src/Sequents/prover.ML
 changeset 7097 5ab37ed3d53c parent 6054 4a4f6ad607a1 child 7122 87b233b31889
```     1.1 --- a/src/Sequents/prover.ML	Tue Jul 27 19:00:55 1999 +0200
1.2 +++ b/src/Sequents/prover.ML	Tue Jul 27 19:01:46 1999 +0200
1.3 @@ -2,12 +2,14 @@
1.4      ID:         \$Id\$
1.5      Author:     Lawrence C Paulson, Cambridge University Computer Laboratory
1.6      Copyright   1992  University of Cambridge
1.7 +
1.8 +Simple classical reasoner for the sequent calculus, based on "theorem packs"
1.9  *)
1.10
1.11
1.12 -(**** Theorem Packs ****)
1.13
1.14 -(* based largely on LK *)
1.15 +(*Higher precedence than := facilitates use of references*)
1.17
1.18  datatype pack = Pack of thm list * thm list;
1.19
1.20 @@ -19,17 +21,37 @@
1.21
1.22  val empty_pack = Pack([],[]);
1.23
1.25 +fun warn_duplicates [] = []
1.26 +  | warn_duplicates dups =
1.27 +      (warning (String.concat ("Ignoring duplicate theorems:\n"::
1.28 +			       map (suffix "\n" o string_of_thm) dups));
1.29 +       dups);
1.30
1.31  fun (Pack(safes,unsafes)) add_safes ths   =
1.32 -    Pack(sort (make_ord less) (ths@safes), unsafes);
1.33 +    let val dups = warn_duplicates (gen_inter eq_thm (ths,safes))
1.34 +	val ths' = gen_rems eq_thm (ths,dups)
1.35 +    in
1.36 +        Pack(sort (make_ord less) (ths'@safes), unsafes)
1.37 +    end;
1.38
1.39  fun (Pack(safes,unsafes)) add_unsafes ths =
1.40 -    Pack(safes, sort (make_ord less) (ths@unsafes));
1.41 +    let val dups = warn_duplicates (gen_inter eq_thm (ths,unsafes))
1.42 +	val ths' = gen_rems eq_thm (ths,dups)
1.43 +    in
1.44 +	Pack(safes, sort (make_ord less) (ths'@unsafes))
1.45 +    end;
1.46 +
1.47 +fun merge_pack (Pack(safes,unsafes), Pack(safes',unsafes')) =
1.48 +        Pack(sort (make_ord less) (safes@safes'),
1.49 +	     sort (make_ord less) (unsafes@unsafes'));
1.50
1.51
1.52 +fun print_pack (Pack(safes,unsafes)) =
1.53 +    (writeln "Safe rules:";  print_thms safes;
1.54 +     writeln "Unsafe rules:"; print_thms unsafes);
1.55 +
1.56  (*Returns the list of all formulas in the sequent*)
1.57 -fun forms_of_seq (Const("Sequents.SeqO'",_) \$ P \$ u) = P :: forms_of_seq u
1.58 +fun forms_of_seq (Const("SeqO'",_) \$ P \$ u) = P :: forms_of_seq u
1.59    | forms_of_seq (H \$ u) = forms_of_seq u
1.60    | forms_of_seq _ = [];
1.61
1.62 @@ -112,11 +134,13 @@
1.63
1.64
1.65  (*Tries safe rules only*)
1.66 -fun safe_goal_tac (Pack(safes,unsafes)) = reresolve_tac safes;
1.67 +fun safe_tac (Pack(safes,unsafes)) = reresolve_tac safes;
1.68 +
1.69 +val safe_goal_tac = safe_tac;   (*backwards compatibility*)
1.70
1.71  (*Tries a safe rule or else a unsafe rule.  Single-step for tracing. *)
1.72  fun step_tac (thm_pack as Pack(safes,unsafes)) =
1.73 -    safe_goal_tac thm_pack  ORELSE'
1.74 +    safe_tac thm_pack  ORELSE'
1.75      filseq_resolve_tac unsafes 9999;
1.76
1.77
1.78 @@ -138,87 +162,38 @@
1.79
1.80
1.81
1.82 -signature MODAL_PROVER_RULE =
1.83 -sig
1.84 -    val rewrite_rls      : thm list
1.85 -    val safe_rls         : thm list
1.86 -    val unsafe_rls       : thm list
1.87 -    val bound_rls        : thm list
1.88 -    val aside_rls        : thm list
1.89 -end;
1.90 -
1.91 -signature MODAL_PROVER =
1.92 -sig
1.93 -    val rule_tac   : thm list -> int ->tactic
1.94 -    val step_tac   : int -> tactic
1.95 -    val solven_tac : int -> int -> tactic
1.96 -    val solve_tac  : int -> tactic
1.97 -end;
1.98 +structure ProverArgs =
1.99 +  struct
1.100 +  val name = "Sequents/prover";
1.101 +  type T = pack ref;
1.102 +  val empty = ref empty_pack
1.103 +  fun copy (ref pack) = ref pack;
1.104 +  val prep_ext = copy;
1.105 +  fun merge (ref pack1, ref pack2) = ref (merge_pack (pack1, pack2));
1.106 +  fun print _ (ref pack) = print_pack pack;
1.107 +  end;
1.108
1.109 -functor Modal_ProverFun (Modal_Rule: MODAL_PROVER_RULE) : MODAL_PROVER =
1.110 -struct
1.111 -local open Modal_Rule
1.112 -in
1.113 +structure ProverData = TheoryDataFun(ProverArgs);
1.114
1.115 -(*Returns the list of all formulas in the sequent*)
1.116 -fun forms_of_seq (Const("Sequents.SeqO",_) \$ P \$ u) = P :: forms_of_seq u
1.117 -  | forms_of_seq (H \$ u) = forms_of_seq u
1.118 -  | forms_of_seq _ = [];
1.119 -
1.120 -(*Tests whether two sequences (left or right sides) could be resolved.
1.121 -  seqp is a premise (subgoal), seqc is a conclusion of an object-rule.
1.122 -  Assumes each formula in seqc is surrounded by sequence variables
1.123 -  -- checks that each concl formula looks like some subgoal formula.*)
1.124 -fun could_res (seqp,seqc) =
1.125 -      forall (fn Qc => exists (fn Qp => could_unify (Qp,Qc))
1.126 -                              (forms_of_seq seqp))
1.127 -             (forms_of_seq seqc);
1.128 +val prover_setup = [ProverData.init];
1.129
1.130 -(*Tests whether two sequents G|-H could be resolved, comparing each side.*)
1.131 -fun could_resolve_seq (prem,conc) =
1.132 -  case (prem,conc) of
1.133 -      (_ \$ Abs(_,_,leftp) \$ Abs(_,_,rightp),
1.134 -       _ \$ Abs(_,_,leftc) \$ Abs(_,_,rightc)) =>
1.135 -          could_res (leftp,leftc)  andalso  could_res (rightp,rightc)
1.136 -    | _ => false;
1.137 +val print_thm_pack = ProverData.print;
1.138 +val thm_pack_ref_of_sg = ProverData.get_sg;
1.139 +val thm_pack_ref_of = ProverData.get;
1.140
1.141 -(*Like filt_resolve_tac, using could_resolve_seq
1.142 -  Much faster than resolve_tac when there are many rules.
1.143 -  Resolve subgoal i using the rules, unless more than maxr are compatible. *)
1.144 -fun filseq_resolve_tac rules maxr = SUBGOAL(fn (prem,i) =>
1.145 -  let val rls = filter_thms could_resolve_seq (maxr+1, prem, rules)
1.146 -  in  if length rls > maxr  then  no_tac  else resolve_tac rls i
1.147 -  end);
1.148 +(* access global thm_pack *)
1.149
1.150 -fun fresolve_tac rls n = filseq_resolve_tac rls 999 n;
1.151 -
1.152 -(* NB No back tracking possible with aside rules *)
1.153 -
1.154 -fun aside_tac n = DETERM(REPEAT (filt_resolve_tac aside_rls 999 n));
1.155 -fun rule_tac rls n = fresolve_tac rls n THEN aside_tac n;
1.156 +val thm_pack_of_sg = ! o thm_pack_ref_of_sg;
1.157 +val thm_pack_of = thm_pack_of_sg o sign_of;
1.158
1.159 -val fres_safe_tac = fresolve_tac safe_rls;
1.160 -val fres_unsafe_tac = fresolve_tac unsafe_rls THEN' aside_tac;
1.161 -val fres_bound_tac = fresolve_tac bound_rls;
1.162 +val thm_pack = thm_pack_of o Context.the_context;
1.163 +val thm_pack_ref = thm_pack_ref_of_sg o sign_of o Context.the_context;
1.164
1.165 -fun UPTOGOAL n tf = let fun tac i = if i<n then all_tac
1.166 -                                    else tf(i) THEN tac(i-1)
1.167 -                    in fn st => tac (nprems_of st) st end;
1.168 +
1.169 +(* change global thm_pack *)
1.170
1.171 -(* Depth first search bounded by d *)
1.172 -fun solven_tac d n state = state |>
1.173 -       (if d<0 then no_tac
1.174 -        else if (nprems_of state = 0) then all_tac
1.175 -        else (DETERM(fres_safe_tac n) THEN UPTOGOAL n (solven_tac d)) ORELSE
1.176 -                 ((fres_unsafe_tac n  THEN UPTOGOAL n (solven_tac d)) APPEND
1.177 -                   (fres_bound_tac n  THEN UPTOGOAL n (solven_tac (d-1)))));
1.178 +fun change_thm_pack f x = thm_pack_ref () := (f (thm_pack (), x));
1.179
1.180 -fun solve_tac d = rewrite_goals_tac rewrite_rls THEN solven_tac d 1;