src/Pure/thm.ML
author wenzelm
Thu Feb 28 19:24:00 2002 +0100 (2002-02-28)
changeset 12982 34a07757634d
parent 12923 9ba7c5358fa0
child 13528 d14fb18343cb
permissions -rw-r--r--
moved match_bvs, match_bvars, renAbs to term.ML;
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@4254
    54
  val transfer_sg	: Sign.sg -> thm -> thm
wenzelm@3895
    55
  val transfer		: theory -> thm -> thm
wenzelm@1238
    56
  val tpairs_of         : thm -> (term * term) list
wenzelm@1238
    57
  val prems_of          : thm -> term list
wenzelm@1238
    58
  val nprems_of         : thm -> int
wenzelm@1238
    59
  val concl_of          : thm -> term
wenzelm@1238
    60
  val cprop_of          : thm -> cterm
wenzelm@1238
    61
  val extra_shyps       : thm -> sort list
wenzelm@1238
    62
  val strip_shyps       : thm -> thm
wenzelm@3812
    63
  val get_axiom         : theory -> xstring -> thm
wenzelm@6368
    64
  val def_name		: string -> string
wenzelm@4847
    65
  val get_def           : theory -> xstring -> thm
wenzelm@1238
    66
  val axioms_of         : theory -> (string * thm) list
wenzelm@1160
    67
wenzelm@1160
    68
  (*meta rules*)
wenzelm@1238
    69
  val assume            : cterm -> thm
paulson@1416
    70
  val compress          : thm -> thm
wenzelm@1238
    71
  val implies_intr      : cterm -> thm -> thm
wenzelm@1238
    72
  val implies_elim      : thm -> thm -> thm
wenzelm@1238
    73
  val forall_intr       : cterm -> thm -> thm
wenzelm@1238
    74
  val forall_elim       : cterm -> thm -> thm
wenzelm@1238
    75
  val reflexive         : cterm -> thm
wenzelm@1238
    76
  val symmetric         : thm -> thm
wenzelm@1238
    77
  val transitive        : thm -> thm -> thm
berghofe@10416
    78
  val beta_conversion   : bool -> cterm -> thm
berghofe@10416
    79
  val eta_conversion    : cterm -> thm
wenzelm@1238
    80
  val abstract_rule     : string -> cterm -> thm -> thm
wenzelm@1238
    81
  val combination       : thm -> thm -> thm
wenzelm@1238
    82
  val equal_intr        : thm -> thm -> thm
wenzelm@1238
    83
  val equal_elim        : thm -> thm -> thm
wenzelm@1238
    84
  val implies_intr_hyps : thm -> thm
wenzelm@4270
    85
  val flexflex_rule     : thm -> thm Seq.seq
wenzelm@1238
    86
  val instantiate       :
wenzelm@1160
    87
    (indexname * ctyp) list * (cterm * cterm) list -> thm -> thm
wenzelm@1238
    88
  val trivial           : cterm -> thm
wenzelm@6368
    89
  val class_triv        : Sign.sg -> class -> thm
wenzelm@1238
    90
  val varifyT           : thm -> thm
wenzelm@12500
    91
  val varifyT'          : string list -> thm -> thm * (string * indexname) list
wenzelm@1238
    92
  val freezeT           : thm -> thm
wenzelm@1238
    93
  val dest_state        : thm * int ->
wenzelm@1160
    94
    (term * term) list * term list * term * term
wenzelm@1238
    95
  val lift_rule         : (thm * int) -> thm -> thm
berghofe@10416
    96
  val incr_indexes      : int -> thm -> thm
wenzelm@4270
    97
  val assumption        : int -> thm -> thm Seq.seq
wenzelm@1238
    98
  val eq_assumption     : int -> thm -> thm
paulson@2671
    99
  val rotate_rule       : int -> int -> thm -> thm
paulson@7248
   100
  val permute_prems     : int -> int -> thm -> thm
wenzelm@1160
   101
  val rename_params_rule: string list * int -> thm -> thm
wenzelm@1238
   102
  val bicompose         : bool -> bool * thm * int ->
wenzelm@4270
   103
    int -> thm -> thm Seq.seq
wenzelm@1238
   104
  val biresolution      : bool -> (bool * thm) list ->
wenzelm@4270
   105
    int -> thm -> thm Seq.seq
wenzelm@4999
   106
  val invoke_oracle     : theory -> xstring -> Sign.sg * Object.T -> thm
wenzelm@250
   107
end;
clasohm@0
   108
wenzelm@6089
   109
signature THM =
wenzelm@6089
   110
sig
wenzelm@6089
   111
  include BASIC_THM
wenzelm@10767
   112
  val dest_comb         : cterm -> cterm * cterm
wenzelm@10767
   113
  val dest_abs          : string option -> cterm -> cterm * cterm
wenzelm@10767
   114
  val capply            : cterm -> cterm -> cterm
wenzelm@10767
   115
  val cabs              : cterm -> cterm -> cterm
wenzelm@8299
   116
  val major_prem_of	: thm -> term
wenzelm@7534
   117
  val no_prems		: thm -> bool
wenzelm@6089
   118
  val no_attributes	: 'a -> 'a * 'b attribute list
wenzelm@6089
   119
  val apply_attributes	: ('a * thm) * 'a attribute list -> ('a * thm)
wenzelm@6089
   120
  val applys_attributes	: ('a * thm list) * 'a attribute list -> ('a * thm list)
wenzelm@6089
   121
  val get_name_tags	: thm -> string * tag list
wenzelm@6089
   122
  val put_name_tags	: string * tag list -> thm -> thm
wenzelm@6089
   123
  val name_of_thm	: thm -> string
wenzelm@6089
   124
  val tags_of_thm	: thm -> tag list
wenzelm@6089
   125
  val name_thm		: string * thm -> thm
berghofe@10416
   126
  val rename_boundvars  : term -> term -> thm -> thm
berghofe@10416
   127
  val cterm_match       : cterm * cterm ->
berghofe@10416
   128
    (indexname * ctyp) list * (cterm * cterm) list
berghofe@10416
   129
  val cterm_first_order_match : cterm * cterm ->
berghofe@10416
   130
    (indexname * ctyp) list * (cterm * cterm) list
berghofe@10416
   131
  val cterm_incr_indexes : int -> cterm -> cterm
wenzelm@6089
   132
end;
wenzelm@6089
   133
wenzelm@3550
   134
structure Thm: THM =
clasohm@0
   135
struct
wenzelm@250
   136
wenzelm@387
   137
(*** Certified terms and types ***)
wenzelm@387
   138
wenzelm@250
   139
(** certified types **)
wenzelm@250
   140
wenzelm@250
   141
(*certified typs under a signature*)
wenzelm@250
   142
wenzelm@3967
   143
datatype ctyp = Ctyp of {sign_ref: Sign.sg_ref, T: typ};
wenzelm@250
   144
wenzelm@3967
   145
fun rep_ctyp (Ctyp {sign_ref, T}) = {sign = Sign.deref sign_ref, T = T};
wenzelm@250
   146
fun typ_of (Ctyp {T, ...}) = T;
wenzelm@250
   147
wenzelm@250
   148
fun ctyp_of sign T =
wenzelm@3967
   149
  Ctyp {sign_ref = Sign.self_ref sign, T = Sign.certify_typ sign T};
wenzelm@250
   150
wenzelm@250
   151
fun read_ctyp sign s =
wenzelm@3967
   152
  Ctyp {sign_ref = Sign.self_ref sign, T = Sign.read_typ (sign, K None) s};
lcp@229
   153
lcp@229
   154
lcp@229
   155
wenzelm@250
   156
(** certified terms **)
lcp@229
   157
wenzelm@250
   158
(*certified terms under a signature, with checked typ and maxidx of Vars*)
lcp@229
   159
wenzelm@3967
   160
datatype cterm = Cterm of {sign_ref: Sign.sg_ref, t: term, T: typ, maxidx: int};
lcp@229
   161
wenzelm@3967
   162
fun rep_cterm (Cterm {sign_ref, t, T, maxidx}) =
wenzelm@3967
   163
  {sign = Sign.deref sign_ref, t = t, T = T, maxidx = maxidx};
wenzelm@3967
   164
wenzelm@4288
   165
fun crep_cterm (Cterm {sign_ref, t, T, maxidx}) =
wenzelm@4288
   166
  {sign = Sign.deref sign_ref, t = t, T = Ctyp {sign_ref = sign_ref, T = T},
wenzelm@4288
   167
    maxidx = maxidx};
wenzelm@4288
   168
wenzelm@9461
   169
fun sign_of_cterm (Cterm {sign_ref, ...}) = Sign.deref sign_ref;
wenzelm@9461
   170
wenzelm@250
   171
fun term_of (Cterm {t, ...}) = t;
lcp@229
   172
wenzelm@3967
   173
fun ctyp_of_term (Cterm {sign_ref, T, ...}) = Ctyp {sign_ref = sign_ref, T = T};
paulson@2671
   174
wenzelm@250
   175
(*create a cterm by checking a "raw" term with respect to a signature*)
wenzelm@250
   176
fun cterm_of sign tm =
wenzelm@250
   177
  let val (t, T, maxidx) = Sign.certify_term sign tm
wenzelm@3967
   178
  in  Cterm {sign_ref = Sign.self_ref sign, t = t, T = T, maxidx = maxidx}
paulson@1394
   179
  end;
lcp@229
   180
wenzelm@3967
   181
fun cterm_fun f (Cterm {sign_ref, t, ...}) = cterm_of (Sign.deref sign_ref) (f t);
wenzelm@250
   182
lcp@229
   183
clasohm@1493
   184
exception CTERM of string;
clasohm@1493
   185
clasohm@1493
   186
(*Destruct application in cterms*)
wenzelm@3967
   187
fun dest_comb (Cterm {sign_ref, T, maxidx, t = A $ B}) =
clasohm@1493
   188
      let val typeA = fastype_of A;
clasohm@1493
   189
          val typeB =
clasohm@1493
   190
            case typeA of Type("fun",[S,T]) => S
clasohm@1493
   191
                        | _ => error "Function type expected in dest_comb";
clasohm@1493
   192
      in
wenzelm@3967
   193
      (Cterm {sign_ref=sign_ref, maxidx=maxidx, t=A, T=typeA},
wenzelm@3967
   194
       Cterm {sign_ref=sign_ref, maxidx=maxidx, t=B, T=typeB})
clasohm@1493
   195
      end
clasohm@1493
   196
  | dest_comb _ = raise CTERM "dest_comb";
clasohm@1493
   197
clasohm@1493
   198
(*Destruct abstraction in cterms*)
berghofe@10416
   199
fun dest_abs a (Cterm {sign_ref, T as Type("fun",[_,S]), maxidx, t=Abs(x,ty,M)}) = 
berghofe@10416
   200
      let val (y,N) = variant_abs (if_none a x,ty,M)
wenzelm@3967
   201
      in (Cterm {sign_ref = sign_ref, T = ty, maxidx = 0, t = Free(y,ty)},
wenzelm@3967
   202
          Cterm {sign_ref = sign_ref, T = S, maxidx = maxidx, t = N})
clasohm@1493
   203
      end
berghofe@10416
   204
  | dest_abs _ _ = raise CTERM "dest_abs";
clasohm@1493
   205
paulson@2147
   206
(*Makes maxidx precise: it is often too big*)
wenzelm@3967
   207
fun adjust_maxidx (ct as Cterm {sign_ref, T, t, maxidx, ...}) =
paulson@2147
   208
  if maxidx = ~1 then ct 
wenzelm@3967
   209
  else  Cterm {sign_ref = sign_ref, T = T, maxidx = maxidx_of_term t, t = t};
clasohm@1703
   210
clasohm@1516
   211
(*Form cterm out of a function and an argument*)
wenzelm@3967
   212
fun capply (Cterm {t=f, sign_ref=sign_ref1, T=Type("fun",[dty,rty]), maxidx=maxidx1})
wenzelm@3967
   213
           (Cterm {t=x, sign_ref=sign_ref2, T, maxidx=maxidx2}) =
wenzelm@8291
   214
      if T = dty then
wenzelm@8291
   215
        Cterm{t=Sign.nodup_vars (f$x), sign_ref=Sign.merge_refs(sign_ref1,sign_ref2), T=rty,
wenzelm@8291
   216
          maxidx=Int.max(maxidx1, maxidx2)}
clasohm@1516
   217
      else raise CTERM "capply: types don't agree"
clasohm@1516
   218
  | capply _ _ = raise CTERM "capply: first arg is not a function"
wenzelm@250
   219
wenzelm@3967
   220
fun cabs (Cterm {t=Free(a,ty), sign_ref=sign_ref1, T=T1, maxidx=maxidx1})
wenzelm@3967
   221
         (Cterm {t=t2, sign_ref=sign_ref2, T=T2, maxidx=maxidx2}) =
wenzelm@8291
   222
      Cterm {t=Sign.nodup_vars (absfree(a,ty,t2)), sign_ref=Sign.merge_refs(sign_ref1,sign_ref2),
paulson@2147
   223
             T = ty --> T2, maxidx=Int.max(maxidx1, maxidx2)}
clasohm@1517
   224
  | cabs _ _ = raise CTERM "cabs: first arg is not a free variable";
lcp@229
   225
berghofe@10416
   226
(*Matching of cterms*)
berghofe@10416
   227
fun gen_cterm_match mtch
berghofe@10416
   228
      (Cterm {sign_ref = sign_ref1, maxidx = maxidx1, t = t1, ...},
berghofe@10416
   229
       Cterm {sign_ref = sign_ref2, maxidx = maxidx2, t = t2, ...}) =
berghofe@10416
   230
  let
berghofe@10416
   231
    val sign_ref = Sign.merge_refs (sign_ref1, sign_ref2);
berghofe@10416
   232
    val tsig = Sign.tsig_of (Sign.deref sign_ref);
berghofe@10416
   233
    val (Tinsts, tinsts) = mtch tsig (t1, t2);
berghofe@10416
   234
    val maxidx = Int.max (maxidx1, maxidx2);
berghofe@10416
   235
    val vars = map dest_Var (term_vars t1);
berghofe@10416
   236
    fun mk_cTinsts (ixn, T) = (ixn, Ctyp {sign_ref = sign_ref, T = T});
berghofe@10416
   237
    fun mk_ctinsts (ixn, t) =
berghofe@10416
   238
      let val T = typ_subst_TVars Tinsts (the (assoc (vars, ixn)))
berghofe@10416
   239
      in
berghofe@10416
   240
        (Cterm {sign_ref = sign_ref, maxidx = maxidx, T = T, t = Var (ixn, T)},
berghofe@10416
   241
         Cterm {sign_ref = sign_ref, maxidx = maxidx, T = T, t = t})
berghofe@10416
   242
      end;
berghofe@10416
   243
  in (map mk_cTinsts Tinsts, map mk_ctinsts tinsts) end;
berghofe@10416
   244
berghofe@10416
   245
val cterm_match = gen_cterm_match Pattern.match;
berghofe@10416
   246
val cterm_first_order_match = gen_cterm_match Pattern.first_order_match;
berghofe@10416
   247
berghofe@10416
   248
(*Incrementing indexes*)
berghofe@10416
   249
fun cterm_incr_indexes i (ct as Cterm {sign_ref, maxidx, t, T}) =
berghofe@10416
   250
  if i < 0 then raise CTERM "negative increment" else 
berghofe@10416
   251
  if i = 0 then ct else
berghofe@10416
   252
    Cterm {sign_ref = sign_ref, maxidx = maxidx + i,
berghofe@10416
   253
      t = Logic.incr_indexes ([], i) t, T = Term.incr_tvar i T};
berghofe@10416
   254
wenzelm@2509
   255
wenzelm@2509
   256
wenzelm@574
   257
(** read cterms **)   (*exception ERROR*)
wenzelm@250
   258
nipkow@4281
   259
(*read terms, infer types, certify terms*)
nipkow@4281
   260
fun read_def_cterms (sign, types, sorts) used freeze sTs =
wenzelm@250
   261
  let
wenzelm@8608
   262
    val (ts', tye) = Sign.read_def_terms (sign, types, sorts) used freeze sTs;
nipkow@4281
   263
    val cts = map (cterm_of sign) ts'
wenzelm@2979
   264
      handle TYPE (msg, _, _) => error msg
wenzelm@2386
   265
           | TERM (msg, _) => error msg;
nipkow@4281
   266
  in (cts, tye) end;
nipkow@4281
   267
nipkow@4281
   268
(*read term, infer types, certify term*)
nipkow@4281
   269
fun read_def_cterm args used freeze aT =
nipkow@4281
   270
  let val ([ct],tye) = read_def_cterms args used freeze [aT]
nipkow@4281
   271
  in (ct,tye) end;
lcp@229
   272
nipkow@949
   273
fun read_cterm sign = #1 o read_def_cterm (sign, K None, K None) [] true;
lcp@229
   274
wenzelm@250
   275
wenzelm@6089
   276
(*tags provide additional comment, apart from the axiom/theorem name*)
wenzelm@6089
   277
type tag = string * string list;
wenzelm@6089
   278
wenzelm@2509
   279
wenzelm@387
   280
(*** Meta theorems ***)
lcp@229
   281
berghofe@11518
   282
structure Pt = Proofterm;
berghofe@11518
   283
clasohm@0
   284
datatype thm = Thm of
wenzelm@3967
   285
 {sign_ref: Sign.sg_ref,       (*mutable reference to signature*)
berghofe@11518
   286
  der: bool * Pt.proof,        (*derivation*)
wenzelm@3967
   287
  maxidx: int,                 (*maximum index of any Var or TVar*)
wenzelm@3967
   288
  shyps: sort list,            (*sort hypotheses*)
wenzelm@3967
   289
  hyps: term list,             (*hypotheses*)
wenzelm@3967
   290
  prop: term};                 (*conclusion*)
clasohm@0
   291
wenzelm@3967
   292
fun rep_thm (Thm {sign_ref, der, maxidx, shyps, hyps, prop}) =
wenzelm@3967
   293
  {sign = Sign.deref sign_ref, der = der, maxidx = maxidx,
wenzelm@3967
   294
    shyps = shyps, hyps = hyps, prop = prop};
clasohm@0
   295
paulson@1529
   296
(*Version of rep_thm returning cterms instead of terms*)
wenzelm@3967
   297
fun crep_thm (Thm {sign_ref, der, maxidx, shyps, hyps, prop}) =
wenzelm@3967
   298
  let fun ctermf max t = Cterm{sign_ref=sign_ref, t=t, T=propT, maxidx=max};
wenzelm@3967
   299
  in {sign = Sign.deref sign_ref, der = der, maxidx = maxidx, shyps = shyps,
paulson@1529
   300
      hyps = map (ctermf ~1) hyps,
paulson@1529
   301
      prop = ctermf maxidx prop}
clasohm@1517
   302
  end;
clasohm@1517
   303
wenzelm@387
   304
(*errors involving theorems*)
clasohm@0
   305
exception THM of string * int * thm list;
clasohm@0
   306
wenzelm@6089
   307
(*attributes subsume any kind of rules or addXXXs modifiers*)
wenzelm@6089
   308
type 'a attribute = 'a * thm -> 'a * thm;
wenzelm@6089
   309
wenzelm@6089
   310
fun no_attributes x = (x, []);
wenzelm@6089
   311
fun apply_attributes (x_th, atts) = Library.apply atts x_th;
wenzelm@6089
   312
fun applys_attributes (x_ths, atts) = foldl_map (Library.apply atts) x_ths;
wenzelm@6089
   313
wenzelm@3994
   314
fun eq_thm (th1, th2) =
wenzelm@3994
   315
  let
berghofe@11518
   316
    val {sign = sg1, shyps = shyps1, hyps = hyps1, prop = prop1, ...} =
wenzelm@9031
   317
      rep_thm th1;
berghofe@11518
   318
    val {sign = sg2, shyps = shyps2, hyps = hyps2, prop = prop2, ...} =
wenzelm@9031
   319
      rep_thm th2;
wenzelm@3994
   320
  in
wenzelm@9031
   321
    Sign.joinable (sg1, sg2) andalso
wenzelm@3994
   322
    eq_set_sort (shyps1, shyps2) andalso
wenzelm@3994
   323
    aconvs (hyps1, hyps2) andalso
wenzelm@3994
   324
    prop1 aconv prop2
wenzelm@3994
   325
  end;
wenzelm@387
   326
wenzelm@3967
   327
fun sign_of_thm (Thm {sign_ref, ...}) = Sign.deref sign_ref;
wenzelm@12803
   328
fun prop_of (Thm {prop, ...}) = prop;
clasohm@0
   329
wenzelm@387
   330
(*merge signatures of two theorems; raise exception if incompatible*)
wenzelm@3967
   331
fun merge_thm_sgs
wenzelm@3967
   332
    (th1 as Thm {sign_ref = sgr1, ...}, th2 as Thm {sign_ref = sgr2, ...}) =
wenzelm@3967
   333
  Sign.merge_refs (sgr1, sgr2) handle TERM (msg, _) => raise THM (msg, 0, [th1, th2]);
wenzelm@387
   334
wenzelm@3967
   335
(*transfer thm to super theory (non-destructive)*)
wenzelm@4254
   336
fun transfer_sg sign' thm =
wenzelm@3895
   337
  let
wenzelm@3967
   338
    val Thm {sign_ref, der, maxidx, shyps, hyps, prop} = thm;
wenzelm@3967
   339
    val sign = Sign.deref sign_ref;
wenzelm@3895
   340
  in
wenzelm@4254
   341
    if Sign.eq_sg (sign, sign') then thm
wenzelm@4254
   342
    else if Sign.subsig (sign, sign') then
wenzelm@3967
   343
      Thm {sign_ref = Sign.self_ref sign', der = der, maxidx = maxidx,
wenzelm@3895
   344
        shyps = shyps, hyps = hyps, prop = prop}
wenzelm@3895
   345
    else raise THM ("transfer: not a super theory", 0, [thm])
wenzelm@3895
   346
  end;
wenzelm@387
   347
wenzelm@6390
   348
val transfer = transfer_sg o Theory.sign_of;
wenzelm@4254
   349
wenzelm@387
   350
(*maps object-rule to tpairs*)
wenzelm@387
   351
fun tpairs_of (Thm {prop, ...}) = #1 (Logic.strip_flexpairs prop);
wenzelm@387
   352
wenzelm@387
   353
(*maps object-rule to premises*)
wenzelm@387
   354
fun prems_of (Thm {prop, ...}) =
wenzelm@387
   355
  Logic.strip_imp_prems (Logic.skip_flexpairs prop);
clasohm@0
   356
clasohm@0
   357
(*counts premises in a rule*)
wenzelm@387
   358
fun nprems_of (Thm {prop, ...}) =
wenzelm@387
   359
  Logic.count_prems (Logic.skip_flexpairs prop, 0);
clasohm@0
   360
wenzelm@8299
   361
fun major_prem_of thm =
wenzelm@8299
   362
  (case prems_of thm of
wenzelm@11692
   363
    prem :: _ => Logic.strip_assums_concl prem
wenzelm@8299
   364
  | [] => raise THM ("major_prem_of: rule with no premises", 0, [thm]));
wenzelm@8299
   365
wenzelm@7534
   366
fun no_prems thm = nprems_of thm = 0;
wenzelm@7534
   367
wenzelm@387
   368
(*maps object-rule to conclusion*)
wenzelm@387
   369
fun concl_of (Thm {prop, ...}) = Logic.strip_imp_concl prop;
clasohm@0
   370
wenzelm@387
   371
(*the statement of any thm is a cterm*)
wenzelm@3967
   372
fun cprop_of (Thm {sign_ref, maxidx, prop, ...}) =
wenzelm@3967
   373
  Cterm {sign_ref = sign_ref, maxidx = maxidx, T = propT, t = prop};
lcp@229
   374
wenzelm@387
   375
clasohm@0
   376
wenzelm@1238
   377
(** sort contexts of theorems **)
wenzelm@1238
   378
wenzelm@1238
   379
(* basic utils *)
wenzelm@1238
   380
wenzelm@2163
   381
(*accumulate sorts suppressing duplicates; these are coded low levelly
wenzelm@1238
   382
  to improve efficiency a bit*)
wenzelm@1238
   383
wenzelm@1238
   384
fun add_typ_sorts (Type (_, Ts), Ss) = add_typs_sorts (Ts, Ss)
paulson@2177
   385
  | add_typ_sorts (TFree (_, S), Ss) = ins_sort(S,Ss)
paulson@2177
   386
  | add_typ_sorts (TVar (_, S), Ss) = ins_sort(S,Ss)
wenzelm@1238
   387
and add_typs_sorts ([], Ss) = Ss
wenzelm@1238
   388
  | add_typs_sorts (T :: Ts, Ss) = add_typs_sorts (Ts, add_typ_sorts (T, Ss));
wenzelm@1238
   389
wenzelm@1238
   390
fun add_term_sorts (Const (_, T), Ss) = add_typ_sorts (T, Ss)
wenzelm@1238
   391
  | add_term_sorts (Free (_, T), Ss) = add_typ_sorts (T, Ss)
wenzelm@1238
   392
  | add_term_sorts (Var (_, T), Ss) = add_typ_sorts (T, Ss)
wenzelm@1238
   393
  | add_term_sorts (Bound _, Ss) = Ss
paulson@2177
   394
  | add_term_sorts (Abs (_,T,t), Ss) = add_term_sorts (t, add_typ_sorts (T,Ss))
wenzelm@1238
   395
  | add_term_sorts (t $ u, Ss) = add_term_sorts (t, add_term_sorts (u, Ss));
wenzelm@1238
   396
wenzelm@1238
   397
fun add_terms_sorts ([], Ss) = Ss
paulson@2177
   398
  | add_terms_sorts (t::ts, Ss) = add_terms_sorts (ts, add_term_sorts (t,Ss));
wenzelm@1238
   399
berghofe@8407
   400
fun env_codT (Envir.Envir {iTs, ...}) = map snd (Vartab.dest iTs);
wenzelm@1258
   401
berghofe@8407
   402
fun add_env_sorts (Envir.Envir {iTs, asol, ...}, Ss) =
berghofe@8407
   403
  Vartab.foldl (add_term_sorts o swap o apsnd snd)
berghofe@8407
   404
    (Vartab.foldl (add_typ_sorts o swap o apsnd snd) (Ss, iTs), asol);
wenzelm@1258
   405
berghofe@10416
   406
fun add_insts_sorts ((iTs, is), Ss) =
berghofe@10416
   407
  add_typs_sorts (map snd iTs, add_terms_sorts (map snd is, Ss));
berghofe@10416
   408
wenzelm@1238
   409
fun add_thm_sorts (Thm {hyps, prop, ...}, Ss) =
wenzelm@1238
   410
  add_terms_sorts (hyps, add_term_sorts (prop, Ss));
wenzelm@1238
   411
wenzelm@1238
   412
fun add_thms_shyps ([], Ss) = Ss
wenzelm@1238
   413
  | add_thms_shyps (Thm {shyps, ...} :: ths, Ss) =
wenzelm@7642
   414
      add_thms_shyps (ths, union_sort (shyps, Ss));
wenzelm@1238
   415
wenzelm@1238
   416
wenzelm@1238
   417
(*get 'dangling' sort constraints of a thm*)
wenzelm@1238
   418
fun extra_shyps (th as Thm {shyps, ...}) =
wenzelm@7642
   419
  Term.rems_sort (shyps, add_thm_sorts (th, []));
wenzelm@1238
   420
wenzelm@1238
   421
wenzelm@1238
   422
(* fix_shyps *)
wenzelm@1238
   423
wenzelm@7642
   424
fun all_sorts_nonempty sign_ref = is_some (Sign.univ_witness (Sign.deref sign_ref));
wenzelm@7642
   425
wenzelm@1238
   426
(*preserve sort contexts of rule premises and substituted types*)
wenzelm@7642
   427
fun fix_shyps thms Ts (thm as Thm {sign_ref, der, maxidx, hyps, prop, ...}) =
wenzelm@7642
   428
  Thm
wenzelm@7642
   429
   {sign_ref = sign_ref,
wenzelm@7642
   430
    der = der,             (*no new derivation, as other rules call this*)
wenzelm@7642
   431
    maxidx = maxidx,
wenzelm@7642
   432
    shyps =
wenzelm@7642
   433
      if all_sorts_nonempty sign_ref then []
wenzelm@7642
   434
      else add_thm_sorts (thm, add_typs_sorts (Ts, add_thms_shyps (thms, []))),
wenzelm@7642
   435
    hyps = hyps, prop = prop}
wenzelm@1238
   436
wenzelm@1238
   437
wenzelm@7642
   438
(* strip_shyps *)
wenzelm@1238
   439
wenzelm@7642
   440
(*remove extra sorts that are non-empty by virtue of type signature information*)
wenzelm@7642
   441
fun strip_shyps (thm as Thm {shyps = [], ...}) = thm
wenzelm@7642
   442
  | strip_shyps (thm as Thm {sign_ref, der, maxidx, shyps, hyps, prop}) =
wenzelm@7642
   443
      let
wenzelm@7642
   444
        val sign = Sign.deref sign_ref;
wenzelm@1238
   445
wenzelm@7642
   446
        val present_sorts = add_thm_sorts (thm, []);
wenzelm@7642
   447
        val extra_shyps = Term.rems_sort (shyps, present_sorts);
wenzelm@7642
   448
        val witnessed_shyps = Sign.witness_sorts sign present_sorts extra_shyps;
wenzelm@7642
   449
      in
wenzelm@7642
   450
        Thm {sign_ref = sign_ref, der = der, maxidx = maxidx,
wenzelm@7642
   451
             shyps = Term.rems_sort (shyps, map #2 witnessed_shyps),
wenzelm@7642
   452
             hyps = hyps, prop = prop}
wenzelm@7642
   453
      end;
wenzelm@1238
   454
wenzelm@1238
   455
wenzelm@1238
   456
paulson@1529
   457
(** Axioms **)
wenzelm@387
   458
wenzelm@387
   459
(*look up the named axiom in the theory*)
wenzelm@3812
   460
fun get_axiom theory raw_name =
wenzelm@387
   461
  let
wenzelm@4847
   462
    val name = Sign.intern (Theory.sign_of theory) Theory.axiomK raw_name;
wenzelm@4847
   463
wenzelm@4847
   464
    fun get_ax [] = None
paulson@1529
   465
      | get_ax (thy :: thys) =
wenzelm@4847
   466
          let val {sign, axioms, ...} = Theory.rep_theory thy in
wenzelm@4847
   467
            (case Symtab.lookup (axioms, name) of
wenzelm@4847
   468
              Some t =>
wenzelm@4847
   469
                Some (fix_shyps [] []
wenzelm@4847
   470
                  (Thm {sign_ref = Sign.self_ref sign,
berghofe@11518
   471
                    der = Pt.infer_derivs' I
berghofe@11518
   472
                      (false, Pt.axm_proof name t),
wenzelm@4847
   473
                    maxidx = maxidx_of_term t,
wenzelm@4847
   474
                    shyps = [], 
wenzelm@4847
   475
                    hyps = [], 
wenzelm@4847
   476
                    prop = t}))
wenzelm@4847
   477
            | None => get_ax thys)
paulson@1529
   478
          end;
wenzelm@387
   479
  in
wenzelm@4847
   480
    (case get_ax (theory :: Theory.ancestors_of theory) of
wenzelm@4847
   481
      Some thm => thm
wenzelm@4847
   482
    | None => raise THEORY ("No axiom " ^ quote name, [theory]))
wenzelm@387
   483
  end;
wenzelm@387
   484
wenzelm@6368
   485
fun def_name name = name ^ "_def";
wenzelm@6368
   486
fun get_def thy = get_axiom thy o def_name;
wenzelm@4847
   487
paulson@1529
   488
wenzelm@776
   489
(*return additional axioms of this theory node*)
wenzelm@776
   490
fun axioms_of thy =
wenzelm@776
   491
  map (fn (s, _) => (s, get_axiom thy s))
wenzelm@6390
   492
    (Symtab.dest (#axioms (Theory.rep_theory thy)));
wenzelm@776
   493
wenzelm@6089
   494
wenzelm@6089
   495
(* name and tags -- make proof objects more readable *)
wenzelm@6089
   496
wenzelm@12923
   497
fun get_name_tags (Thm {hyps, prop, der = (_, prf), ...}) =
wenzelm@12923
   498
  Pt.get_name_tags hyps prop prf;
wenzelm@4018
   499
berghofe@11518
   500
fun put_name_tags x (Thm {sign_ref, der = (ora, prf), maxidx, shyps, hyps, prop}) =
berghofe@11518
   501
  Thm {sign_ref = sign_ref,
berghofe@11518
   502
    der = (ora, Pt.thm_proof (Sign.deref sign_ref) x hyps prop prf),
berghofe@11518
   503
    maxidx = maxidx, shyps = shyps, hyps = hyps, prop = prop};
wenzelm@6089
   504
wenzelm@6089
   505
val name_of_thm = #1 o get_name_tags;
wenzelm@6089
   506
val tags_of_thm = #2 o get_name_tags;
wenzelm@6089
   507
wenzelm@6089
   508
fun name_thm (name, thm) = put_name_tags (name, tags_of_thm thm) thm;
clasohm@0
   509
clasohm@0
   510
paulson@1529
   511
(*Compression of theorems -- a separate rule, not integrated with the others,
paulson@1529
   512
  as it could be slow.*)
wenzelm@3967
   513
fun compress (Thm {sign_ref, der, maxidx, shyps, hyps, prop}) = 
wenzelm@3967
   514
    Thm {sign_ref = sign_ref, 
wenzelm@2386
   515
         der = der,     (*No derivation recorded!*)
wenzelm@2386
   516
         maxidx = maxidx,
wenzelm@2386
   517
         shyps = shyps, 
wenzelm@2386
   518
         hyps = map Term.compress_term hyps, 
wenzelm@2386
   519
         prop = Term.compress_term prop};
wenzelm@564
   520
wenzelm@387
   521
wenzelm@2509
   522
paulson@1529
   523
(*** Meta rules ***)
clasohm@0
   524
paulson@2147
   525
(*Check that term does not contain same var with different typing/sorting.
paulson@2147
   526
  If this check must be made, recalculate maxidx in hope of preventing its
paulson@2147
   527
  recurrence.*)
wenzelm@8291
   528
fun nodup_vars (thm as Thm{sign_ref, der, maxidx, shyps, hyps, prop}) s =
wenzelm@8296
   529
  Thm {sign_ref = sign_ref, 
wenzelm@2386
   530
         der = der,     
wenzelm@2386
   531
         maxidx = maxidx_of_term prop,
wenzelm@2386
   532
         shyps = shyps, 
wenzelm@2386
   533
         hyps = hyps, 
wenzelm@8296
   534
         prop = Sign.nodup_vars prop}
paulson@2147
   535
  handle TYPE(msg,Ts,ts) => raise TYPE(s^": "^msg,Ts,ts);
nipkow@1495
   536
wenzelm@8291
   537
wenzelm@1220
   538
(** 'primitive' rules **)
wenzelm@1220
   539
wenzelm@1220
   540
(*discharge all assumptions t from ts*)
clasohm@0
   541
val disch = gen_rem (op aconv);
clasohm@0
   542
wenzelm@1220
   543
(*The assumption rule A|-A in a theory*)
wenzelm@5344
   544
fun assume raw_ct : thm =
wenzelm@5344
   545
  let val ct as Cterm {sign_ref, t=prop, T, maxidx} = adjust_maxidx raw_ct
wenzelm@250
   546
  in  if T<>propT then
wenzelm@250
   547
        raise THM("assume: assumptions must have type prop", 0, [])
clasohm@0
   548
      else if maxidx <> ~1 then
wenzelm@250
   549
        raise THM("assume: assumptions may not contain scheme variables",
wenzelm@250
   550
                  maxidx, [])
wenzelm@3967
   551
      else Thm{sign_ref   = sign_ref,
berghofe@11518
   552
               der    = Pt.infer_derivs' I (false, Pt.Hyp prop),
wenzelm@2386
   553
               maxidx = ~1, 
wenzelm@2386
   554
               shyps  = add_term_sorts(prop,[]), 
wenzelm@2386
   555
               hyps   = [prop], 
wenzelm@2386
   556
               prop   = prop}
clasohm@0
   557
  end;
clasohm@0
   558
wenzelm@1220
   559
(*Implication introduction
wenzelm@3529
   560
    [A]
wenzelm@3529
   561
     :
wenzelm@3529
   562
     B
wenzelm@1220
   563
  -------
wenzelm@1220
   564
  A ==> B
wenzelm@1220
   565
*)
berghofe@10416
   566
fun implies_intr cA (thB as Thm{sign_ref,der,maxidx,hyps,shyps,prop}) : thm =
wenzelm@3967
   567
  let val Cterm {sign_ref=sign_refA, t=A, T, maxidx=maxidxA} = cA
clasohm@0
   568
  in  if T<>propT then
wenzelm@250
   569
        raise THM("implies_intr: assumptions must have type prop", 0, [thB])
berghofe@10416
   570
      else
berghofe@10416
   571
         Thm{sign_ref = Sign.merge_refs (sign_ref,sign_refA),  
berghofe@11518
   572
             der = Pt.infer_derivs' (Pt.implies_intr_proof A) der,
wenzelm@2386
   573
             maxidx = Int.max(maxidxA, maxidx),
berghofe@10416
   574
             shyps = add_term_sorts (A, shyps),
wenzelm@2386
   575
             hyps = disch(hyps,A),
berghofe@10416
   576
             prop = implies$A$prop}
clasohm@0
   577
      handle TERM _ =>
clasohm@0
   578
        raise THM("implies_intr: incompatible signatures", 0, [thB])
clasohm@0
   579
  end;
clasohm@0
   580
paulson@1529
   581
wenzelm@1220
   582
(*Implication elimination
wenzelm@1220
   583
  A ==> B    A
wenzelm@1220
   584
  ------------
wenzelm@1220
   585
        B
wenzelm@1220
   586
*)
clasohm@0
   587
fun implies_elim thAB thA : thm =
berghofe@10416
   588
    let val Thm{maxidx=maxA, der=derA, hyps=hypsA, shyps=shypsA, prop=propA, ...} = thA
berghofe@10416
   589
        and Thm{der, maxidx, hyps, shyps, prop, ...} = thAB;
wenzelm@250
   590
        fun err(a) = raise THM("implies_elim: "^a, 0, [thAB,thA])
clasohm@0
   591
    in  case prop of
wenzelm@250
   592
            imp$A$B =>
wenzelm@250
   593
                if imp=implies andalso  A aconv propA
berghofe@10416
   594
                then
berghofe@10416
   595
                  Thm{sign_ref= merge_thm_sgs(thAB,thA),
berghofe@11612
   596
                      der = Pt.infer_derivs (curry Pt.%%) der derA,
berghofe@10416
   597
                      maxidx = Int.max(maxA,maxidx),
berghofe@10416
   598
                      shyps = union_sort (shypsA, shyps),
berghofe@10416
   599
                      hyps = union_term(hypsA,hyps),  (*dups suppressed*)
berghofe@10416
   600
                      prop = B}
wenzelm@250
   601
                else err("major premise")
wenzelm@250
   602
          | _ => err("major premise")
clasohm@0
   603
    end;
wenzelm@250
   604
wenzelm@1220
   605
(*Forall introduction.  The Free or Var x must not be free in the hypotheses.
wenzelm@1220
   606
    A
wenzelm@1220
   607
  -----
wenzelm@1220
   608
  !!x.A
wenzelm@1220
   609
*)
wenzelm@3967
   610
fun forall_intr cx (th as Thm{sign_ref,der,maxidx,hyps,prop,...}) =
lcp@229
   611
  let val x = term_of cx;
wenzelm@1238
   612
      fun result(a,T) = fix_shyps [th] []
wenzelm@3967
   613
        (Thm{sign_ref = sign_ref, 
berghofe@11518
   614
             der = Pt.infer_derivs' (Pt.forall_intr_proof x a) der,
wenzelm@2386
   615
             maxidx = maxidx,
wenzelm@2386
   616
             shyps = [],
wenzelm@2386
   617
             hyps = hyps,
wenzelm@2386
   618
             prop = all(T) $ Abs(a, T, abstract_over (x,prop))})
clasohm@0
   619
  in  case x of
wenzelm@250
   620
        Free(a,T) =>
wenzelm@250
   621
          if exists (apl(x, Logic.occs)) hyps
wenzelm@250
   622
          then  raise THM("forall_intr: variable free in assumptions", 0, [th])
wenzelm@250
   623
          else  result(a,T)
clasohm@0
   624
      | Var((a,_),T) => result(a,T)
clasohm@0
   625
      | _ => raise THM("forall_intr: not a variable", 0, [th])
clasohm@0
   626
  end;
clasohm@0
   627
wenzelm@1220
   628
(*Forall elimination
wenzelm@1220
   629
  !!x.A
wenzelm@1220
   630
  ------
wenzelm@1220
   631
  A[t/x]
wenzelm@1220
   632
*)
wenzelm@3967
   633
fun forall_elim ct (th as Thm{sign_ref,der,maxidx,hyps,prop,...}) : thm =
wenzelm@3967
   634
  let val Cterm {sign_ref=sign_reft, t, T, maxidx=maxt} = ct
clasohm@0
   635
  in  case prop of
wenzelm@2386
   636
        Const("all",Type("fun",[Type("fun",[qary,_]),_])) $ A =>
wenzelm@2386
   637
          if T<>qary then
wenzelm@2386
   638
              raise THM("forall_elim: type mismatch", 0, [th])
wenzelm@2386
   639
          else let val thm = fix_shyps [th] []
wenzelm@3967
   640
                    (Thm{sign_ref= Sign.merge_refs(sign_ref,sign_reft),
berghofe@11612
   641
                         der = Pt.infer_derivs' (Pt.% o rpair (Some t)) der,
wenzelm@2386
   642
                         maxidx = Int.max(maxidx, maxt),
wenzelm@2386
   643
                         shyps = [],
wenzelm@2386
   644
                         hyps = hyps,  
wenzelm@2386
   645
                         prop = betapply(A,t)})
wenzelm@2386
   646
               in if maxt >= 0 andalso maxidx >= 0
wenzelm@8291
   647
                  then nodup_vars thm "forall_elim" 
wenzelm@2386
   648
                  else thm (*no new Vars: no expensive check!*)
wenzelm@2386
   649
               end
paulson@2147
   650
      | _ => raise THM("forall_elim: not quantified", 0, [th])
clasohm@0
   651
  end
clasohm@0
   652
  handle TERM _ =>
wenzelm@250
   653
         raise THM("forall_elim: incompatible signatures", 0, [th]);
clasohm@0
   654
clasohm@0
   655
wenzelm@1220
   656
(* Equality *)
clasohm@0
   657
clasohm@0
   658
(*The reflexivity rule: maps  t   to the theorem   t==t   *)
wenzelm@250
   659
fun reflexive ct =
wenzelm@3967
   660
  let val Cterm {sign_ref, t, T, maxidx} = ct
berghofe@10416
   661
  in Thm{sign_ref= sign_ref, 
berghofe@11518
   662
         der = Pt.infer_derivs' I (false, Pt.reflexive),
berghofe@10416
   663
         shyps = add_term_sorts (t, []),
berghofe@10416
   664
         hyps = [], 
berghofe@10416
   665
         maxidx = maxidx,
berghofe@10416
   666
         prop = Logic.mk_equals(t,t)}
clasohm@0
   667
  end;
clasohm@0
   668
clasohm@0
   669
(*The symmetry rule
wenzelm@1220
   670
  t==u
wenzelm@1220
   671
  ----
wenzelm@1220
   672
  u==t
wenzelm@1220
   673
*)
wenzelm@3967
   674
fun symmetric (th as Thm{sign_ref,der,maxidx,shyps,hyps,prop}) =
clasohm@0
   675
  case prop of
berghofe@11518
   676
      (eq as Const("==", Type (_, [T, _]))) $ t $ u =>
wenzelm@1238
   677
        (*no fix_shyps*)
wenzelm@3967
   678
          Thm{sign_ref = sign_ref,
berghofe@11518
   679
              der = Pt.infer_derivs' Pt.symmetric der,
wenzelm@2386
   680
              maxidx = maxidx,
wenzelm@2386
   681
              shyps = shyps,
wenzelm@2386
   682
              hyps = hyps,
wenzelm@2386
   683
              prop = eq$u$t}
clasohm@0
   684
    | _ => raise THM("symmetric", 0, [th]);
clasohm@0
   685
clasohm@0
   686
(*The transitive rule
wenzelm@1220
   687
  t1==u    u==t2
wenzelm@1220
   688
  --------------
wenzelm@1220
   689
      t1==t2
wenzelm@1220
   690
*)
clasohm@0
   691
fun transitive th1 th2 =
berghofe@10416
   692
  let val Thm{der=der1, maxidx=max1, hyps=hyps1, shyps=shyps1, prop=prop1,...} = th1
berghofe@10416
   693
      and Thm{der=der2, maxidx=max2, hyps=hyps2, shyps=shyps2, prop=prop2,...} = th2;
clasohm@0
   694
      fun err(msg) = raise THM("transitive: "^msg, 0, [th1,th2])
clasohm@0
   695
  in case (prop1,prop2) of
berghofe@11518
   696
       ((eq as Const("==", Type (_, [T, _]))) $ t1 $ u, Const("==",_) $ u' $ t2) =>
nipkow@1634
   697
          if not (u aconv u') then err"middle term"
nipkow@1634
   698
          else let val thm =      
berghofe@10416
   699
                 Thm{sign_ref= merge_thm_sgs(th1,th2), 
berghofe@11518
   700
                     der = Pt.infer_derivs (Pt.transitive u T) der1 der2,
paulson@2147
   701
                     maxidx = Int.max(max1,max2), 
berghofe@10416
   702
                     shyps = union_sort (shyps1, shyps2),
wenzelm@2386
   703
                     hyps = union_term(hyps1,hyps2),
berghofe@10416
   704
                     prop = eq$t1$t2}
paulson@2139
   705
                 in if max1 >= 0 andalso max2 >= 0
wenzelm@8291
   706
                    then nodup_vars thm "transitive" 
paulson@2147
   707
                    else thm (*no new Vars: no expensive check!*)
paulson@2139
   708
                 end
clasohm@0
   709
     | _ =>  err"premises"
clasohm@0
   710
  end;
clasohm@0
   711
berghofe@10416
   712
(*Beta-conversion: maps (%x.t)(u) to the theorem (%x.t)(u) == t[u/x]
berghofe@10416
   713
  Fully beta-reduces the term if full=true
berghofe@10416
   714
*)
berghofe@10416
   715
fun beta_conversion full ct =
wenzelm@3967
   716
  let val Cterm {sign_ref, t, T, maxidx} = ct
berghofe@10416
   717
  in Thm
berghofe@10416
   718
    {sign_ref = sign_ref,  
berghofe@11518
   719
     der = Pt.infer_derivs' I (false, Pt.reflexive),
berghofe@10416
   720
     maxidx = maxidx,
berghofe@10416
   721
     shyps = add_term_sorts (t, []),
berghofe@10416
   722
     hyps = [],
wenzelm@10486
   723
     prop = Logic.mk_equals (t, if full then Envir.beta_norm t
berghofe@10416
   724
       else case t of
berghofe@10416
   725
          Abs(_, _, bodt) $ u => subst_bound (u, bodt)
berghofe@10416
   726
        | _ => raise THM ("beta_conversion: not a redex", 0, []))}
berghofe@10416
   727
  end;
berghofe@10416
   728
berghofe@10416
   729
fun eta_conversion ct =
berghofe@10416
   730
  let val Cterm {sign_ref, t, T, maxidx} = ct
berghofe@10416
   731
  in Thm
berghofe@10416
   732
    {sign_ref = sign_ref,  
berghofe@11518
   733
     der = Pt.infer_derivs' I (false, Pt.reflexive),
berghofe@10416
   734
     maxidx = maxidx,
berghofe@10416
   735
     shyps = add_term_sorts (t, []),
berghofe@10416
   736
     hyps = [],
berghofe@10416
   737
     prop = Logic.mk_equals (t, Pattern.eta_contract t)}
clasohm@0
   738
  end;
clasohm@0
   739
clasohm@0
   740
(*The abstraction rule.  The Free or Var x must not be free in the hypotheses.
clasohm@0
   741
  The bound variable will be named "a" (since x will be something like x320)
wenzelm@1220
   742
     t == u
wenzelm@1220
   743
  ------------
wenzelm@1220
   744
  %x.t == %x.u
wenzelm@1220
   745
*)
berghofe@10416
   746
fun abstract_rule a cx (th as Thm{sign_ref,der,maxidx,hyps,shyps,prop}) =
lcp@229
   747
  let val x = term_of cx;
wenzelm@250
   748
      val (t,u) = Logic.dest_equals prop
wenzelm@250
   749
            handle TERM _ =>
wenzelm@250
   750
                raise THM("abstract_rule: premise not an equality", 0, [th])
berghofe@10416
   751
      fun result T =
berghofe@10416
   752
           Thm{sign_ref = sign_ref,
berghofe@11518
   753
               der = Pt.infer_derivs' (Pt.abstract_rule x a) der,
wenzelm@2386
   754
               maxidx = maxidx, 
berghofe@10416
   755
               shyps = add_typ_sorts (T, shyps), 
wenzelm@2386
   756
               hyps = hyps,
wenzelm@2386
   757
               prop = Logic.mk_equals(Abs(a, T, abstract_over (x,t)),
berghofe@10416
   758
                                      Abs(a, T, abstract_over (x,u)))}
clasohm@0
   759
  in  case x of
wenzelm@250
   760
        Free(_,T) =>
wenzelm@250
   761
         if exists (apl(x, Logic.occs)) hyps
wenzelm@250
   762
         then raise THM("abstract_rule: variable free in assumptions", 0, [th])
wenzelm@250
   763
         else result T
clasohm@0
   764
      | Var(_,T) => result T
clasohm@0
   765
      | _ => raise THM("abstract_rule: not a variable", 0, [th])
clasohm@0
   766
  end;
clasohm@0
   767
clasohm@0
   768
(*The combination rule
wenzelm@3529
   769
  f == g  t == u
wenzelm@3529
   770
  --------------
wenzelm@3529
   771
   f(t) == g(u)
wenzelm@1220
   772
*)
clasohm@0
   773
fun combination th1 th2 =
paulson@1529
   774
  let val Thm{der=der1, maxidx=max1, shyps=shyps1, hyps=hyps1, 
wenzelm@2386
   775
              prop=prop1,...} = th1
paulson@1529
   776
      and Thm{der=der2, maxidx=max2, shyps=shyps2, hyps=hyps2, 
wenzelm@2386
   777
              prop=prop2,...} = th2
berghofe@10416
   778
      fun chktypes fT tT =
berghofe@10416
   779
            (case fT of
wenzelm@2386
   780
                Type("fun",[T1,T2]) => 
berghofe@10416
   781
                    if T1 <> tT then
wenzelm@2386
   782
                         raise THM("combination: types", 0, [th1,th2])
wenzelm@2386
   783
                    else ()
wenzelm@2386
   784
                | _ => raise THM("combination: not function type", 0, 
wenzelm@2386
   785
                                 [th1,th2]))
nipkow@1495
   786
  in case (prop1,prop2)  of
berghofe@10416
   787
       (Const ("==", Type ("fun", [fT, _])) $ f $ g,
berghofe@10416
   788
        Const ("==", Type ("fun", [tT, _])) $ t $ u) =>
berghofe@10416
   789
          let val _   = chktypes fT tT
wenzelm@2386
   790
              val thm = (*no fix_shyps*)
wenzelm@3967
   791
                        Thm{sign_ref = merge_thm_sgs(th1,th2), 
berghofe@11518
   792
                            der = Pt.infer_derivs
berghofe@11518
   793
                              (Pt.combination f g t u fT) der1 der2,
wenzelm@2386
   794
                            maxidx = Int.max(max1,max2), 
wenzelm@2386
   795
                            shyps = union_sort(shyps1,shyps2),
wenzelm@2386
   796
                            hyps = union_term(hyps1,hyps2),
wenzelm@2386
   797
                            prop = Logic.mk_equals(f$t, g$u)}
paulson@2139
   798
          in if max1 >= 0 andalso max2 >= 0
wenzelm@8291
   799
             then nodup_vars thm "combination" 
wenzelm@2386
   800
             else thm (*no new Vars: no expensive check!*)  
paulson@2139
   801
          end
clasohm@0
   802
     | _ =>  raise THM("combination: premises", 0, [th1,th2])
clasohm@0
   803
  end;
clasohm@0
   804
clasohm@0
   805
clasohm@0
   806
(* Equality introduction
wenzelm@3529
   807
  A ==> B  B ==> A
wenzelm@3529
   808
  ----------------
wenzelm@3529
   809
       A == B
wenzelm@1220
   810
*)
clasohm@0
   811
fun equal_intr th1 th2 =
berghofe@11518
   812
  let val Thm{der=der1, maxidx=max1, shyps=shyps1, hyps=hyps1, 
wenzelm@2386
   813
              prop=prop1,...} = th1
paulson@1529
   814
      and Thm{der=der2, maxidx=max2, shyps=shyps2, hyps=hyps2, 
wenzelm@2386
   815
              prop=prop2,...} = th2;
paulson@1529
   816
      fun err(msg) = raise THM("equal_intr: "^msg, 0, [th1,th2])
paulson@1529
   817
  in case (prop1,prop2) of
paulson@1529
   818
       (Const("==>",_) $ A $ B, Const("==>",_) $ B' $ A')  =>
wenzelm@2386
   819
          if A aconv A' andalso B aconv B'
wenzelm@2386
   820
          then
wenzelm@2386
   821
            (*no fix_shyps*)
wenzelm@3967
   822
              Thm{sign_ref = merge_thm_sgs(th1,th2),
berghofe@11518
   823
                  der = Pt.infer_derivs (Pt.equal_intr A B) der1 der2,
wenzelm@2386
   824
                  maxidx = Int.max(max1,max2),
wenzelm@2386
   825
                  shyps = union_sort(shyps1,shyps2),
wenzelm@2386
   826
                  hyps = union_term(hyps1,hyps2),
wenzelm@2386
   827
                  prop = Logic.mk_equals(A,B)}
wenzelm@2386
   828
          else err"not equal"
paulson@1529
   829
     | _ =>  err"premises"
paulson@1529
   830
  end;
paulson@1529
   831
paulson@1529
   832
paulson@1529
   833
(*The equal propositions rule
wenzelm@3529
   834
  A == B  A
paulson@1529
   835
  ---------
paulson@1529
   836
      B
paulson@1529
   837
*)
paulson@1529
   838
fun equal_elim th1 th2 =
paulson@1529
   839
  let val Thm{der=der1, maxidx=max1, hyps=hyps1, prop=prop1,...} = th1
paulson@1529
   840
      and Thm{der=der2, maxidx=max2, hyps=hyps2, prop=prop2,...} = th2;
paulson@1529
   841
      fun err(msg) = raise THM("equal_elim: "^msg, 0, [th1,th2])
paulson@1529
   842
  in  case prop1  of
paulson@1529
   843
       Const("==",_) $ A $ B =>
paulson@1529
   844
          if not (prop2 aconv A) then err"not equal"  else
paulson@1529
   845
            fix_shyps [th1, th2] []
wenzelm@3967
   846
              (Thm{sign_ref= merge_thm_sgs(th1,th2), 
berghofe@11518
   847
                   der = Pt.infer_derivs (Pt.equal_elim A B) der1 der2,
wenzelm@2386
   848
                   maxidx = Int.max(max1,max2),
wenzelm@2386
   849
                   shyps = [],
wenzelm@2386
   850
                   hyps = union_term(hyps1,hyps2),
wenzelm@2386
   851
                   prop = B})
paulson@1529
   852
     | _ =>  err"major premise"
paulson@1529
   853
  end;
clasohm@0
   854
wenzelm@1220
   855
wenzelm@1220
   856
clasohm@0
   857
(**** Derived rules ****)
clasohm@0
   858
paulson@1503
   859
(*Discharge all hypotheses.  Need not verify cterms or call fix_shyps.
clasohm@0
   860
  Repeated hypotheses are discharged only once;  fold cannot do this*)
wenzelm@3967
   861
fun implies_intr_hyps (Thm{sign_ref, der, maxidx, shyps, hyps=A::As, prop}) =
wenzelm@1238
   862
      implies_intr_hyps (*no fix_shyps*)
wenzelm@3967
   863
            (Thm{sign_ref = sign_ref, 
berghofe@11518
   864
                 der = Pt.infer_derivs' (Pt.implies_intr_proof A) der,
wenzelm@2386
   865
                 maxidx = maxidx, 
wenzelm@2386
   866
                 shyps = shyps,
paulson@1529
   867
                 hyps = disch(As,A),  
wenzelm@2386
   868
                 prop = implies$A$prop})
clasohm@0
   869
  | implies_intr_hyps th = th;
clasohm@0
   870
clasohm@0
   871
(*Smash" unifies the list of term pairs leaving no flex-flex pairs.
wenzelm@250
   872
  Instantiates the theorem and deletes trivial tpairs.
clasohm@0
   873
  Resulting sequence may contain multiple elements if the tpairs are
clasohm@0
   874
    not all flex-flex. *)
wenzelm@3967
   875
fun flexflex_rule (th as Thm{sign_ref, der, maxidx, hyps, prop,...}) =
wenzelm@250
   876
  let fun newthm env =
paulson@1529
   877
          if Envir.is_empty env then th
paulson@1529
   878
          else
wenzelm@250
   879
          let val (tpairs,horn) =
wenzelm@250
   880
                        Logic.strip_flexpairs (Envir.norm_term env prop)
wenzelm@250
   881
                (*Remove trivial tpairs, of the form t=t*)
wenzelm@250
   882
              val distpairs = filter (not o op aconv) tpairs
wenzelm@250
   883
              val newprop = Logic.list_flexpairs(distpairs, horn)
wenzelm@1220
   884
          in  fix_shyps [th] (env_codT env)
wenzelm@3967
   885
                (Thm{sign_ref = sign_ref, 
berghofe@11518
   886
                     der = Pt.infer_derivs' (Pt.norm_proof' env) der,
wenzelm@2386
   887
                     maxidx = maxidx_of_term newprop, 
wenzelm@2386
   888
                     shyps = [], 
wenzelm@2386
   889
                     hyps = hyps,
wenzelm@2386
   890
                     prop = newprop})
wenzelm@250
   891
          end;
clasohm@0
   892
      val (tpairs,_) = Logic.strip_flexpairs prop
wenzelm@4270
   893
  in Seq.map newthm
wenzelm@3967
   894
            (Unify.smash_unifiers(Sign.deref sign_ref, Envir.empty maxidx, tpairs))
clasohm@0
   895
  end;
clasohm@0
   896
clasohm@0
   897
(*Instantiation of Vars
wenzelm@1220
   898
           A
wenzelm@1220
   899
  -------------------
wenzelm@1220
   900
  A[t1/v1,....,tn/vn]
wenzelm@1220
   901
*)
clasohm@0
   902
wenzelm@6928
   903
local
wenzelm@6928
   904
clasohm@0
   905
(*Check that all the terms are Vars and are distinct*)
clasohm@0
   906
fun instl_ok ts = forall is_Var ts andalso null(findrep ts);
clasohm@0
   907
wenzelm@6928
   908
fun prt_typing sg_ref t T =
wenzelm@6928
   909
  let val sg = Sign.deref sg_ref in
wenzelm@6928
   910
    Pretty.block [Sign.pretty_term sg t, Pretty.str " ::", Pretty.brk 1, Sign.pretty_typ sg T]
wenzelm@6928
   911
  end;
wenzelm@6928
   912
clasohm@0
   913
(*For instantiate: process pair of cterms, merge theories*)
wenzelm@3967
   914
fun add_ctpair ((ct,cu), (sign_ref,tpairs)) =
wenzelm@6928
   915
  let
wenzelm@6928
   916
    val Cterm {sign_ref=sign_reft, t=t, T= T, ...} = ct
wenzelm@6928
   917
    and Cterm {sign_ref=sign_refu, t=u, T= U, ...} = cu;
wenzelm@6928
   918
    val sign_ref_merged = Sign.merge_refs (sign_ref, Sign.merge_refs (sign_reft, sign_refu));
wenzelm@3967
   919
  in
wenzelm@6928
   920
    if T=U then (sign_ref_merged, (t,u)::tpairs)
wenzelm@6928
   921
    else raise TYPE (Pretty.string_of (Pretty.block [Pretty.str "instantiate: type conflict",
wenzelm@6928
   922
      Pretty.fbrk, prt_typing sign_ref_merged t T,
wenzelm@6928
   923
      Pretty.fbrk, prt_typing sign_ref_merged u U]), [T,U], [t,u])
clasohm@0
   924
  end;
clasohm@0
   925
wenzelm@3967
   926
fun add_ctyp ((v,ctyp), (sign_ref',vTs)) =
wenzelm@3967
   927
  let val Ctyp {T,sign_ref} = ctyp
wenzelm@3967
   928
  in (Sign.merge_refs(sign_ref,sign_ref'), (v,T)::vTs) end;
clasohm@0
   929
wenzelm@6928
   930
in
wenzelm@6928
   931
clasohm@0
   932
(*Left-to-right replacements: ctpairs = [...,(vi,ti),...].
clasohm@0
   933
  Instantiates distinct Vars by terms of same type.
paulson@8129
   934
  No longer normalizes the new theorem! *)
paulson@1529
   935
fun instantiate ([], []) th = th
berghofe@10416
   936
  | instantiate (vcTs,ctpairs) (th as Thm{sign_ref,der,maxidx,hyps,shyps,prop}) =
wenzelm@3967
   937
  let val (newsign_ref,tpairs) = foldr add_ctpair (ctpairs, (sign_ref,[]));
wenzelm@3967
   938
      val (newsign_ref,vTs) = foldr add_ctyp (vcTs, (newsign_ref,[]));
paulson@8129
   939
      val newprop = subst_atomic tpairs
paulson@8129
   940
	             (Type.inst_term_tvars
paulson@8129
   941
		      (Sign.tsig_of (Sign.deref newsign_ref),vTs) prop)
wenzelm@1220
   942
      val newth =
berghofe@10416
   943
            (Thm{sign_ref = newsign_ref, 
berghofe@11518
   944
                 der = Pt.infer_derivs' (Pt.instantiate vTs tpairs) der,
berghofe@10416
   945
                 maxidx = maxidx_of_term newprop, 
berghofe@10416
   946
                 shyps = add_insts_sorts ((vTs, tpairs), shyps),
berghofe@10416
   947
                 hyps = hyps,
berghofe@10416
   948
                 prop = newprop})
wenzelm@250
   949
  in  if not(instl_ok(map #1 tpairs))
nipkow@193
   950
      then raise THM("instantiate: variables not distinct", 0, [th])
nipkow@193
   951
      else if not(null(findrep(map #1 vTs)))
nipkow@193
   952
      then raise THM("instantiate: type variables not distinct", 0, [th])
wenzelm@8291
   953
      else nodup_vars newth "instantiate"
clasohm@0
   954
  end
wenzelm@6928
   955
  handle TERM _ => raise THM("instantiate: incompatible signatures", 0, [th])
wenzelm@6928
   956
       | TYPE (msg, _, _) => raise THM (msg, 0, [th]);
wenzelm@6928
   957
wenzelm@6928
   958
end;
wenzelm@6928
   959
clasohm@0
   960
clasohm@0
   961
(*The trivial implication A==>A, justified by assume and forall rules.
clasohm@0
   962
  A can contain Vars, not so for assume!   *)
wenzelm@250
   963
fun trivial ct : thm =
wenzelm@3967
   964
  let val Cterm {sign_ref, t=A, T, maxidx} = ct
wenzelm@250
   965
  in  if T<>propT then
wenzelm@250
   966
            raise THM("trivial: the term must have type prop", 0, [])
wenzelm@1238
   967
      else fix_shyps [] []
wenzelm@3967
   968
        (Thm{sign_ref = sign_ref, 
berghofe@11518
   969
             der = Pt.infer_derivs' I (false, Pt.AbsP ("H", None, Pt.PBound 0)),
wenzelm@2386
   970
             maxidx = maxidx, 
wenzelm@2386
   971
             shyps = [], 
wenzelm@2386
   972
             hyps = [],
wenzelm@2386
   973
             prop = implies$A$A})
clasohm@0
   974
  end;
clasohm@0
   975
paulson@1503
   976
(*Axiom-scheme reflecting signature contents: "OFCLASS(?'a::c, c_class)" *)
wenzelm@6368
   977
fun class_triv sign c =
wenzelm@6368
   978
  let val Cterm {sign_ref, t, maxidx, ...} =
wenzelm@6368
   979
    cterm_of sign (Logic.mk_inclass (TVar (("'a", 0), [c]), c))
wenzelm@6368
   980
      handle TERM (msg, _) => raise THM ("class_triv: " ^ msg, 0, []);
wenzelm@399
   981
  in
wenzelm@1238
   982
    fix_shyps [] []
wenzelm@3967
   983
      (Thm {sign_ref = sign_ref, 
berghofe@11518
   984
            der = Pt.infer_derivs' I
berghofe@11518
   985
              (false, Pt.PAxm ("ProtoPure.class_triv:" ^ c, t, Some [])),
wenzelm@2386
   986
            maxidx = maxidx, 
wenzelm@2386
   987
            shyps = [], 
wenzelm@2386
   988
            hyps = [], 
wenzelm@2386
   989
            prop = t})
wenzelm@399
   990
  end;
wenzelm@399
   991
wenzelm@399
   992
wenzelm@6786
   993
(* Replace all TFrees not fixed or in the hyps by new TVars *)
wenzelm@6786
   994
fun varifyT' fixed (Thm{sign_ref,der,maxidx,shyps,hyps,prop}) =
wenzelm@12500
   995
  let
wenzelm@12500
   996
    val tfrees = foldr add_term_tfree_names (hyps, fixed);
wenzelm@12500
   997
    val (prop', al) = Type.varify (prop, tfrees);
nipkow@1634
   998
  in let val thm = (*no fix_shyps*)
wenzelm@3967
   999
    Thm{sign_ref = sign_ref, 
berghofe@11518
  1000
        der = Pt.infer_derivs' (Pt.varify_proof prop tfrees) der,
wenzelm@2386
  1001
        maxidx = Int.max(0,maxidx), 
wenzelm@2386
  1002
        shyps = shyps, 
wenzelm@2386
  1003
        hyps = hyps,
wenzelm@12500
  1004
        prop = prop'}
wenzelm@12500
  1005
     in (nodup_vars thm "varifyT", al) end
wenzelm@8291
  1006
(* this nodup_vars check can be removed if thms are guaranteed not to contain
wenzelm@8291
  1007
duplicate TVars with different sorts *)
clasohm@0
  1008
  end;
clasohm@0
  1009
wenzelm@12500
  1010
val varifyT = #1 o varifyT' [];
wenzelm@6786
  1011
clasohm@0
  1012
(* Replace all TVars by new TFrees *)
wenzelm@3967
  1013
fun freezeT(Thm{sign_ref,der,maxidx,shyps,hyps,prop}) =
paulson@3410
  1014
  let val (prop',_) = Type.freeze_thaw prop
wenzelm@1238
  1015
  in (*no fix_shyps*)
wenzelm@3967
  1016
    Thm{sign_ref = sign_ref, 
berghofe@11518
  1017
        der = Pt.infer_derivs' (Pt.freezeT prop) der,
wenzelm@2386
  1018
        maxidx = maxidx_of_term prop',
wenzelm@2386
  1019
        shyps = shyps,
wenzelm@2386
  1020
        hyps = hyps,
paulson@1529
  1021
        prop = prop'}
wenzelm@1220
  1022
  end;
clasohm@0
  1023
clasohm@0
  1024
clasohm@0
  1025
(*** Inference rules for tactics ***)
clasohm@0
  1026
clasohm@0
  1027
(*Destruct proof state into constraints, other goals, goal(i), rest *)
clasohm@0
  1028
fun dest_state (state as Thm{prop,...}, i) =
clasohm@0
  1029
  let val (tpairs,horn) = Logic.strip_flexpairs prop
clasohm@0
  1030
  in  case  Logic.strip_prems(i, [], horn) of
clasohm@0
  1031
          (B::rBs, C) => (tpairs, rev rBs, B, C)
clasohm@0
  1032
        | _ => raise THM("dest_state", i, [state])
clasohm@0
  1033
  end
clasohm@0
  1034
  handle TERM _ => raise THM("dest_state", i, [state]);
clasohm@0
  1035
lcp@309
  1036
(*Increment variables and parameters of orule as required for
clasohm@0
  1037
  resolution with goal i of state. *)
clasohm@0
  1038
fun lift_rule (state, i) orule =
wenzelm@3967
  1039
  let val Thm{shyps=sshyps, prop=sprop, maxidx=smax, sign_ref=ssign_ref,...} = state
clasohm@0
  1040
      val (Bi::_, _) = Logic.strip_prems(i, [], Logic.skip_flexpairs sprop)
paulson@1529
  1041
        handle TERM _ => raise THM("lift_rule", i, [orule,state])
wenzelm@3967
  1042
      val ct_Bi = Cterm {sign_ref=ssign_ref, maxidx=smax, T=propT, t=Bi}
paulson@1529
  1043
      val (lift_abs,lift_all) = Logic.lift_fns(Bi,smax+1)
wenzelm@3967
  1044
      val (Thm{sign_ref, der, maxidx,shyps,hyps,prop}) = orule
clasohm@0
  1045
      val (tpairs,As,B) = Logic.strip_horn prop
wenzelm@1238
  1046
  in  (*no fix_shyps*)
wenzelm@3967
  1047
      Thm{sign_ref = merge_thm_sgs(state,orule),
berghofe@11518
  1048
          der = Pt.infer_derivs' (Pt.lift_proof Bi (smax+1) prop) der,
wenzelm@2386
  1049
          maxidx = maxidx+smax+1,
paulson@2177
  1050
          shyps=union_sort(sshyps,shyps), 
wenzelm@2386
  1051
          hyps=hyps, 
paulson@1529
  1052
          prop = Logic.rule_of (map (pairself lift_abs) tpairs,
wenzelm@2386
  1053
                                map lift_all As,    
wenzelm@2386
  1054
                                lift_all B)}
clasohm@0
  1055
  end;
clasohm@0
  1056
berghofe@10416
  1057
fun incr_indexes i (thm as Thm {sign_ref, der, maxidx, shyps, hyps, prop}) =
berghofe@10416
  1058
  if i < 0 then raise THM ("negative increment", 0, [thm]) else
berghofe@10416
  1059
  if i = 0 then thm else
berghofe@10416
  1060
    Thm {sign_ref = sign_ref,
berghofe@11518
  1061
         der = Pt.infer_derivs' (Pt.map_proof_terms
berghofe@11518
  1062
           (Logic.incr_indexes ([], i)) (incr_tvar i)) der,
berghofe@10416
  1063
         maxidx = maxidx + i,
berghofe@10416
  1064
         shyps = shyps,
berghofe@10416
  1065
         hyps = hyps,
berghofe@10416
  1066
         prop = Logic.incr_indexes ([], i) prop};
berghofe@10416
  1067
clasohm@0
  1068
(*Solve subgoal Bi of proof state B1...Bn/C by assumption. *)
clasohm@0
  1069
fun assumption i state =
wenzelm@3967
  1070
  let val Thm{sign_ref,der,maxidx,hyps,prop,...} = state;
clasohm@0
  1071
      val (tpairs, Bs, Bi, C) = dest_state(state,i)
berghofe@11518
  1072
      fun newth n (env as Envir.Envir{maxidx, ...}, tpairs) =
wenzelm@1220
  1073
        fix_shyps [state] (env_codT env)
wenzelm@3967
  1074
          (Thm{sign_ref = sign_ref, 
berghofe@11518
  1075
               der = Pt.infer_derivs'
berghofe@11518
  1076
                 ((if Envir.is_empty env then I else (Pt.norm_proof' env)) o
berghofe@11518
  1077
                   Pt.assumption_proof Bs Bi n) der,
wenzelm@2386
  1078
               maxidx = maxidx,
wenzelm@2386
  1079
               shyps = [],
wenzelm@2386
  1080
               hyps = hyps,
wenzelm@2386
  1081
               prop = 
wenzelm@2386
  1082
               if Envir.is_empty env then (*avoid wasted normalizations*)
wenzelm@2386
  1083
                   Logic.rule_of (tpairs, Bs, C)
wenzelm@2386
  1084
               else (*normalize the new rule fully*)
wenzelm@2386
  1085
                   Envir.norm_term env (Logic.rule_of (tpairs, Bs, C))});
berghofe@11518
  1086
      fun addprfs [] _ = Seq.empty
berghofe@11518
  1087
        | addprfs ((t,u)::apairs) n = Seq.make (fn()=> Seq.pull
berghofe@11518
  1088
             (Seq.mapp (newth n)
wenzelm@3967
  1089
                (Unify.unifiers(Sign.deref sign_ref,Envir.empty maxidx, (t,u)::tpairs))
berghofe@11518
  1090
                (addprfs apairs (n+1))))
berghofe@11518
  1091
  in  addprfs (Logic.assum_pairs Bi) 1 end;
clasohm@0
  1092
wenzelm@250
  1093
(*Solve subgoal Bi of proof state B1...Bn/C by assumption.
clasohm@0
  1094
  Checks if Bi's conclusion is alpha-convertible to one of its assumptions*)
clasohm@0
  1095
fun eq_assumption i state =
wenzelm@3967
  1096
  let val Thm{sign_ref,der,maxidx,hyps,prop,...} = state;
clasohm@0
  1097
      val (tpairs, Bs, Bi, C) = dest_state(state,i)
berghofe@11518
  1098
  in  (case find_index (op aconv) (Logic.assum_pairs Bi) of
berghofe@11518
  1099
         (~1) => raise THM("eq_assumption", 0, [state])
berghofe@11518
  1100
       | n => fix_shyps [state] []
berghofe@11518
  1101
                (Thm{sign_ref = sign_ref, 
berghofe@11518
  1102
                     der = Pt.infer_derivs'
berghofe@11518
  1103
                       (Pt.assumption_proof Bs Bi (n+1)) der,
berghofe@11518
  1104
                     maxidx = maxidx,
berghofe@11518
  1105
                     shyps = [],
berghofe@11518
  1106
                     hyps = hyps,
berghofe@11518
  1107
                     prop = Logic.rule_of(tpairs, Bs, C)}))
clasohm@0
  1108
  end;
clasohm@0
  1109
clasohm@0
  1110
paulson@2671
  1111
(*For rotate_tac: fast rotation of assumptions of subgoal i*)
paulson@2671
  1112
fun rotate_rule k i state =
wenzelm@3967
  1113
  let val Thm{sign_ref,der,maxidx,hyps,prop,shyps} = state;
paulson@2671
  1114
      val (tpairs, Bs, Bi, C) = dest_state(state,i)
paulson@8066
  1115
      val params = Term.strip_all_vars Bi
paulson@8066
  1116
      and rest   = Term.strip_all_body Bi
paulson@8066
  1117
      val asms   = Logic.strip_imp_prems rest
paulson@8066
  1118
      and concl  = Logic.strip_imp_concl rest
paulson@2671
  1119
      val n      = length asms
berghofe@11563
  1120
      val m      = if k<0 then n+k else k
berghofe@11563
  1121
      val Bi'    = if 0=m orelse m=n then Bi
paulson@2671
  1122
		   else if 0<m andalso m<n 
paulson@2671
  1123
		   then list_all 
paulson@2671
  1124
			   (params, 
paulson@2671
  1125
			    Logic.list_implies(List.drop(asms, m) @ 
paulson@2671
  1126
					       List.take(asms, m),
paulson@2671
  1127
					       concl))
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 
paulson@7248
  1153
		   then Logic.list_implies(fixed_prems @
paulson@7248
  1154
					   List.drop(moved_prems, m) @ 
paulson@7248
  1155
					   List.take(moved_prems, m),
paulson@7248
  1156
					   concl)
paulson@7248
  1157
		   else raise THM("permute_prems:k", k, [rl])
wenzelm@7264
  1158
  in  (*no fix_shyps*)
wenzelm@7264
  1159
      Thm{sign_ref = sign_ref, 
berghofe@11563
  1160
          der = Pt.infer_derivs' (Pt.permute_prems_prf prems j m) der,
paulson@7248
  1161
	  maxidx = maxidx,
paulson@7248
  1162
	  shyps = shyps,
paulson@7248
  1163
	  hyps = hyps,
berghofe@11563
  1164
	  prop = prop'}
paulson@7248
  1165
  end;
paulson@7248
  1166
paulson@7248
  1167
clasohm@0
  1168
(** User renaming of parameters in a subgoal **)
clasohm@0
  1169
clasohm@0
  1170
(*Calls error rather than raising an exception because it is intended
clasohm@0
  1171
  for top-level use -- exception handling would not make sense here.
clasohm@0
  1172
  The names in cs, if distinct, are used for the innermost parameters;
clasohm@0
  1173
   preceding parameters may be renamed to make all params distinct.*)
clasohm@0
  1174
fun rename_params_rule (cs, i) state =
wenzelm@3967
  1175
  let val Thm{sign_ref,der,maxidx,hyps,...} = state
clasohm@0
  1176
      val (tpairs, Bs, Bi, C) = dest_state(state,i)
clasohm@0
  1177
      val iparams = map #1 (Logic.strip_params Bi)
clasohm@0
  1178
      val short = length iparams - length cs
wenzelm@250
  1179
      val newnames =
wenzelm@250
  1180
            if short<0 then error"More names than abstractions!"
wenzelm@250
  1181
            else variantlist(take (short,iparams), cs) @ cs
nipkow@3037
  1182
      val freenames = map (#1 o dest_Free) (term_frees Bi)
clasohm@0
  1183
      val newBi = Logic.list_rename_params (newnames, Bi)
wenzelm@250
  1184
  in
clasohm@0
  1185
  case findrep cs of
paulson@3565
  1186
     c::_ => (warning ("Can't rename.  Bound variables not distinct: " ^ c); 
paulson@3565
  1187
	      state)
berghofe@1576
  1188
   | [] => (case cs inter_string freenames of
paulson@3565
  1189
       a::_ => (warning ("Can't rename.  Bound/Free variable clash: " ^ a); 
paulson@3565
  1190
		state)
wenzelm@1220
  1191
     | [] => fix_shyps [state] []
wenzelm@3967
  1192
                (Thm{sign_ref = sign_ref,
berghofe@11518
  1193
                     der = der,
wenzelm@2386
  1194
                     maxidx = maxidx,
wenzelm@2386
  1195
                     shyps = [],
wenzelm@2386
  1196
                     hyps = hyps,
wenzelm@2386
  1197
                     prop = Logic.rule_of(tpairs, Bs@[newBi], C)}))
clasohm@0
  1198
  end;
clasohm@0
  1199
wenzelm@12982
  1200
clasohm@0
  1201
(*** Preservation of bound variable names ***)
clasohm@0
  1202
wenzelm@12982
  1203
fun rename_boundvars pat obj (thm as Thm {sign_ref, der, maxidx, hyps, shyps, prop}) =
wenzelm@12982
  1204
  (case Term.rename_abs pat obj prop of
wenzelm@12982
  1205
    None => thm
wenzelm@12982
  1206
  | Some prop' => Thm
wenzelm@12982
  1207
      {sign_ref = sign_ref,
wenzelm@12982
  1208
       der = der,
wenzelm@12982
  1209
       maxidx = maxidx,
wenzelm@12982
  1210
       hyps = hyps,
wenzelm@12982
  1211
       shyps = shyps,
wenzelm@12982
  1212
       prop = prop'});
berghofe@10416
  1213
clasohm@0
  1214
wenzelm@250
  1215
(* strip_apply f A(,B) strips off all assumptions/parameters from A
clasohm@0
  1216
   introduced by lifting over B, and applies f to remaining part of A*)
clasohm@0
  1217
fun strip_apply f =
clasohm@0
  1218
  let fun strip(Const("==>",_)$ A1 $ B1,
wenzelm@250
  1219
                Const("==>",_)$ _  $ B2) = implies $ A1 $ strip(B1,B2)
wenzelm@250
  1220
        | strip((c as Const("all",_)) $ Abs(a,T,t1),
wenzelm@250
  1221
                      Const("all",_)  $ Abs(_,_,t2)) = c$Abs(a,T,strip(t1,t2))
wenzelm@250
  1222
        | strip(A,_) = f A
clasohm@0
  1223
  in strip end;
clasohm@0
  1224
clasohm@0
  1225
(*Use the alist to rename all bound variables and some unknowns in a term
clasohm@0
  1226
  dpairs = current disagreement pairs;  tpairs = permanent ones (flexflex);
clasohm@0
  1227
  Preserves unknowns in tpairs and on lhs of dpairs. *)
clasohm@0
  1228
fun rename_bvs([],_,_,_) = I
clasohm@0
  1229
  | rename_bvs(al,dpairs,tpairs,B) =
wenzelm@250
  1230
    let val vars = foldr add_term_vars
wenzelm@250
  1231
                        (map fst dpairs @ map fst tpairs @ map snd tpairs, [])
wenzelm@250
  1232
        (*unknowns appearing elsewhere be preserved!*)
wenzelm@250
  1233
        val vids = map (#1 o #1 o dest_Var) vars;
wenzelm@250
  1234
        fun rename(t as Var((x,i),T)) =
wenzelm@250
  1235
                (case assoc(al,x) of
berghofe@1576
  1236
                   Some(y) => if x mem_string vids orelse y mem_string vids then t
wenzelm@250
  1237
                              else Var((y,i),T)
wenzelm@250
  1238
                 | None=> t)
clasohm@0
  1239
          | rename(Abs(x,T,t)) =
nipkow@9721
  1240
              Abs(if_none(assoc_string(al,x)) x, T, rename t)
clasohm@0
  1241
          | rename(f$t) = rename f $ rename t
clasohm@0
  1242
          | rename(t) = t;
wenzelm@250
  1243
        fun strip_ren Ai = strip_apply rename (Ai,B)
clasohm@0
  1244
    in strip_ren end;
clasohm@0
  1245
clasohm@0
  1246
(*Function to rename bounds/unknowns in the argument, lifted over B*)
clasohm@0
  1247
fun rename_bvars(dpairs, tpairs, B) =
wenzelm@12982
  1248
        rename_bvs(foldr Term.match_bvars (dpairs,[]), dpairs, tpairs, B);
clasohm@0
  1249
clasohm@0
  1250
clasohm@0
  1251
(*** RESOLUTION ***)
clasohm@0
  1252
lcp@721
  1253
(** Lifting optimizations **)
lcp@721
  1254
clasohm@0
  1255
(*strip off pairs of assumptions/parameters in parallel -- they are
clasohm@0
  1256
  identical because of lifting*)
wenzelm@250
  1257
fun strip_assums2 (Const("==>", _) $ _ $ B1,
wenzelm@250
  1258
                   Const("==>", _) $ _ $ B2) = strip_assums2 (B1,B2)
clasohm@0
  1259
  | strip_assums2 (Const("all",_)$Abs(a,T,t1),
wenzelm@250
  1260
                   Const("all",_)$Abs(_,_,t2)) =
clasohm@0
  1261
      let val (B1,B2) = strip_assums2 (t1,t2)
clasohm@0
  1262
      in  (Abs(a,T,B1), Abs(a,T,B2))  end
clasohm@0
  1263
  | strip_assums2 BB = BB;
clasohm@0
  1264
clasohm@0
  1265
lcp@721
  1266
(*Faster normalization: skip assumptions that were lifted over*)
lcp@721
  1267
fun norm_term_skip env 0 t = Envir.norm_term env t
lcp@721
  1268
  | norm_term_skip env n (Const("all",_)$Abs(a,T,t)) =
lcp@721
  1269
        let val Envir.Envir{iTs, ...} = env
berghofe@8407
  1270
            val T' = typ_subst_TVars_Vartab iTs T
wenzelm@1238
  1271
            (*Must instantiate types of parameters because they are flattened;
lcp@721
  1272
              this could be a NEW parameter*)
lcp@721
  1273
        in  all T' $ Abs(a, T', norm_term_skip env n t)  end
lcp@721
  1274
  | norm_term_skip env n (Const("==>", _) $ A $ B) =
wenzelm@1238
  1275
        implies $ A $ norm_term_skip env (n-1) B
lcp@721
  1276
  | norm_term_skip env n t = error"norm_term_skip: too few assumptions??";
lcp@721
  1277
lcp@721
  1278
clasohm@0
  1279
(*Composition of object rule r=(A1...Am/B) with proof state s=(B1...Bn/C)
wenzelm@250
  1280
  Unifies B with Bi, replacing subgoal i    (1 <= i <= n)
clasohm@0
  1281
  If match then forbid instantiations in proof state
clasohm@0
  1282
  If lifted then shorten the dpair using strip_assums2.
clasohm@0
  1283
  If eres_flg then simultaneously proves A1 by assumption.
wenzelm@250
  1284
  nsubgoal is the number of new subgoals (written m above).
clasohm@0
  1285
  Curried so that resolution calls dest_state only once.
clasohm@0
  1286
*)
wenzelm@4270
  1287
local exception COMPOSE
clasohm@0
  1288
in
wenzelm@250
  1289
fun bicompose_aux match (state, (stpairs, Bs, Bi, C), lifted)
clasohm@0
  1290
                        (eres_flg, orule, nsubgoal) =
paulson@1529
  1291
 let val Thm{der=sder, maxidx=smax, shyps=sshyps, hyps=shyps, ...} = state
paulson@1529
  1292
     and Thm{der=rder, maxidx=rmax, shyps=rshyps, hyps=rhyps, 
wenzelm@2386
  1293
             prop=rprop,...} = orule
paulson@1529
  1294
         (*How many hyps to skip over during normalization*)
wenzelm@1238
  1295
     and nlift = Logic.count_prems(strip_all_body Bi,
wenzelm@1238
  1296
                                   if eres_flg then ~1 else 0)
wenzelm@3967
  1297
     val sign_ref = merge_thm_sgs(state,orule);
wenzelm@3967
  1298
     val sign = Sign.deref sign_ref;
clasohm@0
  1299
     (** Add new theorem with prop = '[| Bs; As |] ==> C' to thq **)
berghofe@11518
  1300
     fun addth A (As, oldAs, rder', n) ((env as Envir.Envir {maxidx, ...}, tpairs), thq) =
wenzelm@250
  1301
       let val normt = Envir.norm_term env;
wenzelm@250
  1302
           (*perform minimal copying here by examining env*)
wenzelm@250
  1303
           val normp =
wenzelm@250
  1304
             if Envir.is_empty env then (tpairs, Bs @ As, C)
wenzelm@250
  1305
             else
wenzelm@250
  1306
             let val ntps = map (pairself normt) tpairs
paulson@2147
  1307
             in if Envir.above (smax, env) then
wenzelm@1238
  1308
                  (*no assignments in state; normalize the rule only*)
wenzelm@1238
  1309
                  if lifted
wenzelm@1238
  1310
                  then (ntps, Bs @ map (norm_term_skip env nlift) As, C)
wenzelm@1238
  1311
                  else (ntps, Bs @ map normt As, C)
paulson@1529
  1312
                else if match then raise COMPOSE
wenzelm@250
  1313
                else (*normalize the new rule fully*)
wenzelm@250
  1314
                  (ntps, map normt (Bs @ As), normt C)
wenzelm@250
  1315
             end
wenzelm@1258
  1316
           val th = (*tuned fix_shyps*)
wenzelm@3967
  1317
             Thm{sign_ref = sign_ref,
berghofe@11518
  1318
                 der = Pt.infer_derivs
berghofe@11518
  1319
                   ((if Envir.is_empty env then I
berghofe@11518
  1320
                     else if Envir.above (smax, env) then
berghofe@11518
  1321
                       (fn f => fn der => f (Pt.norm_proof' env der))
berghofe@11518
  1322
                     else
berghofe@11518
  1323
                       curry op oo (Pt.norm_proof' env))
berghofe@11518
  1324
                    (Pt.bicompose_proof Bs oldAs As A n)) rder' sder,
wenzelm@2386
  1325
                 maxidx = maxidx,
wenzelm@2386
  1326
                 shyps = add_env_sorts (env, union_sort(rshyps,sshyps)),
wenzelm@2386
  1327
                 hyps = union_term(rhyps,shyps),
wenzelm@2386
  1328
                 prop = Logic.rule_of normp}
berghofe@11518
  1329
        in  Seq.cons(th, thq)  end  handle COMPOSE => thq;
clasohm@0
  1330
     val (rtpairs,rhorn) = Logic.strip_flexpairs(rprop);
clasohm@0
  1331
     val (rAs,B) = Logic.strip_prems(nsubgoal, [], rhorn)
clasohm@0
  1332
       handle TERM _ => raise THM("bicompose: rule", 0, [orule,state]);
clasohm@0
  1333
     (*Modify assumptions, deleting n-th if n>0 for e-resolution*)
clasohm@0
  1334
     fun newAs(As0, n, dpairs, tpairs) =
berghofe@11518
  1335
       let val (As1, rder') =
berghofe@11518
  1336
         if !Logic.auto_rename orelse not lifted then (As0, rder)
berghofe@11518
  1337
         else (map (rename_bvars(dpairs,tpairs,B)) As0,
berghofe@11518
  1338
           Pt.infer_derivs' (Pt.map_proof_terms
berghofe@11518
  1339
             (rename_bvars (dpairs, tpairs, Bound 0)) I) rder);
berghofe@11518
  1340
       in (map (Logic.flatten_params n) As1, As1, rder', n)
wenzelm@250
  1341
          handle TERM _ =>
wenzelm@250
  1342
          raise THM("bicompose: 1st premise", 0, [orule])
clasohm@0
  1343
       end;
paulson@2147
  1344
     val env = Envir.empty(Int.max(rmax,smax));
clasohm@0
  1345
     val BBi = if lifted then strip_assums2(B,Bi) else (B,Bi);
clasohm@0
  1346
     val dpairs = BBi :: (rtpairs@stpairs);
clasohm@0
  1347
     (*elim-resolution: try each assumption in turn.  Initially n=1*)
berghofe@11518
  1348
     fun tryasms (_, _, _, []) = Seq.empty
berghofe@11518
  1349
       | tryasms (A, As, n, (t,u)::apairs) =
wenzelm@4270
  1350
          (case Seq.pull(Unify.unifiers(sign, env, (t,u)::dpairs))  of
berghofe@11518
  1351
               None                   => tryasms (A, As, n+1, apairs)
wenzelm@250
  1352
             | cell as Some((_,tpairs),_) =>
berghofe@11518
  1353
                   Seq.it_right (addth A (newAs(As, n, [BBi,(u,t)], tpairs)))
wenzelm@4270
  1354
                       (Seq.make (fn()=> cell),
berghofe@11518
  1355
                        Seq.make (fn()=> Seq.pull (tryasms (A, As, n+1, apairs)))));
clasohm@0
  1356
     fun eres [] = raise THM("bicompose: no premises", 0, [orule,state])
berghofe@11518
  1357
       | eres (A1::As) = tryasms (Some A1, As, 1, Logic.assum_pairs A1);
clasohm@0
  1358
     (*ordinary resolution*)
wenzelm@4270
  1359
     fun res(None) = Seq.empty
wenzelm@250
  1360
       | res(cell as Some((_,tpairs),_)) =
berghofe@11518
  1361
             Seq.it_right (addth None (newAs(rev rAs, 0, [BBi], tpairs)))
wenzelm@4270
  1362
                       (Seq.make (fn()=> cell), Seq.empty)
clasohm@0
  1363
 in  if eres_flg then eres(rev rAs)
wenzelm@4270
  1364
     else res(Seq.pull(Unify.unifiers(sign, env, dpairs)))
clasohm@0
  1365
 end;
wenzelm@7528
  1366
end;
clasohm@0
  1367
clasohm@0
  1368
clasohm@0
  1369
fun bicompose match arg i state =
clasohm@0
  1370
    bicompose_aux match (state, dest_state(state,i), false) arg;
clasohm@0
  1371
clasohm@0
  1372
(*Quick test whether rule is resolvable with the subgoal with hyps Hs
clasohm@0
  1373
  and conclusion B.  If eres_flg then checks 1st premise of rule also*)
clasohm@0
  1374
fun could_bires (Hs, B, eres_flg, rule) =
clasohm@0
  1375
    let fun could_reshyp (A1::_) = exists (apl(A1,could_unify)) Hs
wenzelm@250
  1376
          | could_reshyp [] = false;  (*no premise -- illegal*)
wenzelm@250
  1377
    in  could_unify(concl_of rule, B) andalso
wenzelm@250
  1378
        (not eres_flg  orelse  could_reshyp (prems_of rule))
clasohm@0
  1379
    end;
clasohm@0
  1380
clasohm@0
  1381
(*Bi-resolution of a state with a list of (flag,rule) pairs.
clasohm@0
  1382
  Puts the rule above:  rule/state.  Renames vars in the rules. *)
wenzelm@250
  1383
fun biresolution match brules i state =
clasohm@0
  1384
    let val lift = lift_rule(state, i);
wenzelm@250
  1385
        val (stpairs, Bs, Bi, C) = dest_state(state,i)
wenzelm@250
  1386
        val B = Logic.strip_assums_concl Bi;
wenzelm@250
  1387
        val Hs = Logic.strip_assums_hyp Bi;
wenzelm@250
  1388
        val comp = bicompose_aux match (state, (stpairs, Bs, Bi, C), true);
wenzelm@4270
  1389
        fun res [] = Seq.empty
wenzelm@250
  1390
          | res ((eres_flg, rule)::brules) =
wenzelm@250
  1391
              if could_bires (Hs, B, eres_flg, rule)
wenzelm@4270
  1392
              then Seq.make (*delay processing remainder till needed*)
wenzelm@250
  1393
                  (fn()=> Some(comp (eres_flg, lift rule, nprems_of rule),
wenzelm@250
  1394
                               res brules))
wenzelm@250
  1395
              else res brules
wenzelm@4270
  1396
    in  Seq.flat (res brules)  end;
clasohm@0
  1397
clasohm@0
  1398
wenzelm@2509
  1399
(*** Oracles ***)
wenzelm@2509
  1400
wenzelm@3812
  1401
fun invoke_oracle thy raw_name =
wenzelm@3812
  1402
  let
wenzelm@6390
  1403
    val {sign = sg, oracles, ...} = Theory.rep_theory thy;
wenzelm@3812
  1404
    val name = Sign.intern sg Theory.oracleK raw_name;
wenzelm@3812
  1405
    val oracle =
wenzelm@3812
  1406
      (case Symtab.lookup (oracles, name) of
wenzelm@3812
  1407
        None => raise THM ("Unknown oracle: " ^ name, 0, [])
wenzelm@3812
  1408
      | Some (f, _) => f);
wenzelm@3812
  1409
  in
wenzelm@3812
  1410
    fn (sign, exn) =>
wenzelm@3812
  1411
      let
wenzelm@3967
  1412
        val sign_ref' = Sign.merge_refs (Sign.self_ref sg, Sign.self_ref sign);
wenzelm@3967
  1413
        val sign' = Sign.deref sign_ref';
wenzelm@3812
  1414
        val (prop, T, maxidx) = Sign.certify_term sign' (oracle (sign', exn));
wenzelm@3812
  1415
      in
wenzelm@3812
  1416
        if T <> propT then
wenzelm@3812
  1417
          raise THM ("Oracle's result must have type prop: " ^ name, 0, [])
wenzelm@3812
  1418
        else fix_shyps [] []
wenzelm@3967
  1419
          (Thm {sign_ref = sign_ref', 
berghofe@11518
  1420
            der = (true, Pt.oracle_proof name prop),
wenzelm@3812
  1421
            maxidx = maxidx,
wenzelm@3812
  1422
            shyps = [], 
wenzelm@3812
  1423
            hyps = [], 
wenzelm@3812
  1424
            prop = prop})
wenzelm@3812
  1425
      end
wenzelm@3812
  1426
  end;
wenzelm@3812
  1427
paulson@1539
  1428
clasohm@0
  1429
end;
paulson@1503
  1430
wenzelm@6089
  1431
wenzelm@6089
  1432
structure BasicThm: BASIC_THM = Thm;
wenzelm@6089
  1433
open BasicThm;