src/Provers/classical.ML
author wenzelm
Sat May 14 17:55:08 2011 +0200 (2011-05-14)
changeset 42807 e639d91d9073
parent 42799 4e33894aec6d
child 42810 2425068fe13a
permissions -rw-r--r--
more precise warnings: observe context visibility;
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(*  Title:      Provers/classical.ML
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    Author:     Lawrence C Paulson, Cambridge University Computer Laboratory
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Theorem prover for classical reasoning, including predicate calculus, set
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theory, etc.
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Rules must be classified as intro, elim, safe, hazardous (unsafe).
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A rule is unsafe unless it can be applied blindly without harmful results.
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For a rule to be safe, its premises and conclusion should be logically
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equivalent.  There should be no variables in the premises that are not in
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the conclusion.
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*)
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(*higher precedence than := facilitates use of references*)
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infix 4 addSIs addSEs addSDs addIs addEs addDs delrules
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  addSWrapper delSWrapper addWrapper delWrapper
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  addSbefore addSafter addbefore addafter
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  addD2 addE2 addSD2 addSE2;
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(*should be a type abbreviation in signature CLASSICAL*)
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type netpair = (int * (bool * thm)) Net.net * (int * (bool * thm)) Net.net;
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type wrapper = (int -> tactic) -> (int -> tactic);
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signature CLASSICAL_DATA =
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sig
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  val imp_elim: thm  (* P --> Q ==> (~ R ==> P) ==> (Q ==> R) ==> R *)
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  val not_elim: thm  (* ~P ==> P ==> R *)
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  val swap: thm  (* ~ P ==> (~ R ==> P) ==> R *)
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  val classical: thm  (* (~ P ==> P) ==> P *)
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  val sizef: thm -> int  (* size function for BEST_FIRST *)
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  val hyp_subst_tacs: (int -> tactic) list
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end;
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signature BASIC_CLASSICAL =
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sig
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  type claset
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  val empty_cs: claset
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  val rep_cs: claset ->
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   {safeIs: thm list,
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    safeEs: thm list,
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    hazIs: thm list,
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    hazEs: thm list,
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    swrappers: (string * (Proof.context -> wrapper)) list,
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    uwrappers: (string * (Proof.context -> wrapper)) list,
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    safe0_netpair: netpair,
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    safep_netpair: netpair,
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    haz_netpair: netpair,
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    dup_netpair: netpair,
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    xtra_netpair: Context_Rules.netpair}
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  val print_claset: Proof.context -> unit
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  val addDs: Proof.context * thm list -> Proof.context
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  val addEs: Proof.context * thm list -> Proof.context
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  val addIs: Proof.context * thm list -> Proof.context
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  val addSDs: Proof.context * thm list -> Proof.context
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  val addSEs: Proof.context * thm list -> Proof.context
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  val addSIs: Proof.context * thm list -> Proof.context
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  val delrules: Proof.context * thm list -> Proof.context
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  val addSWrapper: claset * (string * (Proof.context -> wrapper)) -> claset
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  val delSWrapper: claset *  string -> claset
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  val addWrapper: claset * (string * (Proof.context -> wrapper)) -> claset
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  val delWrapper: claset *  string -> claset
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  val addSbefore: claset * (string * (int -> tactic)) -> claset
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  val addSafter: claset * (string * (int -> tactic)) -> claset
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  val addbefore: claset * (string * (int -> tactic)) -> claset
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  val addafter: claset * (string * (int -> tactic)) -> claset
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  val addD2: claset * (string * thm) -> claset
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  val addE2: claset * (string * thm) -> claset
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  val addSD2: claset * (string * thm) -> claset
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  val addSE2: claset * (string * thm) -> claset
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  val appSWrappers: Proof.context -> wrapper
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  val appWrappers: Proof.context -> wrapper
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  val global_claset_of: theory -> claset
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  val claset_of: Proof.context -> claset
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  val map_claset: (claset -> claset) -> Proof.context -> Proof.context
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  val put_claset: claset -> Proof.context -> Proof.context
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  val fast_tac: Proof.context -> int -> tactic
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  val slow_tac: Proof.context -> int -> tactic
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  val astar_tac: Proof.context -> int -> tactic
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  val slow_astar_tac: Proof.context -> int -> tactic
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  val best_tac: Proof.context -> int -> tactic
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  val first_best_tac: Proof.context -> int -> tactic
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  val slow_best_tac: Proof.context -> int -> tactic
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  val depth_tac: Proof.context -> int -> int -> tactic
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  val deepen_tac: Proof.context -> int -> int -> tactic
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  val contr_tac: int -> tactic
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  val dup_elim: thm -> thm
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  val dup_intr: thm -> thm
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  val dup_step_tac: Proof.context -> int -> tactic
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  val eq_mp_tac: int -> tactic
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  val haz_step_tac: Proof.context -> int -> tactic
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  val joinrules: thm list * thm list -> (bool * thm) list
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  val mp_tac: int -> tactic
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  val safe_tac: Proof.context -> tactic
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  val safe_steps_tac: Proof.context -> int -> tactic
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  val safe_step_tac: Proof.context -> int -> tactic
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  val clarify_tac: Proof.context -> int -> tactic
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  val clarify_step_tac: Proof.context -> int -> tactic
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  val step_tac: Proof.context -> int -> tactic
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  val slow_step_tac: Proof.context -> int -> tactic
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  val swapify: thm list -> thm list
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  val swap_res_tac: thm list -> int -> tactic
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  val inst_step_tac: Proof.context -> int -> tactic
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  val inst0_step_tac: Proof.context -> int -> tactic
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  val instp_step_tac: Proof.context -> int -> tactic
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end;
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signature CLASSICAL =
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sig
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  include BASIC_CLASSICAL
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  val classical_rule: thm -> thm
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  val get_cs: Context.generic -> claset
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  val map_cs: (claset -> claset) -> Context.generic -> Context.generic
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  val safe_dest: int option -> attribute
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  val safe_elim: int option -> attribute
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  val safe_intro: int option -> attribute
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  val haz_dest: int option -> attribute
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  val haz_elim: int option -> attribute
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  val haz_intro: int option -> attribute
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  val rule_del: attribute
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  val cla_modifiers: Method.modifier parser list
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  val cla_method:
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    (Proof.context -> tactic) -> (Proof.context -> Proof.method) context_parser
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  val cla_method':
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    (Proof.context -> int -> tactic) -> (Proof.context -> Proof.method) context_parser
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  val setup: theory -> theory
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end;
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functor Classical(Data: CLASSICAL_DATA): CLASSICAL =
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struct
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(** classical elimination rules **)
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(*
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Classical reasoning requires stronger elimination rules.  For
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instance, make_elim of Pure transforms the HOL rule injD into
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    [| inj f; f x = f y; x = y ==> PROP W |] ==> PROP W
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Such rules can cause fast_tac to fail and blast_tac to report "PROOF
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FAILED"; classical_rule will strenthen this to
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    [| inj f; ~ W ==> f x = f y; x = y ==> W |] ==> W
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*)
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fun classical_rule rule =
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  if is_some (Object_Logic.elim_concl rule) then
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    let
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      val rule' = rule RS Data.classical;
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      val concl' = Thm.concl_of rule';
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      fun redundant_hyp goal =
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        concl' aconv Logic.strip_assums_concl goal orelse
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          (case Logic.strip_assums_hyp goal of
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            hyp :: hyps => exists (fn t => t aconv hyp) hyps
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          | _ => false);
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      val rule'' =
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        rule' |> ALLGOALS (SUBGOAL (fn (goal, i) =>
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          if i = 1 orelse redundant_hyp goal
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          then Tactic.etac thin_rl i
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          else all_tac))
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        |> Seq.hd
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        |> Drule.zero_var_indexes;
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    in if Thm.equiv_thm (rule, rule'') then rule else rule'' end
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  else rule;
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(*flatten nested meta connectives in prems*)
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val flat_rule = Conv.fconv_rule (Conv.prems_conv ~1 Object_Logic.atomize_prems);
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(*** Useful tactics for classical reasoning ***)
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(*Prove goal that assumes both P and ~P.
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  No backtracking if it finds an equal assumption.  Perhaps should call
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  ematch_tac instead of eresolve_tac, but then cannot prove ZF/cantor.*)
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val contr_tac =
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  eresolve_tac [Data.not_elim] THEN' (eq_assume_tac ORELSE' assume_tac);
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(*Finds P-->Q and P in the assumptions, replaces implication by Q.
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  Could do the same thing for P<->Q and P... *)
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fun mp_tac i = eresolve_tac [Data.not_elim, Data.imp_elim] i THEN assume_tac i;
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(*Like mp_tac but instantiates no variables*)
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fun eq_mp_tac i = ematch_tac [Data.not_elim, Data.imp_elim] i THEN eq_assume_tac i;
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(*Creates rules to eliminate ~A, from rules to introduce A*)
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fun swapify intrs = intrs RLN (2, [Data.swap]);
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val swapped = Thm.rule_attribute (fn _ => fn th => th RSN (2, Data.swap));
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(*Uses introduction rules in the normal way, or on negated assumptions,
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  trying rules in order. *)
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fun swap_res_tac rls =
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  let fun addrl rl brls = (false, rl) :: (true, rl RSN (2, Data.swap)) :: brls in
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    assume_tac ORELSE'
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    contr_tac ORELSE'
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    biresolve_tac (fold_rev addrl rls [])
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  end;
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(*Duplication of hazardous rules, for complete provers*)
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fun dup_intr th = zero_var_indexes (th RS Data.classical);
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fun dup_elim th =  (* FIXME proper context!? *)
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  let
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    val rl = (th RSN (2, revcut_rl)) |> Thm.assumption 2 |> Seq.hd;
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    val ctxt = Proof_Context.init_global (Thm.theory_of_thm rl);
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  in rule_by_tactic ctxt (TRYALL (etac revcut_rl)) rl end;
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(**** Classical rule sets ****)
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datatype claset =
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  CS of
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   {safeIs         : thm list,                (*safe introduction rules*)
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    safeEs         : thm list,                (*safe elimination rules*)
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    hazIs          : thm list,                (*unsafe introduction rules*)
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    hazEs          : thm list,                (*unsafe elimination rules*)
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    swrappers      : (string * (Proof.context -> wrapper)) list, (*for transforming safe_step_tac*)
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    uwrappers      : (string * (Proof.context -> wrapper)) list, (*for transforming step_tac*)
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    safe0_netpair  : netpair,                 (*nets for trivial cases*)
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    safep_netpair  : netpair,                 (*nets for >0 subgoals*)
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    haz_netpair    : netpair,                 (*nets for unsafe rules*)
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    dup_netpair    : netpair,                 (*nets for duplication*)
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    xtra_netpair   : Context_Rules.netpair};  (*nets for extra rules*)
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(*Desired invariants are
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        safe0_netpair = build safe0_brls,
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        safep_netpair = build safep_brls,
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        haz_netpair = build (joinrules(hazIs, hazEs)),
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        dup_netpair = build (joinrules(map dup_intr hazIs,
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                                       map dup_elim hazEs))
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where build = build_netpair(Net.empty,Net.empty),
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      safe0_brls contains all brules that solve the subgoal, and
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      safep_brls contains all brules that generate 1 or more new subgoals.
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The theorem lists are largely comments, though they are used in merge_cs and print_cs.
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Nets must be built incrementally, to save space and time.
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*)
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val empty_netpair = (Net.empty, Net.empty);
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val empty_cs =
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  CS
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   {safeIs = [],
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    safeEs = [],
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    hazIs = [],
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    hazEs = [],
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    swrappers = [],
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    uwrappers = [],
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    safe0_netpair = empty_netpair,
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    safep_netpair = empty_netpair,
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    haz_netpair = empty_netpair,
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    dup_netpair = empty_netpair,
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    xtra_netpair = empty_netpair};
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fun rep_cs (CS args) = args;
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(*** Adding (un)safe introduction or elimination rules.
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    In case of overlap, new rules are tried BEFORE old ones!!
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***)
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(*For use with biresolve_tac.  Combines intro rules with swap to handle negated
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  assumptions.  Pairs elim rules with true. *)
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fun joinrules (intrs, elims) =
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  (map (pair true) (elims @ swapify intrs)) @ map (pair false) intrs;
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fun joinrules' (intrs, elims) =
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  map (pair true) elims @ map (pair false) intrs;
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(*Priority: prefer rules with fewest subgoals,
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  then rules added most recently (preferring the head of the list).*)
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fun tag_brls k [] = []
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  | tag_brls k (brl::brls) =
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      (1000000*subgoals_of_brl brl + k, brl) ::
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      tag_brls (k+1) brls;
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fun tag_brls' _ _ [] = []
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  | tag_brls' w k (brl::brls) = ((w, k), brl) :: tag_brls' w (k + 1) brls;
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fun insert_tagged_list rls = fold_rev Tactic.insert_tagged_brl rls;
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(*Insert into netpair that already has nI intr rules and nE elim rules.
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  Count the intr rules double (to account for swapify).  Negate to give the
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  new insertions the lowest priority.*)
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fun insert (nI, nE) = insert_tagged_list o (tag_brls (~(2*nI+nE))) o joinrules;
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fun insert' w (nI, nE) = insert_tagged_list o tag_brls' w (~(nI + nE)) o joinrules';
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fun delete_tagged_list rls = fold_rev Tactic.delete_tagged_brl rls;
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fun delete x = delete_tagged_list (joinrules x);
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fun delete' x = delete_tagged_list (joinrules' x);
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val mem_thm = member Thm.eq_thm_prop
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and rem_thm = remove Thm.eq_thm_prop;
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fun string_of_thm NONE = Display.string_of_thm_without_context
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  | string_of_thm (SOME context) =
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      Display.string_of_thm (Context.cases Syntax.init_pretty_global I context);
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fun make_elim context th =
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  if has_fewer_prems 1 th then
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    error ("Ill-formed destruction rule\n" ^ string_of_thm context th)
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  else Tactic.make_elim th;
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fun warn_thm context msg th =
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  if (case context of SOME (Context.Proof ctxt) => Context_Position.is_visible ctxt | _ => false)
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  then warning (msg ^ string_of_thm context th)
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  else ();
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fun warn_rules context msg rules th =
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  mem_thm rules th andalso (warn_thm context msg th; true);
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fun warn_claset context th (CS {safeIs, safeEs, hazIs, hazEs, ...}) =
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  warn_rules context "Rule already declared as safe introduction (intro!)\n" safeIs th orelse
wenzelm@42807
   319
  warn_rules context "Rule already declared as safe elimination (elim!)\n" safeEs th orelse
wenzelm@42807
   320
  warn_rules context "Rule already declared as introduction (intro)\n" hazIs th orelse
wenzelm@42807
   321
  warn_rules context "Rule already declared as elimination (elim)\n" hazEs th;
paulson@1927
   322
wenzelm@12376
   323
paulson@1800
   324
(*** Safe rules ***)
lcp@982
   325
wenzelm@42793
   326
fun addSI w context th
wenzelm@42790
   327
    (cs as CS {safeIs, safeEs, hazIs, hazEs, swrappers, uwrappers,
wenzelm@42790
   328
      safe0_netpair, safep_netpair, haz_netpair, dup_netpair, xtra_netpair}) =
wenzelm@42807
   329
  if warn_rules context "Ignoring duplicate safe introduction (intro!)\n" safeIs th then cs
paulson@1927
   330
  else
wenzelm@42790
   331
    let
wenzelm@42790
   332
      val th' = flat_rule th;
wenzelm@23594
   333
      val (safe0_rls, safep_rls) = (*0 subgoals vs 1 or more*)
wenzelm@42790
   334
        List.partition Thm.no_prems [th'];
wenzelm@42790
   335
      val nI = length safeIs + 1;
wenzelm@42790
   336
      val nE = length safeEs;
wenzelm@42807
   337
      val _ = warn_claset context th cs;
wenzelm@42790
   338
    in
wenzelm@42790
   339
      CS
wenzelm@42790
   340
       {safeIs  = th::safeIs,
lcp@1073
   341
        safe0_netpair = insert (nI,nE) (safe0_rls, []) safe0_netpair,
wenzelm@9938
   342
        safep_netpair = insert (nI,nE) (safep_rls, []) safep_netpair,
wenzelm@42790
   343
        safeEs = safeEs,
wenzelm@42790
   344
        hazIs = hazIs,
wenzelm@42790
   345
        hazEs = hazEs,
wenzelm@42790
   346
        swrappers = swrappers,
wenzelm@42790
   347
        uwrappers = uwrappers,
wenzelm@42790
   348
        haz_netpair = haz_netpair,
wenzelm@42790
   349
        dup_netpair = dup_netpair,
wenzelm@18691
   350
        xtra_netpair = insert' (the_default 0 w) (nI,nE) ([th], []) xtra_netpair}
wenzelm@42790
   351
    end;
lcp@1073
   352
wenzelm@42793
   353
fun addSE w context th
wenzelm@42790
   354
    (cs as CS {safeIs, safeEs, hazIs, hazEs, swrappers, uwrappers,
wenzelm@42790
   355
      safe0_netpair, safep_netpair, haz_netpair, dup_netpair, xtra_netpair}) =
wenzelm@42807
   356
  if warn_rules context "Ignoring duplicate safe elimination (elim!)\n" safeEs th then cs
paulson@18557
   357
  else if has_fewer_prems 1 th then
wenzelm@42793
   358
    error ("Ill-formed elimination rule\n" ^ string_of_thm context th)
paulson@1927
   359
  else
wenzelm@42790
   360
    let
wenzelm@42790
   361
      val th' = classical_rule (flat_rule th);
wenzelm@18534
   362
      val (safe0_rls, safep_rls) = (*0 subgoals vs 1 or more*)
wenzelm@42790
   363
        List.partition (fn rl => nprems_of rl=1) [th'];
wenzelm@42790
   364
      val nI = length safeIs;
wenzelm@42790
   365
      val nE = length safeEs + 1;
wenzelm@42807
   366
      val _ = warn_claset context th cs;
wenzelm@42790
   367
    in
wenzelm@42790
   368
      CS
wenzelm@42790
   369
       {safeEs  = th::safeEs,
lcp@1073
   370
        safe0_netpair = insert (nI,nE) ([], safe0_rls) safe0_netpair,
wenzelm@9938
   371
        safep_netpair = insert (nI,nE) ([], safep_rls) safep_netpair,
wenzelm@42790
   372
        safeIs = safeIs,
wenzelm@42790
   373
        hazIs = hazIs,
wenzelm@42790
   374
        hazEs = hazEs,
wenzelm@42790
   375
        swrappers = swrappers,
wenzelm@42790
   376
        uwrappers = uwrappers,
wenzelm@42790
   377
        haz_netpair = haz_netpair,
wenzelm@42790
   378
        dup_netpair = dup_netpair,
wenzelm@18691
   379
        xtra_netpair = insert' (the_default 0 w) (nI,nE) ([], [th]) xtra_netpair}
wenzelm@42790
   380
    end;
clasohm@0
   381
wenzelm@42793
   382
fun addSD w context th = addSE w context (make_elim context th);
wenzelm@42793
   383
lcp@1073
   384
paulson@1800
   385
(*** Hazardous (unsafe) rules ***)
clasohm@0
   386
wenzelm@42793
   387
fun addI w context th
wenzelm@42790
   388
    (cs as CS {safeIs, safeEs, hazIs, hazEs, swrappers, uwrappers,
wenzelm@42790
   389
      safe0_netpair, safep_netpair, haz_netpair, dup_netpair, xtra_netpair}) =
wenzelm@42807
   390
  if warn_rules context "Ignoring duplicate introduction (intro)\n" hazIs th then cs
paulson@1927
   391
  else
wenzelm@42790
   392
    let
wenzelm@42790
   393
      val th' = flat_rule th;
wenzelm@42790
   394
      val nI = length hazIs + 1;
wenzelm@42790
   395
      val nE = length hazEs;
wenzelm@42807
   396
      val _ = warn_claset context th cs;
wenzelm@42790
   397
    in
wenzelm@42790
   398
      CS
wenzelm@42790
   399
       {hazIs = th :: hazIs,
wenzelm@42790
   400
        haz_netpair = insert (nI, nE) ([th'], []) haz_netpair,
wenzelm@42790
   401
        dup_netpair = insert (nI, nE) ([dup_intr th'], []) dup_netpair,
wenzelm@42790
   402
        safeIs = safeIs,
wenzelm@42790
   403
        safeEs = safeEs,
wenzelm@42790
   404
        hazEs = hazEs,
wenzelm@42790
   405
        swrappers = swrappers,
wenzelm@42790
   406
        uwrappers = uwrappers,
wenzelm@9938
   407
        safe0_netpair = safe0_netpair,
wenzelm@9938
   408
        safep_netpair = safep_netpair,
wenzelm@42790
   409
        xtra_netpair = insert' (the_default 1 w) (nI, nE) ([th], []) xtra_netpair}
wenzelm@42790
   410
    end
wenzelm@42790
   411
    handle THM ("RSN: no unifiers", _, _) => (*from dup_intr*)  (* FIXME !? *)
wenzelm@42793
   412
      error ("Ill-formed introduction rule\n" ^ string_of_thm context th);
lcp@1073
   413
wenzelm@42793
   414
fun addE w context th
wenzelm@42790
   415
    (cs as CS {safeIs, safeEs, hazIs, hazEs, swrappers, uwrappers,
wenzelm@42790
   416
      safe0_netpair, safep_netpair, haz_netpair, dup_netpair, xtra_netpair}) =
wenzelm@42807
   417
  if warn_rules context "Ignoring duplicate elimination (elim)\n" hazEs th then cs
paulson@18557
   418
  else if has_fewer_prems 1 th then
wenzelm@42793
   419
    error ("Ill-formed elimination rule\n" ^ string_of_thm context th)
paulson@1927
   420
  else
wenzelm@42790
   421
    let
wenzelm@42790
   422
      val th' = classical_rule (flat_rule th);
wenzelm@42790
   423
      val nI = length hazIs;
wenzelm@42790
   424
      val nE = length hazEs + 1;
wenzelm@42807
   425
      val _ = warn_claset context th cs;
wenzelm@42790
   426
    in
wenzelm@42790
   427
      CS
wenzelm@42790
   428
       {hazEs = th :: hazEs,
wenzelm@42790
   429
        haz_netpair = insert (nI, nE) ([], [th']) haz_netpair,
wenzelm@42790
   430
        dup_netpair = insert (nI, nE) ([], [dup_elim th']) dup_netpair,
wenzelm@42790
   431
        safeIs = safeIs,
wenzelm@42790
   432
        safeEs = safeEs,
wenzelm@42790
   433
        hazIs = hazIs,
wenzelm@42790
   434
        swrappers = swrappers,
wenzelm@42790
   435
        uwrappers = uwrappers,
wenzelm@9938
   436
        safe0_netpair = safe0_netpair,
wenzelm@9938
   437
        safep_netpair = safep_netpair,
wenzelm@42790
   438
        xtra_netpair = insert' (the_default 1 w) (nI, nE) ([], [th]) xtra_netpair}
wenzelm@42790
   439
    end;
clasohm@0
   440
wenzelm@42793
   441
fun addD w context th = addE w context (make_elim context th);
wenzelm@42793
   442
clasohm@0
   443
lcp@1073
   444
wenzelm@10736
   445
(*** Deletion of rules
paulson@1800
   446
     Working out what to delete, requires repeating much of the code used
wenzelm@9938
   447
        to insert.
paulson@1800
   448
***)
paulson@1800
   449
wenzelm@10736
   450
fun delSI th
wenzelm@42790
   451
    (cs as CS {safeIs, safeEs, hazIs, hazEs, swrappers, uwrappers,
wenzelm@42790
   452
      safe0_netpair, safep_netpair, haz_netpair, dup_netpair, xtra_netpair}) =
wenzelm@42790
   453
  if mem_thm safeIs th then
wenzelm@18534
   454
    let
wenzelm@42790
   455
      val th' = flat_rule th;
wenzelm@42790
   456
      val (safe0_rls, safep_rls) = List.partition Thm.no_prems [th'];
wenzelm@42790
   457
    in
wenzelm@42790
   458
      CS
wenzelm@42790
   459
       {safe0_netpair = delete (safe0_rls, []) safe0_netpair,
wenzelm@42790
   460
        safep_netpair = delete (safep_rls, []) safep_netpair,
wenzelm@42790
   461
        safeIs = rem_thm th safeIs,
wenzelm@42790
   462
        safeEs = safeEs,
wenzelm@42790
   463
        hazIs = hazIs,
wenzelm@42790
   464
        hazEs = hazEs,
wenzelm@42790
   465
        swrappers = swrappers,
wenzelm@42790
   466
        uwrappers = uwrappers,
wenzelm@42790
   467
        haz_netpair = haz_netpair,
wenzelm@42790
   468
        dup_netpair = dup_netpair,
wenzelm@42790
   469
        xtra_netpair = delete' ([th], []) xtra_netpair}
wenzelm@18534
   470
    end
wenzelm@18534
   471
  else cs;
paulson@1800
   472
wenzelm@42790
   473
fun delSE th
wenzelm@42790
   474
    (cs as CS {safeIs, safeEs, hazIs, hazEs, swrappers, uwrappers,
wenzelm@42790
   475
      safe0_netpair, safep_netpair, haz_netpair, dup_netpair, xtra_netpair}) =
wenzelm@42790
   476
  if mem_thm safeEs th then
wenzelm@42790
   477
    let
wenzelm@42790
   478
      val th' = classical_rule (flat_rule th);
wenzelm@42790
   479
      val (safe0_rls, safep_rls) = List.partition (fn rl => nprems_of rl = 1) [th'];
wenzelm@42790
   480
    in
wenzelm@42790
   481
      CS
wenzelm@42790
   482
       {safe0_netpair = delete ([], safe0_rls) safe0_netpair,
wenzelm@42790
   483
        safep_netpair = delete ([], safep_rls) safep_netpair,
wenzelm@42790
   484
        safeIs = safeIs,
wenzelm@42790
   485
        safeEs = rem_thm th safeEs,
wenzelm@42790
   486
        hazIs = hazIs,
wenzelm@42790
   487
        hazEs = hazEs,
wenzelm@42790
   488
        swrappers = swrappers,
wenzelm@42790
   489
        uwrappers = uwrappers,
wenzelm@42790
   490
        haz_netpair = haz_netpair,
wenzelm@42790
   491
        dup_netpair = dup_netpair,
wenzelm@42790
   492
        xtra_netpair = delete' ([], [th]) xtra_netpair}
wenzelm@42790
   493
    end
wenzelm@42790
   494
  else cs;
paulson@1800
   495
wenzelm@42793
   496
fun delI context th
wenzelm@42790
   497
    (cs as CS {safeIs, safeEs, hazIs, hazEs, swrappers, uwrappers,
wenzelm@42790
   498
      safe0_netpair, safep_netpair, haz_netpair, dup_netpair, xtra_netpair}) =
wenzelm@42790
   499
  if mem_thm hazIs th then
wenzelm@42790
   500
    let val th' = flat_rule th in
wenzelm@42790
   501
      CS
wenzelm@42790
   502
       {haz_netpair = delete ([th'], []) haz_netpair,
wenzelm@23594
   503
        dup_netpair = delete ([dup_intr th'], []) dup_netpair,
wenzelm@42790
   504
        safeIs = safeIs,
wenzelm@42790
   505
        safeEs = safeEs,
wenzelm@42790
   506
        hazIs = rem_thm th hazIs,
wenzelm@42790
   507
        hazEs = hazEs,
wenzelm@42790
   508
        swrappers = swrappers,
wenzelm@42790
   509
        uwrappers = uwrappers,
wenzelm@9938
   510
        safe0_netpair = safe0_netpair,
wenzelm@9938
   511
        safep_netpair = safep_netpair,
wenzelm@12401
   512
        xtra_netpair = delete' ([th], []) xtra_netpair}
wenzelm@23594
   513
    end
wenzelm@42790
   514
  else cs
wenzelm@42790
   515
  handle THM ("RSN: no unifiers", _, _) => (*from dup_intr*)  (* FIXME !? *)
wenzelm@42793
   516
    error ("Ill-formed introduction rule\n" ^ string_of_thm context th);
paulson@1800
   517
paulson@2813
   518
fun delE th
wenzelm@42790
   519
    (cs as CS {safeIs, safeEs, hazIs, hazEs, swrappers, uwrappers,
wenzelm@42790
   520
      safe0_netpair, safep_netpair, haz_netpair, dup_netpair, xtra_netpair}) =
wenzelm@42790
   521
  if mem_thm hazEs th then
wenzelm@42790
   522
    let val th' = classical_rule (flat_rule th) in
wenzelm@42790
   523
      CS
wenzelm@42790
   524
       {haz_netpair = delete ([], [th']) haz_netpair,
wenzelm@18534
   525
        dup_netpair = delete ([], [dup_elim th']) dup_netpair,
wenzelm@42790
   526
        safeIs = safeIs,
wenzelm@42790
   527
        safeEs = safeEs,
wenzelm@42790
   528
        hazIs = hazIs,
wenzelm@42790
   529
        hazEs = rem_thm th hazEs,
wenzelm@42790
   530
        swrappers = swrappers,
wenzelm@42790
   531
        uwrappers = uwrappers,
wenzelm@9938
   532
        safe0_netpair = safe0_netpair,
wenzelm@9938
   533
        safep_netpair = safep_netpair,
wenzelm@12401
   534
        xtra_netpair = delete' ([], [th]) xtra_netpair}
wenzelm@42790
   535
    end
wenzelm@42790
   536
  else cs;
paulson@1800
   537
paulson@2813
   538
(*Delete ALL occurrences of "th" in the claset (perhaps from several lists)*)
wenzelm@42793
   539
fun delrule context th (cs as CS {safeIs, safeEs, hazIs, hazEs, ...}) =
wenzelm@42793
   540
  let val th' = Tactic.make_elim th in
wenzelm@18691
   541
    if mem_thm safeIs th orelse mem_thm safeEs th orelse
wenzelm@18691
   542
      mem_thm hazIs th orelse mem_thm hazEs th orelse
wenzelm@18691
   543
      mem_thm safeEs th' orelse mem_thm hazEs th'
wenzelm@42793
   544
    then delSI th (delSE th (delI context th (delE th (delSE th' (delE th' cs)))))
wenzelm@42807
   545
    else (warn_thm context "Undeclared classical rule\n" th; cs)
wenzelm@9938
   546
  end;
paulson@1800
   547
paulson@1800
   548
wenzelm@42793
   549
wenzelm@42793
   550
(** claset data **)
wenzelm@42790
   551
wenzelm@42793
   552
(* wrappers *)
wenzelm@42790
   553
haftmann@22674
   554
fun map_swrappers f
haftmann@22674
   555
  (CS {safeIs, safeEs, hazIs, hazEs, swrappers, uwrappers,
haftmann@22674
   556
    safe0_netpair, safep_netpair, haz_netpair, dup_netpair, xtra_netpair}) =
haftmann@22674
   557
  CS {safeIs = safeIs, safeEs = safeEs, hazIs = hazIs, hazEs = hazEs,
oheimb@4767
   558
    swrappers = f swrappers, uwrappers = uwrappers,
oheimb@4767
   559
    safe0_netpair = safe0_netpair, safep_netpair = safep_netpair,
wenzelm@6955
   560
    haz_netpair = haz_netpair, dup_netpair = dup_netpair, xtra_netpair = xtra_netpair};
oheimb@4767
   561
haftmann@22674
   562
fun map_uwrappers f
wenzelm@42793
   563
  (CS {safeIs, safeEs, hazIs, hazEs, swrappers, uwrappers,
haftmann@22674
   564
    safe0_netpair, safep_netpair, haz_netpair, dup_netpair, xtra_netpair}) =
haftmann@22674
   565
  CS {safeIs = safeIs, safeEs = safeEs, hazIs = hazIs, hazEs = hazEs,
oheimb@4767
   566
    swrappers = swrappers, uwrappers = f uwrappers,
oheimb@4767
   567
    safe0_netpair = safe0_netpair, safep_netpair = safep_netpair,
wenzelm@6955
   568
    haz_netpair = haz_netpair, dup_netpair = dup_netpair, xtra_netpair = xtra_netpair};
oheimb@4767
   569
haftmann@22674
   570
wenzelm@42793
   571
(* merge_cs *)
lcp@982
   572
paulson@1711
   573
(*Merge works by adding all new rules of the 2nd claset into the 1st claset.
paulson@1711
   574
  Merging the term nets may look more efficient, but the rather delicate
paulson@1711
   575
  treatment of priority might get muddled up.*)
haftmann@22674
   576
fun merge_cs (cs as CS {safeIs, safeEs, hazIs, hazEs, ...},
wenzelm@24358
   577
    cs' as CS {safeIs = safeIs2, safeEs = safeEs2, hazIs = hazIs2, hazEs = hazEs2,
haftmann@22674
   578
      swrappers, uwrappers, ...}) =
wenzelm@24358
   579
  if pointer_eq (cs, cs') then cs
wenzelm@24358
   580
  else
wenzelm@24358
   581
    let
wenzelm@24358
   582
      val safeIs' = fold rem_thm safeIs safeIs2;
wenzelm@24358
   583
      val safeEs' = fold rem_thm safeEs safeEs2;
wenzelm@24358
   584
      val hazIs' = fold rem_thm hazIs hazIs2;
wenzelm@24358
   585
      val hazEs' = fold rem_thm hazEs hazEs2;
wenzelm@42793
   586
    in
wenzelm@42793
   587
      cs
wenzelm@42793
   588
      |> fold_rev (addSI NONE NONE) safeIs'
wenzelm@42793
   589
      |> fold_rev (addSE NONE NONE) safeEs'
wenzelm@42793
   590
      |> fold_rev (addI NONE NONE) hazIs'
wenzelm@42793
   591
      |> fold_rev (addE NONE NONE) hazEs'
wenzelm@42793
   592
      |> map_swrappers (fn ws => AList.merge (op =) (K true) (ws, swrappers))
wenzelm@42793
   593
      |> map_uwrappers (fn ws => AList.merge (op =) (K true) (ws, uwrappers))
wenzelm@42793
   594
    end;
wenzelm@42793
   595
wenzelm@42793
   596
wenzelm@42793
   597
(* data *)
wenzelm@42793
   598
wenzelm@42793
   599
structure Claset = Generic_Data
wenzelm@42793
   600
(
wenzelm@42793
   601
  type T = claset;
wenzelm@42793
   602
  val empty = empty_cs;
wenzelm@42793
   603
  val extend = I;
wenzelm@42793
   604
  val merge = merge_cs;
wenzelm@42793
   605
);
wenzelm@42793
   606
wenzelm@42793
   607
val global_claset_of = Claset.get o Context.Theory;
wenzelm@42793
   608
val claset_of = Claset.get o Context.Proof;
wenzelm@42793
   609
val rep_claset_of = rep_cs o claset_of;
wenzelm@42793
   610
wenzelm@42793
   611
val get_cs = Claset.get;
wenzelm@42793
   612
val map_cs = Claset.map;
wenzelm@42793
   613
wenzelm@42793
   614
fun map_claset f = Context.proof_map (map_cs f);
wenzelm@42793
   615
fun put_claset cs = map_claset (K cs);
wenzelm@42793
   616
wenzelm@42793
   617
fun print_claset ctxt =
wenzelm@42793
   618
  let
wenzelm@42793
   619
    val {safeIs, safeEs, hazIs, hazEs, swrappers, uwrappers, ...} = rep_claset_of ctxt;
wenzelm@42793
   620
    val pretty_thms = map (Display.pretty_thm ctxt);
wenzelm@42793
   621
  in
wenzelm@42793
   622
    [Pretty.big_list "safe introduction rules (intro!):" (pretty_thms safeIs),
wenzelm@42793
   623
      Pretty.big_list "introduction rules (intro):" (pretty_thms hazIs),
wenzelm@42793
   624
      Pretty.big_list "safe elimination rules (elim!):" (pretty_thms safeEs),
wenzelm@42793
   625
      Pretty.big_list "elimination rules (elim):" (pretty_thms hazEs),
wenzelm@42793
   626
      Pretty.strs ("safe wrappers:" :: map #1 swrappers),
wenzelm@42793
   627
      Pretty.strs ("unsafe wrappers:" :: map #1 uwrappers)]
wenzelm@42793
   628
    |> Pretty.chunks |> Pretty.writeln
wenzelm@42793
   629
  end;
wenzelm@42793
   630
wenzelm@42793
   631
wenzelm@42793
   632
(* old-style declarations *)
wenzelm@42793
   633
wenzelm@42793
   634
fun decl f (ctxt, ths) = map_claset (fold_rev (f (SOME (Context.Proof ctxt))) ths) ctxt;
wenzelm@42793
   635
wenzelm@42793
   636
val op addSIs = decl (addSI NONE);
wenzelm@42793
   637
val op addSEs = decl (addSE NONE);
wenzelm@42793
   638
val op addSDs = decl (addSD NONE);
wenzelm@42793
   639
val op addIs = decl (addI NONE);
wenzelm@42793
   640
val op addEs = decl (addE NONE);
wenzelm@42793
   641
val op addDs = decl (addD NONE);
wenzelm@42793
   642
val op delrules = decl delrule;
wenzelm@42793
   643
wenzelm@42793
   644
wenzelm@42793
   645
wenzelm@42793
   646
(*** Modifying the wrapper tacticals ***)
wenzelm@42793
   647
wenzelm@42793
   648
fun appSWrappers ctxt = fold (fn (_, w) => w ctxt) (#swrappers (rep_claset_of ctxt));
wenzelm@42793
   649
fun appWrappers ctxt = fold (fn (_, w) => w ctxt) (#uwrappers (rep_claset_of ctxt));
wenzelm@42793
   650
wenzelm@42793
   651
fun update_warn msg (p as (key : string, _)) xs =
wenzelm@42793
   652
  (if AList.defined (op =) xs key then warning msg else (); AList.update (op =) p xs);
wenzelm@42793
   653
wenzelm@42793
   654
fun delete_warn msg (key : string) xs =
wenzelm@42793
   655
  if AList.defined (op =) xs key then AList.delete (op =) key xs
wenzelm@42793
   656
  else (warning msg; xs);
wenzelm@42793
   657
wenzelm@42793
   658
(*Add/replace a safe wrapper*)
wenzelm@42793
   659
fun cs addSWrapper new_swrapper =
wenzelm@42793
   660
  map_swrappers (update_warn ("Overwriting safe wrapper " ^ fst new_swrapper) new_swrapper) cs;
wenzelm@42793
   661
wenzelm@42793
   662
(*Add/replace an unsafe wrapper*)
wenzelm@42793
   663
fun cs addWrapper new_uwrapper =
wenzelm@42793
   664
  map_uwrappers (update_warn ("Overwriting unsafe wrapper " ^ fst new_uwrapper) new_uwrapper) cs;
wenzelm@42793
   665
wenzelm@42793
   666
(*Remove a safe wrapper*)
wenzelm@42793
   667
fun cs delSWrapper name =
wenzelm@42793
   668
  map_swrappers (delete_warn ("No such safe wrapper in claset: " ^ name) name) cs;
wenzelm@42793
   669
wenzelm@42793
   670
(*Remove an unsafe wrapper*)
wenzelm@42793
   671
fun cs delWrapper name =
wenzelm@42793
   672
  map_uwrappers (delete_warn ("No such unsafe wrapper in claset: " ^ name) name) cs;
wenzelm@42793
   673
wenzelm@42793
   674
(* compose a safe tactic alternatively before/after safe_step_tac *)
wenzelm@42793
   675
fun cs addSbefore (name, tac1) = cs addSWrapper (name, fn _ => fn tac2 => tac1 ORELSE' tac2);
wenzelm@42793
   676
fun cs addSafter (name, tac2) = cs addSWrapper (name, fn _ => fn tac1 => tac1 ORELSE' tac2);
wenzelm@42793
   677
wenzelm@42793
   678
(*compose a tactic alternatively before/after the step tactic *)
wenzelm@42793
   679
fun cs addbefore (name, tac1) = cs addWrapper (name, fn _ => fn tac2 => tac1 APPEND' tac2);
wenzelm@42793
   680
fun cs addafter (name, tac2) = cs addWrapper (name, fn _ => fn tac1 => tac1 APPEND' tac2);
wenzelm@42793
   681
wenzelm@42793
   682
fun cs addD2 (name, thm) = cs addafter (name, datac thm 1);
wenzelm@42793
   683
fun cs addE2 (name, thm) = cs addafter (name, eatac thm 1);
wenzelm@42793
   684
fun cs addSD2 (name, thm) = cs addSafter (name, dmatch_tac [thm] THEN' eq_assume_tac);
wenzelm@42793
   685
fun cs addSE2 (name, thm) = cs addSafter (name, ematch_tac [thm] THEN' eq_assume_tac);
wenzelm@42793
   686
paulson@1711
   687
lcp@982
   688
paulson@1800
   689
(**** Simple tactics for theorem proving ****)
clasohm@0
   690
clasohm@0
   691
(*Attack subgoals using safe inferences -- matching, not resolution*)
wenzelm@42793
   692
fun safe_step_tac ctxt =
wenzelm@42793
   693
  let val {safe0_netpair, safep_netpair, ...} = rep_claset_of ctxt in
wenzelm@42793
   694
    appSWrappers ctxt
wenzelm@42793
   695
      (FIRST'
wenzelm@42793
   696
       [eq_assume_tac,
wenzelm@9938
   697
        eq_mp_tac,
wenzelm@9938
   698
        bimatch_from_nets_tac safe0_netpair,
wenzelm@42792
   699
        FIRST' Data.hyp_subst_tacs,
wenzelm@42793
   700
        bimatch_from_nets_tac safep_netpair])
wenzelm@42793
   701
  end;
clasohm@0
   702
oheimb@5757
   703
(*Repeatedly attack a subgoal using safe inferences -- it's deterministic!*)
wenzelm@42793
   704
fun safe_steps_tac ctxt =
wenzelm@42793
   705
  REPEAT_DETERM1 o (fn i => COND (has_fewer_prems i) no_tac (safe_step_tac ctxt i));
oheimb@5757
   706
clasohm@0
   707
(*Repeatedly attack subgoals using safe inferences -- it's deterministic!*)
wenzelm@42793
   708
fun safe_tac ctxt = REPEAT_DETERM1 (FIRSTGOAL (safe_steps_tac ctxt));
lcp@747
   709
paulson@3705
   710
paulson@3705
   711
(*** Clarify_tac: do safe steps without causing branching ***)
paulson@3705
   712
wenzelm@42790
   713
fun nsubgoalsP n (k, brl) = (subgoals_of_brl brl = n);
paulson@3705
   714
paulson@3705
   715
(*version of bimatch_from_nets_tac that only applies rules that
paulson@3705
   716
  create precisely n subgoals.*)
wenzelm@10736
   717
fun n_bimatch_from_nets_tac n =
wenzelm@42790
   718
  biresolution_from_nets_tac (order_list o filter (nsubgoalsP n)) true;
paulson@3705
   719
wenzelm@42792
   720
fun eq_contr_tac i = ematch_tac [Data.not_elim] i THEN eq_assume_tac i;
paulson@3705
   721
val eq_assume_contr_tac = eq_assume_tac ORELSE' eq_contr_tac;
paulson@3705
   722
paulson@3705
   723
(*Two-way branching is allowed only if one of the branches immediately closes*)
paulson@3705
   724
fun bimatch2_tac netpair i =
wenzelm@42790
   725
  n_bimatch_from_nets_tac 2 netpair i THEN
wenzelm@42790
   726
  (eq_assume_contr_tac i ORELSE eq_assume_contr_tac (i + 1));
paulson@3705
   727
paulson@3705
   728
(*Attack subgoals using safe inferences -- matching, not resolution*)
wenzelm@42793
   729
fun clarify_step_tac ctxt =
wenzelm@42793
   730
  let val {safe0_netpair, safep_netpair, ...} = rep_claset_of ctxt in
wenzelm@42793
   731
    appSWrappers ctxt
wenzelm@42793
   732
     (FIRST'
wenzelm@42793
   733
       [eq_assume_contr_tac,
wenzelm@9938
   734
        bimatch_from_nets_tac safe0_netpair,
wenzelm@42792
   735
        FIRST' Data.hyp_subst_tacs,
wenzelm@9938
   736
        n_bimatch_from_nets_tac 1 safep_netpair,
wenzelm@42793
   737
        bimatch2_tac safep_netpair])
wenzelm@42793
   738
  end;
paulson@3705
   739
wenzelm@42793
   740
fun clarify_tac ctxt = SELECT_GOAL (REPEAT_DETERM (clarify_step_tac ctxt 1));
paulson@3705
   741
paulson@3705
   742
paulson@3705
   743
(*** Unsafe steps instantiate variables or lose information ***)
paulson@3705
   744
paulson@4066
   745
(*Backtracking is allowed among the various these unsafe ways of
paulson@4066
   746
  proving a subgoal.  *)
wenzelm@42793
   747
fun inst0_step_tac ctxt =
wenzelm@32862
   748
  assume_tac APPEND'
wenzelm@32862
   749
  contr_tac APPEND'
wenzelm@42793
   750
  biresolve_from_nets_tac (#safe0_netpair (rep_claset_of ctxt));
lcp@747
   751
paulson@4066
   752
(*These unsafe steps could generate more subgoals.*)
wenzelm@42793
   753
fun instp_step_tac ctxt =
wenzelm@42793
   754
  biresolve_from_nets_tac (#safep_netpair (rep_claset_of ctxt));
clasohm@0
   755
clasohm@0
   756
(*These steps could instantiate variables and are therefore unsafe.*)
wenzelm@42793
   757
fun inst_step_tac ctxt = inst0_step_tac ctxt APPEND' instp_step_tac ctxt;
clasohm@0
   758
wenzelm@42793
   759
fun haz_step_tac ctxt =
wenzelm@42793
   760
  biresolve_from_nets_tac (#haz_netpair (rep_claset_of ctxt));
lcp@681
   761
clasohm@0
   762
(*Single step for the prover.  FAILS unless it makes progress. *)
wenzelm@42793
   763
fun step_tac ctxt i =
wenzelm@42793
   764
  safe_tac ctxt ORELSE appWrappers ctxt (inst_step_tac ctxt ORELSE' haz_step_tac ctxt) i;
clasohm@0
   765
clasohm@0
   766
(*Using a "safe" rule to instantiate variables is unsafe.  This tactic
clasohm@0
   767
  allows backtracking from "safe" rules to "unsafe" rules here.*)
wenzelm@42793
   768
fun slow_step_tac ctxt i =
wenzelm@42793
   769
  safe_tac ctxt ORELSE appWrappers ctxt (inst_step_tac ctxt APPEND' haz_step_tac ctxt) i;
clasohm@0
   770
wenzelm@42791
   771
paulson@1800
   772
(**** The following tactics all fail unless they solve one goal ****)
clasohm@0
   773
clasohm@0
   774
(*Dumb but fast*)
wenzelm@42793
   775
fun fast_tac ctxt =
wenzelm@42793
   776
  Object_Logic.atomize_prems_tac THEN' SELECT_GOAL (DEPTH_SOLVE (step_tac ctxt 1));
clasohm@0
   777
clasohm@0
   778
(*Slower but smarter than fast_tac*)
wenzelm@42793
   779
fun best_tac ctxt =
wenzelm@35625
   780
  Object_Logic.atomize_prems_tac THEN'
wenzelm@42793
   781
  SELECT_GOAL (BEST_FIRST (has_fewer_prems 1, Data.sizef) (step_tac ctxt 1));
clasohm@0
   782
oheimb@9402
   783
(*even a bit smarter than best_tac*)
wenzelm@42793
   784
fun first_best_tac ctxt =
wenzelm@35625
   785
  Object_Logic.atomize_prems_tac THEN'
wenzelm@42793
   786
  SELECT_GOAL (BEST_FIRST (has_fewer_prems 1, Data.sizef) (FIRSTGOAL (step_tac ctxt)));
oheimb@9402
   787
wenzelm@42793
   788
fun slow_tac ctxt =
wenzelm@35625
   789
  Object_Logic.atomize_prems_tac THEN'
wenzelm@42793
   790
  SELECT_GOAL (DEPTH_SOLVE (slow_step_tac ctxt 1));
clasohm@0
   791
wenzelm@42793
   792
fun slow_best_tac ctxt =
wenzelm@35625
   793
  Object_Logic.atomize_prems_tac THEN'
wenzelm@42793
   794
  SELECT_GOAL (BEST_FIRST (has_fewer_prems 1, Data.sizef) (slow_step_tac ctxt 1));
clasohm@0
   795
lcp@681
   796
wenzelm@10736
   797
(***ASTAR with weight weight_ASTAR, by Norbert Voelker*)
wenzelm@42791
   798
wenzelm@42791
   799
val weight_ASTAR = 5;
paulson@1587
   800
wenzelm@42793
   801
fun astar_tac ctxt =
wenzelm@35625
   802
  Object_Logic.atomize_prems_tac THEN'
wenzelm@10382
   803
  SELECT_GOAL
wenzelm@42791
   804
    (ASTAR (has_fewer_prems 1, fn lev => fn thm => size_of_thm thm + weight_ASTAR * lev)
wenzelm@42793
   805
      (step_tac ctxt 1));
paulson@1587
   806
wenzelm@42793
   807
fun slow_astar_tac ctxt =
wenzelm@35625
   808
  Object_Logic.atomize_prems_tac THEN'
wenzelm@10382
   809
  SELECT_GOAL
wenzelm@42791
   810
    (ASTAR (has_fewer_prems 1, fn lev => fn thm => size_of_thm thm + weight_ASTAR * lev)
wenzelm@42793
   811
      (slow_step_tac ctxt 1));
paulson@1587
   812
wenzelm@42790
   813
paulson@1800
   814
(**** Complete tactic, loosely based upon LeanTaP.  This tactic is the outcome
lcp@747
   815
  of much experimentation!  Changing APPEND to ORELSE below would prove
lcp@747
   816
  easy theorems faster, but loses completeness -- and many of the harder
paulson@1800
   817
  theorems such as 43. ****)
lcp@681
   818
lcp@747
   819
(*Non-deterministic!  Could always expand the first unsafe connective.
lcp@747
   820
  That's hard to implement and did not perform better in experiments, due to
lcp@747
   821
  greater search depth required.*)
wenzelm@42793
   822
fun dup_step_tac ctxt =
wenzelm@42793
   823
  biresolve_from_nets_tac (#dup_netpair (rep_claset_of ctxt));
lcp@681
   824
oheimb@5523
   825
(*Searching to depth m. A variant called nodup_depth_tac appears in clasimp.ML*)
oheimb@5757
   826
local
wenzelm@42793
   827
  fun slow_step_tac' ctxt = appWrappers ctxt (instp_step_tac ctxt APPEND' dup_step_tac ctxt);
wenzelm@42790
   828
in
wenzelm@42793
   829
  fun depth_tac ctxt m i state = SELECT_GOAL
wenzelm@42793
   830
    (safe_steps_tac ctxt 1 THEN_ELSE
wenzelm@42793
   831
      (DEPTH_SOLVE (depth_tac ctxt m 1),
wenzelm@42793
   832
        inst0_step_tac ctxt 1 APPEND COND (K (m = 0)) no_tac
wenzelm@42793
   833
          (slow_step_tac' ctxt 1 THEN DEPTH_SOLVE (depth_tac ctxt (m - 1) 1)))) i state;
oheimb@5757
   834
end;
lcp@747
   835
wenzelm@10736
   836
(*Search, with depth bound m.
paulson@2173
   837
  This is the "entry point", which does safe inferences first.*)
wenzelm@42793
   838
fun safe_depth_tac ctxt m = SUBGOAL (fn (prem, i) =>
wenzelm@42793
   839
  let
wenzelm@42793
   840
    val deti = (*No Vars in the goal?  No need to backtrack between goals.*)
wenzelm@42793
   841
      if exists_subterm (fn Var _ => true | _ => false) prem then DETERM else I;
wenzelm@42790
   842
  in
wenzelm@42793
   843
    SELECT_GOAL (TRY (safe_tac ctxt) THEN DEPTH_SOLVE (deti (depth_tac ctxt m 1))) i
wenzelm@42790
   844
  end);
lcp@681
   845
wenzelm@42793
   846
fun deepen_tac ctxt = DEEPEN (2, 10) (safe_depth_tac ctxt);
wenzelm@24021
   847
wenzelm@24021
   848
wenzelm@5885
   849
(* attributes *)
wenzelm@5885
   850
wenzelm@42793
   851
fun attrib f =
wenzelm@42793
   852
  Thm.declaration_attribute (fn th => fn context => map_cs (f (SOME context) th) context);
wenzelm@5885
   853
wenzelm@18691
   854
val safe_elim = attrib o addSE;
wenzelm@18691
   855
val safe_intro = attrib o addSI;
wenzelm@42793
   856
val safe_dest = attrib o addSD;
wenzelm@18691
   857
val haz_elim = attrib o addE;
wenzelm@18691
   858
val haz_intro = attrib o addI;
wenzelm@42793
   859
val haz_dest = attrib o addD;
wenzelm@33369
   860
val rule_del = attrib delrule o Context_Rules.rule_del;
wenzelm@5885
   861
wenzelm@5885
   862
wenzelm@5841
   863
wenzelm@5885
   864
(** concrete syntax of attributes **)
wenzelm@5841
   865
wenzelm@5841
   866
val introN = "intro";
wenzelm@5841
   867
val elimN = "elim";
wenzelm@5841
   868
val destN = "dest";
wenzelm@5841
   869
wenzelm@30528
   870
val setup_attrs =
wenzelm@30528
   871
  Attrib.setup @{binding swapped} (Scan.succeed swapped)
wenzelm@30528
   872
    "classical swap of introduction rule" #>
wenzelm@33369
   873
  Attrib.setup @{binding dest} (Context_Rules.add safe_dest haz_dest Context_Rules.dest_query)
wenzelm@30528
   874
    "declaration of Classical destruction rule" #>
wenzelm@33369
   875
  Attrib.setup @{binding elim} (Context_Rules.add safe_elim haz_elim Context_Rules.elim_query)
wenzelm@30528
   876
    "declaration of Classical elimination rule" #>
wenzelm@33369
   877
  Attrib.setup @{binding intro} (Context_Rules.add safe_intro haz_intro Context_Rules.intro_query)
wenzelm@30528
   878
    "declaration of Classical introduction rule" #>
wenzelm@30528
   879
  Attrib.setup @{binding rule} (Scan.lift Args.del >> K rule_del)
wenzelm@30528
   880
    "remove declaration of intro/elim/dest rule";
wenzelm@5841
   881
wenzelm@5841
   882
wenzelm@5841
   883
wenzelm@7230
   884
(** proof methods **)
wenzelm@7230
   885
wenzelm@7230
   886
local
wenzelm@7230
   887
wenzelm@30609
   888
fun some_rule_tac ctxt facts = SUBGOAL (fn (goal, i) =>
wenzelm@5841
   889
  let
wenzelm@33369
   890
    val [rules1, rules2, rules4] = Context_Rules.find_rules false facts goal ctxt;
wenzelm@42793
   891
    val {xtra_netpair, ...} = rep_claset_of ctxt;
wenzelm@33369
   892
    val rules3 = Context_Rules.find_rules_netpair true facts goal xtra_netpair;
wenzelm@12376
   893
    val rules = rules1 @ rules2 @ rules3 @ rules4;
wenzelm@18223
   894
    val ruleq = Drule.multi_resolves facts rules;
wenzelm@12376
   895
  in
wenzelm@12376
   896
    Method.trace ctxt rules;
wenzelm@32952
   897
    fn st => Seq.maps (fn rule => Tactic.rtac rule i st) ruleq
wenzelm@18834
   898
  end)
wenzelm@21687
   899
  THEN_ALL_NEW Goal.norm_hhf_tac;
wenzelm@5841
   900
wenzelm@30609
   901
in
wenzelm@7281
   902
wenzelm@30609
   903
fun rule_tac ctxt [] facts = some_rule_tac ctxt facts
wenzelm@30609
   904
  | rule_tac _ rules facts = Method.rule_tac rules facts;
wenzelm@30609
   905
wenzelm@30609
   906
fun default_tac ctxt rules facts =
wenzelm@30609
   907
  HEADGOAL (rule_tac ctxt rules facts) ORELSE
haftmann@26470
   908
  Class.default_intro_tac ctxt facts;
wenzelm@10309
   909
wenzelm@7230
   910
end;
wenzelm@5841
   911
wenzelm@5841
   912
wenzelm@7230
   913
(* contradiction method *)
wenzelm@6502
   914
wenzelm@7425
   915
val contradiction = Method.rule [Data.not_elim, Data.not_elim COMP Drule.swap_prems_rl];
wenzelm@6502
   916
wenzelm@6502
   917
wenzelm@6502
   918
(* automatic methods *)
wenzelm@5841
   919
wenzelm@5927
   920
val cla_modifiers =
wenzelm@18728
   921
 [Args.$$$ destN -- Args.bang_colon >> K ((I, safe_dest NONE): Method.modifier),
wenzelm@18728
   922
  Args.$$$ destN -- Args.colon >> K (I, haz_dest NONE),
wenzelm@18728
   923
  Args.$$$ elimN -- Args.bang_colon >> K (I, safe_elim NONE),
wenzelm@18728
   924
  Args.$$$ elimN -- Args.colon >> K (I, haz_elim NONE),
wenzelm@18728
   925
  Args.$$$ introN -- Args.bang_colon >> K (I, safe_intro NONE),
wenzelm@18728
   926
  Args.$$$ introN -- Args.colon >> K (I, haz_intro NONE),
wenzelm@18728
   927
  Args.del -- Args.colon >> K (I, rule_del)];
wenzelm@5927
   928
wenzelm@42793
   929
fun cla_method tac = Method.sections cla_modifiers >> K (SIMPLE_METHOD o tac);
wenzelm@42793
   930
fun cla_method' tac = Method.sections cla_modifiers >> K (SIMPLE_METHOD' o tac);
wenzelm@5841
   931
wenzelm@5841
   932
wenzelm@5841
   933
wenzelm@5841
   934
(** setup_methods **)
wenzelm@5841
   935
wenzelm@30541
   936
val setup_methods =
wenzelm@30609
   937
  Method.setup @{binding default}
wenzelm@30609
   938
   (Attrib.thms >> (fn rules => fn ctxt => METHOD (default_tac ctxt rules)))
wenzelm@30541
   939
    "apply some intro/elim rule (potentially classical)" #>
wenzelm@30609
   940
  Method.setup @{binding rule}
wenzelm@30609
   941
    (Attrib.thms >> (fn rules => fn ctxt => METHOD (HEADGOAL o rule_tac ctxt rules)))
wenzelm@30541
   942
    "apply some intro/elim rule (potentially classical)" #>
wenzelm@30541
   943
  Method.setup @{binding contradiction} (Scan.succeed (K contradiction))
wenzelm@30541
   944
    "proof by contradiction" #>
wenzelm@30541
   945
  Method.setup @{binding clarify} (cla_method' (CHANGED_PROP oo clarify_tac))
wenzelm@30541
   946
    "repeatedly apply safe steps" #>
wenzelm@30541
   947
  Method.setup @{binding fast} (cla_method' fast_tac) "classical prover (depth-first)" #>
wenzelm@30541
   948
  Method.setup @{binding slow} (cla_method' slow_tac) "classical prover (slow depth-first)" #>
wenzelm@30541
   949
  Method.setup @{binding best} (cla_method' best_tac) "classical prover (best-first)" #>
wenzelm@42798
   950
  Method.setup @{binding deepen}
wenzelm@42798
   951
    (Scan.lift (Scan.optional Parse.nat 4) --| Method.sections cla_modifiers
wenzelm@42798
   952
      >> (fn n => fn ctxt => SIMPLE_METHOD' (deepen_tac ctxt n)))
wenzelm@30541
   953
    "classical prover (iterative deepening)" #>
wenzelm@30541
   954
  Method.setup @{binding safe} (cla_method (CHANGED_PROP o safe_tac))
wenzelm@30541
   955
    "classical prover (apply safe rules)";
wenzelm@5841
   956
wenzelm@5841
   957
wenzelm@5841
   958
wenzelm@5841
   959
(** theory setup **)
wenzelm@5841
   960
wenzelm@26497
   961
val setup = setup_attrs #> setup_methods;
wenzelm@5841
   962
wenzelm@5841
   963
wenzelm@8667
   964
wenzelm@8667
   965
(** outer syntax **)
wenzelm@8667
   966
wenzelm@24867
   967
val _ =
wenzelm@36960
   968
  Outer_Syntax.improper_command "print_claset" "print context of Classical Reasoner"
wenzelm@36960
   969
    Keyword.diag
wenzelm@26497
   970
    (Scan.succeed (Toplevel.no_timing o Toplevel.unknown_context o
wenzelm@42439
   971
      Toplevel.keep (fn state =>
wenzelm@42439
   972
        let val ctxt = Toplevel.context_of state
wenzelm@42793
   973
        in print_claset ctxt end)));
wenzelm@8667
   974
wenzelm@5841
   975
end;