src/Pure/tactic.ML
author paulson
Fri Feb 16 12:34:18 1996 +0100 (1996-02-16)
changeset 1501 bb7f99a0a6f0
parent 1460 5a6f2aabd538
child 1801 927a31ba4346
permissions -rw-r--r--
Elimination of fully-functorial style.
Type tactic changed to a type abbrevation (from a datatype).
Constructor tactic and function apply deleted.
clasohm@1460
     1
(*  Title: 	tactic
clasohm@0
     2
    ID:         $Id$
clasohm@1460
     3
    Author: 	Lawrence C Paulson, Cambridge University Computer Laboratory
clasohm@0
     4
    Copyright   1991  University of Cambridge
clasohm@0
     5
clasohm@0
     6
Tactics 
clasohm@0
     7
*)
clasohm@0
     8
clasohm@0
     9
signature TACTIC =
paulson@1501
    10
  sig
clasohm@0
    11
  val ares_tac: thm list -> int -> tactic
clasohm@0
    12
  val asm_rewrite_goal_tac:
nipkow@214
    13
        bool*bool -> (meta_simpset -> tactic) -> meta_simpset -> int -> tactic
clasohm@0
    14
  val assume_tac: int -> tactic
clasohm@0
    15
  val atac: int ->tactic
lcp@670
    16
  val bimatch_from_nets_tac: 
paulson@1501
    17
      (int*(bool*thm)) Net.net * (int*(bool*thm)) Net.net -> int -> tactic
clasohm@0
    18
  val bimatch_tac: (bool*thm)list -> int -> tactic
lcp@670
    19
  val biresolve_from_nets_tac: 
paulson@1501
    20
      (int*(bool*thm)) Net.net * (int*(bool*thm)) Net.net -> int -> tactic
clasohm@0
    21
  val biresolve_tac: (bool*thm)list -> int -> tactic
paulson@1501
    22
  val build_net: thm list -> (int*thm) Net.net
paulson@1501
    23
  val build_netpair:    (int*(bool*thm)) Net.net * (int*(bool*thm)) Net.net ->
paulson@1501
    24
      (bool*thm)list -> (int*(bool*thm)) Net.net * (int*(bool*thm)) Net.net
clasohm@0
    25
  val compose_inst_tac: (string*string)list -> (bool*thm*int) -> int -> tactic
clasohm@0
    26
  val compose_tac: (bool * thm * int) -> int -> tactic 
clasohm@0
    27
  val cut_facts_tac: thm list -> int -> tactic
lcp@270
    28
  val cut_inst_tac: (string*string)list -> thm -> int -> tactic   
clasohm@0
    29
  val dmatch_tac: thm list -> int -> tactic
clasohm@0
    30
  val dresolve_tac: thm list -> int -> tactic
clasohm@0
    31
  val dres_inst_tac: (string*string)list -> thm -> int -> tactic   
clasohm@0
    32
  val dtac: thm -> int ->tactic
clasohm@0
    33
  val etac: thm -> int ->tactic
clasohm@0
    34
  val eq_assume_tac: int -> tactic   
clasohm@0
    35
  val ematch_tac: thm list -> int -> tactic
clasohm@0
    36
  val eresolve_tac: thm list -> int -> tactic
clasohm@0
    37
  val eres_inst_tac: (string*string)list -> thm -> int -> tactic   
clasohm@0
    38
  val filter_thms: (term*term->bool) -> int*term*thm list -> thm list
clasohm@0
    39
  val filt_resolve_tac: thm list -> int -> int -> tactic
clasohm@0
    40
  val flexflex_tac: tactic
clasohm@0
    41
  val fold_goals_tac: thm list -> tactic
clasohm@0
    42
  val fold_tac: thm list -> tactic
clasohm@0
    43
  val forward_tac: thm list -> int -> tactic   
clasohm@0
    44
  val forw_inst_tac: (string*string)list -> thm -> int -> tactic
lcp@947
    45
  val freeze: thm -> thm   
lcp@1077
    46
  val insert_tagged_brl:  ('a*(bool*thm)) * 
paulson@1501
    47
                    (('a*(bool*thm))Net.net * ('a*(bool*thm))Net.net) ->
paulson@1501
    48
                    ('a*(bool*thm))Net.net * ('a*(bool*thm))Net.net
clasohm@0
    49
  val is_fact: thm -> bool
clasohm@0
    50
  val lessb: (bool * thm) * (bool * thm) -> bool
clasohm@0
    51
  val lift_inst_rule: thm * int * (string*string)list * thm -> thm
clasohm@0
    52
  val make_elim: thm -> thm
paulson@1501
    53
  val match_from_net_tac: (int*thm) Net.net -> int -> tactic
clasohm@0
    54
  val match_tac: thm list -> int -> tactic
clasohm@0
    55
  val metacut_tac: thm -> int -> tactic   
clasohm@0
    56
  val net_bimatch_tac: (bool*thm) list -> int -> tactic
clasohm@0
    57
  val net_biresolve_tac: (bool*thm) list -> int -> tactic
clasohm@0
    58
  val net_match_tac: thm list -> int -> tactic
clasohm@0
    59
  val net_resolve_tac: thm list -> int -> tactic
clasohm@0
    60
  val PRIMITIVE: (thm -> thm) -> tactic  
clasohm@0
    61
  val PRIMSEQ: (thm -> thm Sequence.seq) -> tactic  
clasohm@0
    62
  val prune_params_tac: tactic
clasohm@0
    63
  val rename_tac: string -> int -> tactic
clasohm@0
    64
  val rename_last_tac: string -> string list -> int -> tactic
paulson@1501
    65
  val resolve_from_net_tac: (int*thm) Net.net -> int -> tactic
clasohm@0
    66
  val resolve_tac: thm list -> int -> tactic
clasohm@0
    67
  val res_inst_tac: (string*string)list -> thm -> int -> tactic   
clasohm@0
    68
  val rewrite_goals_tac: thm list -> tactic
clasohm@0
    69
  val rewrite_tac: thm list -> tactic
clasohm@0
    70
  val rewtac: thm -> tactic
nipkow@1209
    71
  val rotate_tac: int -> int -> tactic
clasohm@0
    72
  val rtac: thm -> int -> tactic
clasohm@0
    73
  val rule_by_tactic: tactic -> thm -> thm
lcp@439
    74
  val subgoal_tac: string -> int -> tactic
lcp@439
    75
  val subgoals_tac: string list -> int -> tactic
clasohm@0
    76
  val subgoals_of_brl: bool * thm -> int
clasohm@0
    77
  val trace_goalno_tac: (int -> tactic) -> int -> tactic
paulson@1501
    78
  end;
clasohm@0
    79
clasohm@0
    80
paulson@1501
    81
structure Tactic : TACTIC = 
clasohm@0
    82
struct
clasohm@0
    83
paulson@1501
    84
(*Discover which goal is chosen:  SOMEGOAL(trace_goalno_tac tac) *)
paulson@1501
    85
fun trace_goalno_tac tac i st =  
paulson@1501
    86
    case Sequence.pull(tac i st) of
clasohm@1460
    87
	None    => Sequence.null
clasohm@0
    88
      | seqcell => (prs("Subgoal " ^ string_of_int i ^ " selected\n"); 
paulson@1501
    89
    			 Sequence.seqof(fn()=> seqcell));
clasohm@0
    90
clasohm@0
    91
fun string_of (a,0) = a
clasohm@0
    92
  | string_of (a,i) = a ^ "_" ^ string_of_int i;
clasohm@0
    93
lcp@947
    94
(*convert all Vars in a theorem to Frees*)
clasohm@0
    95
fun freeze th =
clasohm@0
    96
  let val fth = freezeT th
clasohm@0
    97
      val {prop,sign,...} = rep_thm fth
clasohm@0
    98
      fun mk_inst (Var(v,T)) = 
clasohm@1460
    99
	  (cterm_of sign (Var(v,T)),
clasohm@1460
   100
	   cterm_of sign (Free(string_of v, T)))
clasohm@0
   101
      val insts = map mk_inst (term_vars prop)
clasohm@0
   102
  in  instantiate ([],insts) fth  end;
clasohm@0
   103
clasohm@0
   104
(*Makes a rule by applying a tactic to an existing rule*)
paulson@1501
   105
fun rule_by_tactic tac rl =
paulson@1501
   106
    case Sequence.pull(tac (freeze (standard rl))) of
clasohm@1460
   107
	None        => raise THM("rule_by_tactic", 0, [rl])
clasohm@0
   108
      | Some(rl',_) => standard rl';
clasohm@0
   109
 
clasohm@0
   110
(*** Basic tactics ***)
clasohm@0
   111
clasohm@0
   112
(*Makes a tactic whose effect on a state is given by thmfun: thm->thm seq.*)
paulson@1501
   113
fun PRIMSEQ thmfun st =  thmfun st handle THM _ => Sequence.null;
clasohm@0
   114
clasohm@0
   115
(*Makes a tactic whose effect on a state is given by thmfun: thm->thm.*)
clasohm@0
   116
fun PRIMITIVE thmfun = PRIMSEQ (Sequence.single o thmfun);
clasohm@0
   117
clasohm@0
   118
(*** The following fail if the goal number is out of range:
clasohm@0
   119
     thus (REPEAT (resolve_tac rules i)) stops once subgoal i disappears. *)
clasohm@0
   120
clasohm@0
   121
(*Solve subgoal i by assumption*)
clasohm@0
   122
fun assume_tac i = PRIMSEQ (assumption i);
clasohm@0
   123
clasohm@0
   124
(*Solve subgoal i by assumption, using no unification*)
clasohm@0
   125
fun eq_assume_tac i = PRIMITIVE (eq_assumption i);
clasohm@0
   126
clasohm@0
   127
(** Resolution/matching tactics **)
clasohm@0
   128
clasohm@0
   129
(*The composition rule/state: no lifting or var renaming.
clasohm@0
   130
  The arg = (bires_flg, orule, m) ;  see bicompose for explanation.*)
clasohm@0
   131
fun compose_tac arg i = PRIMSEQ (bicompose false arg i);
clasohm@0
   132
clasohm@0
   133
(*Converts a "destruct" rule like P&Q==>P to an "elimination" rule
clasohm@0
   134
  like [| P&Q; P==>R |] ==> R *)
clasohm@0
   135
fun make_elim rl = zero_var_indexes (rl RS revcut_rl);
clasohm@0
   136
clasohm@0
   137
(*Attack subgoal i by resolution, using flags to indicate elimination rules*)
clasohm@0
   138
fun biresolve_tac brules i = PRIMSEQ (biresolution false brules i);
clasohm@0
   139
clasohm@0
   140
(*Resolution: the simple case, works for introduction rules*)
clasohm@0
   141
fun resolve_tac rules = biresolve_tac (map (pair false) rules);
clasohm@0
   142
clasohm@0
   143
(*Resolution with elimination rules only*)
clasohm@0
   144
fun eresolve_tac rules = biresolve_tac (map (pair true) rules);
clasohm@0
   145
clasohm@0
   146
(*Forward reasoning using destruction rules.*)
clasohm@0
   147
fun forward_tac rls = resolve_tac (map make_elim rls) THEN' assume_tac;
clasohm@0
   148
clasohm@0
   149
(*Like forward_tac, but deletes the assumption after use.*)
clasohm@0
   150
fun dresolve_tac rls = eresolve_tac (map make_elim rls);
clasohm@0
   151
clasohm@0
   152
(*Shorthand versions: for resolution with a single theorem*)
clasohm@1460
   153
fun rtac rl = resolve_tac [rl];
clasohm@1460
   154
fun etac rl = eresolve_tac [rl];
clasohm@1460
   155
fun dtac rl = dresolve_tac [rl];
clasohm@0
   156
val atac = assume_tac;
clasohm@0
   157
clasohm@0
   158
(*Use an assumption or some rules ... A popular combination!*)
clasohm@0
   159
fun ares_tac rules = assume_tac  ORELSE'  resolve_tac rules;
clasohm@0
   160
clasohm@0
   161
(*Matching tactics -- as above, but forbid updating of state*)
clasohm@0
   162
fun bimatch_tac brules i = PRIMSEQ (biresolution true brules i);
clasohm@0
   163
fun match_tac rules  = bimatch_tac (map (pair false) rules);
clasohm@0
   164
fun ematch_tac rules = bimatch_tac (map (pair true) rules);
clasohm@0
   165
fun dmatch_tac rls   = ematch_tac (map make_elim rls);
clasohm@0
   166
clasohm@0
   167
(*Smash all flex-flex disagreement pairs in the proof state.*)
clasohm@0
   168
val flexflex_tac = PRIMSEQ flexflex_rule;
clasohm@0
   169
clasohm@0
   170
(*Lift and instantiate a rule wrt the given state and subgoal number *)
paulson@1501
   171
fun lift_inst_rule (st, i, sinsts, rule) =
paulson@1501
   172
let val {maxidx,sign,...} = rep_thm st
paulson@1501
   173
    val (_, _, Bi, _) = dest_state(st,i)
clasohm@1460
   174
    val params = Logic.strip_params Bi	        (*params of subgoal i*)
clasohm@0
   175
    val params = rev(rename_wrt_term Bi params) (*as they are printed*)
clasohm@0
   176
    val paramTs = map #2 params
clasohm@0
   177
    and inc = maxidx+1
clasohm@0
   178
    fun liftvar (Var ((a,j), T)) = Var((a, j+inc), paramTs---> incr_tvar inc T)
clasohm@0
   179
      | liftvar t = raise TERM("Variable expected", [t]);
clasohm@0
   180
    fun liftterm t = list_abs_free (params, 
clasohm@1460
   181
				    Logic.incr_indexes(paramTs,inc) t)
clasohm@0
   182
    (*Lifts instantiation pair over params*)
lcp@230
   183
    fun liftpair (cv,ct) = (cterm_fun liftvar cv, cterm_fun liftterm ct)
clasohm@0
   184
    fun lifttvar((a,i),ctyp) =
clasohm@1460
   185
	let val {T,sign} = rep_ctyp ctyp
clasohm@1460
   186
	in  ((a,i+inc), ctyp_of sign (incr_tvar inc T)) end
paulson@1501
   187
    val rts = types_sorts rule and (types,sorts) = types_sorts st
clasohm@0
   188
    fun types'(a,~1) = (case assoc(params,a) of None => types(a,~1) | sm => sm)
clasohm@0
   189
      | types'(ixn) = types ixn;
nipkow@949
   190
    val used = add_term_tvarnames
paulson@1501
   191
                  (#prop(rep_thm st) $ #prop(rep_thm rule),[])
nipkow@949
   192
    val (Tinsts,insts) = read_insts sign rts (types',sorts) used sinsts
clasohm@0
   193
in instantiate (map lifttvar Tinsts, map liftpair insts)
paulson@1501
   194
               (lift_rule (st,i) rule)
clasohm@0
   195
end;
clasohm@0
   196
clasohm@0
   197
clasohm@0
   198
(*** Resolve after lifting and instantation; may refer to parameters of the
clasohm@0
   199
     subgoal.  Fails if "i" is out of range.  ***)
clasohm@0
   200
clasohm@0
   201
(*compose version: arguments are as for bicompose.*)
clasohm@0
   202
fun compose_inst_tac sinsts (bires_flg, rule, nsubgoal) i =
paulson@1501
   203
  STATE ( fn st => 
paulson@1501
   204
	   compose_tac (bires_flg, lift_inst_rule (st, i, sinsts, rule),
clasohm@1460
   205
			nsubgoal) i
clasohm@1460
   206
	   handle TERM (msg,_) => (writeln msg;  no_tac)
clasohm@1460
   207
		| THM  (msg,_,_) => (writeln msg;  no_tac) );
clasohm@0
   208
lcp@761
   209
(*"Resolve" version.  Note: res_inst_tac cannot behave sensibly if the
lcp@761
   210
  terms that are substituted contain (term or type) unknowns from the
lcp@761
   211
  goal, because it is unable to instantiate goal unknowns at the same time.
lcp@761
   212
nipkow@952
   213
  The type checker is instructed not to freezes flexible type vars that
nipkow@952
   214
  were introduced during type inference and still remain in the term at the
nipkow@952
   215
  end.  This increases flexibility but can introduce schematic type vars in
nipkow@952
   216
  goals.
lcp@761
   217
*)
clasohm@0
   218
fun res_inst_tac sinsts rule i =
clasohm@0
   219
    compose_inst_tac sinsts (false, rule, nprems_of rule) i;
clasohm@0
   220
paulson@1501
   221
(*eresolve elimination version*)
clasohm@0
   222
fun eres_inst_tac sinsts rule i =
clasohm@0
   223
    compose_inst_tac sinsts (true, rule, nprems_of rule) i;
clasohm@0
   224
lcp@270
   225
(*For forw_inst_tac and dres_inst_tac.  Preserve Var indexes of rl;
lcp@270
   226
  increment revcut_rl instead.*)
clasohm@0
   227
fun make_elim_preserve rl = 
lcp@270
   228
  let val {maxidx,...} = rep_thm rl
clasohm@922
   229
      fun cvar ixn = cterm_of Sign.proto_pure (Var(ixn,propT));
lcp@270
   230
      val revcut_rl' = 
clasohm@1460
   231
	  instantiate ([],  [(cvar("V",0), cvar("V",maxidx+1)),
clasohm@1460
   232
			     (cvar("W",0), cvar("W",maxidx+1))]) revcut_rl
clasohm@0
   233
      val arg = (false, rl, nprems_of rl)
clasohm@0
   234
      val [th] = Sequence.list_of_s (bicompose false arg 1 revcut_rl')
clasohm@0
   235
  in  th  end
clasohm@0
   236
  handle Bind => raise THM("make_elim_preserve", 1, [rl]);
clasohm@0
   237
lcp@270
   238
(*instantiate and cut -- for a FACT, anyway...*)
lcp@270
   239
fun cut_inst_tac sinsts rule = res_inst_tac sinsts (make_elim_preserve rule);
clasohm@0
   240
lcp@270
   241
(*forward tactic applies a RULE to an assumption without deleting it*)
lcp@270
   242
fun forw_inst_tac sinsts rule = cut_inst_tac sinsts rule THEN' assume_tac;
lcp@270
   243
lcp@270
   244
(*dresolve tactic applies a RULE to replace an assumption*)
clasohm@0
   245
fun dres_inst_tac sinsts rule = eres_inst_tac sinsts (make_elim_preserve rule);
clasohm@0
   246
lcp@270
   247
(*** Applications of cut_rl ***)
clasohm@0
   248
clasohm@0
   249
(*Used by metacut_tac*)
clasohm@0
   250
fun bires_cut_tac arg i =
clasohm@1460
   251
    resolve_tac [cut_rl] i  THEN  biresolve_tac arg (i+1) ;
clasohm@0
   252
clasohm@0
   253
(*The conclusion of the rule gets assumed in subgoal i,
clasohm@0
   254
  while subgoal i+1,... are the premises of the rule.*)
clasohm@0
   255
fun metacut_tac rule = bires_cut_tac [(false,rule)];
clasohm@0
   256
clasohm@0
   257
(*Recognizes theorems that are not rules, but simple propositions*)
clasohm@0
   258
fun is_fact rl =
clasohm@0
   259
    case prems_of rl of
clasohm@1460
   260
	[] => true  |  _::_ => false;
clasohm@0
   261
clasohm@0
   262
(*"Cut" all facts from theorem list into the goal as assumptions. *)
clasohm@0
   263
fun cut_facts_tac ths i =
clasohm@0
   264
    EVERY (map (fn th => metacut_tac th i) (filter is_fact ths));
clasohm@0
   265
clasohm@0
   266
(*Introduce the given proposition as a lemma and subgoal*)
clasohm@0
   267
fun subgoal_tac sprop = res_inst_tac [("psi", sprop)] cut_rl;
clasohm@0
   268
lcp@439
   269
(*Introduce a list of lemmas and subgoals*)
lcp@439
   270
fun subgoals_tac sprops = EVERY' (map subgoal_tac sprops);
lcp@439
   271
clasohm@0
   272
clasohm@0
   273
(**** Indexing and filtering of theorems ****)
clasohm@0
   274
clasohm@0
   275
(*Returns the list of potentially resolvable theorems for the goal "prem",
clasohm@1460
   276
	using the predicate  could(subgoal,concl).
clasohm@0
   277
  Resulting list is no longer than "limit"*)
clasohm@0
   278
fun filter_thms could (limit, prem, ths) =
clasohm@0
   279
  let val pb = Logic.strip_assums_concl prem;   (*delete assumptions*)
clasohm@0
   280
      fun filtr (limit, []) = []
clasohm@1460
   281
	| filtr (limit, th::ths) =
clasohm@1460
   282
	    if limit=0 then  []
clasohm@1460
   283
	    else if could(pb, concl_of th)  then th :: filtr(limit-1, ths)
clasohm@1460
   284
	    else filtr(limit,ths)
clasohm@0
   285
  in  filtr(limit,ths)  end;
clasohm@0
   286
clasohm@0
   287
clasohm@0
   288
(*** biresolution and resolution using nets ***)
clasohm@0
   289
clasohm@0
   290
(** To preserve the order of the rules, tag them with increasing integers **)
clasohm@0
   291
clasohm@0
   292
(*insert tags*)
clasohm@0
   293
fun taglist k [] = []
clasohm@0
   294
  | taglist k (x::xs) = (k,x) :: taglist (k+1) xs;
clasohm@0
   295
clasohm@0
   296
(*remove tags and suppress duplicates -- list is assumed sorted!*)
clasohm@0
   297
fun untaglist [] = []
clasohm@0
   298
  | untaglist [(k:int,x)] = [x]
clasohm@0
   299
  | untaglist ((k,x) :: (rest as (k',x')::_)) =
clasohm@0
   300
      if k=k' then untaglist rest
clasohm@0
   301
      else    x :: untaglist rest;
clasohm@0
   302
clasohm@0
   303
(*return list elements in original order*)
clasohm@0
   304
val orderlist = untaglist o sort (fn(x,y)=> #1 x < #1 y); 
clasohm@0
   305
clasohm@0
   306
(*insert one tagged brl into the pair of nets*)
lcp@1077
   307
fun insert_tagged_brl (kbrl as (k,(eres,th)), (inet,enet)) =
clasohm@0
   308
    if eres then 
clasohm@1460
   309
	case prems_of th of
clasohm@1460
   310
	    prem::_ => (inet, Net.insert_term ((prem,kbrl), enet, K false))
clasohm@1460
   311
	  | [] => error"insert_tagged_brl: elimination rule with no premises"
clasohm@0
   312
    else (Net.insert_term ((concl_of th, kbrl), inet, K false), enet);
clasohm@0
   313
clasohm@0
   314
(*build a pair of nets for biresolution*)
lcp@670
   315
fun build_netpair netpair brls = 
lcp@1077
   316
    foldr insert_tagged_brl (taglist 1 brls, netpair);
clasohm@0
   317
clasohm@0
   318
(*biresolution using a pair of nets rather than rules*)
clasohm@0
   319
fun biresolution_from_nets_tac match (inet,enet) =
clasohm@0
   320
  SUBGOAL
clasohm@0
   321
    (fn (prem,i) =>
clasohm@0
   322
      let val hyps = Logic.strip_assums_hyp prem
clasohm@0
   323
          and concl = Logic.strip_assums_concl prem 
clasohm@0
   324
          val kbrls = Net.unify_term inet concl @
clasohm@0
   325
                      flat (map (Net.unify_term enet) hyps)
clasohm@0
   326
      in PRIMSEQ (biresolution match (orderlist kbrls) i) end);
clasohm@0
   327
clasohm@0
   328
(*versions taking pre-built nets*)
clasohm@0
   329
val biresolve_from_nets_tac = biresolution_from_nets_tac false;
clasohm@0
   330
val bimatch_from_nets_tac = biresolution_from_nets_tac true;
clasohm@0
   331
clasohm@0
   332
(*fast versions using nets internally*)
lcp@670
   333
val net_biresolve_tac =
lcp@670
   334
    biresolve_from_nets_tac o build_netpair(Net.empty,Net.empty);
lcp@670
   335
lcp@670
   336
val net_bimatch_tac =
lcp@670
   337
    bimatch_from_nets_tac o build_netpair(Net.empty,Net.empty);
clasohm@0
   338
clasohm@0
   339
(*** Simpler version for resolve_tac -- only one net, and no hyps ***)
clasohm@0
   340
clasohm@0
   341
(*insert one tagged rl into the net*)
clasohm@0
   342
fun insert_krl (krl as (k,th), net) =
clasohm@0
   343
    Net.insert_term ((concl_of th, krl), net, K false);
clasohm@0
   344
clasohm@0
   345
(*build a net of rules for resolution*)
clasohm@0
   346
fun build_net rls = 
clasohm@0
   347
    foldr insert_krl (taglist 1 rls, Net.empty);
clasohm@0
   348
clasohm@0
   349
(*resolution using a net rather than rules; pred supports filt_resolve_tac*)
clasohm@0
   350
fun filt_resolution_from_net_tac match pred net =
clasohm@0
   351
  SUBGOAL
clasohm@0
   352
    (fn (prem,i) =>
clasohm@0
   353
      let val krls = Net.unify_term net (Logic.strip_assums_concl prem)
clasohm@0
   354
      in 
clasohm@1460
   355
	 if pred krls  
clasohm@0
   356
         then PRIMSEQ
clasohm@1460
   357
		(biresolution match (map (pair false) (orderlist krls)) i)
clasohm@0
   358
         else no_tac
clasohm@0
   359
      end);
clasohm@0
   360
clasohm@0
   361
(*Resolve the subgoal using the rules (making a net) unless too flexible,
clasohm@0
   362
   which means more than maxr rules are unifiable.      *)
clasohm@0
   363
fun filt_resolve_tac rules maxr = 
clasohm@0
   364
    let fun pred krls = length krls <= maxr
clasohm@0
   365
    in  filt_resolution_from_net_tac false pred (build_net rules)  end;
clasohm@0
   366
clasohm@0
   367
(*versions taking pre-built nets*)
clasohm@0
   368
val resolve_from_net_tac = filt_resolution_from_net_tac false (K true);
clasohm@0
   369
val match_from_net_tac = filt_resolution_from_net_tac true (K true);
clasohm@0
   370
clasohm@0
   371
(*fast versions using nets internally*)
clasohm@0
   372
val net_resolve_tac = resolve_from_net_tac o build_net;
clasohm@0
   373
val net_match_tac = match_from_net_tac o build_net;
clasohm@0
   374
clasohm@0
   375
clasohm@0
   376
(*** For Natural Deduction using (bires_flg, rule) pairs ***)
clasohm@0
   377
clasohm@0
   378
(*The number of new subgoals produced by the brule*)
lcp@1077
   379
fun subgoals_of_brl (true,rule)  = nprems_of rule - 1
lcp@1077
   380
  | subgoals_of_brl (false,rule) = nprems_of rule;
clasohm@0
   381
clasohm@0
   382
(*Less-than test: for sorting to minimize number of new subgoals*)
clasohm@0
   383
fun lessb (brl1,brl2) = subgoals_of_brl brl1 < subgoals_of_brl brl2;
clasohm@0
   384
clasohm@0
   385
clasohm@0
   386
(*** Meta-Rewriting Tactics ***)
clasohm@0
   387
clasohm@0
   388
fun result1 tacf mss thm =
paulson@1501
   389
  case Sequence.pull(tacf mss thm) of
clasohm@0
   390
    None => None
clasohm@0
   391
  | Some(thm,_) => Some(thm);
clasohm@0
   392
clasohm@0
   393
(*Rewrite subgoal i only *)
nipkow@214
   394
fun asm_rewrite_goal_tac mode prover_tac mss i =
nipkow@214
   395
      PRIMITIVE(rewrite_goal_rule mode (result1 prover_tac) mss i);
clasohm@0
   396
lcp@69
   397
(*Rewrite throughout proof state. *)
lcp@69
   398
fun rewrite_tac defs = PRIMITIVE(rewrite_rule defs);
clasohm@0
   399
clasohm@0
   400
(*Rewrite subgoals only, not main goal. *)
lcp@69
   401
fun rewrite_goals_tac defs = PRIMITIVE (rewrite_goals_rule defs);
clasohm@0
   402
clasohm@1460
   403
fun rewtac def = rewrite_goals_tac [def];
clasohm@0
   404
clasohm@0
   405
paulson@1501
   406
(*** for folding definitions, handling critical pairs ***)
lcp@69
   407
lcp@69
   408
(*The depth of nesting in a term*)
lcp@69
   409
fun term_depth (Abs(a,T,t)) = 1 + term_depth t
lcp@69
   410
  | term_depth (f$t) = 1 + max [term_depth f, term_depth t]
lcp@69
   411
  | term_depth _ = 0;
lcp@69
   412
lcp@69
   413
val lhs_of_thm = #1 o Logic.dest_equals o #prop o rep_thm;
lcp@69
   414
lcp@69
   415
(*folding should handle critical pairs!  E.g. K == Inl(0),  S == Inr(Inl(0))
lcp@69
   416
  Returns longest lhs first to avoid folding its subexpressions.*)
lcp@69
   417
fun sort_lhs_depths defs =
lcp@69
   418
  let val keylist = make_keylist (term_depth o lhs_of_thm) defs
lcp@69
   419
      val keys = distinct (sort op> (map #2 keylist))
lcp@69
   420
  in  map (keyfilter keylist) keys  end;
lcp@69
   421
lcp@69
   422
fun fold_tac defs = EVERY 
lcp@69
   423
    (map rewrite_tac (sort_lhs_depths (map symmetric defs)));
lcp@69
   424
lcp@69
   425
fun fold_goals_tac defs = EVERY 
lcp@69
   426
    (map rewrite_goals_tac (sort_lhs_depths (map symmetric defs)));
lcp@69
   427
lcp@69
   428
lcp@69
   429
(*** Renaming of parameters in a subgoal
lcp@69
   430
     Names may contain letters, digits or primes and must be
lcp@69
   431
     separated by blanks ***)
clasohm@0
   432
clasohm@0
   433
(*Calling this will generate the warning "Same as previous level" since
clasohm@0
   434
  it affects nothing but the names of bound variables!*)
clasohm@0
   435
fun rename_tac str i = 
clasohm@0
   436
  let val cs = explode str 
clasohm@0
   437
  in  
clasohm@0
   438
  if !Logic.auto_rename 
clasohm@0
   439
  then (writeln"Note: setting Logic.auto_rename := false"; 
clasohm@1460
   440
	Logic.auto_rename := false)
clasohm@0
   441
  else ();
clasohm@0
   442
  case #2 (take_prefix (is_letdig orf is_blank) cs) of
clasohm@0
   443
      [] => PRIMITIVE (rename_params_rule (scanwords is_letdig cs, i))
clasohm@0
   444
    | c::_ => error ("Illegal character: " ^ c)
clasohm@0
   445
  end;
clasohm@0
   446
paulson@1501
   447
(*Rename recent parameters using names generated from a and the suffixes,
paulson@1501
   448
  provided the string a, which represents a term, is an identifier. *)
clasohm@0
   449
fun rename_last_tac a sufs i = 
clasohm@0
   450
  let val names = map (curry op^ a) sufs
clasohm@0
   451
  in  if Syntax.is_identifier a
clasohm@0
   452
      then PRIMITIVE (rename_params_rule (names,i))
clasohm@0
   453
      else all_tac
clasohm@0
   454
  end;
clasohm@0
   455
clasohm@0
   456
(*Prunes all redundant parameters from the proof state by rewriting*)
clasohm@0
   457
val prune_params_tac = rewrite_tac [triv_forall_equality];
clasohm@0
   458
paulson@1501
   459
(*rotate_tac n i: rotate the assumptions of subgoal i by n positions, from
paulson@1501
   460
  right to left if n is positive, and from left to right if n is negative.*)
nipkow@1209
   461
fun rotate_tac n =
nipkow@1209
   462
  let fun rot(n) = EVERY'(replicate n (dtac asm_rl));
nipkow@1209
   463
  in if n >= 0 then rot n
nipkow@1209
   464
     else SUBGOAL (fn (t,i) => rot(length(Logic.strip_assums_hyp t)+n) i)
nipkow@1209
   465
  end;
nipkow@1209
   466
clasohm@0
   467
end;
paulson@1501
   468
paulson@1501
   469
open Tactic;