val applys_attributes	: ('a * thm list) * 'a attribute list -> ('a * thm list)
wenzelm@6089
   122
  val get_name_tags	: thm -> string * tag list
wenzelm@6089
   123
  val put_name_tags	: string * tag list -> thm -> thm
wenzelm@6089
   124
  val name_of_thm	: thm -> string
wenzelm@6089
   125
  val tags_of_thm	: thm -> tag list
wenzelm@6089
   126
  val name_thm		: string * thm -> thm
berghofe@10416
   127
  val rename_boundvars  : term -> term -> thm -> thm
berghofe@10416
   128
  val cterm_match       : cterm * cterm ->
berghofe@10416
   129
    (indexname * ctyp) list * (cterm * cterm) list
berghofe@10416
   130
  val cterm_first_order_match : cterm * cterm ->
berghofe@10416
   131
    (indexname * ctyp) list * (cterm * cterm) list
berghofe@10416
   132
  val cterm_incr_indexes : int -> cterm -> cterm
wenzelm@6089
   133
end;
wenzelm@6089
   134
wenzelm@3550
   135
structure Thm: THM =
clasohm@0
   136
struct
wenzelm@250
   137
wenzelm@387
   138
(*** Certified terms and types ***)
wenzelm@387
   139
wenzelm@250
   140
(** certified types **)
wenzelm@250
   141
wenzelm@250
   142
(*certified typs under a signature*)
wenzelm@250
   143
wenzelm@3967
   144
datatype ctyp = Ctyp of {sign_ref: Sign.sg_ref, T: typ};
wenzelm@250
   145
wenzelm@3967
   146
fun rep_ctyp (Ctyp {sign_ref, T}) = {sign = Sign.deref sign_ref, T = T};
wenzelm@250
   147
fun typ_of (Ctyp {T, ...}) = T;
wenzelm@250
   148
wenzelm@250
   149
fun ctyp_of sign T =
wenzelm@3967
   150
  Ctyp {sign_ref = Sign.self_ref sign, T = Sign.certify_typ sign T};
wenzelm@250
   151
wenzelm@250
   152
fun read_ctyp sign s =
wenzelm@3967
   153
  Ctyp {sign_ref = Sign.self_ref sign, T = Sign.read_typ (sign, K None) s};
lcp@229
   154
lcp@229
   155
lcp@229
   156
wenzelm@250
   157
(** certified terms **)
lcp@229
   158
wenzelm@250
   159
(*certified terms under a signature, with checked typ and maxidx of Vars*)
lcp@229
   160
wenzelm@3967
   161
datatype cterm = Cterm of {sign_ref: Sign.sg_ref, t: term, T: typ, maxidx: int};
lcp@229
   162
wenzelm@3967
   163
fun rep_cterm (Cterm {sign_ref, t, T, maxidx}) =
wenzelm@3967
   164
  {sign = Sign.deref sign_ref, t = t, T = T, maxidx = maxidx};
wenzelm@3967
   165
wenzelm@4288
   166
fun crep_cterm (Cterm {sign_ref, t, T, maxidx}) =
wenzelm@4288
   167
  {sign = Sign.deref sign_ref, t = t, T = Ctyp {sign_ref = sign_ref, T = T},
wenzelm@4288
   168
    maxidx = maxidx};
wenzelm@4288
   169
wenzelm@9461
   170
fun sign_of_cterm (Cterm {sign_ref, ...}) = Sign.deref sign_ref;
wenzelm@9461
   171
wenzelm@250
   172
fun term_of (Cterm {t, ...}) = t;
lcp@229
   173
wenzelm@3967
   174
fun ctyp_of_term (Cterm {sign_ref, T, ...}) = Ctyp {sign_ref = sign_ref, T = T};
paulson@2671
   175
wenzelm@250
   176
(*create a cterm by checking a "raw" term with respect to a signature*)
wenzelm@250
   177
fun cterm_of sign tm =
wenzelm@250
   178
  let val (t, T, maxidx) = Sign.certify_term sign tm
wenzelm@3967
   179
  in  Cterm {sign_ref = Sign.self_ref sign, t = t, T = T, maxidx = maxidx}
paulson@1394
   180
  end;
lcp@229
   181
wenzelm@3967
   182
fun cterm_fun f (Cterm {sign_ref, t, ...}) = cterm_of (Sign.deref sign_ref) (f t);
wenzelm@250
   183
lcp@229
   184
clasohm@1493
   185
exception CTERM of string;
clasohm@1493
   186
clasohm@1493
   187
(*Destruct application in cterms*)
wenzelm@3967
   188
fun dest_comb (Cterm {sign_ref, T, maxidx, t = A $ B}) =
clasohm@1493
   189
      let val typeA = fastype_of A;
clasohm@1493
   190
          val typeB =
clasohm@1493
   191
            case typeA of Type("fun",[S,T]) => S
clasohm@1493
   192
                        | _ => error "Function type expected in dest_comb";
clasohm@1493
   193
      in
wenzelm@3967
   194
      (Cterm {sign_ref=sign_ref, maxidx=maxidx, t=A, T=typeA},
wenzelm@3967
   195
       Cterm {sign_ref=sign_ref, maxidx=maxidx, t=B, T=typeB})
clasohm@1493
   196
      end
clasohm@1493
   197
  | dest_comb _ = raise CTERM "dest_comb";
clasohm@1493
   198
clasohm@1493
   199
(*Destruct abstraction in cterms*)
berghofe@10416
   200
fun dest_abs a (Cterm {sign_ref, T as Type("fun",[_,S]), maxidx, t=Abs(x,ty,M)}) = 
berghofe@10416
   201
      let val (y,N) = variant_abs (if_none a x,ty,M)
wenzelm@3967
   202
      in (Cterm {sign_ref = sign_ref, T = ty, maxidx = 0, t = Free(y,ty)},
wenzelm@3967
   203
          Cterm {sign_ref = sign_ref, T = S, maxidx = maxidx, t = N})
clasohm@1493
   204
      end
berghofe@10416
   205
  | dest_abs _ _ = raise CTERM "dest_abs";
clasohm@1493
   206
paulson@2147
   207
(*Makes maxidx precise: it is often too big*)
wenzelm@3967
   208
fun adjust_maxidx (ct as Cterm {sign_ref, T, t, maxidx, ...}) =
paulson@2147
   209
  if maxidx = ~1 then ct 
wenzelm@3967
   210
  else  Cterm {sign_ref = sign_ref, T = T, maxidx = maxidx_of_term t, t = t};
clasohm@1703
   211
clasohm@1516
   212
(*Form cterm out of a function and an argument*)
wenzelm@3967
   213
fun capply (Cterm {t=f, sign_ref=sign_ref1, T=Type("fun",[dty,rty]), maxidx=maxidx1})
wenzelm@3967
   214
           (Cterm {t=x, sign_ref=sign_ref2, T, maxidx=maxidx2}) =
wenzelm@8291
   215
      if T = dty then
wenzelm@8291
   216
        Cterm{t=Sign.nodup_vars (f$x), sign_ref=Sign.merge_refs(sign_ref1,sign_ref2), T=rty,
wenzelm@8291
   217
          maxidx=Int.max(maxidx1, maxidx2)}
clasohm@1516
   218
      else raise CTERM "capply: types don't agree"
clasohm@1516
   219
  | capply _ _ = raise CTERM "capply: first arg is not a function"
wenzelm@250
   220
wenzelm@3967
   221
fun cabs (Cterm {t=Free(a,ty), sign_ref=sign_ref1, T=T1, maxidx=maxidx1})
wenzelm@3967
   222
         (Cterm {t=t2, sign_ref=sign_ref2, T=T2, maxidx=maxidx2}) =
wenzelm@8291
   223
      Cterm {t=Sign.nodup_vars (absfree(a,ty,t2)), sign_ref=Sign.merge_refs(sign_ref1,sign_ref2),
paulson@2147
   224
             T = ty --> T2, maxidx=Int.max(maxidx1, maxidx2)}
clasohm@1517
   225
  | cabs _ _ = raise CTERM "cabs: first arg is not a free variable";
lcp@229
   226
berghofe@10416
   227
(*Matching of cterms*)
berghofe@10416
   228
fun gen_cterm_match mtch
berghofe@10416
   229
      (Cterm {sign_ref = sign_ref1, maxidx = maxidx1, t = t1, ...},
berghofe@10416
   230
       Cterm {sign_ref = sign_ref2, maxidx = maxidx2, t = t2, ...}) =
berghofe@10416
   231
  let
berghofe@10416
   232
    val sign_ref = Sign.merge_refs (sign_ref1, sign_ref2);
berghofe@10416
   233
    val tsig = Sign.tsig_of (Sign.deref sign_ref);
berghofe@10416
   234
    val (Tinsts, tinsts) = mtch tsig (t1, t2);
berghofe@10416
   235
    val maxidx = Int.max (maxidx1, maxidx2);
berghofe@10416
   236
    val vars = map dest_Var (term_vars t1);
berghofe@10416
   237
    fun mk_cTinsts (ixn, T) = (ixn, Ctyp {sign_ref = sign_ref, T = T});
berghofe@10416
   238
    fun mk_ctinsts (ixn, t) =
berghofe@10416
   239
      let val T = typ_subst_TVars Tinsts (the (assoc (vars, ixn)))
berghofe@10416
   240
      in
berghofe@10416
   241
        (Cterm {sign_ref = sign_ref, maxidx = maxidx, T = T, t = Var (ixn, T)},
berghofe@10416
   242
         Cterm {sign_ref = sign_ref, maxidx = maxidx, T = T, t = t})
berghofe@10416
   243
      end;
berghofe@10416
   244
  in (map mk_cTinsts Tinsts, map mk_ctinsts tinsts) end;
berghofe@10416
   245
berghofe@10416
   246
val cterm_match = gen_cterm_match Pattern.match;
berghofe@10416
   247
val cterm_first_order_match = gen_cterm_match Pattern.first_order_match;
berghofe@10416
   248
berghofe@10416
   249
(*Incrementing indexes*)
berghofe@10416
   250
fun cterm_incr_indexes i (ct as Cterm {sign_ref, maxidx, t, T}) =
berghofe@10416
   251
  if i < 0 then raise CTERM "negative increment" else 
berghofe@10416
   252
  if i = 0 then ct else
berghofe@10416
   253
    Cterm {sign_ref = sign_ref, maxidx = maxidx + i,
berghofe@10416
   254
      t = Logic.incr_indexes ([], i) t, T = Term.incr_tvar i T};
berghofe@10416
   255
wenzelm@2509
   256
wenzelm@2509
   257
wenzelm@574
   258
(** read cterms **)   (*exception ERROR*)
wenzelm@250
   259
nipkow@4281
   260
(*read terms, infer types, certify terms*)
nipkow@4281
   261
fun read_def_cterms (sign, types, sorts) used freeze sTs =
wenzelm@250
   262
  let
wenzelm@8608
   263
    val (ts', tye) = Sign.read_def_terms (sign, types, sorts) used freeze sTs;
nipkow@4281
   264
    val cts = map (cterm_of sign) ts'
wenzelm@2979
   265
      handle TYPE (msg, _, _) => error msg
wenzelm@2386
   266
           | TERM (msg, _) => error msg;
nipkow@4281
   267
  in (cts, tye) end;
nipkow@4281
   268
nipkow@4281
   269
(*read term, infer types, certify term*)
nipkow@4281
   270
fun read_def_cterm args used freeze aT =
nipkow@4281
   271
  let val ([ct],tye) = read_def_cterms args used freeze [aT]
nipkow@4281
   272
  in (ct,tye) end;
lcp@229
   273
nipkow@949
   274
fun read_cterm sign = #1 o read_def_cterm (sign, K None, K None) [] true;
lcp@229
   275
wenzelm@250
   276
wenzelm@6089
   277
(*tags provide additional comment, apart from the axiom/theorem name*)
wenzelm@6089
   278
type tag = string * string list;
wenzelm@6089
   279
wenzelm@2509
   280
wenzelm@387
   281
(*** Meta theorems ***)
lcp@229
   282
berghofe@11518
   283
structure Pt = Proofterm;
berghofe@11518
   284
clasohm@0
   285
datatype thm = Thm of
wenzelm@3967
   286
 {sign_ref: Sign.sg_ref,       (*mutable reference to signature*)
berghofe@11518
   287
  der: bool * Pt.proof,        (*derivation*)
wenzelm@3967
   288
  maxidx: int,                 (*maximum index of any Var or TVar*)
wenzelm@3967
   289
  shyps: sort list,            (*sort hypotheses*)
wenzelm@3967
   290
  hyps: term list,             (*hypotheses*)
wenzelm@3967
   291
  prop: term};                 (*conclusion*)
clasohm@0
   292
wenzelm@3967
   293
fun rep_thm (Thm {sign_ref, der, maxidx, shyps, hyps, prop}) =
wenzelm@3967
   294
  {sign = Sign.deref sign_ref, der = der, maxidx = maxidx,
wenzelm@3967
   295
    shyps = shyps, hyps = hyps, prop = prop};
clasohm@0
   296
paulson@1529
   297
(*Version of rep_thm returning cterms instead of terms*)
wenzelm@3967
   298
fun crep_thm (Thm {sign_ref, der, maxidx, shyps, hyps, prop}) =
wenzelm@3967
   299
  let fun ctermf max t = Cterm{sign_ref=sign_ref, t=t, T=propT, maxidx=max};
wenzelm@3967
   300
  in {sign = Sign.deref sign_ref, der = der, maxidx = maxidx, shyps = shyps,
paulson@1529
   301
      hyps = map (ctermf ~1) hyps,
paulson@1529
   302
      prop = ctermf maxidx prop}
clasohm@1517
   303
  end;
clasohm@1517
   304
wenzelm@387
   305
(*errors involving theorems*)
clasohm@0
   306
exception THM of string * int * thm list;
clasohm@0
   307
wenzelm@6089
   308
(*attributes subsume any kind of rules or addXXXs modifiers*)
wenzelm@6089
   309
type 'a attribute = 'a * thm -> 'a * thm;
wenzelm@6089
   310
wenzelm@6089
   311
fun no_attributes x = (x, []);
wenzelm@6089
   312
fun apply_attributes (x_th, atts) = Library.apply atts x_th;
wenzelm@6089
   313
fun applys_attributes (x_ths, atts) = foldl_map (Library.apply atts) x_ths;
wenzelm@6089
   314
wenzelm@3994
   315
fun eq_thm (th1, th2) =
wenzelm@3994
   316
  let
berghofe@11518
   317
    val {sign = sg1, shyps = shyps1, hyps = hyps1, prop = prop1, ...} =
wenzelm@9031
   318
      rep_thm th1;
berghofe@11518
   319
    val {sign = sg2, shyps = shyps2, hyps = hyps2, prop = prop2, ...} =
wenzelm@9031
   320
      rep_thm th2;
wenzelm@3994
   321
  in
wenzelm@9031
   322
    Sign.joinable (sg1, sg2) andalso
wenzelm@3994
   323
    eq_set_sort (shyps1, shyps2) andalso
wenzelm@3994
   324
    aconvs (hyps1, hyps2) andalso
wenzelm@3994
   325
    prop1 aconv prop2
wenzelm@3994
   326
  end;
wenzelm@387
   327
wenzelm@3967
   328
fun sign_of_thm (Thm {sign_ref, ...}) = Sign.deref sign_ref;
wenzelm@12803
   329
fun prop_of (Thm {prop, ...}) = prop;
wenzelm@13528
   330
fun proof_of (Thm {der = (_, proof), ...}) = proof;
clasohm@0
   331
wenzelm@387
   332
(*merge signatures of two theorems; raise exception if incompatible*)
wenzelm@3967
   333
fun merge_thm_sgs
wenzelm@3967
   334
    (th1 as Thm {sign_ref = sgr1, ...}, th2 as Thm {sign_ref = sgr2, ...}) =
wenzelm@3967
   335
  Sign.merge_refs (sgr1, sgr2) handle TERM (msg, _) => raise THM (msg, 0, [th1, th2]);
wenzelm@387
   336
wenzelm@3967
   337
(*transfer thm to super theory (non-destructive)*)
wenzelm@4254
   338
fun transfer_sg sign' thm =
wenzelm@3895
   339
  let
wenzelm@3967
   340
    val Thm {sign_ref, der, maxidx, shyps, hyps, prop} = thm;
wenzelm@3967
   341
    val sign = Sign.deref sign_ref;
wenzelm@3895
   342
  in
wenzelm@4254
   343
    if Sign.eq_sg (sign, sign') then thm
wenzelm@4254
   344
    else if Sign.subsig (sign, sign') then
wenzelm@3967
   345
      Thm {sign_ref = Sign.self_ref sign', der = der, maxidx = maxidx,
wenzelm@3895
   346
        shyps = shyps, hyps = hyps, prop = prop}
wenzelm@3895
   347
    else raise THM ("transfer: not a super theory", 0, [thm])
wenzelm@3895
   348
  end;
wenzelm@387
   349
wenzelm@6390
   350
val transfer = transfer_sg o Theory.sign_of;
wenzelm@4254
   351
wenzelm@387
   352
(*maps object-rule to tpairs*)
wenzelm@387
   353
fun tpairs_of (Thm {prop, ...}) = #1 (Logic.strip_flexpairs prop);
wenzelm@387
   354
wenzelm@387
   355
(*maps object-rule to premises*)
wenzelm@387
   356
fun prems_of (Thm {prop, ...}) =
wenzelm@387
   357
  Logic.strip_imp_prems (Logic.skip_flexpairs prop);
clasohm@0
   358
clasohm@0
   359
(*counts premises in a rule*)
wenzelm@387
   360
fun nprems_of (Thm {prop, ...}) =
wenzelm@387
   361
  Logic.count_prems (Logic.skip_flexpairs prop, 0);
clasohm@0
   362
wenzelm@8299
   363
fun major_prem_of thm =
wenzelm@8299
   364
  (case prems_of thm of
wenzelm@11692
   365
    prem :: _ => Logic.strip_assums_concl prem
wenzelm@8299
   366
  | [] => raise THM ("major_prem_of: rule with no premises", 0, [thm]));
wenzelm@8299
   367
wenzelm@7534
   368
fun no_prems thm = nprems_of thm = 0;
wenzelm@7534
   369
wenzelm@387
   370
(*maps object-rule to conclusion*)
wenzelm@387
   371
fun concl_of (Thm {prop, ...}) = Logic.strip_imp_concl prop;
clasohm@0
   372
wenzelm@387
   373
(*the statement of any thm is a cterm*)
wenzelm@3967
   374
fun cprop_of (Thm {sign_ref, maxidx, prop, ...}) =
wenzelm@3967
   375
  Cterm {sign_ref = sign_ref, maxidx = maxidx, T = propT, t = prop};
lcp@229
   376
wenzelm@387
   377
clasohm@0
   378
wenzelm@1238
   379
(** sort contexts of theorems **)
wenzelm@1238
   380
wenzelm@1238
   381
(* basic utils *)
wenzelm@1238
   382
wenzelm@2163
   383
(*accumulate sorts suppressing duplicates; these are coded low levelly
wenzelm@1238
   384
  to improve efficiency a bit*)
wenzelm@1238
   385
wenzelm@1238
   386
fun add_typ_sorts (Type (_, Ts), Ss) = add_typs_sorts (Ts, Ss)
paulson@2177
   387
  | add_typ_sorts (TFree (_, S), Ss) = ins_sort(S,Ss)
paulson@2177
   388
  | add_typ_sorts (TVar (_, S), Ss) = ins_sort(S,Ss)
wenzelm@1238
   389
and add_typs_sorts ([], Ss) = Ss
wenzelm@1238
   390
  | add_typs_sorts (T :: Ts, Ss) = add_typs_sorts (Ts, add_typ_sorts (T, Ss));
wenzelm@1238
   391
wenzelm@1238
   392
fun add_term_sorts (Const (_, T), Ss) = add_typ_sorts (T, Ss)
wenzelm@1238
   393
  | add_term_sorts (Free (_, T), Ss) = add_typ_sorts (T, Ss)
wenzelm@1238
   394
  | add_term_sorts (Var (_, T), Ss) = add_typ_sorts (T, Ss)
wenzelm@1238
   395
  | add_term_sorts (Bound _, Ss) = Ss
paulson@2177
   396
  | add_term_sorts (Abs (_,T,t), Ss) = add_term_sorts (t, add_typ_sorts (T,Ss))
wenzelm@1238
   397
  | add_term_sorts (t $ u, Ss) = add_term_sorts (t, add_term_sorts (u, Ss));
wenzelm@1238
   398
wenzelm@1238
   399
fun add_terms_sorts ([], Ss) = Ss
paulson@2177
   400
  | add_terms_sorts (t::ts, Ss) = add_terms_sorts (ts, add_term_sorts (t,Ss));
wenzelm@1238
   401
berghofe@8407
   402
fun env_codT (Envir.Envir {iTs, ...}) = map snd (Vartab.dest iTs);
wenzelm@1258
   403
berghofe@8407
   404
fun add_env_sorts (Envir.Envir {iTs, asol, ...}, Ss) =
berghofe@8407
   405
  Vartab.foldl (add_term_sorts o swap o apsnd snd)
berghofe@8407
   406
    (Vartab.foldl (add_typ_sorts o swap o apsnd snd) (Ss, iTs), asol);
wenzelm@1258
   407
berghofe@10416
   408
fun add_insts_sorts ((iTs, is), Ss) =
berghofe@10416
   409
  add_typs_sorts (map snd iTs, add_terms_sorts (map snd is, Ss));
berghofe@10416
   410
wenzelm@1238
   411
fun add_thm_sorts (Thm {hyps, prop, ...}, Ss) =
wenzelm@1238
   412
  add_terms_sorts (hyps, add_term_sorts (prop, Ss));
wenzelm@1238
   413
wenzelm@1238
   414
fun add_thms_shyps ([], Ss) = Ss
wenzelm@1238
   415
  | add_thms_shyps (Thm {shyps, ...} :: ths, Ss) =
wenzelm@7642
   416
      add_thms_shyps (ths, union_sort (shyps, Ss));
wenzelm@1238
   417
wenzelm@1238
   418
wenzelm@1238
   419
(*get 'dangling' sort constraints of a thm*)
wenzelm@1238
   420
fun extra_shyps (th as Thm {shyps, ...}) =
wenzelm@7642
   421
  Term.rems_sort (shyps, add_thm_sorts (th, []));
wenzelm@1238
   422
wenzelm@1238
   423
wenzelm@1238
   424
(* fix_shyps *)
wenzelm@1238
   425
wenzelm@7642
   426
fun all_sorts_nonempty sign_ref = is_some (Sign.univ_witness (Sign.deref sign_ref));
wenzelm@7642
   427
wenzelm@1238
   428
(*preserve sort contexts of rule premises and substituted types*)
wenzelm@7642
   429
fun fix_shyps thms Ts (thm as Thm {sign_ref, der, maxidx, hyps, prop, ...}) =
wenzelm@7642
   430
  Thm
wenzelm@7642
   431
   {sign_ref = sign_ref,
wenzelm@7642
   432
    der = der,             (*no new derivation, as other rules call this*)
wenzelm@7642
   433
    maxidx = maxidx,
wenzelm@7642
   434
    shyps =
wenzelm@7642
   435
      if all_sorts_nonempty sign_ref then []
wenzelm@7642
   436
      else add_thm_sorts (thm, add_typs_sorts (Ts, add_thms_shyps (thms, []))),
wenzelm@7642
   437
    hyps = hyps, prop = prop}
wenzelm@1238
   438
wenzelm@1238
   439
wenzelm@7642
   440
(* strip_shyps *)
wenzelm@1238
   441
wenzelm@7642
   442
(*remove extra sorts that are non-empty by virtue of type signature information*)
wenzelm@7642
   443
fun strip_shyps (thm as Thm {shyps = [], ...}) = thm
wenzelm@7642
   444
  | strip_shyps (thm as Thm {sign_ref, der, maxidx, shyps, hyps, prop}) =
wenzelm@7642
   445
      let
wenzelm@7642
   446
        val sign = Sign.deref sign_ref;
wenzelm@1238
   447
wenzelm@7642
   448
        val present_sorts = add_thm_sorts (thm, []);
wenzelm@7642
   449
        val extra_shyps = Term.rems_sort (shyps, present_sorts);
wenzelm@7642
   450
        val witnessed_shyps = Sign.witness_sorts sign present_sorts extra_shyps;
wenzelm@7642
   451
      in
wenzelm@7642
   452
        Thm {sign_ref = sign_ref, der = der, maxidx = maxidx,
wenzelm@7642
   453
             shyps = Term.rems_sort (shyps, map #2 witnessed_shyps),
wenzelm@7642
   454
             hyps = hyps, prop = prop}
wenzelm@7642
   455
      end;
wenzelm@1238
   456
wenzelm@1238
   457
wenzelm@1238
   458
paulson@1529
   459
(** Axioms **)
wenzelm@387
   460
wenzelm@387
   461
(*look up the named axiom in the theory*)
wenzelm@3812
   462
fun get_axiom theory raw_name =
wenzelm@387
   463
  let
wenzelm@4847
   464
    val name = Sign.intern (Theory.sign_of theory) Theory.axiomK raw_name;
wenzelm@4847
   465
wenzelm@4847
   466
    fun get_ax [] = None
paulson@1529
   467
      | get_ax (thy :: thys) =
wenzelm@4847
   468
          let val {sign, axioms, ...} = Theory.rep_theory thy in
wenzelm@4847
   469
            (case Symtab.lookup (axioms, name) of
wenzelm@4847
   470
              Some t =>
wenzelm@4847
   471
                Some (fix_shyps [] []
wenzelm@4847
   472
                  (Thm {sign_ref = Sign.self_ref sign,
berghofe@11518
   473
                    der = Pt.infer_derivs' I
berghofe@11518
   474
                      (false, Pt.axm_proof name t),
wenzelm@4847
   475
                    maxidx = maxidx_of_term t,
wenzelm@4847
   476
                    shyps = [], 
wenzelm@4847
   477
                    hyps = [], 
wenzelm@4847
   478
                    prop = t}))
wenzelm@4847
   479
            | None => get_ax thys)
paulson@1529
   480
          end;
wenzelm@387
   481
  in
wenzelm@4847
   482
    (case get_ax (theory :: Theory.ancestors_of theory) of
wenzelm@4847
   483
      Some thm => thm
wenzelm@4847
   484
    | None => raise THEORY ("No axiom " ^ quote name, [theory]))
wenzelm@387
   485
  end;
wenzelm@387
   486
wenzelm@6368
   487
fun def_name name = name ^ "_def";
wenzelm@6368
   488
fun get_def thy = get_axiom thy o def_name;
wenzelm@4847
   489
paulson@1529
   490
wenzelm@776
   491
(*return additional axioms of this theory node*)
wenzelm@776
   492
fun axioms_of thy =
wenzelm@776
   493
  map (fn (s, _) => (s, get_axiom thy s))
wenzelm@6390
   494
    (Symtab.dest (#axioms (Theory.rep_theory thy)));
wenzelm@776
   495
wenzelm@6089
   496
wenzelm@6089
   497
(* name and tags -- make proof objects more readable *)
wenzelm@6089
   498
wenzelm@12923
   499
fun get_name_tags (Thm {hyps, prop, der = (_, prf), ...}) =
wenzelm@12923
   500
  Pt.get_name_tags hyps prop prf;
wenzelm@4018
   501
berghofe@11518
   502
fun put_name_tags x (Thm {sign_ref, der = (ora, prf), maxidx, shyps, hyps, prop}) =
berghofe@11518
   503
  Thm {sign_ref = sign_ref,
berghofe@11518
   504
    der = (ora, Pt.thm_proof (Sign.deref sign_ref) x hyps prop prf),
berghofe@11518
   505
    maxidx = maxidx, shyps = shyps, hyps = hyps, prop = prop};
wenzelm@6089
   506
wenzelm@6089
   507
val name_of_thm = #1 o get_name_tags;
wenzelm@6089
   508
val tags_of_thm = #2 o get_name_tags;
wenzelm@6089
   509
wenzelm@6089
   510
fun name_thm (name, thm) = put_name_tags (name, tags_of_thm thm) thm;
clasohm@0
   511
clasohm@0
   512
paulson@1529
   513
(*Compression of theorems -- a separate rule, not integrated with the others,
paulson@1529
   514
  as it could be slow.*)
wenzelm@3967
   515
fun compress (Thm {sign_ref, der, maxidx, shyps, hyps, prop}) = 
wenzelm@3967
   516
    Thm {sign_ref = sign_ref, 
wenzelm@2386
   517
         der = der,     (*No derivation recorded!*)
wenzelm@2386
   518
         maxidx = maxidx,
wenzelm@2386
   519
         shyps = shyps, 
wenzelm@2386
   520
         hyps = map Term.compress_term hyps, 
wenzelm@2386
   521
         prop = Term.compress_term prop};
wenzelm@564
   522
wenzelm@387
   523
wenzelm@2509
   524
paulson@1529
   525
(*** Meta rules ***)
clasohm@0
   526
paulson@2147
   527
(*Check that term does not contain same var with different typing/sorting.
paulson@2147
   528
  If this check must be made, recalculate maxidx in hope of preventing its
paulson@2147
   529
  recurrence.*)
wenzelm@8291
   530
fun nodup_vars (thm as Thm{sign_ref, der, maxidx, shyps, hyps, prop}) s =
wenzelm@8296
   531
  Thm {sign_ref = sign_ref, 
wenzelm@2386
   532
         der = der,     
wenzelm@2386
   533
         maxidx = maxidx_of_term prop,
wenzelm@2386
   534
         shyps = shyps, 
wenzelm@2386
   535
         hyps = hyps, 
wenzelm@8296
   536
         prop = Sign.nodup_vars prop}
paulson@2147
   537
  handle TYPE(msg,Ts,ts) => raise TYPE(s^": "^msg,Ts,ts);
nipkow@1495
   538
wenzelm@8291
   539
wenzelm@1220
   540
(** 'primitive' rules **)
wenzelm@1220
   541
wenzelm@1220
   542
(*discharge all assumptions t from ts*)
clasohm@0
   543
val disch = gen_rem (op aconv);
clasohm@0
   544
wenzelm@1220
   545
(*The assumption rule A|-A in a theory*)
wenzelm@5344
   546
fun assume raw_ct : thm =
wenzelm@5344
   547
  let val ct as Cterm {sign_ref, t=prop, T, maxidx} = adjust_maxidx raw_ct
wenzelm@250
   548
  in  if T<>propT then
wenzelm@250
   549
        raise THM("assume: assumptions must have type prop", 0, [])
clasohm@0
   550
      else if maxidx <> ~1 then
wenzelm@250
   551
        raise THM("assume: assumptions may not contain scheme variables",
wenzelm@250
   552
                  maxidx, [])
wenzelm@3967
   553
      else Thm{sign_ref   = sign_ref,
berghofe@11518
   554
               der    = Pt.infer_derivs' I (false, Pt.Hyp prop),
wenzelm@2386
   555
               maxidx = ~1, 
wenzelm@2386
   556
               shyps  = add_term_sorts(prop,[]), 
wenzelm@2386
   557
               hyps   = [prop], 
wenzelm@2386
   558
               prop   = prop}
clasohm@0
   559
  end;
clasohm@0
   560
wenzelm@1220
   561
(*Implication introduction
wenzelm@3529
   562
    [A]
wenzelm@3529
   563
     :
wenzelm@3529
   564
     B
wenzelm@1220
   565
  -------
wenzelm@1220
   566
  A ==> B
wenzelm@1220
   567
*)
berghofe@10416
   568
fun implies_intr cA (thB as Thm{sign_ref,der,maxidx,hyps,shyps,prop}) : thm =
wenzelm@3967
   569
  let val Cterm {sign_ref=sign_refA, t=A, T, maxidx=maxidxA} = cA
clasohm@0
   570
  in  if T<>propT then
wenzelm@250
   571
        raise THM("implies_intr: assumptions must have type prop", 0, [thB])
berghofe@10416
   572
      else
berghofe@10416
   573
         Thm{sign_ref = Sign.merge_refs (sign_ref,sign_refA),  
berghofe@11518
   574
             der = Pt.infer_derivs' (Pt.implies_intr_proof A) der,
wenzelm@2386
   575
             maxidx = Int.max(maxidxA, maxidx),
berghofe@10416
   576
             shyps = add_term_sorts (A, shyps),
wenzelm@2386
   577
             hyps = disch(hyps,A),
berghofe@10416
   578
             prop = implies$A$prop}
clasohm@0
   579
      handle TERM _ =>
clasohm@0
   580
        raise THM("implies_intr: incompatible signatures", 0, [thB])
clasohm@0
   581
  end;
clasohm@0
   582
paulson@1529
   583
wenzelm@1220
   584
(*Implication elimination
wenzelm@1220
   585
  A ==> B    A
wenzelm@1220
   586
  ------------
wenzelm@1220
   587
        B
wenzelm@1220
   588
*)
clasohm@0
   589
fun implies_elim thAB thA : thm =
berghofe@10416
   590
    let val Thm{maxidx=maxA, der=derA, hyps=hypsA, shyps=shypsA, prop=propA, ...} = thA
berghofe@10416
   591
        and Thm{der, maxidx, hyps, shyps, prop, ...} = thAB;
wenzelm@250
   592
        fun err(a) = raise THM("implies_elim: "^a, 0, [thAB,thA])
clasohm@0
   593
    in  case prop of
wenzelm@250
   594
            imp$A$B =>
wenzelm@250
   595
                if imp=implies andalso  A aconv propA
berghofe@10416
   596
                then
berghofe@10416
   597
                  Thm{sign_ref= merge_thm_sgs(thAB,thA),
berghofe@11612
   598
                      der = Pt.infer_derivs (curry Pt.%%) der derA,
berghofe@10416
   599
                      maxidx = Int.max(maxA,maxidx),
berghofe@10416
   600
                      shyps = union_sort (shypsA, shyps),
berghofe@10416
   601
                      hyps = union_term(hypsA,hyps),  (*dups suppressed*)
berghofe@10416
   602
                      prop = B}
wenzelm@250
   603
                else err("major premise")
wenzelm@250
   604
          | _ => err("major premise")
clasohm@0
   605
    end;
wenzelm@250
   606
wenzelm@1220
   607
(*Forall introduction.  The Free or Var x must not be free in the hypotheses.
wenzelm@1220
   608
    A
wenzelm@1220
   609
  -----
wenzelm@1220
   610
  !!x.A
wenzelm@1220
   611
*)
wenzelm@3967
   612
fun forall_intr cx (th as Thm{sign_ref,der,maxidx,hyps,prop,...}) =
lcp@229
   613
  let val x = term_of cx;
wenzelm@1238
   614
      fun result(a,T) = fix_shyps [th] []
wenzelm@3967
   615
        (Thm{sign_ref = sign_ref, 
berghofe@11518
   616
             der = Pt.infer_derivs' (Pt.forall_intr_proof x a) der,
wenzelm@2386
   617
             maxidx = maxidx,
wenzelm@2386
   618
             shyps = [],
wenzelm@2386
   619
             hyps = hyps,
wenzelm@2386
   620
             prop = all(T) $ Abs(a, T, abstract_over (x,prop))})
clasohm@0
   621
  in  case x of
wenzelm@250
   622
        Free(a,T) =>
wenzelm@250
   623
          if exists (apl(x, Logic.occs)) hyps
wenzelm@250
   624
          then  raise THM("forall_intr: variable free in assumptions", 0, [th])
wenzelm@250
   625
          else  result(a,T)
clasohm@0
   626
      | Var((a,_),T) => result(a,T)
clasohm@0
   627
      | _ => raise THM("forall_intr: not a variable", 0, [th])
clasohm@0
   628
  end;
clasohm@0
   629
wenzelm@1220
   630
(*Forall elimination
wenzelm@1220
   631
  !!x.A
wenzelm@1220
   632
  ------
wenzelm@1220
   633
  A[t/x]
wenzelm@1220
   634
*)
wenzelm@3967
   635
fun forall_elim ct (th as Thm{sign_ref,der,maxidx,hyps,prop,...}) : thm =
wenzelm@3967
   636
  let val Cterm {sign_ref=sign_reft, t, T, maxidx=maxt} = ct
clasohm@0
   637
  in  case prop of
wenzelm@2386
   638
        Const("all",Type("fun",[Type("fun",[qary,_]),_])) $ A =>
wenzelm@2386
   639
          if T<>qary then
wenzelm@2386
   640
              raise THM("forall_elim: type mismatch", 0, [th])
wenzelm@2386
   641
          else let val thm = fix_shyps [th] []
wenzelm@3967
   642
                    (Thm{sign_ref= Sign.merge_refs(sign_ref,sign_reft),
berghofe@11612
   643
                         der = Pt.infer_derivs' (Pt.% o rpair (Some t)) der,
wenzelm@2386
   644
                         maxidx = Int.max(maxidx, maxt),
wenzelm@2386
   645
                         shyps = [],
wenzelm@2386
   646
                         hyps = hyps,  
wenzelm@2386
   647
                         prop = betapply(A,t)})
wenzelm@2386
   648
               in if maxt >= 0 andalso maxidx >= 0
wenzelm@8291
   649
                  then nodup_vars thm "forall_elim" 
wenzelm@2386
   650
                  else thm (*no new Vars: no expensive check!*)
wenzelm@2386
   651
               end
paulson@2147
   652
      | _ => raise THM("forall_elim: not quantified", 0, [th])
clasohm@0
   653
  end
clasohm@0
   654
  handle TERM _ =>
wenzelm@250
   655
         raise THM("forall_elim: incompatible signatures", 0, [th]);
clasohm@0
   656
clasohm@0
   657
wenzelm@1220
   658
(* Equality *)
clasohm@0
   659
clasohm@0
   660
(*The reflexivity rule: maps  t   to the theorem   t==t   *)
wenzelm@250
   661
fun reflexive ct =
wenzelm@3967
   662
  let val Cterm {sign_ref, t, T, maxidx} = ct
berghofe@10416
   663
  in Thm{sign_ref= sign_ref, 
berghofe@11518
   664
         der = Pt.infer_derivs' I (false, Pt.reflexive),
berghofe@10416
   665
         shyps = add_term_sorts (t, []),
berghofe@10416
   666
         hyps = [], 
berghofe@10416
   667
         maxidx = maxidx,
berghofe@10416
   668
         prop = Logic.mk_equals(t,t)}
clasohm@0
   669
  end;
clasohm@0
   670
clasohm@0
   671
(*The symmetry rule
wenzelm@1220
   672
  t==u
wenzelm@1220
   673
  ----
wenzelm@1220
   674
  u==t
wenzelm@1220
   675
*)
wenzelm@3967
   676
fun symmetric (th as Thm{sign_ref,der,maxidx,shyps,hyps,prop}) =
clasohm@0
   677
  case prop of
berghofe@11518
   678
      (eq as Const("==", Type (_, [T, _]))) $ t $ u =>
wenzelm@1238
   679
        (*no fix_shyps*)
wenzelm@3967
   680
          Thm{sign_ref = sign_ref,
berghofe@11518
   681
              der = Pt.infer_derivs' Pt.symmetric der,
wenzelm@2386
   682
              maxidx = maxidx,
wenzelm@2386
   683
              shyps = shyps,
wenzelm@2386
   684
              hyps = hyps,
wenzelm@2386
   685
              prop = eq$u$t}
clasohm@0
   686
    | _ => raise THM("symmetric", 0, [th]);
clasohm@0
   687
clasohm@0
   688
(*The transitive rule
wenzelm@1220
   689
  t1==u    u==t2
wenzelm@1220
   690
  --------------
wenzelm@1220
   691
      t1==t2
wenzelm@1220
   692
*)
clasohm@0
   693
fun transitive th1 th2 =
berghofe@10416
   694
  let val Thm{der=der1, maxidx=max1, hyps=hyps1, shyps=shyps1, prop=prop1,...} = th1
berghofe@10416
   695
      and Thm{der=der2, maxidx=max2, hyps=hyps2, shyps=shyps2, prop=prop2,...} = th2;
clasohm@0
   696
      fun err(msg) = raise THM("transitive: "^msg, 0, [th1,th2])
clasohm@0
   697
  in case (prop1,prop2) of
berghofe@11518
   698
       ((eq as Const("==", Type (_, [T, _]))) $ t1 $ u, Const("==",_) $ u' $ t2) =>
nipkow@1634
   699
          if not (u aconv u') then err"middle term"
nipkow@1634
   700
          else let val thm =      
berghofe@10416
   701
                 Thm{sign_ref= merge_thm_sgs(th1,th2), 
berghofe@11518
   702
                     der = Pt.infer_derivs (Pt.transitive u T) der1 der2,
paulson@2147
   703
                     maxidx = Int.max(max1,max2), 
berghofe@10416
   704
                     shyps = union_sort (shyps1, shyps2),
wenzelm@2386
   705
                     hyps = union_term(hyps1,hyps2),
berghofe@10416
   706
                     prop = eq$t1$t2}
paulson@2139
   707
                 in if max1 >= 0 andalso max2 >= 0
wenzelm@8291
   708
                    then nodup_vars thm "transitive" 
paulson@2147
   709
                    else thm (*no new Vars: no expensive check!*)
paulson@2139
   710
                 end
clasohm@0
   711
     | _ =>  err"premises"
clasohm@0
   712
  end;
clasohm@0
   713
berghofe@10416
   714
(*Beta-conversion: maps (%x.t)(u) to the theorem (%x.t)(u) == t[u/x]
berghofe@10416
   715
  Fully beta-reduces the term if full=true
berghofe@10416
   716
*)
berghofe@10416
   717
fun beta_conversion full ct =
wenzelm@3967
   718
  let val Cterm {sign_ref, t, T, maxidx} = ct
berghofe@10416
   719
  in Thm
berghofe@10416
   720
    {sign_ref = sign_ref,  
berghofe@11518
   721
     der = Pt.infer_derivs' I (false, Pt.reflexive),
berghofe@10416
   722
     maxidx = maxidx,
berghofe@10416
   723
     shyps = add_term_sorts (t, []),
berghofe@10416
   724
     hyps = [],
wenzelm@10486
   725
     prop = Logic.mk_equals (t, if full then Envir.beta_norm t
berghofe@10416
   726
       else case t of
berghofe@10416
   727
          Abs(_, _, bodt) $ u => subst_bound (u, bodt)
berghofe@10416
   728
        | _ => raise THM ("beta_conversion: not a redex", 0, []))}
berghofe@10416
   729
  end;
berghofe@10416
   730
berghofe@10416
   731
fun eta_conversion ct =
berghofe@10416
   732
  let val Cterm {sign_ref, t, T, maxidx} = ct
berghofe@10416
   733
  in Thm
berghofe@10416
   734
    {sign_ref = sign_ref,  
berghofe@11518
   735
     der = Pt.infer_derivs' I (false, Pt.reflexive),
berghofe@10416
   736
     maxidx = maxidx,
berghofe@10416
   737
     shyps = add_term_sorts (t, []),
berghofe@10416
   738
     hyps = [],
berghofe@10416
   739
     prop = Logic.mk_equals (t, Pattern.eta_contract t)}
clasohm@0
   740
  end;
clasohm@0
   741
clasohm@0
   742
(*The abstraction rule.  The Free or Var x must not be free in the hypotheses.
clasohm@0
   743
  The bound variable will be named "a" (since x will be something like x320)
wenzelm@1220
   744
     t == u
wenzelm@1220
   745
  ------------
wenzelm@1220
   746
  %x.t == %x.u
wenzelm@1220
   747
*)
berghofe@10416
   748
fun abstract_rule a cx (th as Thm{sign_ref,der,maxidx,hyps,shyps,prop}) =
lcp@229
   749
  let val x = term_of cx;
wenzelm@250
   750
      val (t,u) = Logic.dest_equals prop
wenzelm@250
   751
            handle TERM _ =>
wenzelm@250
   752
                raise THM("abstract_rule: premise not an equality", 0, [th])
berghofe@10416
   753
      fun result T =
berghofe@10416
   754
           Thm{sign_ref = sign_ref,
berghofe@11518
   755
               der = Pt.infer_derivs' (Pt.abstract_rule x a) der,
wenzelm@2386
   756
               maxidx = maxidx, 
berghofe@10416
   757
               shyps = add_typ_sorts (T, shyps), 
wenzelm@2386
   758
               hyps = hyps,
wenzelm@2386
   759
               prop = Logic.mk_equals(Abs(a, T, abstract_over (x,t)),
berghofe@10416
   760
                                      Abs(a, T, abstract_over (x,u)))}
clasohm@0
   761
  in  case x of
wenzelm@250
   762
        Free(_,T) =>
wenzelm@250
   763
         if exists (apl(x, Logic.occs)) hyps
wenzelm@250
   764
         then raise THM("abstract_rule: variable free in assumptions", 0, [th])
wenzelm@250
   765
         else result T
clasohm@0
   766
      | Var(_,T) => result T
clasohm@0
   767
      | _ => raise THM("abstract_rule: not a variable", 0, [th])
clasohm@0
   768
  end;
clasohm@0
   769
clasohm@0
   770
(*The combination rule
wenzelm@3529
   771
  f == g  t == u
wenzelm@3529
   772
  --------------
wenzelm@3529
   773
   f(t) == g(u)
wenzelm@1220
   774
*)
clasohm@0
   775
fun combination th1 th2 =
paulson@1529
   776
  let val Thm{der=der1, maxidx=max1, shyps=shyps1, hyps=hyps1, 
wenzelm@2386
   777
              prop=prop1,...} = th1
paulson@1529
   778
      and Thm{der=der2, maxidx=max2, shyps=shyps2, hyps=hyps2, 
wenzelm@2386
   779
              prop=prop2,...} = th2
berghofe@10416
   780
      fun chktypes fT tT =
berghofe@10416
   781
            (case fT of
wenzelm@2386
   782
                Type("fun",[T1,T2]) => 
berghofe@10416
   783
                    if T1 <> tT then
wenzelm@2386
   784
                         raise THM("combination: types", 0, [th1,th2])
wenzelm@2386
   785
                    else ()
wenzelm@2386
   786
                | _ => raise THM("combination: not function type", 0, 
wenzelm@2386
   787
                                 [th1,th2]))
nipkow@1495
   788
  in case (prop1,prop2)  of
berghofe@10416
   789
       (Const ("==", Type ("fun", [fT, _])) $ f $ g,
berghofe@10416
   790
        Const ("==", Type ("fun", [tT, _])) $ t $ u) =>
berghofe@10416
   791
          let val _   = chktypes fT tT
wenzelm@2386
   792
              val thm = (*no fix_shyps*)
wenzelm@3967
   793
                        Thm{sign_ref = merge_thm_sgs(th1,th2), 
berghofe@11518
   794
                            der = Pt.infer_derivs
berghofe@11518
   795
                              (Pt.combination f g t u fT) der1 der2,
wenzelm@2386
   796
                            maxidx = Int.max(max1,max2), 
wenzelm@2386
   797
                            shyps = union_sort(shyps1,shyps2),
wenzelm@2386
   798
                            hyps = union_term(hyps1,hyps2),
wenzelm@2386
   799
                            prop = Logic.mk_equals(f$t, g$u)}
paulson@2139
   800
          in if max1 >= 0 andalso max2 >= 0
wenzelm@8291
   801
             then nodup_vars thm "combination" 
wenzelm@2386
   802
             else thm (*no new Vars: no expensive check!*)  
paulson@2139
   803
          end
clasohm@0
   804
     | _ =>  raise THM("combination: premises", 0, [th1,th2])
clasohm@0
   805
  end;
clasohm@0
   806
clasohm@0
   807
clasohm@0
   808
(* Equality introduction
wenzelm@3529
   809
  A ==> B  B ==> A
wenzelm@3529
   810
  ----------------
wenzelm@3529
   811
       A == B
wenzelm@1220
   812
*)
clasohm@0
   813
fun equal_intr th1 th2 =
berghofe@11518
   814
  let val Thm{der=der1, maxidx=max1, shyps=shyps1, hyps=hyps1, 
wenzelm@2386
   815
              prop=prop1,...} = th1
paulson@1529
   816
      and Thm{der=der2, maxidx=max2, shyps=shyps2, hyps=hyps2, 
wenzelm@2386
   817
              prop=prop2,...} = th2;
paulson@1529
   818
      fun err(msg) = raise THM("equal_intr: "^msg, 0, [th1,th2])
paulson@1529
   819
  in case (prop1,prop2) of
paulson@1529
   820
       (Const("==>",_) $ A $ B, Const("==>",_) $ B' $ A')  =>
wenzelm@2386
   821
          if A aconv A' andalso B aconv B'
wenzelm@2386
   822
          then
wenzelm@2386
   823
            (*no fix_shyps*)
wenzelm@3967
   824
              Thm{sign_ref = merge_thm_sgs(th1,th2),
berghofe@11518
   825
                  der = Pt.infer_derivs (Pt.equal_intr A B) der1 der2,
wenzelm@2386
   826
                  maxidx = Int.max(max1,max2),
wenzelm@2386
   827
                  shyps = union_sort(shyps1,shyps2),
wenzelm@2386
   828
                  hyps = union_term(hyps1,hyps2),
wenzelm@2386
   829
                  prop = Logic.mk_equals(A,B)}
wenzelm@2386
   830
          else err"not equal"
paulson@1529
   831
     | _ =>  err"premises"
paulson@1529
   832
  end;
paulson@1529
   833
paulson@1529
   834
paulson@1529
   835
(*The equal propositions rule
wenzelm@3529
   836
  A == B  A
paulson@1529
   837
  ---------
paulson@1529
   838
      B
paulson@1529
   839
*)
paulson@1529
   840
fun equal_elim th1 th2 =
paulson@1529
   841
  let val Thm{der=der1, maxidx=max1, hyps=hyps1, prop=prop1,...} = th1
paulson@1529
   842
      and Thm{der=der2, maxidx=max2, hyps=hyps2, prop=prop2,...} = th2;
paulson@1529
   843
      fun err(msg) = raise THM("equal_elim: "^msg, 0, [th1,th2])
paulson@1529
   844
  in  case prop1  of
paulson@1529
   845
       Const("==",_) $ A $ B =>
paulson@1529
   846
          if not (prop2 aconv A) then err"not equal"  else
paulson@1529
   847
            fix_shyps [th1, th2] []
wenzelm@3967
   848
              (Thm{sign_ref= merge_thm_sgs(th1,th2), 
berghofe@11518
   849
                   der = Pt.infer_derivs (Pt.equal_elim A B) der1 der2,
wenzelm@2386
   850
                   maxidx = Int.max(max1,max2),
wenzelm@2386
   851
                   shyps = [],
wenzelm@2386
   852
                   hyps = union_term(hyps1,hyps2),
wenzelm@2386
   853
                   prop = B})
paulson@1529
   854
     | _ =>  err"major premise"
paulson@1529
   855
  end;
clasohm@0
   856
wenzelm@1220
   857
wenzelm@1220
   858
clasohm@0
   859
(**** Derived rules ****)
clasohm@0
   860
paulson@1503
   861
(*Discharge all hypotheses.  Need not verify cterms or call fix_shyps.
clasohm@0
   862
  Repeated hypotheses are discharged only once;  fold cannot do this*)
wenzelm@3967
   863
fun implies_intr_hyps (Thm{sign_ref, der, maxidx, shyps, hyps=A::As, prop}) =
wenzelm@1238
   864
      implies_intr_hyps (*no fix_shyps*)
wenzelm@3967
   865
            (Thm{sign_ref = sign_ref, 
berghofe@11518
   866
                 der = Pt.infer_derivs' (Pt.implies_intr_proof A) der,
wenzelm@2386
   867
                 maxidx = maxidx, 
wenzelm@2386
   868
                 shyps = shyps,
paulson@1529
   869
                 hyps = disch(As,A),  
wenzelm@2386
   870
                 prop = implies$A$prop})
clasohm@0
   871
  | implies_intr_hyps th = th;
clasohm@0
   872
clasohm@0
   873
(*Smash" unifies the list of term pairs leaving no flex-flex pairs.
wenzelm@250
   874
  Instantiates the theorem and deletes trivial tpairs.
clasohm@0
   875
  Resulting sequence may contain multiple elements if the tpairs are
clasohm@0
   876
    not all flex-flex. *)
wenzelm@3967
   877
fun flexflex_rule (th as Thm{sign_ref, der, maxidx, hyps, prop,...}) =
wenzelm@250
   878
  let fun newthm env =
paulson@1529
   879
          if Envir.is_empty env then th
paulson@1529
   880
          else
wenzelm@250
   881
          let val (tpairs,horn) =
wenzelm@250
   882
                        Logic.strip_flexpairs (Envir.norm_term env prop)
wenzelm@250
   883
                (*Remove trivial tpairs, of the form t=t*)
wenzelm@250
   884
              val distpairs = filter (not o op aconv) tpairs
wenzelm@250
   885
              val newprop = Logic.list_flexpairs(distpairs, horn)
wenzelm@1220
   886
          in  fix_shyps [th] (env_codT env)
wenzelm@3967
   887
                (Thm{sign_ref = sign_ref, 
berghofe@11518
   888
                     der = Pt.infer_derivs' (Pt.norm_proof' env) der,
wenzelm@2386
   889
                     maxidx = maxidx_of_term newprop, 
wenzelm@2386
   890
                     shyps = [], 
wenzelm@2386
   891
                     hyps = hyps,
wenzelm@2386
   892
                     prop = newprop})
wenzelm@250
   893
          end;
clasohm@0
   894
      val (tpairs,_) = Logic.strip_flexpairs prop
wenzelm@4270
   895
  in Seq.map newthm
wenzelm@3967
   896
            (Unify.smash_unifiers(Sign.deref sign_ref, Envir.empty maxidx, tpairs))
clasohm@0
   897
  end;
clasohm@0
   898
clasohm@0
   899
(*Instantiation of Vars
wenzelm@1220
   900
           A
wenzelm@1220
   901
  -------------------
wenzelm@1220
   902
  A[t1/v1,....,tn/vn]
wenzelm@1220
   903
*)
clasohm@0
   904
wenzelm@6928
   905
local
wenzelm@6928
   906
clasohm@0
   907
(*Check that all the terms are Vars and are distinct*)
clasohm@0
   908
fun instl_ok ts = forall is_Var ts andalso null(findrep ts);
clasohm@0
   909
wenzelm@6928
   910
fun prt_typing sg_ref t T =
wenzelm@6928
   911
  let val sg = Sign.deref sg_ref in
wenzelm@6928
   912
    Pretty.block [Sign.pretty_term sg t, Pretty.str " ::", Pretty.brk 1, Sign.pretty_typ sg T]
wenzelm@6928
   913
  end;
wenzelm@6928
   914
clasohm@0
   915
(*For instantiate: process pair of cterms, merge theories*)
wenzelm@3967
   916
fun add_ctpair ((ct,cu), (sign_ref,tpairs)) =
wenzelm@6928
   917
  let
wenzelm@6928
   918
    val Cterm {sign_ref=sign_reft, t=t, T= T, ...} = ct
wenzelm@6928
   919
    and Cterm {sign_ref=sign_refu, t=u, T= U, ...} = cu;
wenzelm@6928
   920
    val sign_ref_merged = Sign.merge_refs (sign_ref, Sign.merge_refs (sign_reft, sign_refu));
wenzelm@3967
   921
  in
wenzelm@6928
   922
    if T=U then (sign_ref_merged, (t,u)::tpairs)
wenzelm@6928
   923
    else raise TYPE (Pretty.string_of (Pretty.block [Pretty.str "instantiate: type conflict",
wenzelm@6928
   924
      Pretty.fbrk, prt_typing sign_ref_merged t T,
wenzelm@6928
   925
      Pretty.fbrk, prt_typing sign_ref_merged u U]), [T,U], [t,u])
clasohm@0
   926
  end;
clasohm@0
   927
wenzelm@3967
   928
fun add_ctyp ((v,ctyp), (sign_ref',vTs)) =
wenzelm@3967
   929
  let val Ctyp {T,sign_ref} = ctyp
wenzelm@3967
   930
  in (Sign.merge_refs(sign_ref,sign_ref'), (v,T)::vTs) end;
clasohm@0
   931
wenzelm@6928
   932
in
wenzelm@6928
   933
clasohm@0
   934
(*Left-to-right replacements: ctpairs = [...,(vi,ti),...].
clasohm@0
   935
  Instantiates distinct Vars by terms of same type.
paulson@8129
   936
  No longer normalizes the new theorem! *)
paulson@1529
   937
fun instantiate ([], []) th = th
berghofe@10416
   938
  | instantiate (vcTs,ctpairs) (th as Thm{sign_ref,der,maxidx,hyps,shyps,prop}) =
wenzelm@3967
   939
  let val (newsign_ref,tpairs) = foldr add_ctpair (ctpairs, (sign_ref,[]));
wenzelm@3967
   940
      val (newsign_ref,vTs) = foldr add_ctyp (vcTs, (newsign_ref,[]));
paulson@8129
   941
      val newprop = subst_atomic tpairs
paulson@8129
   942
	             (Type.inst_term_tvars
paulson@8129
   943
		      (Sign.tsig_of (Sign.deref newsign_ref),vTs) prop)
wenzelm@1220
   944
      val newth =
berghofe@10416
   945
            (Thm{sign_ref = newsign_ref, 
berghofe@11518
   946
                 der = Pt.infer_derivs' (Pt.instantiate vTs tpairs) der,
berghofe@10416
   947
                 maxidx = maxidx_of_term newprop, 
berghofe@10416
   948
                 shyps = add_insts_sorts ((vTs, tpairs), shyps),
berghofe@10416
   949
                 hyps = hyps,
berghofe@10416
   950
                 prop = newprop})
wenzelm@250
   951
  in  if not(instl_ok(map #1 tpairs))
nipkow@193
   952
      then raise THM("instantiate: variables not distinct", 0, [th])
nipkow@193
   953
      else if not(null(findrep(map #1 vTs)))
nipkow@193
   954
      then raise THM("instantiate: type variables not distinct", 0, [th])
wenzelm@8291
   955
      else nodup_vars newth "instantiate"
clasohm@0
   956
  end
wenzelm@6928
   957
  handle TERM _ => raise THM("instantiate: incompatible signatures", 0, [th])
wenzelm@6928
   958
       | TYPE (msg, _, _) => raise THM (msg, 0, [th]);
wenzelm@6928
   959
wenzelm@6928
   960
end;
wenzelm@6928
   961
clasohm@0
   962
clasohm@0
   963
(*The trivial implication A==>A, justified by assume and forall rules.
clasohm@0
   964
  A can contain Vars, not so for assume!   *)
wenzelm@250
   965
fun trivial ct : thm =
wenzelm@3967
   966
  let val Cterm {sign_ref, t=A, T, maxidx} = ct
wenzelm@250
   967
  in  if T<>propT then
wenzelm@250
   968
            raise THM("trivial: the term must have type prop", 0, [])
wenzelm@1238
   969
      else fix_shyps [] []
wenzelm@3967
   970
        (Thm{sign_ref = sign_ref, 
berghofe@11518
   971
             der = Pt.infer_derivs' I (false, Pt.AbsP ("H", None, Pt.PBound 0)),
wenzelm@2386
   972
             maxidx = maxidx, 
wenzelm@2386
   973
             shyps = [], 
wenzelm@2386
   974
             hyps = [],
wenzelm@2386
   975
             prop = implies$A$A})
clasohm@0
   976
  end;
clasohm@0
   977
paulson@1503
   978
(*Axiom-scheme reflecting signature contents: "OFCLASS(?'a::c, c_class)" *)
wenzelm@6368
   979
fun class_triv sign c =
wenzelm@6368
   980
  let val Cterm {sign_ref, t, maxidx, ...} =
wenzelm@6368
   981
    cterm_of sign (Logic.mk_inclass (TVar (("'a", 0), [c]), c))
wenzelm@6368
   982
      handle TERM (msg, _) => raise THM ("class_triv: " ^ msg, 0, []);
wenzelm@399
   983
  in
wenzelm@1238
   984
    fix_shyps [] []
wenzelm@3967
   985
      (Thm {sign_ref = sign_ref, 
berghofe@11518
   986
            der = Pt.infer_derivs' I
berghofe@11518
   987
              (false, Pt.PAxm ("ProtoPure.class_triv:" ^ c, t, Some [])),
wenzelm@2386
   988
            maxidx = maxidx, 
wenzelm@2386
   989
            shyps = [], 
wenzelm@2386
   990
            hyps = [], 
wenzelm@2386
   991
            prop = t})
wenzelm@399
   992
  end;
wenzelm@399
   993
wenzelm@399
   994
wenzelm@6786
   995
(* Replace all TFrees not fixed or in the hyps by new TVars *)
wenzelm@6786
   996
fun varifyT' fixed (Thm{sign_ref,der,maxidx,shyps,hyps,prop}) =
wenzelm@12500
   997
  let
wenzelm@12500
   998
    val tfrees = foldr add_term_tfree_names (hyps, fixed);
wenzelm@12500
   999
    val (prop', al) = Type.varify (prop, tfrees);
nipkow@1634
  1000
  in let val thm = (*no fix_shyps*)
wenzelm@3967
  1001
    Thm{sign_ref = sign_ref, 
berghofe@11518
  1002
        der = Pt.infer_derivs' (Pt.varify_proof prop tfrees) der,
wenzelm@2386
  1003
        maxidx = Int.max(0,maxidx), 
wenzelm@2386
  1004
        shyps = shyps, 
wenzelm@2386
  1005
        hyps = hyps,
wenzelm@12500
  1006
        prop = prop'}
wenzelm@12500
  1007
     in (nodup_vars thm "varifyT", al) end
wenzelm@8291
  1008
(* this nodup_vars check can be removed if thms are guaranteed not to contain
wenzelm@8291
  1009
duplicate TVars with different sorts *)
clasohm@0
  1010
  end;
clasohm@0
  1011
wenzelm@12500
  1012
val varifyT = #1 o varifyT' [];
wenzelm@6786
  1013
clasohm@0
  1014
(* Replace all TVars by new TFrees *)
wenzelm@3967
  1015
fun freezeT(Thm{sign_ref,der,maxidx,shyps,hyps,prop}) =
paulson@3410
  1016
  let val (prop',_) = Type.freeze_thaw prop
wenzelm@1238
  1017
  in (*no fix_shyps*)
wenzelm@3967
  1018
    Thm{sign_ref = sign_ref, 
berghofe@11518
  1019
        der = Pt.infer_derivs' (Pt.freezeT prop) der,
wenzelm@2386
  1020
        maxidx = maxidx_of_term prop',
wenzelm@2386
  1021
        shyps = shyps,
wenzelm@2386
  1022
        hyps = hyps,
paulson@1529
  1023
        prop = prop'}
wenzelm@1220
  1024
  end;
clasohm@0
  1025
clasohm@0
  1026
clasohm@0
  1027
(*** Inference rules for tactics ***)
clasohm@0
  1028
clasohm@0
  1029
(*Destruct proof state into constraints, other goals, goal(i), rest *)
clasohm@0
  1030
fun dest_state (state as Thm{prop,...}, i) =
clasohm@0
  1031
  let val (tpairs,horn) = Logic.strip_flexpairs prop
clasohm@0
  1032
  in  case  Logic.strip_prems(i, [], horn) of
clasohm@0
  1033
          (B::rBs, C) => (tpairs, rev rBs, B, C)
clasohm@0
  1034
        | _ => raise THM("dest_state", i, [state])
clasohm@0
  1035
  end
clasohm@0
  1036
  handle TERM _ => raise THM("dest_state", i, [state]);
clasohm@0
  1037
lcp@309
  1038
(*Increment variables and parameters of orule as required for
clasohm@0
  1039
  resolution with goal i of state. *)
clasohm@0
  1040
fun lift_rule (state, i) orule =
wenzelm@3967
  1041
  let val Thm{shyps=sshyps, prop=sprop, maxidx=smax, sign_ref=ssign_ref,...} = state
clasohm@0
  1042
      val (Bi::_, _) = Logic.strip_prems(i, [], Logic.skip_flexpairs sprop)
paulson@1529
  1043
        handle TERM _ => raise THM("lift_rule", i, [orule,state])
wenzelm@3967
  1044
      val ct_Bi = Cterm {sign_ref=ssign_ref, maxidx=smax, T=propT, t=Bi}
paulson@1529
  1045
      val (lift_abs,lift_all) = Logic.lift_fns(Bi,smax+1)
wenzelm@3967
  1046
      val (Thm{sign_ref, der, maxidx,shyps,hyps,prop}) = orule
clasohm@0
  1047
      val (tpairs,As,B) = Logic.strip_horn prop
wenzelm@1238
  1048
  in  (*no fix_shyps*)
wenzelm@3967
  1049
      Thm{sign_ref = merge_thm_sgs(state,orule),
berghofe@11518
  1050
          der = Pt.infer_derivs' (Pt.lift_proof Bi (smax+1) prop) der,
wenzelm@2386
  1051
          maxidx = maxidx+smax+1,
paulson@2177
  1052
          shyps=union_sort(sshyps,shyps), 
wenzelm@2386
  1053
          hyps=hyps, 
paulson@1529
  1054
          prop = Logic.rule_of (map (pairself lift_abs) tpairs,
wenzelm@2386
  1055
                                map lift_all As,    
wenzelm@2386
  1056
                                lift_all B)}
clasohm@0
  1057
  end;
clasohm@0
  1058
berghofe@10416
  1059
fun incr_indexes i (thm as Thm {sign_ref, der, maxidx, shyps, hyps, prop}) =
berghofe@10416
  1060
  if i < 0 then raise THM ("negative increment", 0, [thm]) else
berghofe@10416
  1061
  if i = 0 then thm else
berghofe@10416
  1062
    Thm {sign_ref = sign_ref,
berghofe@11518
  1063
         der = Pt.infer_derivs' (Pt.map_proof_terms
berghofe@11518
  1064
           (Logic.incr_indexes ([], i)) (incr_tvar i)) der,
berghofe@10416
  1065
         maxidx = maxidx + i,
berghofe@10416
  1066
         shyps = shyps,
berghofe@10416
  1067
         hyps = hyps,
berghofe@10416
  1068
         prop = Logic.incr_indexes ([], i) prop};
berghofe@10416
  1069
clasohm@0
  1070
(*Solve subgoal Bi of proof state B1...Bn/C by assumption. *)
clasohm@0
  1071
fun assumption i state =
wenzelm@3967
  1072
  let val Thm{sign_ref,der,maxidx,hyps,prop,...} = state;
clasohm@0
  1073
      val (tpairs, Bs, Bi, C) = dest_state(state,i)
berghofe@11518
  1074
      fun newth n (env as Envir.Envir{maxidx, ...}, tpairs) =
wenzelm@1220
  1075
        fix_shyps [state] (env_codT env)
wenzelm@3967
  1076
          (Thm{sign_ref = sign_ref, 
berghofe@11518
  1077
               der = Pt.infer_derivs'
berghofe@11518
  1078
                 ((if Envir.is_empty env then I else (Pt.norm_proof' env)) o
berghofe@11518
  1079
                   Pt.assumption_proof Bs Bi n) der,
wenzelm@2386
  1080
               maxidx = maxidx,
wenzelm@2386
  1081
               shyps = [],
wenzelm@2386
  1082
               hyps = hyps,
wenzelm@2386
  1083
               prop = 
wenzelm@2386
  1084
               if Envir.is_empty env then (*avoid wasted normalizations*)
wenzelm@2386
  1085
                   Logic.rule_of (tpairs, Bs, C)
wenzelm@2386
  1086
               else (*normalize the new rule fully*)
wenzelm@2386
  1087
                   Envir.norm_term env (Logic.rule_of (tpairs, Bs, C))});
berghofe@11518
  1088
      fun addprfs [] _ = Seq.empty
berghofe@11518
  1089
        | addprfs ((t,u)::apairs) n = Seq.make (fn()=> Seq.pull
berghofe@11518
  1090
             (Seq.mapp (newth n)
wenzelm@3967
  1091
                (Unify.unifiers(Sign.deref sign_ref,Envir.empty maxidx, (t,u)::tpairs))
berghofe@11518
  1092
                (addprfs apairs (n+1))))
berghofe@11518
  1093
  in  addprfs (Logic.assum_pairs Bi) 1 end;
clasohm@0
  1094
wenzelm@250
  1095
(*Solve subgoal Bi of proof state B1...Bn/C by assumption.
clasohm@0
  1096
  Checks if Bi's conclusion is alpha-convertible to one of its assumptions*)
clasohm@0
  1097
fun eq_assumption i state =
wenzelm@3967
  1098
  let val Thm{sign_ref,der,maxidx,hyps,prop,...} = state;
clasohm@0
  1099
      val (tpairs, Bs, Bi, C) = dest_state(state,i)
berghofe@11518
  1100
  in  (case find_index (op aconv) (Logic.assum_pairs Bi) of
berghofe@11518
  1101
         (~1) => raise THM("eq_assumption", 0, [state])
berghofe@11518
  1102
       | n => fix_shyps [state] []
berghofe@11518
  1103
                (Thm{sign_ref = sign_ref, 
berghofe@11518
  1104
                     der = Pt.infer_derivs'
berghofe@11518
  1105
                       (Pt.assumption_proof Bs Bi (n+1)) der,
berghofe@11518
  1106
                     maxidx = maxidx,
berghofe@11518
  1107
                     shyps = [],
berghofe@11518
  1108
                     hyps = hyps,
berghofe@11518
  1109
                     prop = Logic.rule_of(tpairs, Bs, C)}))
clasohm@0
  1110
  end;
clasohm@0
  1111
clasohm@0
  1112
paulson@2671
  1113
(*For rotate_tac: fast rotation of assumptions of subgoal i*)
paulson@2671
  1114
fun rotate_rule k i state =
wenzelm@3967
  1115
  let val Thm{sign_ref,der,maxidx,hyps,prop,shyps} = state;
paulson@2671
  1116
      val (tpairs, Bs, Bi, C) = dest_state(state,i)
paulson@8066
  1117
      val params = Term.strip_all_vars Bi
paulson@8066
  1118
      and rest   = Term.strip_all_body Bi
paulson@8066
  1119
      val asms   = Logic.strip_imp_prems rest
paulson@8066
  1120
      and concl  = Logic.strip_imp_concl rest
paulson@2671
  1121
      val n      = length asms
berghofe@11563
  1122
      val m      = if k<0 then n+k else k
berghofe@11563
  1123
      val Bi'    = if 0=m orelse m=n then Bi
paulson@2671
  1124
		   else if 0<m andalso m<n 
nipkow@13629
  1125
		   then let val (ps,qs) = splitAt(m,asms)
nipkow@13629
  1126
                        in list_all(params, Logic.list_implies(qs @ ps, concl))
nipkow@13629
  1127
			end
paulson@7248
  1128
		   else raise THM("rotate_rule", k, [state])
wenzelm@7264
  1129
  in  (*no fix_shyps*)
wenzelm@7264
  1130
      Thm{sign_ref = sign_ref, 
berghofe@11563
  1131
          der = Pt.infer_derivs' (Pt.rotate_proof Bs Bi m) der,
paulson@2671
  1132
	  maxidx = maxidx,
paulson@2671
  1133
	  shyps = shyps,
paulson@2671
  1134
	  hyps = hyps,
berghofe@11563
  1135
	  prop = Logic.rule_of (tpairs, Bs @ [Bi'], C)}
paulson@2671
  1136
  end;
paulson@2671
  1137
paulson@2671
  1138
paulson@7248
  1139
(*Rotates a rule's premises to the left by k, leaving the first j premises
paulson@7248
  1140
  unchanged.  Does nothing if k=0 or if k equals n-j, where n is the
paulson@7248
  1141
  number of premises.  Useful with etac and underlies tactic/defer_tac*)
paulson@7248
  1142
fun permute_prems j k rl =
paulson@7248
  1143
  let val Thm{sign_ref,der,maxidx,hyps,prop,shyps} = rl
paulson@7248
  1144
      val prems  = Logic.strip_imp_prems prop
paulson@7248
  1145
      and concl  = Logic.strip_imp_concl prop
paulson@7248
  1146
      val moved_prems = List.drop(prems, j)
paulson@7248
  1147
      and fixed_prems = List.take(prems, j)
paulson@7248
  1148
        handle Subscript => raise THM("permute_prems:j", j, [rl])
paulson@7248
  1149
      val n_j    = length moved_prems
berghofe@11563
  1150
      val m = if k<0 then n_j + k else k
berghofe@11563
  1151
      val prop'  = if 0 = m orelse m = n_j then prop
paulson@7248
  1152
		   else if 0<m andalso m<n_j 
nipkow@13629
  1153
		   then let val (ps,qs) = splitAt(m,moved_prems)
nipkow@13629
  1154
			in Logic.list_implies(fixed_prems @ qs @ ps, concl) end
paulson@7248
  1155
		   else raise THM("permute_prems:k", k, [rl])
wenzelm@7264
  1156
  in  (*no fix_shyps*)
wenzelm@7264
  1157
      Thm{sign_ref = sign_ref, 
berghofe@11563
  1158
          der = Pt.infer_derivs' (Pt.permute_prems_prf prems j m) der,
paulson@7248
  1159
	  maxidx = maxidx,
paulson@7248
  1160
	  shyps = shyps,
paulson@7248
  1161
	  hyps = hyps,
berghofe@11563
  1162
	  prop = prop'}
paulson@7248
  1163
  end;
paulson@7248
  1164
paulson@7248
  1165
clasohm@0
  1166
(** User renaming of parameters in a subgoal **)
clasohm@0
  1167
clasohm@0
  1168
(*Calls error rather than raising an exception because it is intended
clasohm@0
  1169
  for top-level use -- exception handling would not make sense here.
clasohm@0
  1170
  The names in cs, if distinct, are used for the innermost parameters;
clasohm@0
  1171
   preceding parameters may be renamed to make all params distinct.*)
clasohm@0
  1172
fun rename_params_rule (cs, i) state =
wenzelm@3967
  1173
  let val Thm{sign_ref,der,maxidx,hyps,...} = state
clasohm@0
  1174
      val (tpairs, Bs, Bi, C) = dest_state(state,i)
clasohm@0
  1175
      val iparams = map #1 (Logic.strip_params Bi)
clasohm@0
  1176
      val short = length iparams - length cs
wenzelm@250
  1177
      val newnames =
wenzelm@250
  1178
            if short<0 then error"More names than abstractions!"
wenzelm@250
  1179
            else variantlist(take (short,iparams), cs) @ cs
nipkow@3037
  1180
      val freenames = map (#1 o dest_Free) (term_frees Bi)
clasohm@0
  1181
      val newBi = Logic.list_rename_params (newnames, Bi)
wenzelm@250
  1182
  in
clasohm@0
  1183
  case findrep cs of
paulson@3565
  1184
     c::_ => (warning ("Can't rename.  Bound variables not distinct: " ^ c); 
paulson@3565
  1185
	      state)
berghofe@1576
  1186
   | [] => (case cs inter_string freenames of
paulson@3565
  1187
       a::_ => (warning ("Can't rename.  Bound/Free variable clash: " ^ a); 
paulson@3565
  1188
		state)
wenzelm@1220
  1189
     | [] => fix_shyps [state] []
wenzelm@3967
  1190
                (Thm{sign_ref = sign_ref,
berghofe@11518
  1191
                     der = der,
wenzelm@2386
  1192
                     maxidx = maxidx,
wenzelm@2386
  1193
                     shyps = [],
wenzelm@2386
  1194
                     hyps = hyps,
wenzelm@2386
  1195
                     prop = Logic.rule_of(tpairs, Bs@[newBi], C)}))
clasohm@0
  1196
  end;
clasohm@0
  1197
wenzelm@12982
  1198
clasohm@0
  1199
(*** Preservation of bound variable names ***)
clasohm@0
  1200
wenzelm@12982
  1201
fun rename_boundvars pat obj (thm as Thm {sign_ref, der, maxidx, hyps, shyps, prop}) =
wenzelm@12982
  1202
  (case Term.rename_abs pat obj prop of
wenzelm@12982
  1203
    None => thm
wenzelm@12982
  1204
  | Some prop' => Thm
wenzelm@12982
  1205
      {sign_ref = sign_ref,
wenzelm@12982
  1206
       der = der,
wenzelm@12982
  1207
       maxidx = maxidx,
wenzelm@12982
  1208
       hyps = hyps,
wenzelm@12982
  1209
       shyps = shyps,
wenzelm@12982
  1210
       prop = prop'});
berghofe@10416
  1211
clasohm@0
  1212
wenzelm@250
  1213
(* strip_apply f A(,B) strips off all assumptions/parameters from A
clasohm@0
  1214
   introduced by lifting over B, and applies f to remaining part of A*)
clasohm@0
  1215
fun strip_apply f =
clasohm@0
  1216
  let fun strip(Const("==>",_)$ A1 $ B1,
wenzelm@250
  1217
                Const("==>",_)$ _  $ B2) = implies $ A1 $ strip(B1,B2)
wenzelm@250
  1218
        | strip((c as Const("all",_)) $ Abs(a,T,t1),
wenzelm@250
  1219
                      Const("all",_)  $ Abs(_,_,t2)) = c$Abs(a,T,strip(t1,t2))
wenzelm@250
  1220
        | strip(A,_) = f A
clasohm@0
  1221
  in strip end;
clasohm@0
  1222
clasohm@0
  1223
(*Use the alist to rename all bound variables and some unknowns in a term
clasohm@0
  1224
  dpairs = current disagreement pairs;  tpairs = permanent ones (flexflex);
clasohm@0
  1225
  Preserves unknowns in tpairs and on lhs of dpairs. *)
clasohm@0
  1226
fun rename_bvs([],_,_,_) = I
clasohm@0
  1227
  | rename_bvs(al,dpairs,tpairs,B) =
wenzelm@250
  1228
    let val vars = foldr add_term_vars
wenzelm@250
  1229
                        (map fst dpairs @ map fst tpairs @ map snd tpairs, [])
wenzelm@250
  1230
        (*unknowns appearing elsewhere be preserved!*)
wenzelm@250
  1231
        val vids = map (#1 o #1 o dest_Var) vars;
wenzelm@250
  1232
        fun rename(t as Var((x,i),T)) =
wenzelm@250
  1233
                (case assoc(al,x) of
berghofe@1576
  1234
                   Some(y) => if x mem_string vids orelse y mem_string vids then t
wenzelm@250
  1235
                              else Var((y,i),T)
wenzelm@250
  1236
                 | None=> t)
clasohm@0
  1237
          | rename(Abs(x,T,t)) =
nipkow@9721
  1238
              Abs(if_none(assoc_string(al,x)) x, T, rename t)
clasohm@0
  1239
          | rename(f$t) = rename f $ rename t
clasohm@0
  1240
          | rename(t) = t;
wenzelm@250
  1241
        fun strip_ren Ai = strip_apply rename (Ai,B)
clasohm@0
  1242
    in strip_ren end;
clasohm@0
  1243
clasohm@0
  1244
(*Function to rename bounds/unknowns in the argument, lifted over B*)
clasohm@0
  1245
fun rename_bvars(dpairs, tpairs, B) =
wenzelm@12982
  1246
        rename_bvs(foldr Term.match_bvars (dpairs,[]), dpairs, tpairs, B);
clasohm@0
  1247
clasohm@0
  1248
clasohm@0
  1249
(*** RESOLUTION ***)
clasohm@0
  1250
lcp@721
  1251
(** Lifting optimizations **)
lcp@721
  1252
clasohm@0
  1253
(*strip off pairs of assumptions/parameters in parallel -- they are
clasohm@0
  1254
  identical because of lifting*)
wenzelm@250
  1255
fun strip_assums2 (Const("==>", _) $ _ $ B1,
wenzelm@250
  1256
                   Const("==>", _) $ _ $ B2) = strip_assums2 (B1,B2)
clasohm@0
  1257
  | strip_assums2 (Const("all",_)$Abs(a,T,t1),
wenzelm@250
  1258
                   Const("all",_)$Abs(_,_,t2)) =
clasohm@0
  1259
      let val (B1,B2) = strip_assums2 (t1,t2)
clasohm@0
  1260
      in  (Abs(a,T,B1), Abs(a,T,B2))  end
clasohm@0
  1261
  | strip_assums2 BB = BB;
clasohm@0
  1262
clasohm@0
  1263
lcp@721
  1264
(*Faster normalization: skip assumptions that were lifted over*)
lcp@721
  1265
fun norm_term_skip env 0 t = Envir.norm_term env t
lcp@721
  1266
  | norm_term_skip env n (Const("all",_)$Abs(a,T,t)) =
lcp@721
  1267
        let val Envir.Envir{iTs, ...} = env
berghofe@8407
  1268
            val T' = typ_subst_TVars_Vartab iTs T
wenzelm@1238
  1269
            (*Must instantiate types of parameters because they are flattened;
lcp@721
  1270
              this could be a NEW parameter*)
lcp@721
  1271
        in  all T' $ Abs(a, T', norm_term_skip env n t)  end
lcp@721
  1272
  | norm_term_skip env n (Const("==>", _) $ A $ B) =
wenzelm@1238
  1273
        implies $ A $ norm_term_skip env (n-1) B
lcp@721
  1274
  | norm_term_skip env n t = error"norm_term_skip: too few assumptions??";
lcp@721
  1275
lcp@721
  1276
clasohm@0
  1277
(*Composition of object rule r=(A1...Am/B) with proof state s=(B1...Bn/C)
wenzelm@250
  1278
  Unifies B with Bi, replacing subgoal i    (1 <= i <= n)
clasohm@0
  1279
  If match then forbid instantiations in proof state
clasohm@0
  1280
  If lifted then shorten the dpair using strip_assums2.
clasohm@0
  1281
  If eres_flg then simultaneously proves A1 by assumption.
wenzelm@250
  1282
  nsubgoal is the number of new subgoals (written m above).
clasohm@0
  1283
  Curried so that resolution calls dest_state only once.
clasohm@0
  1284
*)
wenzelm@4270
  1285
local exception COMPOSE
clasohm@0
  1286
in
wenzelm@250
  1287
fun bicompose_aux match (state, (stpairs, Bs, Bi, C), lifted)
clasohm@0
  1288
                        (eres_flg, orule, nsubgoal) =
paulson@1529
  1289
 let val Thm{der=sder, maxidx=smax, shyps=sshyps, hyps=shyps, ...} = state
paulson@1529
  1290
     and Thm{der=rder, maxidx=rmax, shyps=rshyps, hyps=rhyps, 
wenzelm@2386
  1291
             prop=rprop,...} = orule
paulson@1529
  1292
         (*How many hyps to skip over during normalization*)
wenzelm@1238
  1293
     and nlift = Logic.count_prems(strip_all_body Bi,
wenzelm@1238
  1294
                                   if eres_flg then ~1 else 0)
wenzelm@3967
  1295
     val sign_ref = merge_thm_sgs(state,orule);
wenzelm@3967
  1296
     val sign = Sign.deref sign_ref;
clasohm@0
  1297
     (** Add new theorem with prop = '[| Bs; As |] ==> C' to thq **)
berghofe@11518
  1298
     fun addth A (As, oldAs, rder', n) ((env as Envir.Envir {maxidx, ...}, tpairs), thq) =
wenzelm@250
  1299
       let val normt = Envir.norm_term env;
wenzelm@250
  1300
           (*perform minimal copying here by examining env*)
wenzelm@250
  1301
           val normp =
wenzelm@250
  1302
             if Envir.is_empty env then (tpairs, Bs @ As, C)
wenzelm@250
  1303
             else
wenzelm@250
  1304
             let val ntps = map (pairself normt) tpairs
paulson@2147
  1305
             in if Envir.above (smax, env) then
wenzelm@1238
  1306
                  (*no assignments in state; normalize the rule only*)
wenzelm@1238
  1307
                  if lifted
wenzelm@1238
  1308
                  then (ntps, Bs @ map (norm_term_skip env nlift) As, C)
wenzelm@1238
  1309
                  else (ntps, Bs @ map normt As, C)
paulson@1529
  1310
                else if match then raise COMPOSE
wenzelm@250
  1311
                else (*normalize the new rule fully*)
wenzelm@250
  1312
                  (ntps, map normt (Bs @ As), normt C)
wenzelm@250
  1313
             end
wenzelm@1258
  1314
           val th = (*tuned fix_shyps*)
wenzelm@3967
  1315
             Thm{sign_ref = sign_ref,
berghofe@11518
  1316
                 der = Pt.infer_derivs
berghofe@11518
  1317
                   ((if Envir.is_empty env then I
berghofe@11518
  1318
                     else if Envir.above (smax, env) then
berghofe@11518
  1319
                       (fn f => fn der => f (Pt.norm_proof' env der))
berghofe@11518
  1320
                     else
berghofe@11518
  1321
                       curry op oo (Pt.norm_proof' env))
berghofe@11518
  1322
                    (Pt.bicompose_proof Bs oldAs As A n)) rder' sder,
wenzelm@2386
  1323
                 maxidx = maxidx,
wenzelm@2386
  1324
                 shyps = add_env_sorts (env, union_sort(rshyps,sshyps)),
wenzelm@2386
  1325
                 hyps = union_term(rhyps,shyps),
wenzelm@2386
  1326
                 prop = Logic.rule_of normp}
berghofe@11518
  1327
        in  Seq.cons(th, thq)  end  handle COMPOSE => thq;
clasohm@0
  1328
     val (rtpairs,rhorn) = Logic.strip_flexpairs(rprop);
clasohm@0
  1329
     val (rAs,B) = Logic.strip_prems(nsubgoal, [], rhorn)
clasohm@0
  1330
       handle TERM _ => raise THM("bicompose: rule", 0, [orule,state]);
clasohm@0
  1331
     (*Modify assumptions, deleting n-th if n>0 for e-resolution*)
clasohm@0
  1332
     fun newAs(As0, n, dpairs, tpairs) =
berghofe@11518
  1333
       let val (As1, rder') =
berghofe@11518
  1334
         if !Logic.auto_rename orelse not lifted then (As0, rder)
berghofe@11518
  1335
         else (map (rename_bvars(dpairs,tpairs,B)) As0,
berghofe@11518
  1336
           Pt.infer_derivs' (Pt.map_proof_terms
berghofe@11518
  1337
             (rename_bvars (dpairs, tpairs, Bound 0)) I) rder);
berghofe@11518
  1338
       in (map (Logic.flatten_params n) As1, As1, rder', n)
wenzelm@250
  1339
          handle TERM _ =>
wenzelm@250
  1340
          raise THM("bicompose: 1st premise", 0, [orule])
clasohm@0
  1341
       end;
paulson@2147
  1342
     val env = Envir.empty(Int.max(rmax,smax));
clasohm@0
  1343
     val BBi = if lifted then strip_assums2(B,Bi) else (B,Bi);
clasohm@0
  1344
     val dpairs = BBi :: (rtpairs@stpairs);
clasohm@0
  1345
     (*elim-resolution: try each assumption in turn.  Initially n=1*)
berghofe@11518
  1346
     fun tryasms (_, _, _, []) = Seq.empty
berghofe@11518
  1347
       | tryasms (A, As, n, (t,u)::apairs) =
wenzelm@4270
  1348
          (case Seq.pull(Unify.unifiers(sign, env, (t,u)::dpairs))  of
berghofe@11518
  1349
               None                   => tryasms (A, As, n+1, apairs)
wenzelm@250
  1350
             | cell as Some((_,tpairs),_) =>
berghofe@11518
  1351
                   Seq.it_right (addth A (newAs(As, n, [BBi,(u,t)], tpairs)))
wenzelm@4270
  1352
                       (Seq.make (fn()=> cell),
berghofe@11518
  1353
                        Seq.make (fn()=> Seq.pull (tryasms (A, As, n+1, apairs)))));
clasohm@0
  1354
     fun eres [] = raise THM("bicompose: no premises", 0, [orule,state])
berghofe@11518
  1355
       | eres (A1::As) = tryasms (Some A1, As, 1, Logic.assum_pairs A1);
clasohm@0
  1356
     (*ordinary resolution*)
wenzelm@4270
  1357
     fun res(None) = Seq.empty
wenzelm@250
  1358
       | res(cell as Some((_,tpairs),_)) =
berghofe@11518
  1359
             Seq.it_right (addth None (newAs(rev rAs, 0, [BBi], tpairs)))
wenzelm@4270
  1360
                       (Seq.make (fn()=> cell), Seq.empty)
clasohm@0
  1361
 in  if eres_flg then eres(rev rAs)
wenzelm@4270
  1362
     else res(Seq.pull(Unify.unifiers(sign, env, dpairs)))
clasohm@0
  1363
 end;
wenzelm@7528
  1364
end;
clasohm@0
  1365
clasohm@0
  1366
clasohm@0
  1367
fun bicompose match arg i state =
clasohm@0
  1368
    bicompose_aux match (state, dest_state(state,i), false) arg;
clasohm@0
  1369
clasohm@0
  1370
(*Quick test whether rule is resolvable with the subgoal with hyps Hs
clasohm@0
  1371
  and conclusion B.  If eres_flg then checks 1st premise of rule also*)
clasohm@0
  1372
fun could_bires (Hs, B, eres_flg, rule) =
clasohm@0
  1373
    let fun could_reshyp (A1::_) = exists (apl(A1,could_unify)) Hs
wenzelm@250
  1374
          | could_reshyp [] = false;  (*no premise -- illegal*)
wenzelm@250
  1375
    in  could_unify(concl_of rule, B) andalso
wenzelm@250
  1376
        (not eres_flg  orelse  could_reshyp (prems_of rule))
clasohm@0
  1377
    end;
clasohm@0
  1378
clasohm@0
  1379
(*Bi-resolution of a state with a list of (flag,rule) pairs.
clasohm@0
  1380
  Puts the rule above:  rule/state.  Renames vars in the rules. *)
wenzelm@250
  1381
fun biresolution match brules i state =
clasohm@0
  1382
    let val lift = lift_rule(state, i);
wenzelm@250
  1383
        val (stpairs, Bs, Bi, C) = dest_state(state,i)
wenzelm@250
  1384
        val B = Logic.strip_assums_concl Bi;
wenzelm@250
  1385
        val Hs = Logic.strip_assums_hyp Bi;
wenzelm@250
  1386
        val comp = bicompose_aux match (state, (stpairs, Bs, Bi, C), true);
wenzelm@4270
  1387
        fun res [] = Seq.empty
wenzelm@250
  1388
          | res ((eres_flg, rule)::brules) =
wenzelm@250
  1389
              if could_bires (Hs, B, eres_flg, rule)
wenzelm@4270
  1390
              then Seq.make (*delay processing remainder till needed*)
wenzelm@250
  1391
                  (fn()=> Some(comp (eres_flg, lift rule, nprems_of rule),
wenzelm@250
  1392
                               res brules))
wenzelm@250
  1393
              else res brules
wenzelm@4270
  1394
    in  Seq.flat (res brules)  end;
clasohm@0
  1395
clasohm@0
  1396
wenzelm@2509
  1397
(*** Oracles ***)
wenzelm@2509
  1398
wenzelm@3812
  1399
fun invoke_oracle thy raw_name =
wenzelm@3812
  1400
  let
wenzelm@6390
  1401
    val {sign = sg, oracles, ...} = Theory.rep_theory thy;
wenzelm@3812
  1402
    val name = Sign.intern sg Theory.oracleK raw_name;
wenzelm@3812
  1403
    val oracle =
wenzelm@3812
  1404
      (case Symtab.lookup (oracles, name) of
wenzelm@3812
  1405
        None => raise THM ("Unknown oracle: " ^ name, 0, [])
wenzelm@3812
  1406
      | Some (f, _) => f);
wenzelm@3812
  1407
  in
wenzelm@3812
  1408
    fn (sign, exn) =>
wenzelm@3812
  1409
      let
wenzelm@3967
  1410
        val sign_ref' = Sign.merge_refs (Sign.self_ref sg, Sign.self_ref sign);
wenzelm@3967
  1411
        val sign' = Sign.deref sign_ref';
wenzelm@3812
  1412
        val (prop, T, maxidx) = Sign.certify_term sign' (oracle (sign', exn));
wenzelm@3812
  1413
      in
wenzelm@3812
  1414
        if T <> propT then
wenzelm@3812
  1415
          raise THM ("Oracle's result must have type prop: " ^ name, 0, [])
wenzelm@3812
  1416
        else fix_shyps [] []
wenzelm@3967
  1417
          (Thm {sign_ref = sign_ref', 
berghofe@11518
  1418
            der = (true, Pt.oracle_proof name prop),
wenzelm@3812
  1419
            maxidx = maxidx,
wenzelm@3812
  1420
            shyps = [], 
wenzelm@3812
  1421
            hyps = [], 
wenzelm@3812
  1422
            prop = prop})
wenzelm@3812
  1423
      end
wenzelm@3812
  1424
  end;
wenzelm@3812
  1425
paulson@1539
  1426
clasohm@0
  1427
end;
paulson@1503
  1428
wenzelm@6089
  1429
wenzelm@6089
  1430
structure BasicThm: BASIC_THM = Thm;
wenzelm@6089
  1431
open BasicThm;