src/Pure/goal.ML
author wenzelm
Wed, 16 Nov 2005 17:45:26 +0100
changeset 18180 db712213504d
parent 18145 6757627acf59
child 18207 9edbeda7e39a
permissions -rw-r--r--
norm_hhf: no normalization of protected props;
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
17980
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
     1
(*  Title:      Pure/goal.ML
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
     2
    ID:         $Id$
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
     3
    Author:     Makarius and Lawrence C Paulson
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
     4
18139
wenzelm
parents: 18119
diff changeset
     5
Goals in tactical theorem proving.
17980
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
     6
*)
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
     7
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
     8
signature BASIC_GOAL =
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
     9
sig
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
    10
  val SELECT_GOAL: tactic -> int -> tactic
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
    11
end;
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
    12
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
    13
signature GOAL =
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
    14
sig
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
    15
  include BASIC_GOAL
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
    16
  val init: cterm -> thm
18027
09ab79d4e8e1 renamed Goal constant to prop, more general protect/unprotect interfaces;
wenzelm
parents: 17986
diff changeset
    17
  val protect: thm -> thm
17980
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
    18
  val conclude: thm -> thm
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
    19
  val finish: thm -> thm
18027
09ab79d4e8e1 renamed Goal constant to prop, more general protect/unprotect interfaces;
wenzelm
parents: 17986
diff changeset
    20
  val norm_hhf: thm -> thm
18180
db712213504d norm_hhf: no normalization of protected props;
wenzelm
parents: 18145
diff changeset
    21
  val norm_hhf': thm -> thm
18119
63901a9b99dc export compose_hhf;
wenzelm
parents: 18027
diff changeset
    22
  val compose_hhf: thm -> int -> thm -> thm Seq.seq
63901a9b99dc export compose_hhf;
wenzelm
parents: 18027
diff changeset
    23
  val compose_hhf_tac: thm -> int -> tactic
18027
09ab79d4e8e1 renamed Goal constant to prop, more general protect/unprotect interfaces;
wenzelm
parents: 17986
diff changeset
    24
  val comp_hhf: thm -> thm -> thm
17980
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
    25
  val prove_multi: theory -> string list -> term list -> term list ->
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
    26
    (thm list -> tactic) -> thm list
18139
wenzelm
parents: 18119
diff changeset
    27
  val prove: theory -> string list -> term list -> term -> (thm list -> tactic) -> thm
18027
09ab79d4e8e1 renamed Goal constant to prop, more general protect/unprotect interfaces;
wenzelm
parents: 17986
diff changeset
    28
  val prove_raw: cterm list -> cterm -> (thm list -> tactic) -> thm
17980
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
    29
end;
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
    30
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
    31
structure Goal: GOAL =
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
    32
struct
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
    33
18027
09ab79d4e8e1 renamed Goal constant to prop, more general protect/unprotect interfaces;
wenzelm
parents: 17986
diff changeset
    34
(** goals **)
09ab79d4e8e1 renamed Goal constant to prop, more general protect/unprotect interfaces;
wenzelm
parents: 17986
diff changeset
    35
09ab79d4e8e1 renamed Goal constant to prop, more general protect/unprotect interfaces;
wenzelm
parents: 17986
diff changeset
    36
(*
09ab79d4e8e1 renamed Goal constant to prop, more general protect/unprotect interfaces;
wenzelm
parents: 17986
diff changeset
    37
  -------- (init)
09ab79d4e8e1 renamed Goal constant to prop, more general protect/unprotect interfaces;
wenzelm
parents: 17986
diff changeset
    38
  C ==> #C
09ab79d4e8e1 renamed Goal constant to prop, more general protect/unprotect interfaces;
wenzelm
parents: 17986
diff changeset
    39
*)
09ab79d4e8e1 renamed Goal constant to prop, more general protect/unprotect interfaces;
wenzelm
parents: 17986
diff changeset
    40
fun init ct = Drule.instantiate' [] [SOME ct] Drule.protectI;
17980
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
    41
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
    42
(*
18119
63901a9b99dc export compose_hhf;
wenzelm
parents: 18027
diff changeset
    43
   C
63901a9b99dc export compose_hhf;
wenzelm
parents: 18027
diff changeset
    44
  --- (protect)
63901a9b99dc export compose_hhf;
wenzelm
parents: 18027
diff changeset
    45
  #C
17980
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
    46
*)
18027
09ab79d4e8e1 renamed Goal constant to prop, more general protect/unprotect interfaces;
wenzelm
parents: 17986
diff changeset
    47
fun protect th = th COMP Drule.incr_indexes th Drule.protectI;
17980
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
    48
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
    49
(*
18027
09ab79d4e8e1 renamed Goal constant to prop, more general protect/unprotect interfaces;
wenzelm
parents: 17986
diff changeset
    50
  A ==> ... ==> #C
09ab79d4e8e1 renamed Goal constant to prop, more general protect/unprotect interfaces;
wenzelm
parents: 17986
diff changeset
    51
  ---------------- (conclude)
17980
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
    52
  A ==> ... ==> C
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
    53
*)
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
    54
fun conclude th =
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
    55
  (case SINGLE (Thm.bicompose false (false, th, Thm.nprems_of th) 1)
18027
09ab79d4e8e1 renamed Goal constant to prop, more general protect/unprotect interfaces;
wenzelm
parents: 17986
diff changeset
    56
      (Drule.incr_indexes th Drule.protectD) of
17980
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
    57
    SOME th' => th'
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
    58
  | NONE => raise THM ("Failed to conclude goal", 0, [th]));
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
    59
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
    60
(*
18027
09ab79d4e8e1 renamed Goal constant to prop, more general protect/unprotect interfaces;
wenzelm
parents: 17986
diff changeset
    61
  #C
09ab79d4e8e1 renamed Goal constant to prop, more general protect/unprotect interfaces;
wenzelm
parents: 17986
diff changeset
    62
  --- (finish)
09ab79d4e8e1 renamed Goal constant to prop, more general protect/unprotect interfaces;
wenzelm
parents: 17986
diff changeset
    63
   C
17983
wenzelm
parents: 17980
diff changeset
    64
*)
17980
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
    65
fun finish th =
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
    66
  (case Thm.nprems_of th of
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
    67
    0 => conclude th
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
    68
  | n => raise THM ("Proof failed.\n" ^
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
    69
      Pretty.string_of (Pretty.chunks (Display.pretty_goals n th)) ^
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
    70
      ("\n" ^ string_of_int n ^ " unsolved goal(s)!"), 0, [th]));
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
    71
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
    72
18027
09ab79d4e8e1 renamed Goal constant to prop, more general protect/unprotect interfaces;
wenzelm
parents: 17986
diff changeset
    73
09ab79d4e8e1 renamed Goal constant to prop, more general protect/unprotect interfaces;
wenzelm
parents: 17986
diff changeset
    74
(** results **)
09ab79d4e8e1 renamed Goal constant to prop, more general protect/unprotect interfaces;
wenzelm
parents: 17986
diff changeset
    75
09ab79d4e8e1 renamed Goal constant to prop, more general protect/unprotect interfaces;
wenzelm
parents: 17986
diff changeset
    76
(* HHF normal form *)
17980
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
    77
18180
db712213504d norm_hhf: no normalization of protected props;
wenzelm
parents: 18145
diff changeset
    78
val norm_hhf_ss =
db712213504d norm_hhf: no normalization of protected props;
wenzelm
parents: 18145
diff changeset
    79
  MetaSimplifier.theory_context ProtoPure.thy MetaSimplifier.empty_ss
db712213504d norm_hhf: no normalization of protected props;
wenzelm
parents: 18145
diff changeset
    80
    addsimps [Drule.norm_hhf_eq];
db712213504d norm_hhf: no normalization of protected props;
wenzelm
parents: 18145
diff changeset
    81
db712213504d norm_hhf: no normalization of protected props;
wenzelm
parents: 18145
diff changeset
    82
val norm_hhf_ss' = norm_hhf_ss addeqcongs [Drule.protect_cong];
db712213504d norm_hhf: no normalization of protected props;
wenzelm
parents: 18145
diff changeset
    83
db712213504d norm_hhf: no normalization of protected props;
wenzelm
parents: 18145
diff changeset
    84
fun gen_norm_hhf protected =
17980
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
    85
  (not o Drule.is_norm_hhf o Thm.prop_of) ?
18180
db712213504d norm_hhf: no normalization of protected props;
wenzelm
parents: 18145
diff changeset
    86
    Drule.fconv_rule (MetaSimplifier.rewrite_cterm (true, false, false) (K (K NONE))
db712213504d norm_hhf: no normalization of protected props;
wenzelm
parents: 18145
diff changeset
    87
      (if protected then norm_hhf_ss else norm_hhf_ss'))
17980
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
    88
  #> Thm.adjust_maxidx_thm
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
    89
  #> Drule.gen_all;
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
    90
18180
db712213504d norm_hhf: no normalization of protected props;
wenzelm
parents: 18145
diff changeset
    91
val norm_hhf = gen_norm_hhf true;
db712213504d norm_hhf: no normalization of protected props;
wenzelm
parents: 18145
diff changeset
    92
val norm_hhf' = gen_norm_hhf false;
db712213504d norm_hhf: no normalization of protected props;
wenzelm
parents: 18145
diff changeset
    93
18027
09ab79d4e8e1 renamed Goal constant to prop, more general protect/unprotect interfaces;
wenzelm
parents: 17986
diff changeset
    94
09ab79d4e8e1 renamed Goal constant to prop, more general protect/unprotect interfaces;
wenzelm
parents: 17986
diff changeset
    95
(* composition of normal results *)
09ab79d4e8e1 renamed Goal constant to prop, more general protect/unprotect interfaces;
wenzelm
parents: 17986
diff changeset
    96
09ab79d4e8e1 renamed Goal constant to prop, more general protect/unprotect interfaces;
wenzelm
parents: 17986
diff changeset
    97
fun compose_hhf tha i thb =
18145
6757627acf59 renamed Thm.cgoal_of to Thm.cprem_of;
wenzelm
parents: 18139
diff changeset
    98
  Thm.bicompose false (false, Drule.lift_all (Thm.cprem_of thb i) tha, 0) i thb;
18027
09ab79d4e8e1 renamed Goal constant to prop, more general protect/unprotect interfaces;
wenzelm
parents: 17986
diff changeset
    99
18119
63901a9b99dc export compose_hhf;
wenzelm
parents: 18027
diff changeset
   100
fun compose_hhf_tac th i = PRIMSEQ (compose_hhf th i);
63901a9b99dc export compose_hhf;
wenzelm
parents: 18027
diff changeset
   101
18027
09ab79d4e8e1 renamed Goal constant to prop, more general protect/unprotect interfaces;
wenzelm
parents: 17986
diff changeset
   102
fun comp_hhf tha thb =
18119
63901a9b99dc export compose_hhf;
wenzelm
parents: 18027
diff changeset
   103
  (case Seq.chop (2, compose_hhf tha 1 thb) of
63901a9b99dc export compose_hhf;
wenzelm
parents: 18027
diff changeset
   104
    ([th], _) => th
63901a9b99dc export compose_hhf;
wenzelm
parents: 18027
diff changeset
   105
  | ([], _) => raise THM ("comp_hhf: no unifiers", 1, [tha, thb])
63901a9b99dc export compose_hhf;
wenzelm
parents: 18027
diff changeset
   106
  | _  => raise THM ("comp_hhf: multiple unifiers", 1, [tha, thb]));
17986
0450847646c3 prove_raw: cterms, explicit asms;
wenzelm
parents: 17983
diff changeset
   107
0450847646c3 prove_raw: cterms, explicit asms;
wenzelm
parents: 17983
diff changeset
   108
18027
09ab79d4e8e1 renamed Goal constant to prop, more general protect/unprotect interfaces;
wenzelm
parents: 17986
diff changeset
   109
09ab79d4e8e1 renamed Goal constant to prop, more general protect/unprotect interfaces;
wenzelm
parents: 17986
diff changeset
   110
(** tactical theorem proving **)
09ab79d4e8e1 renamed Goal constant to prop, more general protect/unprotect interfaces;
wenzelm
parents: 17986
diff changeset
   111
18119
63901a9b99dc export compose_hhf;
wenzelm
parents: 18027
diff changeset
   112
(* prove_multi *)
17986
0450847646c3 prove_raw: cterms, explicit asms;
wenzelm
parents: 17983
diff changeset
   113
18119
63901a9b99dc export compose_hhf;
wenzelm
parents: 18027
diff changeset
   114
fun prove_multi thy xs asms props tac =
17980
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
   115
  let
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
   116
    val prop = Logic.mk_conjunction_list props;
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
   117
    val statement = Logic.list_implies (asms, prop);
18139
wenzelm
parents: 18119
diff changeset
   118
    val frees = Term.add_frees statement [];
17980
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
   119
    val fixed_frees = filter_out (member (op =) xs o #1) frees;
18139
wenzelm
parents: 18119
diff changeset
   120
    val fixed_tfrees = fold (Term.add_tfreesT o #2) fixed_frees [];
17980
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
   121
    val params = List.mapPartial (fn x => Option.map (pair x) (AList.lookup (op =) frees x)) xs;
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
   122
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
   123
    fun err msg = raise ERROR_MESSAGE
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
   124
      (msg ^ "\nThe error(s) above occurred for the goal statement:\n" ^
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
   125
        Sign.string_of_term thy (Term.list_all_free (params, statement)));
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
   126
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
   127
    fun cert_safe t = Thm.cterm_of thy (Envir.beta_norm t)
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
   128
      handle TERM (msg, _) => err msg | TYPE (msg, _, _) => err msg;
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
   129
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
   130
    val _ = cert_safe statement;
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
   131
    val _ = Term.no_dummy_patterns statement handle TERM (msg, _) => err msg;
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
   132
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
   133
    val cparams = map (cert_safe o Free) params;
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
   134
    val casms = map cert_safe asms;
18027
09ab79d4e8e1 renamed Goal constant to prop, more general protect/unprotect interfaces;
wenzelm
parents: 17986
diff changeset
   135
    val prems = map (norm_hhf o Thm.assume) casms;
17980
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
   136
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
   137
    val goal = init (cert_safe prop);
18119
63901a9b99dc export compose_hhf;
wenzelm
parents: 18027
diff changeset
   138
    val goal' = case SINGLE (tac prems) goal of SOME goal' => goal' | _ => err "Tactic failed.";
17980
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
   139
    val raw_result = finish goal' handle THM (msg, _, _) => err msg;
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
   140
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
   141
    val prop' = Thm.prop_of raw_result;
17986
0450847646c3 prove_raw: cterms, explicit asms;
wenzelm
parents: 17983
diff changeset
   142
    val _ = conditional (not (Pattern.matches thy (Envir.beta_norm prop, prop'))) (fn () =>
17980
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
   143
      err ("Proved a different theorem: " ^ Sign.string_of_term thy prop'));
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
   144
  in
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
   145
    Drule.conj_elim_precise (length props) raw_result
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
   146
    |> map
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
   147
      (Drule.implies_intr_list casms
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
   148
        #> Drule.forall_intr_list cparams
18119
63901a9b99dc export compose_hhf;
wenzelm
parents: 18027
diff changeset
   149
        #> norm_hhf
18139
wenzelm
parents: 18119
diff changeset
   150
        #> Thm.varifyT' fixed_tfrees
wenzelm
parents: 18119
diff changeset
   151
        #-> K Drule.zero_var_indexes)
17980
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
   152
  end;
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
   153
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
   154
18119
63901a9b99dc export compose_hhf;
wenzelm
parents: 18027
diff changeset
   155
(* prove *)
17980
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
   156
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
   157
fun prove thy xs asms prop tac = hd (prove_multi thy xs asms [prop] tac);
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
   158
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
   159
18027
09ab79d4e8e1 renamed Goal constant to prop, more general protect/unprotect interfaces;
wenzelm
parents: 17986
diff changeset
   160
(* prove_raw -- no checks, no normalization of result! *)
09ab79d4e8e1 renamed Goal constant to prop, more general protect/unprotect interfaces;
wenzelm
parents: 17986
diff changeset
   161
09ab79d4e8e1 renamed Goal constant to prop, more general protect/unprotect interfaces;
wenzelm
parents: 17986
diff changeset
   162
fun prove_raw casms cprop tac =
09ab79d4e8e1 renamed Goal constant to prop, more general protect/unprotect interfaces;
wenzelm
parents: 17986
diff changeset
   163
  (case SINGLE (tac (map (norm_hhf o Thm.assume) casms)) (init cprop) of
09ab79d4e8e1 renamed Goal constant to prop, more general protect/unprotect interfaces;
wenzelm
parents: 17986
diff changeset
   164
    SOME th => Drule.implies_intr_list casms (finish th)
09ab79d4e8e1 renamed Goal constant to prop, more general protect/unprotect interfaces;
wenzelm
parents: 17986
diff changeset
   165
  | NONE => raise ERROR_MESSAGE "Tactic failed.");
09ab79d4e8e1 renamed Goal constant to prop, more general protect/unprotect interfaces;
wenzelm
parents: 17986
diff changeset
   166
09ab79d4e8e1 renamed Goal constant to prop, more general protect/unprotect interfaces;
wenzelm
parents: 17986
diff changeset
   167
17980
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
   168
(* SELECT_GOAL *)
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
   169
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
   170
(*Tactical for restricting the effect of a tactic to subgoal i.  Works
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
   171
  by making a new state from subgoal i, applying tac to it, and
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
   172
  composing the resulting thm with the original state.*)
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
   173
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
   174
fun SELECT tac i st =
18145
6757627acf59 renamed Thm.cgoal_of to Thm.cprem_of;
wenzelm
parents: 18139
diff changeset
   175
  init (Thm.adjust_maxidx (Thm.cprem_of st i))
17980
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
   176
  |> tac
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
   177
  |> Seq.maps (fn st' => Thm.bicompose false (false, conclude st', Thm.nprems_of st') i st);
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
   178
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
   179
fun SELECT_GOAL tac i st =
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
   180
  let val n = Thm.nprems_of st in
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
   181
    if 1 <= i andalso i <= n then
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
   182
      if n = 1 then tac st else SELECT tac i st
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
   183
    else Seq.empty
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
   184
  end;
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
   185
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
   186
end;
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
   187
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
   188
structure BasicGoal: BASIC_GOAL = Goal;
788836292b1a Internal goals.
wenzelm
parents:
diff changeset
   189
open BasicGoal;