src/Pure/tactic.ML
author wenzelm
Mon Jun 25 00:36:41 2007 +0200 (2007-06-25)
changeset 23492 60cf5cf30b81
parent 23223 7791128b39a9
child 23539 df5440e241a1
permissions -rw-r--r--
added eta_long_tac;
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(*  Title:      Pure/tactic.ML
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    ID:         $Id$
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    Author:     Lawrence C Paulson, Cambridge University Computer Laboratory
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    Copyright   1991  University of Cambridge
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Tactics.
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*)
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signature BASIC_TACTIC =
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sig
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  val trace_goalno_tac: (int -> tactic) -> int -> tactic
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  val rule_by_tactic: tactic -> thm -> thm
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  val assume_tac: int -> tactic
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  val eq_assume_tac: int -> tactic
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  val compose_tac: (bool * thm * int) -> int -> tactic
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  val make_elim: thm -> thm
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  val biresolve_tac: (bool * thm) list -> int -> tactic
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  val resolve_tac: thm list -> int -> tactic
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  val eresolve_tac: thm list -> int -> tactic
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  val forward_tac: thm list -> int -> tactic
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  val dresolve_tac: thm list -> int -> tactic
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  val atac: int -> tactic
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  val rtac: thm -> int -> tactic
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  val dtac: thm -> int ->tactic
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  val etac: thm -> int ->tactic
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  val ftac: thm -> int ->tactic
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  val datac: thm -> int -> int -> tactic
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  val eatac: thm -> int -> int -> tactic
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  val fatac: thm -> int -> int -> tactic
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  val ares_tac: thm list -> int -> tactic
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  val solve_tac: thm list -> int -> tactic
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  val bimatch_tac: (bool * thm) list -> int -> tactic
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  val match_tac: thm list -> int -> tactic
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  val ematch_tac: thm list -> int -> tactic
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  val dmatch_tac: thm list -> int -> tactic
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  val flexflex_tac: tactic
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  val distinct_subgoal_tac: int -> tactic
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  val distinct_subgoals_tac: tactic
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  val lift_inst_rule: thm * int * (string*string)list * thm -> thm
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  val term_lift_inst_rule:
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    thm * int * ((indexname * sort) * typ) list * ((indexname * typ) * term) list * thm -> thm
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  val compose_inst_tac: (string * string) list -> (bool * thm * int) -> int -> tactic
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  val res_inst_tac: (string * string) list -> thm -> int -> tactic
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  val eres_inst_tac: (string * string) list -> thm -> int -> tactic
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  val cut_inst_tac: (string * string) list -> thm -> int -> tactic
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  val forw_inst_tac: (string * string) list -> thm -> int -> tactic
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  val dres_inst_tac: (string * string) list -> thm -> int -> tactic
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  val instantiate_tac: (string * string) list -> tactic
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  val thin_tac: string -> int -> tactic
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  val metacut_tac: thm -> int -> tactic
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  val cut_rules_tac: thm list -> int -> tactic
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  val cut_facts_tac: thm list -> int -> tactic
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  val subgoal_tac: string -> int -> tactic
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  val subgoals_tac: string list -> int -> tactic
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  val filter_thms: (term * term -> bool) -> int * term * thm list -> thm list
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  val biresolution_from_nets_tac: ('a list -> (bool * thm) list) ->
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    bool -> 'a Net.net * 'a Net.net -> int -> tactic
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  val biresolve_from_nets_tac: (int * (bool * thm)) Net.net * (int * (bool * thm)) Net.net ->
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    int -> tactic
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  val bimatch_from_nets_tac: (int * (bool * thm)) Net.net * (int * (bool * thm)) Net.net ->
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    int -> tactic
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  val net_biresolve_tac: (bool * thm) list -> int -> tactic
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  val net_bimatch_tac: (bool * thm) list -> int -> tactic
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  val build_net: thm list -> (int * thm) Net.net
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  val filt_resolve_tac: thm list -> int -> int -> tactic
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  val resolve_from_net_tac: (int * thm) Net.net -> int -> tactic
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  val match_from_net_tac: (int * thm) Net.net -> int -> tactic
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  val net_resolve_tac: thm list -> int -> tactic
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  val net_match_tac: thm list -> int -> tactic
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  val subgoals_of_brl: bool * thm -> int
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  val lessb: (bool * thm) * (bool * thm) -> bool
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  val rename_params_tac: string list -> int -> tactic
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  val rename_tac: string -> int -> tactic
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  val rename_last_tac: string -> string list -> int -> tactic
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  val rotate_tac: int -> int -> tactic
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  val defer_tac: int -> tactic
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  val filter_prems_tac: (term -> bool) -> int -> tactic
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  val eta_long_tac: int -> tactic
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end;
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signature TACTIC =
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sig
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  include BASIC_TACTIC
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  val innermost_params: int -> thm -> (string * typ) list
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  val lift_inst_rule': thm * int * (indexname * string) list * thm -> thm
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  val compose_inst_tac': (indexname * string) list -> (bool * thm * int) -> int -> tactic
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  val res_inst_tac': (indexname * string) list -> thm -> int -> tactic
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  val eres_inst_tac': (indexname * string) list -> thm -> int -> tactic
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  val make_elim_preserve: thm -> thm
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  val instantiate_tac': (indexname * string) list -> tactic
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  val untaglist: (int * 'a) list -> 'a list
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  val orderlist: (int * 'a) list -> 'a list
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  val insert_tagged_brl: 'a * (bool * thm) ->
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    ('a * (bool * thm)) Net.net * ('a * (bool * thm)) Net.net ->
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      ('a * (bool * thm)) Net.net * ('a * (bool * thm)) Net.net
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  val build_netpair: (int * (bool * thm)) Net.net * (int * (bool * thm)) Net.net ->
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    (bool * thm) list -> (int * (bool * thm)) Net.net * (int * (bool * thm)) Net.net
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  val delete_tagged_brl: bool * thm ->
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    ('a * (bool * thm)) Net.net * ('a * (bool * thm)) Net.net ->
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      ('a * (bool * thm)) Net.net * ('a * (bool * thm)) Net.net
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  val eq_kbrl: ('a * (bool * thm)) * ('a * (bool * thm)) -> bool
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end;
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structure Tactic: TACTIC =
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struct
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(*Discover which goal is chosen:  SOMEGOAL(trace_goalno_tac tac) *)
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fun trace_goalno_tac tac i st =
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    case Seq.pull(tac i st) of
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        NONE    => Seq.empty
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      | seqcell => (tracing ("Subgoal " ^ string_of_int i ^ " selected");
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                         Seq.make(fn()=> seqcell));
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(*Makes a rule by applying a tactic to an existing rule*)
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fun rule_by_tactic tac rl =
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  let
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    val ctxt = Variable.thm_context rl;
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    val ((_, [st]), ctxt') = Variable.import_thms true [rl] ctxt;
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  in
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    (case Seq.pull (tac st) of
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      NONE => raise THM ("rule_by_tactic", 0, [rl])
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    | SOME (st', _) => zero_var_indexes (singleton (Variable.export ctxt' ctxt) st'))
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  end;
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(*** Basic tactics ***)
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(*** The following fail if the goal number is out of range:
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     thus (REPEAT (resolve_tac rules i)) stops once subgoal i disappears. *)
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(*Solve subgoal i by assumption*)
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fun assume_tac i = PRIMSEQ (assumption i);
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(*Solve subgoal i by assumption, using no unification*)
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fun eq_assume_tac i = PRIMITIVE (eq_assumption i);
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(** Resolution/matching tactics **)
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(*The composition rule/state: no lifting or var renaming.
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  The arg = (bires_flg, orule, m) ;  see bicompose for explanation.*)
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fun compose_tac arg i = PRIMSEQ (bicompose false arg i);
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(*Converts a "destruct" rule like P&Q==>P to an "elimination" rule
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  like [| P&Q; P==>R |] ==> R *)
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fun make_elim rl = zero_var_indexes (rl RS revcut_rl);
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(*Attack subgoal i by resolution, using flags to indicate elimination rules*)
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fun biresolve_tac brules i = PRIMSEQ (biresolution false brules i);
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(*Resolution: the simple case, works for introduction rules*)
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fun resolve_tac rules = biresolve_tac (map (pair false) rules);
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(*Resolution with elimination rules only*)
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fun eresolve_tac rules = biresolve_tac (map (pair true) rules);
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(*Forward reasoning using destruction rules.*)
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fun forward_tac rls = resolve_tac (map make_elim rls) THEN' assume_tac;
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(*Like forward_tac, but deletes the assumption after use.*)
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fun dresolve_tac rls = eresolve_tac (map make_elim rls);
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(*Shorthand versions: for resolution with a single theorem*)
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val atac    =   assume_tac;
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fun rtac rl =  resolve_tac [rl];
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fun dtac rl = dresolve_tac [rl];
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fun etac rl = eresolve_tac [rl];
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fun ftac rl =  forward_tac [rl];
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fun datac thm j = EVERY' (dtac thm::replicate j atac);
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fun eatac thm j = EVERY' (etac thm::replicate j atac);
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fun fatac thm j = EVERY' (ftac thm::replicate j atac);
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(*Use an assumption or some rules ... A popular combination!*)
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fun ares_tac rules = assume_tac  ORELSE'  resolve_tac rules;
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fun solve_tac rules = resolve_tac rules THEN_ALL_NEW assume_tac;
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(*Matching tactics -- as above, but forbid updating of state*)
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fun bimatch_tac brules i = PRIMSEQ (biresolution true brules i);
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fun match_tac rules  = bimatch_tac (map (pair false) rules);
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fun ematch_tac rules = bimatch_tac (map (pair true) rules);
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fun dmatch_tac rls   = ematch_tac (map make_elim rls);
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(*Smash all flex-flex disagreement pairs in the proof state.*)
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val flexflex_tac = PRIMSEQ flexflex_rule;
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(*Remove duplicate subgoals.*)
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val perm_tac = PRIMITIVE oo Thm.permute_prems;
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fun distinct_tac (i, k) =
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  perm_tac 0 (i - 1) THEN
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  perm_tac 1 (k - 1) THEN
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  DETERM (PRIMSEQ (fn st =>
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    Thm.compose_no_flatten false (st, 0) 1
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      (Drule.incr_indexes st Drule.distinct_prems_rl))) THEN
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  perm_tac 1 (1 - k) THEN
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  perm_tac 0 (1 - i);
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fun distinct_subgoal_tac i st =
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  (case Library.drop (i - 1, Thm.prems_of st) of
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    [] => no_tac st
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  | A :: Bs =>
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      st |> EVERY (fold (fn (B, k) =>
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        if A aconv B then cons (distinct_tac (i, k)) else I) (Bs ~~ (1 upto length Bs)) []));
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fun distinct_subgoals_tac state =
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  let
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    val goals = Thm.prems_of state;
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    val dups = distinct (eq_fst (op aconv)) (goals ~~ (1 upto length goals));
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  in EVERY (rev (map (distinct_subgoal_tac o snd) dups)) state end;
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(*Determine print names of goal parameters (reversed)*)
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fun innermost_params i st =
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  let val (_, _, Bi, _) = dest_state (st, i)
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  in rename_wrt_term Bi (Logic.strip_params Bi) end;
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(*params of subgoal i as they are printed*)
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fun params_of_state i st = rev (innermost_params i st);
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(*read instantiations with respect to subgoal i of proof state st*)
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fun read_insts_in_state (st, i, sinsts, rule) =
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  let val thy = Thm.theory_of_thm st
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      and params = params_of_state i st
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      and rts = types_sorts rule and (types,sorts) = types_sorts st
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      fun types'(a, ~1) = (case AList.lookup (op =) params a of NONE => types (a, ~1) | sm => sm)
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        | types' ixn = types ixn;
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      val used = Drule.add_used rule (Drule.add_used st []);
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  in read_insts thy rts (types',sorts) used sinsts end;
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(*Lift and instantiate a rule wrt the given state and subgoal number *)
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fun lift_inst_rule' (st, i, sinsts, rule) =
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let val (Tinsts,insts) = read_insts_in_state (st, i, sinsts, rule)
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    and {maxidx,...} = rep_thm st
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    and params = params_of_state i st
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    val paramTs = map #2 params
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    and inc = maxidx+1
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    fun liftvar (Var ((a,j), T)) = Var((a, j+inc), paramTs---> Logic.incr_tvar inc T)
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      | liftvar t = raise TERM("Variable expected", [t]);
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    fun liftterm t = list_abs_free (params,
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                                    Logic.incr_indexes(paramTs,inc) t)
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    (*Lifts instantiation pair over params*)
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    fun liftpair (cv,ct) = (cterm_fun liftvar cv, cterm_fun liftterm ct)
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    val lifttvar = pairself (ctyp_fun (Logic.incr_tvar inc))
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in Drule.instantiate (map lifttvar Tinsts, map liftpair insts)
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                     (Thm.lift_rule (Thm.cprem_of st i) rule)
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end;
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fun lift_inst_rule (st, i, sinsts, rule) = lift_inst_rule'
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  (st, i, map (apfst Syntax.read_indexname) sinsts, rule);
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(*
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Like lift_inst_rule but takes terms, not strings, where the terms may contain
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Bounds referring to parameters of the subgoal.
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insts: [...,(vj,tj),...]
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The tj may contain references to parameters of subgoal i of the state st
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in the form of Bound k, i.e. the tj may be subterms of the subgoal.
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To saturate the lose bound vars, the tj are enclosed in abstractions
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corresponding to the parameters of subgoal i, thus turning them into
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functions. At the same time, the types of the vj are lifted.
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NB: the types in insts must be correctly instantiated already,
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    i.e. Tinsts is not applied to insts.
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*)
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fun term_lift_inst_rule (st, i, Tinsts, insts, rule) =
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let val {maxidx,thy,...} = rep_thm st
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    val paramTs = map #2 (params_of_state i st)
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    and inc = maxidx+1
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    fun liftvar ((a,j), T) = Var((a, j+inc), paramTs---> Logic.incr_tvar inc T)
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    (*lift only Var, not term, which must be lifted already*)
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    fun liftpair (v,t) = (cterm_of thy (liftvar v), cterm_of thy t)
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    fun liftTpair (((a, i), S), T) =
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      (ctyp_of thy (TVar ((a, i + inc), S)),
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       ctyp_of thy (Logic.incr_tvar inc T))
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in Drule.instantiate (map liftTpair Tinsts, map liftpair insts)
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                     (Thm.lift_rule (Thm.cprem_of st i) rule)
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end;
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(*** Resolve after lifting and instantation; may refer to parameters of the
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     subgoal.  Fails if "i" is out of range.  ***)
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(*compose version: arguments are as for bicompose.*)
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fun gen_compose_inst_tac instf sinsts (bires_flg, rule, nsubgoal) i st =
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  if i > nprems_of st then no_tac st
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  else st |>
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    (compose_tac (bires_flg, instf (st, i, sinsts, rule), nsubgoal) i
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     handle TERM (msg,_)   => (warning msg;  no_tac)
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          | THM  (msg,_,_) => (warning msg;  no_tac));
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val compose_inst_tac = gen_compose_inst_tac lift_inst_rule;
berghofe@15442
   292
val compose_inst_tac' = gen_compose_inst_tac lift_inst_rule';
berghofe@15442
   293
lcp@761
   294
(*"Resolve" version.  Note: res_inst_tac cannot behave sensibly if the
lcp@761
   295
  terms that are substituted contain (term or type) unknowns from the
lcp@761
   296
  goal, because it is unable to instantiate goal unknowns at the same time.
lcp@761
   297
paulson@2029
   298
  The type checker is instructed not to freeze flexible type vars that
nipkow@952
   299
  were introduced during type inference and still remain in the term at the
nipkow@952
   300
  end.  This increases flexibility but can introduce schematic type vars in
nipkow@952
   301
  goals.
lcp@761
   302
*)
clasohm@0
   303
fun res_inst_tac sinsts rule i =
clasohm@0
   304
    compose_inst_tac sinsts (false, rule, nprems_of rule) i;
clasohm@0
   305
berghofe@15442
   306
fun res_inst_tac' sinsts rule i =
berghofe@15442
   307
    compose_inst_tac' sinsts (false, rule, nprems_of rule) i;
berghofe@15442
   308
paulson@1501
   309
(*eresolve elimination version*)
clasohm@0
   310
fun eres_inst_tac sinsts rule i =
clasohm@0
   311
    compose_inst_tac sinsts (true, rule, nprems_of rule) i;
clasohm@0
   312
berghofe@15464
   313
fun eres_inst_tac' sinsts rule i =
berghofe@15464
   314
    compose_inst_tac' sinsts (true, rule, nprems_of rule) i;
berghofe@15464
   315
lcp@270
   316
(*For forw_inst_tac and dres_inst_tac.  Preserve Var indexes of rl;
lcp@270
   317
  increment revcut_rl instead.*)
wenzelm@10817
   318
fun make_elim_preserve rl =
lcp@270
   319
  let val {maxidx,...} = rep_thm rl
wenzelm@16425
   320
      fun cvar ixn = cterm_of ProtoPure.thy (Var(ixn,propT));
wenzelm@10817
   321
      val revcut_rl' =
wenzelm@10805
   322
          instantiate ([],  [(cvar("V",0), cvar("V",maxidx+1)),
wenzelm@10805
   323
                             (cvar("W",0), cvar("W",maxidx+1))]) revcut_rl
clasohm@0
   324
      val arg = (false, rl, nprems_of rl)
wenzelm@4270
   325
      val [th] = Seq.list_of (bicompose false arg 1 revcut_rl')
clasohm@0
   326
  in  th  end
clasohm@0
   327
  handle Bind => raise THM("make_elim_preserve", 1, [rl]);
clasohm@0
   328
lcp@270
   329
(*instantiate and cut -- for a FACT, anyway...*)
lcp@270
   330
fun cut_inst_tac sinsts rule = res_inst_tac sinsts (make_elim_preserve rule);
clasohm@0
   331
lcp@270
   332
(*forward tactic applies a RULE to an assumption without deleting it*)
lcp@270
   333
fun forw_inst_tac sinsts rule = cut_inst_tac sinsts rule THEN' assume_tac;
lcp@270
   334
lcp@270
   335
(*dresolve tactic applies a RULE to replace an assumption*)
clasohm@0
   336
fun dres_inst_tac sinsts rule = eres_inst_tac sinsts (make_elim_preserve rule);
clasohm@0
   337
oheimb@10347
   338
(*instantiate variables in the whole state*)
oheimb@10347
   339
val instantiate_tac = PRIMITIVE o read_instantiate;
oheimb@10347
   340
berghofe@15797
   341
val instantiate_tac' = PRIMITIVE o Drule.read_instantiate';
berghofe@15797
   342
paulson@1951
   343
(*Deletion of an assumption*)
paulson@1951
   344
fun thin_tac s = eres_inst_tac [("V",s)] thin_rl;
paulson@1951
   345
lcp@270
   346
(*** Applications of cut_rl ***)
clasohm@0
   347
clasohm@0
   348
(*Used by metacut_tac*)
clasohm@0
   349
fun bires_cut_tac arg i =
clasohm@1460
   350
    resolve_tac [cut_rl] i  THEN  biresolve_tac arg (i+1) ;
clasohm@0
   351
clasohm@0
   352
(*The conclusion of the rule gets assumed in subgoal i,
clasohm@0
   353
  while subgoal i+1,... are the premises of the rule.*)
clasohm@0
   354
fun metacut_tac rule = bires_cut_tac [(false,rule)];
clasohm@0
   355
paulson@13650
   356
(*"Cut" a list of rules into the goal.  Their premises will become new
paulson@13650
   357
  subgoals.*)
paulson@13650
   358
fun cut_rules_tac ths i = EVERY (map (fn th => metacut_tac th i) ths);
paulson@13650
   359
paulson@13650
   360
(*As above, but inserts only facts (unconditional theorems);
paulson@13650
   361
  generates no additional subgoals. *)
wenzelm@20232
   362
fun cut_facts_tac ths = cut_rules_tac (filter Thm.no_prems ths);
clasohm@0
   363
clasohm@0
   364
(*Introduce the given proposition as a lemma and subgoal*)
wenzelm@12847
   365
fun subgoal_tac sprop =
wenzelm@12847
   366
  DETERM o res_inst_tac [("psi", sprop)] cut_rl THEN' SUBGOAL (fn (prop, _) =>
wenzelm@12847
   367
    let val concl' = Logic.strip_assums_concl prop in
paulson@4178
   368
      if null (term_tvars concl') then ()
paulson@4178
   369
      else warning"Type variables in new subgoal: add a type constraint?";
wenzelm@12847
   370
      all_tac
wenzelm@12847
   371
  end);
clasohm@0
   372
lcp@439
   373
(*Introduce a list of lemmas and subgoals*)
lcp@439
   374
fun subgoals_tac sprops = EVERY' (map subgoal_tac sprops);
lcp@439
   375
clasohm@0
   376
clasohm@0
   377
(**** Indexing and filtering of theorems ****)
clasohm@0
   378
clasohm@0
   379
(*Returns the list of potentially resolvable theorems for the goal "prem",
wenzelm@10805
   380
        using the predicate  could(subgoal,concl).
clasohm@0
   381
  Resulting list is no longer than "limit"*)
clasohm@0
   382
fun filter_thms could (limit, prem, ths) =
clasohm@0
   383
  let val pb = Logic.strip_assums_concl prem;   (*delete assumptions*)
clasohm@0
   384
      fun filtr (limit, []) = []
wenzelm@10805
   385
        | filtr (limit, th::ths) =
wenzelm@10805
   386
            if limit=0 then  []
wenzelm@10805
   387
            else if could(pb, concl_of th)  then th :: filtr(limit-1, ths)
wenzelm@10805
   388
            else filtr(limit,ths)
clasohm@0
   389
  in  filtr(limit,ths)  end;
clasohm@0
   390
clasohm@0
   391
clasohm@0
   392
(*** biresolution and resolution using nets ***)
clasohm@0
   393
clasohm@0
   394
(** To preserve the order of the rules, tag them with increasing integers **)
clasohm@0
   395
clasohm@0
   396
(*insert tags*)
clasohm@0
   397
fun taglist k [] = []
clasohm@0
   398
  | taglist k (x::xs) = (k,x) :: taglist (k+1) xs;
clasohm@0
   399
clasohm@0
   400
(*remove tags and suppress duplicates -- list is assumed sorted!*)
clasohm@0
   401
fun untaglist [] = []
clasohm@0
   402
  | untaglist [(k:int,x)] = [x]
clasohm@0
   403
  | untaglist ((k,x) :: (rest as (k',x')::_)) =
clasohm@0
   404
      if k=k' then untaglist rest
clasohm@0
   405
      else    x :: untaglist rest;
clasohm@0
   406
clasohm@0
   407
(*return list elements in original order*)
wenzelm@10817
   408
fun orderlist kbrls = untaglist (sort (int_ord o pairself fst) kbrls);
clasohm@0
   409
clasohm@0
   410
(*insert one tagged brl into the pair of nets*)
wenzelm@23178
   411
fun insert_tagged_brl (kbrl as (k, (eres, th))) (inet, enet) =
wenzelm@12320
   412
  if eres then
wenzelm@12320
   413
    (case try Thm.major_prem_of th of
wenzelm@16809
   414
      SOME prem => (inet, Net.insert_term (K false) (prem, kbrl) enet)
skalberg@15531
   415
    | NONE => error "insert_tagged_brl: elimination rule with no premises")
wenzelm@16809
   416
  else (Net.insert_term (K false) (concl_of th, kbrl) inet, enet);
clasohm@0
   417
clasohm@0
   418
(*build a pair of nets for biresolution*)
wenzelm@10817
   419
fun build_netpair netpair brls =
wenzelm@23178
   420
    fold_rev insert_tagged_brl (taglist 1 brls) netpair;
clasohm@0
   421
wenzelm@12320
   422
(*delete one kbrl from the pair of nets*)
wenzelm@22360
   423
fun eq_kbrl ((_, (_, th)), (_, (_, th'))) = Thm.eq_thm_prop (th, th')
wenzelm@16809
   424
wenzelm@23178
   425
fun delete_tagged_brl (brl as (eres, th)) (inet, enet) =
paulson@13925
   426
  (if eres then
wenzelm@12320
   427
    (case try Thm.major_prem_of th of
wenzelm@16809
   428
      SOME prem => (inet, Net.delete_term eq_kbrl (prem, ((), brl)) enet)
skalberg@15531
   429
    | NONE => (inet, enet))  (*no major premise: ignore*)
wenzelm@16809
   430
  else (Net.delete_term eq_kbrl (Thm.concl_of th, ((), brl)) inet, enet))
paulson@13925
   431
  handle Net.DELETE => (inet,enet);
paulson@1801
   432
paulson@1801
   433
wenzelm@10817
   434
(*biresolution using a pair of nets rather than rules.
paulson@3706
   435
    function "order" must sort and possibly filter the list of brls.
paulson@3706
   436
    boolean "match" indicates matching or unification.*)
paulson@3706
   437
fun biresolution_from_nets_tac order match (inet,enet) =
clasohm@0
   438
  SUBGOAL
clasohm@0
   439
    (fn (prem,i) =>
clasohm@0
   440
      let val hyps = Logic.strip_assums_hyp prem
wenzelm@10817
   441
          and concl = Logic.strip_assums_concl prem
wenzelm@19482
   442
          val kbrls = Net.unify_term inet concl @ maps (Net.unify_term enet) hyps
paulson@3706
   443
      in PRIMSEQ (biresolution match (order kbrls) i) end);
clasohm@0
   444
paulson@3706
   445
(*versions taking pre-built nets.  No filtering of brls*)
paulson@3706
   446
val biresolve_from_nets_tac = biresolution_from_nets_tac orderlist false;
paulson@3706
   447
val bimatch_from_nets_tac   = biresolution_from_nets_tac orderlist true;
clasohm@0
   448
clasohm@0
   449
(*fast versions using nets internally*)
lcp@670
   450
val net_biresolve_tac =
lcp@670
   451
    biresolve_from_nets_tac o build_netpair(Net.empty,Net.empty);
lcp@670
   452
lcp@670
   453
val net_bimatch_tac =
lcp@670
   454
    bimatch_from_nets_tac o build_netpair(Net.empty,Net.empty);
clasohm@0
   455
clasohm@0
   456
(*** Simpler version for resolve_tac -- only one net, and no hyps ***)
clasohm@0
   457
clasohm@0
   458
(*insert one tagged rl into the net*)
wenzelm@23178
   459
fun insert_krl (krl as (k,th)) =
wenzelm@23178
   460
  Net.insert_term (K false) (concl_of th, krl);
clasohm@0
   461
clasohm@0
   462
(*build a net of rules for resolution*)
wenzelm@10817
   463
fun build_net rls =
wenzelm@23178
   464
  fold_rev insert_krl (taglist 1 rls) Net.empty;
clasohm@0
   465
clasohm@0
   466
(*resolution using a net rather than rules; pred supports filt_resolve_tac*)
clasohm@0
   467
fun filt_resolution_from_net_tac match pred net =
clasohm@0
   468
  SUBGOAL
clasohm@0
   469
    (fn (prem,i) =>
clasohm@0
   470
      let val krls = Net.unify_term net (Logic.strip_assums_concl prem)
wenzelm@10817
   471
      in
wenzelm@10817
   472
         if pred krls
clasohm@0
   473
         then PRIMSEQ
wenzelm@10805
   474
                (biresolution match (map (pair false) (orderlist krls)) i)
clasohm@0
   475
         else no_tac
clasohm@0
   476
      end);
clasohm@0
   477
clasohm@0
   478
(*Resolve the subgoal using the rules (making a net) unless too flexible,
clasohm@0
   479
   which means more than maxr rules are unifiable.      *)
wenzelm@10817
   480
fun filt_resolve_tac rules maxr =
clasohm@0
   481
    let fun pred krls = length krls <= maxr
clasohm@0
   482
    in  filt_resolution_from_net_tac false pred (build_net rules)  end;
clasohm@0
   483
clasohm@0
   484
(*versions taking pre-built nets*)
clasohm@0
   485
val resolve_from_net_tac = filt_resolution_from_net_tac false (K true);
clasohm@0
   486
val match_from_net_tac = filt_resolution_from_net_tac true (K true);
clasohm@0
   487
clasohm@0
   488
(*fast versions using nets internally*)
clasohm@0
   489
val net_resolve_tac = resolve_from_net_tac o build_net;
clasohm@0
   490
val net_match_tac = match_from_net_tac o build_net;
clasohm@0
   491
clasohm@0
   492
clasohm@0
   493
(*** For Natural Deduction using (bires_flg, rule) pairs ***)
clasohm@0
   494
clasohm@0
   495
(*The number of new subgoals produced by the brule*)
lcp@1077
   496
fun subgoals_of_brl (true,rule)  = nprems_of rule - 1
lcp@1077
   497
  | subgoals_of_brl (false,rule) = nprems_of rule;
clasohm@0
   498
clasohm@0
   499
(*Less-than test: for sorting to minimize number of new subgoals*)
clasohm@0
   500
fun lessb (brl1,brl2) = subgoals_of_brl brl1 < subgoals_of_brl brl2;
clasohm@0
   501
clasohm@0
   502
lcp@69
   503
(*** Renaming of parameters in a subgoal
lcp@69
   504
     Names may contain letters, digits or primes and must be
lcp@69
   505
     separated by blanks ***)
clasohm@0
   506
wenzelm@9535
   507
fun rename_params_tac xs i =
wenzelm@14673
   508
  case Library.find_first (not o Syntax.is_identifier) xs of
skalberg@15531
   509
      SOME x => error ("Not an identifier: " ^ x)
wenzelm@16425
   510
    | NONE =>
paulson@13559
   511
       (if !Logic.auto_rename
wenzelm@16425
   512
         then (warning "Resetting Logic.auto_rename";
wenzelm@16425
   513
             Logic.auto_rename := false)
wenzelm@16425
   514
        else (); PRIMITIVE (rename_params_rule (xs, i)));
wenzelm@9535
   515
wenzelm@22583
   516
(*scan a list of characters into "words" composed of "letters" (recognized by
wenzelm@22583
   517
  is_let) and separated by any number of non-"letters"*)
wenzelm@22583
   518
fun scanwords is_let cs =
wenzelm@22583
   519
  let fun scan1 [] = []
wenzelm@22583
   520
        | scan1 cs =
wenzelm@22583
   521
            let val (lets, rest) = take_prefix is_let cs
wenzelm@22583
   522
            in implode lets :: scanwords is_let rest end;
wenzelm@22583
   523
  in scan1 (#2 (take_prefix (not o is_let) cs)) end;
wenzelm@22583
   524
wenzelm@10817
   525
fun rename_tac str i =
wenzelm@10817
   526
  let val cs = Symbol.explode str in
wenzelm@4693
   527
  case #2 (take_prefix (Symbol.is_letdig orf Symbol.is_blank) cs) of
wenzelm@9535
   528
      [] => rename_params_tac (scanwords Symbol.is_letdig cs) i
clasohm@0
   529
    | c::_ => error ("Illegal character: " ^ c)
clasohm@0
   530
  end;
clasohm@0
   531
paulson@1501
   532
(*Rename recent parameters using names generated from a and the suffixes,
paulson@1501
   533
  provided the string a, which represents a term, is an identifier. *)
wenzelm@10817
   534
fun rename_last_tac a sufs i =
clasohm@0
   535
  let val names = map (curry op^ a) sufs
clasohm@0
   536
  in  if Syntax.is_identifier a
clasohm@0
   537
      then PRIMITIVE (rename_params_rule (names,i))
clasohm@0
   538
      else all_tac
clasohm@0
   539
  end;
clasohm@0
   540
paulson@1501
   541
(*rotate_tac n i: rotate the assumptions of subgoal i by n positions, from
paulson@1501
   542
  right to left if n is positive, and from left to right if n is negative.*)
paulson@2672
   543
fun rotate_tac 0 i = all_tac
paulson@2672
   544
  | rotate_tac k i = PRIMITIVE (rotate_rule k i);
nipkow@1209
   545
paulson@7248
   546
(*Rotates the given subgoal to be the last.*)
paulson@7248
   547
fun defer_tac i = PRIMITIVE (permute_prems (i-1) 1);
paulson@7248
   548
nipkow@5974
   549
(* remove premises that do not satisfy p; fails if all prems satisfy p *)
nipkow@5974
   550
fun filter_prems_tac p =
skalberg@15531
   551
  let fun Then NONE tac = SOME tac
skalberg@15531
   552
        | Then (SOME tac) tac' = SOME(tac THEN' tac');
wenzelm@19473
   553
      fun thins H (tac,n) =
nipkow@5974
   554
        if p H then (tac,n+1)
nipkow@5974
   555
        else (Then tac (rotate_tac n THEN' etac thin_rl),0);
nipkow@5974
   556
  in SUBGOAL(fn (subg,n) =>
nipkow@5974
   557
       let val Hs = Logic.strip_assums_hyp subg
wenzelm@19473
   558
       in case fst(fold thins Hs (NONE,0)) of
skalberg@15531
   559
            NONE => no_tac | SOME tac => tac n
nipkow@5974
   560
       end)
nipkow@5974
   561
  end;
nipkow@5974
   562
wenzelm@23492
   563
(*eta long beta normal form*)
wenzelm@23492
   564
fun eta_long_tac i =
wenzelm@23492
   565
  PRIMITIVE (Conv.fconv_rule (Conv.goals_conv (fn j => i = j) Thm.eta_long_conversion));
wenzelm@23492
   566
clasohm@0
   567
end;
paulson@1501
   568
wenzelm@11774
   569
structure BasicTactic: BASIC_TACTIC = Tactic;
wenzelm@11774
   570
open BasicTactic;