src/Pure/tactic.ML
author wenzelm
Thu Dec 07 00:42:04 2006 +0100 (2006-12-07)
changeset 21687 f689f729afab
parent 20302 265b2342cf21
child 21708 45e7491bea47
permissions -rw-r--r--
reorganized structure Goal vs. Tactic;
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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 ares_tac          : thm list -> int -> tactic
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  val assume_tac        : int -> tactic
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  val atac      : int ->tactic
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  val bimatch_from_nets_tac:
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      (int*(bool*thm)) Net.net * (int*(bool*thm)) Net.net -> int -> tactic
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  val bimatch_tac       : (bool*thm)list -> int -> tactic
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  val biresolution_from_nets_tac:
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        ('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:
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      (int*(bool*thm)) Net.net * (int*(bool*thm)) Net.net -> int -> tactic
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  val biresolve_tac     : (bool*thm)list -> int -> tactic
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  val build_net : thm list -> (int*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 compose_inst_tac  : (string*string)list -> (bool*thm*int) ->
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                          int -> tactic
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  val compose_tac       : (bool * thm * int) -> int -> tactic
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  val cut_facts_tac     : thm list -> int -> tactic
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  val cut_rules_tac     : thm list -> int -> tactic
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  val cut_inst_tac      : (string*string)list -> thm -> int -> tactic
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  val datac             : thm -> int -> int -> tactic
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  val defer_tac         : int -> tactic
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  val distinct_subgoals_tac     : tactic
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  val dmatch_tac        : thm list -> int -> tactic
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  val dresolve_tac      : thm list -> int -> tactic
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  val dres_inst_tac     : (string*string)list -> thm -> int -> tactic
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  val dtac              : thm -> int ->tactic
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  val eatac             : thm -> int -> int -> tactic
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  val etac              : thm -> int ->tactic
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  val eq_assume_tac     : int -> tactic
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  val ematch_tac        : thm list -> int -> tactic
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  val eresolve_tac      : thm list -> int -> tactic
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  val eres_inst_tac     : (string*string)list -> thm -> int -> tactic
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  val fatac             : thm -> int -> int -> tactic
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  val filter_prems_tac  : (term -> bool) -> int -> tactic
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  val filter_thms       : (term*term->bool) -> int*term*thm list -> thm list
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  val filt_resolve_tac  : thm list -> int -> int -> tactic
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  val flexflex_tac      : tactic
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  val fold_goals_tac    : thm list -> tactic
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  val fold_rule         : thm list -> thm -> thm
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  val fold_tac          : thm list -> tactic
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  val forward_tac       : thm list -> int -> tactic
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  val forw_inst_tac     : (string*string)list -> thm -> int -> tactic
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  val ftac              : thm -> int ->tactic
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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 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 lessb             : (bool * thm) * (bool * thm) -> bool
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  val lift_inst_rule    : thm * int * (string*string)list * thm -> thm
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  val make_elim         : thm -> thm
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  val match_from_net_tac        : (int*thm) Net.net -> int -> tactic
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  val match_tac : thm list -> int -> tactic
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  val metacut_tac       : thm -> int -> tactic
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  val net_bimatch_tac   : (bool*thm) list -> int -> tactic
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  val net_biresolve_tac : (bool*thm) list -> int -> tactic
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  val net_match_tac     : thm list -> int -> tactic
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  val net_resolve_tac   : thm list -> int -> tactic
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  val prune_params_tac  : tactic
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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 resolve_from_net_tac      : (int*thm) Net.net -> int -> tactic
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  val resolve_tac       : thm list -> int -> tactic
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  val res_inst_tac      : (string*string)list -> thm -> int -> tactic
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  val rewrite_goals_rule: thm list -> thm -> thm
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  val rewrite_rule      : thm list -> thm -> thm
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  val rewrite_goals_tac : thm list -> tactic
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  val rewrite_tac       : thm list -> tactic
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  val rewtac            : thm -> tactic
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  val rotate_tac        : int -> int -> tactic
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  val rtac              : thm -> int -> tactic
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  val rule_by_tactic    : tactic -> thm -> thm
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  val solve_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 subgoals_of_brl   : bool * thm -> int
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  val term_lift_inst_rule       :
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      thm * int * ((indexname * sort) * typ) list * ((indexname * typ) * term) list * thm
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      -> thm
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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 trace_goalno_tac  : (int -> tactic) -> 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 untaglist: (int * 'a) list -> 'a list
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  val eq_kbrl: ('a * (bool * thm)) * ('a * (bool * thm)) -> bool
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  val orderlist: (int * 'a) list -> 'a list
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  val rewrite: bool -> thm list -> cterm -> thm
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  val simplify: bool -> thm list -> thm -> thm
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  val compose_inst_tac' : (indexname * string) list -> (bool * thm * int) ->
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                          int -> tactic
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  val lift_inst_rule'   : thm * int * (indexname * string) list * thm -> thm
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  val eres_inst_tac'    : (indexname * string) list -> thm -> int -> tactic
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  val res_inst_tac'     : (indexname * string) list -> thm -> int -> tactic
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  val instantiate_tac'  : (indexname * string) list -> tactic
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  val make_elim_preserve: thm -> thm
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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 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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fun distinct_subgoals_tac state =
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  let
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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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    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
clasohm@0
   293
     subgoal.  Fails if "i" is out of range.  ***)
clasohm@0
   294
clasohm@0
   295
(*compose version: arguments are as for bicompose.*)
berghofe@15442
   296
fun gen_compose_inst_tac instf sinsts (bires_flg, rule, nsubgoal) i st =
paulson@8977
   297
  if i > nprems_of st then no_tac st
paulson@8977
   298
  else st |>
berghofe@15442
   299
    (compose_tac (bires_flg, instf (st, i, sinsts, rule), nsubgoal) i
wenzelm@12262
   300
     handle TERM (msg,_)   => (warning msg;  no_tac)
wenzelm@12262
   301
          | THM  (msg,_,_) => (warning msg;  no_tac));
clasohm@0
   302
berghofe@15442
   303
val compose_inst_tac = gen_compose_inst_tac lift_inst_rule;
berghofe@15442
   304
val compose_inst_tac' = gen_compose_inst_tac lift_inst_rule';
berghofe@15442
   305
lcp@761
   306
(*"Resolve" version.  Note: res_inst_tac cannot behave sensibly if the
lcp@761
   307
  terms that are substituted contain (term or type) unknowns from the
lcp@761
   308
  goal, because it is unable to instantiate goal unknowns at the same time.
lcp@761
   309
paulson@2029
   310
  The type checker is instructed not to freeze flexible type vars that
nipkow@952
   311
  were introduced during type inference and still remain in the term at the
nipkow@952
   312
  end.  This increases flexibility but can introduce schematic type vars in
nipkow@952
   313
  goals.
lcp@761
   314
*)
clasohm@0
   315
fun res_inst_tac sinsts rule i =
clasohm@0
   316
    compose_inst_tac sinsts (false, rule, nprems_of rule) i;
clasohm@0
   317
berghofe@15442
   318
fun res_inst_tac' sinsts rule i =
berghofe@15442
   319
    compose_inst_tac' sinsts (false, rule, nprems_of rule) i;
berghofe@15442
   320
paulson@1501
   321
(*eresolve elimination version*)
clasohm@0
   322
fun eres_inst_tac sinsts rule i =
clasohm@0
   323
    compose_inst_tac sinsts (true, rule, nprems_of rule) i;
clasohm@0
   324
berghofe@15464
   325
fun eres_inst_tac' sinsts rule i =
berghofe@15464
   326
    compose_inst_tac' sinsts (true, rule, nprems_of rule) i;
berghofe@15464
   327
lcp@270
   328
(*For forw_inst_tac and dres_inst_tac.  Preserve Var indexes of rl;
lcp@270
   329
  increment revcut_rl instead.*)
wenzelm@10817
   330
fun make_elim_preserve rl =
lcp@270
   331
  let val {maxidx,...} = rep_thm rl
wenzelm@16425
   332
      fun cvar ixn = cterm_of ProtoPure.thy (Var(ixn,propT));
wenzelm@10817
   333
      val revcut_rl' =
wenzelm@10805
   334
          instantiate ([],  [(cvar("V",0), cvar("V",maxidx+1)),
wenzelm@10805
   335
                             (cvar("W",0), cvar("W",maxidx+1))]) revcut_rl
clasohm@0
   336
      val arg = (false, rl, nprems_of rl)
wenzelm@4270
   337
      val [th] = Seq.list_of (bicompose false arg 1 revcut_rl')
clasohm@0
   338
  in  th  end
clasohm@0
   339
  handle Bind => raise THM("make_elim_preserve", 1, [rl]);
clasohm@0
   340
lcp@270
   341
(*instantiate and cut -- for a FACT, anyway...*)
lcp@270
   342
fun cut_inst_tac sinsts rule = res_inst_tac sinsts (make_elim_preserve rule);
clasohm@0
   343
lcp@270
   344
(*forward tactic applies a RULE to an assumption without deleting it*)
lcp@270
   345
fun forw_inst_tac sinsts rule = cut_inst_tac sinsts rule THEN' assume_tac;
lcp@270
   346
lcp@270
   347
(*dresolve tactic applies a RULE to replace an assumption*)
clasohm@0
   348
fun dres_inst_tac sinsts rule = eres_inst_tac sinsts (make_elim_preserve rule);
clasohm@0
   349
oheimb@10347
   350
(*instantiate variables in the whole state*)
oheimb@10347
   351
val instantiate_tac = PRIMITIVE o read_instantiate;
oheimb@10347
   352
berghofe@15797
   353
val instantiate_tac' = PRIMITIVE o Drule.read_instantiate';
berghofe@15797
   354
paulson@1951
   355
(*Deletion of an assumption*)
paulson@1951
   356
fun thin_tac s = eres_inst_tac [("V",s)] thin_rl;
paulson@1951
   357
lcp@270
   358
(*** Applications of cut_rl ***)
clasohm@0
   359
clasohm@0
   360
(*Used by metacut_tac*)
clasohm@0
   361
fun bires_cut_tac arg i =
clasohm@1460
   362
    resolve_tac [cut_rl] i  THEN  biresolve_tac arg (i+1) ;
clasohm@0
   363
clasohm@0
   364
(*The conclusion of the rule gets assumed in subgoal i,
clasohm@0
   365
  while subgoal i+1,... are the premises of the rule.*)
clasohm@0
   366
fun metacut_tac rule = bires_cut_tac [(false,rule)];
clasohm@0
   367
paulson@13650
   368
(*"Cut" a list of rules into the goal.  Their premises will become new
paulson@13650
   369
  subgoals.*)
paulson@13650
   370
fun cut_rules_tac ths i = EVERY (map (fn th => metacut_tac th i) ths);
paulson@13650
   371
paulson@13650
   372
(*As above, but inserts only facts (unconditional theorems);
paulson@13650
   373
  generates no additional subgoals. *)
wenzelm@20232
   374
fun cut_facts_tac ths = cut_rules_tac (filter Thm.no_prems ths);
clasohm@0
   375
clasohm@0
   376
(*Introduce the given proposition as a lemma and subgoal*)
wenzelm@12847
   377
fun subgoal_tac sprop =
wenzelm@12847
   378
  DETERM o res_inst_tac [("psi", sprop)] cut_rl THEN' SUBGOAL (fn (prop, _) =>
wenzelm@12847
   379
    let val concl' = Logic.strip_assums_concl prop in
paulson@4178
   380
      if null (term_tvars concl') then ()
paulson@4178
   381
      else warning"Type variables in new subgoal: add a type constraint?";
wenzelm@12847
   382
      all_tac
wenzelm@12847
   383
  end);
clasohm@0
   384
lcp@439
   385
(*Introduce a list of lemmas and subgoals*)
lcp@439
   386
fun subgoals_tac sprops = EVERY' (map subgoal_tac sprops);
lcp@439
   387
clasohm@0
   388
clasohm@0
   389
(**** Indexing and filtering of theorems ****)
clasohm@0
   390
clasohm@0
   391
(*Returns the list of potentially resolvable theorems for the goal "prem",
wenzelm@10805
   392
        using the predicate  could(subgoal,concl).
clasohm@0
   393
  Resulting list is no longer than "limit"*)
clasohm@0
   394
fun filter_thms could (limit, prem, ths) =
clasohm@0
   395
  let val pb = Logic.strip_assums_concl prem;   (*delete assumptions*)
clasohm@0
   396
      fun filtr (limit, []) = []
wenzelm@10805
   397
        | filtr (limit, th::ths) =
wenzelm@10805
   398
            if limit=0 then  []
wenzelm@10805
   399
            else if could(pb, concl_of th)  then th :: filtr(limit-1, ths)
wenzelm@10805
   400
            else filtr(limit,ths)
clasohm@0
   401
  in  filtr(limit,ths)  end;
clasohm@0
   402
clasohm@0
   403
clasohm@0
   404
(*** biresolution and resolution using nets ***)
clasohm@0
   405
clasohm@0
   406
(** To preserve the order of the rules, tag them with increasing integers **)
clasohm@0
   407
clasohm@0
   408
(*insert tags*)
clasohm@0
   409
fun taglist k [] = []
clasohm@0
   410
  | taglist k (x::xs) = (k,x) :: taglist (k+1) xs;
clasohm@0
   411
clasohm@0
   412
(*remove tags and suppress duplicates -- list is assumed sorted!*)
clasohm@0
   413
fun untaglist [] = []
clasohm@0
   414
  | untaglist [(k:int,x)] = [x]
clasohm@0
   415
  | untaglist ((k,x) :: (rest as (k',x')::_)) =
clasohm@0
   416
      if k=k' then untaglist rest
clasohm@0
   417
      else    x :: untaglist rest;
clasohm@0
   418
clasohm@0
   419
(*return list elements in original order*)
wenzelm@10817
   420
fun orderlist kbrls = untaglist (sort (int_ord o pairself fst) kbrls);
clasohm@0
   421
clasohm@0
   422
(*insert one tagged brl into the pair of nets*)
wenzelm@12320
   423
fun insert_tagged_brl (kbrl as (k, (eres, th)), (inet, enet)) =
wenzelm@12320
   424
  if eres then
wenzelm@12320
   425
    (case try Thm.major_prem_of th of
wenzelm@16809
   426
      SOME prem => (inet, Net.insert_term (K false) (prem, kbrl) enet)
skalberg@15531
   427
    | NONE => error "insert_tagged_brl: elimination rule with no premises")
wenzelm@16809
   428
  else (Net.insert_term (K false) (concl_of th, kbrl) inet, enet);
clasohm@0
   429
clasohm@0
   430
(*build a pair of nets for biresolution*)
wenzelm@10817
   431
fun build_netpair netpair brls =
skalberg@15574
   432
    foldr insert_tagged_brl netpair (taglist 1 brls);
clasohm@0
   433
wenzelm@12320
   434
(*delete one kbrl from the pair of nets*)
wenzelm@16809
   435
fun eq_kbrl ((_, (_, th)), (_, (_, th'))) = Drule.eq_thm_prop (th, th')
wenzelm@16809
   436
wenzelm@12320
   437
fun delete_tagged_brl (brl as (eres, th), (inet, enet)) =
paulson@13925
   438
  (if eres then
wenzelm@12320
   439
    (case try Thm.major_prem_of th of
wenzelm@16809
   440
      SOME prem => (inet, Net.delete_term eq_kbrl (prem, ((), brl)) enet)
skalberg@15531
   441
    | NONE => (inet, enet))  (*no major premise: ignore*)
wenzelm@16809
   442
  else (Net.delete_term eq_kbrl (Thm.concl_of th, ((), brl)) inet, enet))
paulson@13925
   443
  handle Net.DELETE => (inet,enet);
paulson@1801
   444
paulson@1801
   445
wenzelm@10817
   446
(*biresolution using a pair of nets rather than rules.
paulson@3706
   447
    function "order" must sort and possibly filter the list of brls.
paulson@3706
   448
    boolean "match" indicates matching or unification.*)
paulson@3706
   449
fun biresolution_from_nets_tac order match (inet,enet) =
clasohm@0
   450
  SUBGOAL
clasohm@0
   451
    (fn (prem,i) =>
clasohm@0
   452
      let val hyps = Logic.strip_assums_hyp prem
wenzelm@10817
   453
          and concl = Logic.strip_assums_concl prem
wenzelm@19482
   454
          val kbrls = Net.unify_term inet concl @ maps (Net.unify_term enet) hyps
paulson@3706
   455
      in PRIMSEQ (biresolution match (order kbrls) i) end);
clasohm@0
   456
paulson@3706
   457
(*versions taking pre-built nets.  No filtering of brls*)
paulson@3706
   458
val biresolve_from_nets_tac = biresolution_from_nets_tac orderlist false;
paulson@3706
   459
val bimatch_from_nets_tac   = biresolution_from_nets_tac orderlist true;
clasohm@0
   460
clasohm@0
   461
(*fast versions using nets internally*)
lcp@670
   462
val net_biresolve_tac =
lcp@670
   463
    biresolve_from_nets_tac o build_netpair(Net.empty,Net.empty);
lcp@670
   464
lcp@670
   465
val net_bimatch_tac =
lcp@670
   466
    bimatch_from_nets_tac o build_netpair(Net.empty,Net.empty);
clasohm@0
   467
clasohm@0
   468
(*** Simpler version for resolve_tac -- only one net, and no hyps ***)
clasohm@0
   469
clasohm@0
   470
(*insert one tagged rl into the net*)
clasohm@0
   471
fun insert_krl (krl as (k,th), net) =
wenzelm@16809
   472
    Net.insert_term (K false) (concl_of th, krl) net;
clasohm@0
   473
clasohm@0
   474
(*build a net of rules for resolution*)
wenzelm@10817
   475
fun build_net rls =
skalberg@15574
   476
    foldr insert_krl Net.empty (taglist 1 rls);
clasohm@0
   477
clasohm@0
   478
(*resolution using a net rather than rules; pred supports filt_resolve_tac*)
clasohm@0
   479
fun filt_resolution_from_net_tac match pred net =
clasohm@0
   480
  SUBGOAL
clasohm@0
   481
    (fn (prem,i) =>
clasohm@0
   482
      let val krls = Net.unify_term net (Logic.strip_assums_concl prem)
wenzelm@10817
   483
      in
wenzelm@10817
   484
         if pred krls
clasohm@0
   485
         then PRIMSEQ
wenzelm@10805
   486
                (biresolution match (map (pair false) (orderlist krls)) i)
clasohm@0
   487
         else no_tac
clasohm@0
   488
      end);
clasohm@0
   489
clasohm@0
   490
(*Resolve the subgoal using the rules (making a net) unless too flexible,
clasohm@0
   491
   which means more than maxr rules are unifiable.      *)
wenzelm@10817
   492
fun filt_resolve_tac rules maxr =
clasohm@0
   493
    let fun pred krls = length krls <= maxr
clasohm@0
   494
    in  filt_resolution_from_net_tac false pred (build_net rules)  end;
clasohm@0
   495
clasohm@0
   496
(*versions taking pre-built nets*)
clasohm@0
   497
val resolve_from_net_tac = filt_resolution_from_net_tac false (K true);
clasohm@0
   498
val match_from_net_tac = filt_resolution_from_net_tac true (K true);
clasohm@0
   499
clasohm@0
   500
(*fast versions using nets internally*)
clasohm@0
   501
val net_resolve_tac = resolve_from_net_tac o build_net;
clasohm@0
   502
val net_match_tac = match_from_net_tac o build_net;
clasohm@0
   503
clasohm@0
   504
clasohm@0
   505
(*** For Natural Deduction using (bires_flg, rule) pairs ***)
clasohm@0
   506
clasohm@0
   507
(*The number of new subgoals produced by the brule*)
lcp@1077
   508
fun subgoals_of_brl (true,rule)  = nprems_of rule - 1
lcp@1077
   509
  | subgoals_of_brl (false,rule) = nprems_of rule;
clasohm@0
   510
clasohm@0
   511
(*Less-than test: for sorting to minimize number of new subgoals*)
clasohm@0
   512
fun lessb (brl1,brl2) = subgoals_of_brl brl1 < subgoals_of_brl brl2;
clasohm@0
   513
clasohm@0
   514
clasohm@0
   515
(*** Meta-Rewriting Tactics ***)
clasohm@0
   516
wenzelm@3575
   517
val simple_prover =
wenzelm@15021
   518
  SINGLE o (fn ss => ALLGOALS (resolve_tac (MetaSimplifier.prems_of_ss ss)));
wenzelm@3575
   519
wenzelm@11768
   520
val rewrite = MetaSimplifier.rewrite_aux simple_prover;
wenzelm@11768
   521
val simplify = MetaSimplifier.simplify_aux simple_prover;
wenzelm@11768
   522
val rewrite_rule = simplify true;
berghofe@10415
   523
val rewrite_goals_rule = MetaSimplifier.rewrite_goals_rule_aux simple_prover;
wenzelm@3575
   524
lcp@69
   525
(*Rewrite throughout proof state. *)
lcp@69
   526
fun rewrite_tac defs = PRIMITIVE(rewrite_rule defs);
clasohm@0
   527
clasohm@0
   528
(*Rewrite subgoals only, not main goal. *)
lcp@69
   529
fun rewrite_goals_tac defs = PRIMITIVE (rewrite_goals_rule defs);
clasohm@1460
   530
fun rewtac def = rewrite_goals_tac [def];
clasohm@0
   531
clasohm@0
   532
paulson@1501
   533
(*** for folding definitions, handling critical pairs ***)
lcp@69
   534
lcp@69
   535
(*The depth of nesting in a term*)
lcp@69
   536
fun term_depth (Abs(a,T,t)) = 1 + term_depth t
paulson@2145
   537
  | term_depth (f$t) = 1 + Int.max(term_depth f, term_depth t)
lcp@69
   538
  | term_depth _ = 0;
lcp@69
   539
wenzelm@12801
   540
val lhs_of_thm = #1 o Logic.dest_equals o prop_of;
lcp@69
   541
lcp@69
   542
(*folding should handle critical pairs!  E.g. K == Inl(0),  S == Inr(Inl(0))
lcp@69
   543
  Returns longest lhs first to avoid folding its subexpressions.*)
lcp@69
   544
fun sort_lhs_depths defs =
haftmann@17496
   545
  let val keylist = AList.make (term_depth o lhs_of_thm) defs
wenzelm@19056
   546
      val keys = sort_distinct (rev_order o int_ord) (map #2 keylist)
haftmann@17496
   547
  in map (AList.find (op =) keylist) keys end;
lcp@69
   548
wenzelm@7596
   549
val rev_defs = sort_lhs_depths o map symmetric;
lcp@69
   550
wenzelm@19473
   551
fun fold_rule defs = fold rewrite_rule (rev_defs defs);
wenzelm@7596
   552
fun fold_tac defs = EVERY (map rewrite_tac (rev_defs defs));
wenzelm@7596
   553
fun fold_goals_tac defs = EVERY (map rewrite_goals_tac (rev_defs defs));
lcp@69
   554
lcp@69
   555
lcp@69
   556
(*** Renaming of parameters in a subgoal
lcp@69
   557
     Names may contain letters, digits or primes and must be
lcp@69
   558
     separated by blanks ***)
clasohm@0
   559
wenzelm@9535
   560
fun rename_params_tac xs i =
wenzelm@14673
   561
  case Library.find_first (not o Syntax.is_identifier) xs of
skalberg@15531
   562
      SOME x => error ("Not an identifier: " ^ x)
wenzelm@16425
   563
    | NONE =>
paulson@13559
   564
       (if !Logic.auto_rename
wenzelm@16425
   565
         then (warning "Resetting Logic.auto_rename";
wenzelm@16425
   566
             Logic.auto_rename := false)
wenzelm@16425
   567
        else (); PRIMITIVE (rename_params_rule (xs, i)));
wenzelm@9535
   568
wenzelm@10817
   569
fun rename_tac str i =
wenzelm@10817
   570
  let val cs = Symbol.explode str in
wenzelm@4693
   571
  case #2 (take_prefix (Symbol.is_letdig orf Symbol.is_blank) cs) of
wenzelm@9535
   572
      [] => rename_params_tac (scanwords Symbol.is_letdig cs) i
clasohm@0
   573
    | c::_ => error ("Illegal character: " ^ c)
clasohm@0
   574
  end;
clasohm@0
   575
paulson@1501
   576
(*Rename recent parameters using names generated from a and the suffixes,
paulson@1501
   577
  provided the string a, which represents a term, is an identifier. *)
wenzelm@10817
   578
fun rename_last_tac a sufs i =
clasohm@0
   579
  let val names = map (curry op^ a) sufs
clasohm@0
   580
  in  if Syntax.is_identifier a
clasohm@0
   581
      then PRIMITIVE (rename_params_rule (names,i))
clasohm@0
   582
      else all_tac
clasohm@0
   583
  end;
clasohm@0
   584
paulson@2043
   585
(*Prunes all redundant parameters from the proof state by rewriting.
paulson@2043
   586
  DOES NOT rewrite main goal, where quantification over an unused bound
paulson@2043
   587
    variable is sometimes done to avoid the need for cut_facts_tac.*)
paulson@2043
   588
val prune_params_tac = rewrite_goals_tac [triv_forall_equality];
clasohm@0
   589
paulson@1501
   590
(*rotate_tac n i: rotate the assumptions of subgoal i by n positions, from
paulson@1501
   591
  right to left if n is positive, and from left to right if n is negative.*)
paulson@2672
   592
fun rotate_tac 0 i = all_tac
paulson@2672
   593
  | rotate_tac k i = PRIMITIVE (rotate_rule k i);
nipkow@1209
   594
paulson@7248
   595
(*Rotates the given subgoal to be the last.*)
paulson@7248
   596
fun defer_tac i = PRIMITIVE (permute_prems (i-1) 1);
paulson@7248
   597
nipkow@5974
   598
(* remove premises that do not satisfy p; fails if all prems satisfy p *)
nipkow@5974
   599
fun filter_prems_tac p =
skalberg@15531
   600
  let fun Then NONE tac = SOME tac
skalberg@15531
   601
        | Then (SOME tac) tac' = SOME(tac THEN' tac');
wenzelm@19473
   602
      fun thins H (tac,n) =
nipkow@5974
   603
        if p H then (tac,n+1)
nipkow@5974
   604
        else (Then tac (rotate_tac n THEN' etac thin_rl),0);
nipkow@5974
   605
  in SUBGOAL(fn (subg,n) =>
nipkow@5974
   606
       let val Hs = Logic.strip_assums_hyp subg
wenzelm@19473
   607
       in case fst(fold thins Hs (NONE,0)) of
skalberg@15531
   608
            NONE => no_tac | SOME tac => tac n
nipkow@5974
   609
       end)
nipkow@5974
   610
  end;
nipkow@5974
   611
clasohm@0
   612
end;
paulson@1501
   613
wenzelm@11774
   614
structure BasicTactic: BASIC_TACTIC = Tactic;
wenzelm@11774
   615
open BasicTactic;