src/Pure/raw_simplifier.ML
author wenzelm
Fri Jan 17 20:51:36 2014 +0100 (2014-01-17)
changeset 55032 b49366215417
parent 55031 e58066daa065
child 55316 885500f4aa6a
permissions -rw-r--r--
back to conditional tracing instead of noisy warning (see also 00e849f5b397): these incidents happen occasionally;
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(*  Title:      Pure/raw_simplifier.ML
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    Author:     Tobias Nipkow and Stefan Berghofer, TU Muenchen
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Higher-order Simplification.
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*)
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infix 4
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  addsimps delsimps addsimprocs delsimprocs
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  setloop addloop delloop
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  setSSolver addSSolver setSolver addSolver;
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signature BASIC_RAW_SIMPLIFIER =
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sig
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  val simp_depth_limit: int Config.T
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  val simp_trace_depth_limit: int Config.T
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  val simp_debug: bool Config.T
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  val simp_trace: bool Config.T
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  type cong_name = bool * string
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  type rrule
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  val eq_rrule: rrule * rrule -> bool
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  type proc
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  type solver
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  val mk_solver: string -> (Proof.context -> int -> tactic) -> solver
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  type simpset
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  val empty_ss: simpset
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  val merge_ss: simpset * simpset -> simpset
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  val dest_ss: simpset ->
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   {simps: (string * thm) list,
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    procs: (string * cterm list) list,
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    congs: (cong_name * thm) list,
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    weak_congs: cong_name list,
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    loopers: string list,
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    unsafe_solvers: string list,
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    safe_solvers: string list}
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  type simproc
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  val eq_simproc: simproc * simproc -> bool
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  val transform_simproc: morphism -> simproc -> simproc
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  val make_simproc: {name: string, lhss: cterm list,
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    proc: morphism -> Proof.context -> cterm -> thm option, identifier: thm list} -> simproc
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  val mk_simproc: string -> cterm list -> (Proof.context -> term -> thm option) -> simproc
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  val simpset_of: Proof.context -> simpset
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  val put_simpset: simpset -> Proof.context -> Proof.context
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  val simpset_map: Proof.context -> (Proof.context -> Proof.context) -> simpset -> simpset
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  val map_theory_simpset: (Proof.context -> Proof.context) -> theory -> theory
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  val empty_simpset: Proof.context -> Proof.context
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  val clear_simpset: Proof.context -> Proof.context
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  val addsimps: Proof.context * thm list -> Proof.context
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  val delsimps: Proof.context * thm list -> Proof.context
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  val addsimprocs: Proof.context * simproc list -> Proof.context
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  val delsimprocs: Proof.context * simproc list -> Proof.context
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  val setloop: Proof.context * (Proof.context -> int -> tactic) -> Proof.context
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  val addloop: Proof.context * (string * (Proof.context -> int -> tactic)) -> Proof.context
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  val delloop: Proof.context * string -> Proof.context
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  val setSSolver: Proof.context * solver -> Proof.context
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  val addSSolver: Proof.context * solver -> Proof.context
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  val setSolver: Proof.context * solver -> Proof.context
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  val addSolver: Proof.context * solver -> Proof.context
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  val rewrite_rule: Proof.context -> thm list -> thm -> thm
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  val rewrite_goals_rule: Proof.context -> thm list -> thm -> thm
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  val rewrite_goals_tac: Proof.context -> thm list -> tactic
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  val rewrite_goal_tac: Proof.context -> thm list -> int -> tactic
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  val prune_params_tac: Proof.context -> tactic
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  val fold_rule: Proof.context -> thm list -> thm -> thm
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  val fold_goals_tac: Proof.context -> thm list -> tactic
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  val norm_hhf: Proof.context -> thm -> thm
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  val norm_hhf_protect: Proof.context -> thm -> thm
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end;
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signature RAW_SIMPLIFIER =
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sig
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  include BASIC_RAW_SIMPLIFIER
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  exception SIMPLIFIER of string * thm list
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  type trace_ops
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  val set_trace_ops: trace_ops -> theory -> theory
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  val internal_ss: simpset ->
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   {congs: (cong_name * thm) list * cong_name list,
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    procs: proc Net.net,
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    mk_rews:
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     {mk: Proof.context -> thm -> thm list,
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      mk_cong: Proof.context -> thm -> thm,
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      mk_sym: Proof.context -> thm -> thm option,
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      mk_eq_True: Proof.context -> thm -> thm option,
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      reorient: Proof.context -> term list -> term -> term -> bool},
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    termless: term * term -> bool,
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    subgoal_tac: Proof.context -> int -> tactic,
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    loop_tacs: (string * (Proof.context -> int -> tactic)) list,
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    solvers: solver list * solver list}
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  val map_ss: (Proof.context -> Proof.context) -> Context.generic -> Context.generic
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  val prems_of: Proof.context -> thm list
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  val add_simp: thm -> Proof.context -> Proof.context
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  val del_simp: thm -> Proof.context -> Proof.context
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  val add_eqcong: thm -> Proof.context -> Proof.context
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  val del_eqcong: thm -> Proof.context -> Proof.context
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  val add_cong: thm -> Proof.context -> Proof.context
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  val del_cong: thm -> Proof.context -> Proof.context
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  val mksimps: Proof.context -> thm -> thm list
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  val set_mksimps: (Proof.context -> thm -> thm list) -> Proof.context -> Proof.context
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  val set_mkcong: (Proof.context -> thm -> thm) -> Proof.context -> Proof.context
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  val set_mksym: (Proof.context -> thm -> thm option) -> Proof.context -> Proof.context
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  val set_mkeqTrue: (Proof.context -> thm -> thm option) -> Proof.context -> Proof.context
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  val set_termless: (term * term -> bool) -> Proof.context -> Proof.context
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  val set_subgoaler: (Proof.context -> int -> tactic) -> Proof.context -> Proof.context
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  val solver: Proof.context -> solver -> int -> tactic
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  val simp_depth_limit_raw: Config.raw
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  val default_mk_sym: Proof.context -> thm -> thm option
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  val simproc_global_i: theory -> string -> term list ->
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    (Proof.context -> term -> thm option) -> simproc
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  val simproc_global: theory -> string -> string list ->
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    (Proof.context -> term -> thm option) -> simproc
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  val simp_trace_depth_limit_raw: Config.raw
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  val simp_trace_depth_limit_default: int Unsynchronized.ref
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  val simp_trace_default: bool Unsynchronized.ref
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  val simp_trace_raw: Config.raw
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  val simp_debug_raw: Config.raw
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  val add_prems: thm list -> Proof.context -> Proof.context
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  val set_reorient: (Proof.context -> term list -> term -> term -> bool) ->
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    Proof.context -> Proof.context
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  val set_solvers: solver list -> Proof.context -> Proof.context
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  val rewrite_cterm: bool * bool * bool ->
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    (Proof.context -> thm -> thm option) -> Proof.context -> conv
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  val rewrite_term: theory -> thm list -> (term -> term option) list -> term -> term
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  val rewrite_thm: bool * bool * bool ->
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    (Proof.context -> thm -> thm option) -> Proof.context -> thm -> thm
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  val generic_rewrite_goal_tac: bool * bool * bool ->
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    (Proof.context -> tactic) -> Proof.context -> int -> tactic
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  val rewrite: Proof.context -> bool -> thm list -> conv
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end;
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structure Raw_Simplifier: RAW_SIMPLIFIER =
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struct
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(** datatype simpset **)
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(* congruence rules *)
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type cong_name = bool * string;
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fun cong_name (Const (a, _)) = SOME (true, a)
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  | cong_name (Free (a, _)) = SOME (false, a)
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  | cong_name _ = NONE;
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(* rewrite rules *)
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type rrule =
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 {thm: thm,         (*the rewrite rule*)
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  name: string,     (*name of theorem from which rewrite rule was extracted*)
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  lhs: term,        (*the left-hand side*)
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  elhs: cterm,      (*the etac-contracted lhs*)
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  extra: bool,      (*extra variables outside of elhs*)
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  fo: bool,         (*use first-order matching*)
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  perm: bool};      (*the rewrite rule is permutative*)
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(*
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Remarks:
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  - elhs is used for matching,
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    lhs only for preservation of bound variable names;
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  - fo is set iff
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    either elhs is first-order (no Var is applied),
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      in which case fo-matching is complete,
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    or elhs is not a pattern,
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      in which case there is nothing better to do;
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*)
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fun eq_rrule ({thm = thm1, ...}: rrule, {thm = thm2, ...}: rrule) =
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  Thm.eq_thm_prop (thm1, thm2);
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(* FIXME: it seems that the conditions on extra variables are too liberal if
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prems are nonempty: does solving the prems really guarantee instantiation of
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all its Vars? Better: a dynamic check each time a rule is applied.
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*)
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fun rewrite_rule_extra_vars prems elhs erhs =
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  let
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    val elhss = elhs :: prems;
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    val tvars = fold Term.add_tvars elhss [];
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    val vars = fold Term.add_vars elhss [];
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  in
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    erhs |> Term.exists_type (Term.exists_subtype
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      (fn TVar v => not (member (op =) tvars v) | _ => false)) orelse
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    erhs |> Term.exists_subterm
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      (fn Var v => not (member (op =) vars v) | _ => false)
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  end;
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fun rrule_extra_vars elhs thm =
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  rewrite_rule_extra_vars [] (term_of elhs) (Thm.full_prop_of thm);
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fun mk_rrule2 {thm, name, lhs, elhs, perm} =
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  let
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    val t = term_of elhs;
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    val fo = Pattern.first_order t orelse not (Pattern.pattern t);
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    val extra = rrule_extra_vars elhs thm;
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  in {thm = thm, name = name, lhs = lhs, elhs = elhs, extra = extra, fo = fo, perm = perm} end;
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(*simple test for looping rewrite rules and stupid orientations*)
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fun default_reorient ctxt prems lhs rhs =
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  rewrite_rule_extra_vars prems lhs rhs
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    orelse
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  is_Var (head_of lhs)
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    orelse
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(* turns t = x around, which causes a headache if x is a local variable -
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   usually it is very useful :-(
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  is_Free rhs andalso not(is_Free lhs) andalso not(Logic.occs(rhs,lhs))
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  andalso not(exists_subterm is_Var lhs)
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    orelse
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*)
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  exists (fn t => Logic.occs (lhs, t)) (rhs :: prems)
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    orelse
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  null prems andalso Pattern.matches (Proof_Context.theory_of ctxt) (lhs, rhs)
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    (*the condition "null prems" is necessary because conditional rewrites
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      with extra variables in the conditions may terminate although
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      the rhs is an instance of the lhs; example: ?m < ?n ==> f(?n) == f(?m)*)
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    orelse
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  is_Const lhs andalso not (is_Const rhs);
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(* simplification procedures *)
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datatype proc =
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  Proc of
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   {name: string,
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    lhs: cterm,
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    proc: Proof.context -> cterm -> thm option,
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    id: stamp * thm list};
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fun eq_procid ((s1: stamp, ths1: thm list), (s2, ths2)) =
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  s1 = s2 andalso eq_list Thm.eq_thm (ths1, ths2);
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fun eq_proc (Proc {id = id1, ...}, Proc {id = id2, ...}) = eq_procid (id1, id2);
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(* solvers *)
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datatype solver =
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  Solver of
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   {name: string,
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    solver: Proof.context -> int -> tactic,
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    id: stamp};
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fun mk_solver name solver = Solver {name = name, solver = solver, id = stamp ()};
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fun solver_name (Solver {name, ...}) = name;
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fun solver ctxt (Solver {solver = tac, ...}) = tac ctxt;
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fun eq_solver (Solver {id = id1, ...}, Solver {id = id2, ...}) = (id1 = id2);
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(* simplification sets *)
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(*A simpset contains data required during conversion:
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    rules: discrimination net of rewrite rules;
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    prems: current premises;
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    depth: simp_depth and exceeded flag;
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    congs: association list of congruence rules and
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           a list of `weak' congruence constants.
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           A congruence is `weak' if it avoids normalization of some argument.
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    procs: discrimination net of simplification procedures
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      (functions that prove rewrite rules on the fly);
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    mk_rews:
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      mk: turn simplification thms into rewrite rules;
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      mk_cong: prepare congruence rules;
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      mk_sym: turn == around;
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      mk_eq_True: turn P into P == True;
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    termless: relation for ordered rewriting;*)
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datatype simpset =
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  Simpset of
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   {rules: rrule Net.net,
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    prems: thm list,
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    depth: int * bool Unsynchronized.ref} *
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   {congs: (cong_name * thm) list * cong_name list,
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    procs: proc Net.net,
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    mk_rews:
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     {mk: Proof.context -> thm -> thm list,
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      mk_cong: Proof.context -> thm -> thm,
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      mk_sym: Proof.context -> thm -> thm option,
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      mk_eq_True: Proof.context -> thm -> thm option,
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      reorient: Proof.context -> term list -> term -> term -> bool},
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    termless: term * term -> bool,
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    subgoal_tac: Proof.context -> int -> tactic,
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    loop_tacs: (string * (Proof.context -> int -> tactic)) list,
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    solvers: solver list * solver list};
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fun internal_ss (Simpset (_, ss2)) = ss2;
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fun make_ss1 (rules, prems, depth) = {rules = rules, prems = prems, depth = depth};
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fun map_ss1 f {rules, prems, depth} = make_ss1 (f (rules, prems, depth));
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fun make_ss2 (congs, procs, mk_rews, termless, subgoal_tac, loop_tacs, solvers) =
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  {congs = congs, procs = procs, mk_rews = mk_rews, termless = termless,
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    subgoal_tac = subgoal_tac, loop_tacs = loop_tacs, solvers = solvers};
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fun map_ss2 f {congs, procs, mk_rews, termless, subgoal_tac, loop_tacs, solvers} =
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  make_ss2 (f (congs, procs, mk_rews, termless, subgoal_tac, loop_tacs, solvers));
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fun make_simpset (args1, args2) = Simpset (make_ss1 args1, make_ss2 args2);
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fun dest_ss (Simpset ({rules, ...}, {congs, procs, loop_tacs, solvers, ...})) =
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 {simps = Net.entries rules
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    |> map (fn {name, thm, ...} => (name, thm)),
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  procs = Net.entries procs
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    |> map (fn Proc {name, lhs, id, ...} => ((name, lhs), id))
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    |> partition_eq (eq_snd eq_procid)
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    |> map (fn ps => (fst (fst (hd ps)), map (snd o fst) ps)),
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  congs = #1 congs,
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  weak_congs = #2 congs,
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  loopers = map fst loop_tacs,
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  unsafe_solvers = map solver_name (#1 solvers),
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   309
  safe_solvers = map solver_name (#2 solvers)};
wenzelm@51717
   310
wenzelm@51717
   311
wenzelm@51717
   312
(* empty *)
wenzelm@51717
   313
wenzelm@55014
   314
fun init_ss depth mk_rews termless subgoal_tac solvers =
wenzelm@55014
   315
  make_simpset ((Net.empty, [], depth),
wenzelm@54731
   316
    (([], []), Net.empty, mk_rews, termless, subgoal_tac, [], solvers));
wenzelm@51717
   317
wenzelm@51717
   318
fun default_mk_sym _ th = SOME (th RS Drule.symmetric_thm);
wenzelm@51717
   319
wenzelm@51717
   320
val empty_ss =
wenzelm@55014
   321
  init_ss (0, Unsynchronized.ref false)
wenzelm@51717
   322
    {mk = fn _ => fn th => if can Logic.dest_equals (Thm.concl_of th) then [th] else [],
wenzelm@51717
   323
      mk_cong = K I,
wenzelm@51717
   324
      mk_sym = default_mk_sym,
wenzelm@51717
   325
      mk_eq_True = K (K NONE),
wenzelm@51717
   326
      reorient = default_reorient}
wenzelm@54731
   327
    Term_Ord.termless (K (K no_tac)) ([], []);
wenzelm@51717
   328
wenzelm@51717
   329
wenzelm@51717
   330
(* merge *)  (*NOTE: ignores some fields of 2nd simpset*)
wenzelm@51717
   331
wenzelm@51717
   332
fun merge_ss (ss1, ss2) =
wenzelm@51717
   333
  if pointer_eq (ss1, ss2) then ss1
wenzelm@51717
   334
  else
wenzelm@51717
   335
    let
wenzelm@55014
   336
      val Simpset ({rules = rules1, prems = prems1, depth = depth1},
wenzelm@51717
   337
       {congs = (congs1, weak1), procs = procs1, mk_rews, termless, subgoal_tac,
wenzelm@54731
   338
        loop_tacs = loop_tacs1, solvers = (unsafe_solvers1, solvers1)}) = ss1;
wenzelm@55014
   339
      val Simpset ({rules = rules2, prems = prems2, depth = depth2},
wenzelm@51717
   340
       {congs = (congs2, weak2), procs = procs2, mk_rews = _, termless = _, subgoal_tac = _,
wenzelm@54731
   341
        loop_tacs = loop_tacs2, solvers = (unsafe_solvers2, solvers2)}) = ss2;
wenzelm@51717
   342
wenzelm@51717
   343
      val rules' = Net.merge eq_rrule (rules1, rules2);
wenzelm@51717
   344
      val prems' = Thm.merge_thms (prems1, prems2);
wenzelm@51717
   345
      val depth' = if #1 depth1 < #1 depth2 then depth2 else depth1;
wenzelm@51717
   346
      val congs' = merge (Thm.eq_thm_prop o pairself #2) (congs1, congs2);
wenzelm@51717
   347
      val weak' = merge (op =) (weak1, weak2);
wenzelm@51717
   348
      val procs' = Net.merge eq_proc (procs1, procs2);
wenzelm@51717
   349
      val loop_tacs' = AList.merge (op =) (K true) (loop_tacs1, loop_tacs2);
wenzelm@51717
   350
      val unsafe_solvers' = merge eq_solver (unsafe_solvers1, unsafe_solvers2);
wenzelm@51717
   351
      val solvers' = merge eq_solver (solvers1, solvers2);
wenzelm@51717
   352
    in
wenzelm@55014
   353
      make_simpset ((rules', prems', depth'), ((congs', weak'), procs',
wenzelm@54731
   354
        mk_rews, termless, subgoal_tac, loop_tacs', (unsafe_solvers', solvers')))
wenzelm@51717
   355
    end;
wenzelm@51717
   356
wenzelm@51717
   357
wenzelm@51717
   358
wenzelm@51717
   359
(** context data **)
wenzelm@51717
   360
wenzelm@51717
   361
structure Simpset = Generic_Data
wenzelm@51717
   362
(
wenzelm@51717
   363
  type T = simpset;
wenzelm@51717
   364
  val empty = empty_ss;
wenzelm@51717
   365
  val extend = I;
wenzelm@51717
   366
  val merge = merge_ss;
wenzelm@51717
   367
);
wenzelm@51717
   368
wenzelm@51717
   369
val simpset_of = Simpset.get o Context.Proof;
wenzelm@51717
   370
wenzelm@51717
   371
fun map_simpset f = Context.proof_map (Simpset.map f);
wenzelm@51717
   372
fun map_simpset1 f = map_simpset (fn Simpset (ss1, ss2) => Simpset (map_ss1 f ss1, ss2));
wenzelm@51717
   373
fun map_simpset2 f = map_simpset (fn Simpset (ss1, ss2) => Simpset (ss1, map_ss2 f ss2));
wenzelm@51717
   374
wenzelm@51717
   375
fun simpset_map ctxt f ss = ctxt |> map_simpset (K ss) |> f |> Context.Proof |> Simpset.get;
wenzelm@51717
   376
wenzelm@54729
   377
fun put_simpset ss = map_simpset (fn context_ss =>
wenzelm@54729
   378
  let
wenzelm@54731
   379
    val Simpset ({rules, prems, ...}, ss2) = ss;  (* FIXME prems from context (!?) *)
wenzelm@55014
   380
    val Simpset ({depth, ...}, _) = context_ss;
wenzelm@55014
   381
  in Simpset (make_ss1 (rules, prems, depth), ss2) end);
wenzelm@51717
   382
wenzelm@51717
   383
val empty_simpset = put_simpset empty_ss;
wenzelm@51717
   384
wenzelm@51717
   385
fun map_theory_simpset f thy =
wenzelm@51717
   386
  let
wenzelm@51717
   387
    val ctxt' = f (Proof_Context.init_global thy);
wenzelm@51717
   388
    val thy' = Proof_Context.theory_of ctxt';
wenzelm@51717
   389
  in Context.theory_map (Simpset.map (K (simpset_of ctxt'))) thy' end;
wenzelm@51717
   390
wenzelm@51717
   391
fun map_ss f = Context.mapping (map_theory_simpset f) f;
wenzelm@51717
   392
wenzelm@51717
   393
val clear_simpset =
wenzelm@55014
   394
  map_simpset (fn Simpset ({depth, ...}, {mk_rews, termless, subgoal_tac, solvers, ...}) =>
wenzelm@55014
   395
    init_ss depth mk_rews termless subgoal_tac solvers);
wenzelm@51717
   396
wenzelm@51717
   397
wenzelm@51717
   398
(* simp depth *)
wenzelm@51717
   399
wenzelm@51717
   400
val simp_depth_limit_raw = Config.declare "simp_depth_limit" (K (Config.Int 100));
wenzelm@51717
   401
val simp_depth_limit = Config.int simp_depth_limit_raw;
wenzelm@51717
   402
wenzelm@51717
   403
val simp_trace_depth_limit_default = Unsynchronized.ref 1;
wenzelm@51717
   404
val simp_trace_depth_limit_raw = Config.declare "simp_trace_depth_limit"
wenzelm@51717
   405
  (fn _ => Config.Int (! simp_trace_depth_limit_default));
wenzelm@51717
   406
val simp_trace_depth_limit = Config.int simp_trace_depth_limit_raw;
wenzelm@51717
   407
wenzelm@51717
   408
fun inc_simp_depth ctxt =
wenzelm@55014
   409
  ctxt |> map_simpset1 (fn (rules, prems, (depth, exceeded)) =>
wenzelm@55014
   410
    (rules, prems,
wenzelm@51717
   411
      (depth + 1,
wenzelm@51717
   412
        if depth = Config.get ctxt simp_trace_depth_limit
wenzelm@51717
   413
        then Unsynchronized.ref false else exceeded)));
wenzelm@51717
   414
wenzelm@51717
   415
fun simp_depth ctxt =
wenzelm@51717
   416
  let val Simpset ({depth = (depth, _), ...}, _) = simpset_of ctxt
wenzelm@51717
   417
  in depth end;
wenzelm@51717
   418
wenzelm@51717
   419
wenzelm@51717
   420
(* diagnostics *)
wenzelm@51717
   421
wenzelm@54997
   422
exception SIMPLIFIER of string * thm list;
wenzelm@51717
   423
wenzelm@51717
   424
val simp_debug_raw = Config.declare "simp_debug" (K (Config.Bool false));
wenzelm@51717
   425
val simp_debug = Config.bool simp_debug_raw;
wenzelm@51717
   426
wenzelm@51717
   427
val simp_trace_default = Unsynchronized.ref false;
wenzelm@51717
   428
val simp_trace_raw = Config.declare "simp_trace" (fn _ => Config.Bool (! simp_trace_default));
wenzelm@51717
   429
val simp_trace = Config.bool simp_trace_raw;
wenzelm@51717
   430
wenzelm@55028
   431
fun cond_warning ctxt msg =
wenzelm@55028
   432
  if Context_Position.is_visible ctxt then warning (msg ()) else ();
wenzelm@51717
   433
wenzelm@55031
   434
fun cond_tracing' ctxt flag msg =
wenzelm@55028
   435
  if Config.get ctxt flag then
wenzelm@55028
   436
    let
wenzelm@55028
   437
      val Simpset ({depth = (depth, exceeded), ...}, _) = simpset_of ctxt;
wenzelm@55028
   438
      val depth_limit = Config.get ctxt simp_trace_depth_limit;
wenzelm@55028
   439
    in
wenzelm@55028
   440
      if depth > depth_limit then
wenzelm@55028
   441
        if ! exceeded then () else (tracing "simp_trace_depth_limit exceeded!"; exceeded := true)
wenzelm@55028
   442
      else (tracing (enclose "[" "]" (string_of_int depth) ^ msg ()); exceeded := false)
wenzelm@55028
   443
    end
wenzelm@55028
   444
  else ();
wenzelm@51717
   445
wenzelm@55031
   446
fun cond_tracing ctxt = cond_tracing' ctxt simp_trace;
wenzelm@55031
   447
wenzelm@55028
   448
fun print_term ctxt s t =
wenzelm@55028
   449
  s ^ "\n" ^ Syntax.string_of_term ctxt t;
wenzelm@51717
   450
wenzelm@55028
   451
fun print_thm ctxt s (name, th) =
wenzelm@55028
   452
  print_term ctxt (if name = "" then s else s ^ " " ^ quote name ^ ":") (Thm.full_prop_of th);
wenzelm@51717
   453
wenzelm@51717
   454
wenzelm@51717
   455
wenzelm@51717
   456
(** simpset operations **)
wenzelm@51717
   457
wenzelm@55014
   458
(* prems *)
wenzelm@51717
   459
wenzelm@51717
   460
fun prems_of ctxt =
wenzelm@51717
   461
  let val Simpset ({prems, ...}, _) = simpset_of ctxt in prems end;
wenzelm@51717
   462
wenzelm@51717
   463
fun add_prems ths =
wenzelm@55014
   464
  map_simpset1 (fn (rules, prems, depth) => (rules, ths @ prems, depth));
wenzelm@51717
   465
wenzelm@51717
   466
wenzelm@51717
   467
(* maintain simp rules *)
wenzelm@51717
   468
wenzelm@51717
   469
fun del_rrule (rrule as {thm, elhs, ...}) ctxt =
wenzelm@55014
   470
  ctxt |> map_simpset1 (fn (rules, prems, depth) =>
wenzelm@55014
   471
    (Net.delete_term eq_rrule (term_of elhs, rrule) rules, prems, depth))
wenzelm@55028
   472
  handle Net.DELETE =>
wenzelm@55028
   473
    (cond_warning ctxt (fn () => print_thm ctxt "Rewrite rule not in simpset:" ("", thm)); ctxt);
wenzelm@51717
   474
wenzelm@51717
   475
fun insert_rrule (rrule as {thm, name, ...}) ctxt =
wenzelm@55031
   476
 (cond_tracing ctxt (fn () => print_thm ctxt "Adding rewrite rule" (name, thm));
wenzelm@55014
   477
  ctxt |> map_simpset1 (fn (rules, prems, depth) =>
wenzelm@51717
   478
    let
wenzelm@51717
   479
      val rrule2 as {elhs, ...} = mk_rrule2 rrule;
wenzelm@51717
   480
      val rules' = Net.insert_term eq_rrule (term_of elhs, rrule2) rules;
wenzelm@55014
   481
    in (rules', prems, depth) end)
wenzelm@55028
   482
  handle Net.INSERT =>
wenzelm@55028
   483
    (cond_warning ctxt (fn () => print_thm ctxt "Ignoring duplicate rewrite rule:" ("", thm));
wenzelm@55028
   484
      ctxt));
wenzelm@51717
   485
wenzelm@51717
   486
local
wenzelm@51717
   487
wenzelm@51717
   488
fun vperm (Var _, Var _) = true
wenzelm@51717
   489
  | vperm (Abs (_, _, s), Abs (_, _, t)) = vperm (s, t)
wenzelm@51717
   490
  | vperm (t1 $ t2, u1 $ u2) = vperm (t1, u1) andalso vperm (t2, u2)
wenzelm@51717
   491
  | vperm (t, u) = (t = u);
wenzelm@51717
   492
wenzelm@51717
   493
fun var_perm (t, u) =
wenzelm@51717
   494
  vperm (t, u) andalso eq_set (op =) (Term.add_vars t [], Term.add_vars u []);
wenzelm@51717
   495
wenzelm@51717
   496
in
wenzelm@51717
   497
berghofe@10413
   498
fun decomp_simp thm =
wenzelm@15023
   499
  let
wenzelm@26626
   500
    val prop = Thm.prop_of thm;
wenzelm@15023
   501
    val prems = Logic.strip_imp_prems prop;
wenzelm@15023
   502
    val concl = Drule.strip_imp_concl (Thm.cprop_of thm);
wenzelm@22902
   503
    val (lhs, rhs) = Thm.dest_equals concl handle TERM _ =>
wenzelm@54997
   504
      raise SIMPLIFIER ("Rewrite rule not a meta-equality", [thm]);
wenzelm@20579
   505
    val elhs = Thm.dest_arg (Thm.cprop_of (Thm.eta_conversion lhs));
wenzelm@18929
   506
    val erhs = Envir.eta_contract (term_of rhs);
wenzelm@15023
   507
    val perm =
wenzelm@15023
   508
      var_perm (term_of elhs, erhs) andalso
wenzelm@15023
   509
      not (term_of elhs aconv erhs) andalso
wenzelm@15023
   510
      not (is_Var (term_of elhs));
wenzelm@52091
   511
  in (prems, term_of lhs, elhs, term_of rhs, perm) end;
berghofe@10413
   512
wenzelm@51717
   513
end;
wenzelm@51717
   514
wenzelm@12783
   515
fun decomp_simp' thm =
wenzelm@52091
   516
  let val (_, lhs, _, rhs, _) = decomp_simp thm in
wenzelm@54997
   517
    if Thm.nprems_of thm > 0 then raise SIMPLIFIER ("Bad conditional rewrite rule", [thm])
wenzelm@12979
   518
    else (lhs, rhs)
wenzelm@12783
   519
  end;
wenzelm@12783
   520
wenzelm@51717
   521
fun mk_eq_True ctxt (thm, name) =
wenzelm@51717
   522
  let val Simpset (_, {mk_rews = {mk_eq_True, ...}, ...}) = simpset_of ctxt in
wenzelm@51717
   523
    (case mk_eq_True ctxt thm of
wenzelm@51717
   524
      NONE => []
wenzelm@51717
   525
    | SOME eq_True =>
wenzelm@52091
   526
        let val (_, lhs, elhs, _, _) = decomp_simp eq_True;
wenzelm@51717
   527
        in [{thm = eq_True, name = name, lhs = lhs, elhs = elhs, perm = false}] end)
wenzelm@51717
   528
  end;
berghofe@10413
   529
wenzelm@15023
   530
(*create the rewrite rule and possibly also the eq_True variant,
wenzelm@15023
   531
  in case there are extra vars on the rhs*)
wenzelm@52082
   532
fun rrule_eq_True ctxt thm name lhs elhs rhs thm2 =
wenzelm@15023
   533
  let val rrule = {thm = thm, name = name, lhs = lhs, elhs = elhs, perm = false} in
wenzelm@20546
   534
    if rewrite_rule_extra_vars [] lhs rhs then
wenzelm@51717
   535
      mk_eq_True ctxt (thm2, name) @ [rrule]
wenzelm@20546
   536
    else [rrule]
berghofe@10413
   537
  end;
berghofe@10413
   538
wenzelm@51717
   539
fun mk_rrule ctxt (thm, name) =
wenzelm@52091
   540
  let val (prems, lhs, elhs, rhs, perm) = decomp_simp thm in
wenzelm@15023
   541
    if perm then [{thm = thm, name = name, lhs = lhs, elhs = elhs, perm = true}]
wenzelm@15023
   542
    else
wenzelm@15023
   543
      (*weak test for loops*)
wenzelm@15023
   544
      if rewrite_rule_extra_vars prems lhs rhs orelse is_Var (term_of elhs)
wenzelm@51717
   545
      then mk_eq_True ctxt (thm, name)
wenzelm@52082
   546
      else rrule_eq_True ctxt thm name lhs elhs rhs thm
berghofe@10413
   547
  end;
berghofe@10413
   548
wenzelm@51717
   549
fun orient_rrule ctxt (thm, name) =
wenzelm@18208
   550
  let
wenzelm@52091
   551
    val (prems, lhs, elhs, rhs, perm) = decomp_simp thm;
wenzelm@51717
   552
    val Simpset (_, {mk_rews = {reorient, mk_sym, ...}, ...}) = simpset_of ctxt;
wenzelm@18208
   553
  in
wenzelm@15023
   554
    if perm then [{thm = thm, name = name, lhs = lhs, elhs = elhs, perm = true}]
wenzelm@51717
   555
    else if reorient ctxt prems lhs rhs then
wenzelm@51717
   556
      if reorient ctxt prems rhs lhs
wenzelm@51717
   557
      then mk_eq_True ctxt (thm, name)
wenzelm@15023
   558
      else
wenzelm@51717
   559
        (case mk_sym ctxt thm of
wenzelm@18208
   560
          NONE => []
wenzelm@18208
   561
        | SOME thm' =>
wenzelm@52091
   562
            let val (_, lhs', elhs', rhs', _) = decomp_simp thm'
wenzelm@52082
   563
            in rrule_eq_True ctxt thm' name lhs' elhs' rhs' thm end)
wenzelm@52082
   564
    else rrule_eq_True ctxt thm name lhs elhs rhs thm
berghofe@10413
   565
  end;
berghofe@10413
   566
wenzelm@54982
   567
fun extract_rews ctxt thms =
wenzelm@51717
   568
  let val Simpset (_, {mk_rews = {mk, ...}, ...}) = simpset_of ctxt
wenzelm@51717
   569
  in maps (fn thm => map (rpair (Thm.get_name_hint thm)) (mk ctxt thm)) thms end;
berghofe@10413
   570
wenzelm@54982
   571
fun extract_safe_rrules ctxt thm =
wenzelm@54982
   572
  maps (orient_rrule ctxt) (extract_rews ctxt [thm]);
berghofe@10413
   573
berghofe@10413
   574
wenzelm@20028
   575
(* add/del rules explicitly *)
berghofe@10413
   576
wenzelm@54982
   577
fun comb_simps ctxt comb mk_rrule thms =
wenzelm@20028
   578
  let
wenzelm@54982
   579
    val rews = extract_rews ctxt thms;
wenzelm@51717
   580
  in fold (fold comb o mk_rrule) rews ctxt end;
berghofe@10413
   581
wenzelm@51717
   582
fun ctxt addsimps thms =
wenzelm@54982
   583
  comb_simps ctxt insert_rrule (mk_rrule ctxt) thms;
berghofe@10413
   584
wenzelm@51717
   585
fun ctxt delsimps thms =
wenzelm@54982
   586
  comb_simps ctxt del_rrule (map mk_rrule2 o mk_rrule ctxt) thms;
wenzelm@15023
   587
wenzelm@51717
   588
fun add_simp thm ctxt = ctxt addsimps [thm];
wenzelm@51717
   589
fun del_simp thm ctxt = ctxt delsimps [thm];
wenzelm@15023
   590
wenzelm@30318
   591
wenzelm@15023
   592
(* congs *)
berghofe@10413
   593
wenzelm@15023
   594
local
wenzelm@15023
   595
wenzelm@15023
   596
fun is_full_cong_prems [] [] = true
wenzelm@15023
   597
  | is_full_cong_prems [] _ = false
wenzelm@15023
   598
  | is_full_cong_prems (p :: prems) varpairs =
wenzelm@15023
   599
      (case Logic.strip_assums_concl p of
wenzelm@15023
   600
        Const ("==", _) $ lhs $ rhs =>
wenzelm@15023
   601
          let val (x, xs) = strip_comb lhs and (y, ys) = strip_comb rhs in
wenzelm@15023
   602
            is_Var x andalso forall is_Bound xs andalso
haftmann@20972
   603
            not (has_duplicates (op =) xs) andalso xs = ys andalso
wenzelm@20671
   604
            member (op =) varpairs (x, y) andalso
wenzelm@19303
   605
            is_full_cong_prems prems (remove (op =) (x, y) varpairs)
wenzelm@15023
   606
          end
wenzelm@15023
   607
      | _ => false);
wenzelm@15023
   608
wenzelm@15023
   609
fun is_full_cong thm =
berghofe@10413
   610
  let
wenzelm@43597
   611
    val prems = Thm.prems_of thm and concl = Thm.concl_of thm;
wenzelm@15023
   612
    val (lhs, rhs) = Logic.dest_equals concl;
wenzelm@15023
   613
    val (f, xs) = strip_comb lhs and (g, ys) = strip_comb rhs;
berghofe@10413
   614
  in
haftmann@20972
   615
    f = g andalso not (has_duplicates (op =) (xs @ ys)) andalso length xs = length ys andalso
wenzelm@15023
   616
    is_full_cong_prems prems (xs ~~ ys)
berghofe@10413
   617
  end;
berghofe@10413
   618
wenzelm@51717
   619
fun mk_cong ctxt =
wenzelm@51717
   620
  let val Simpset (_, {mk_rews = {mk_cong = f, ...}, ...}) = simpset_of ctxt
wenzelm@51717
   621
  in f ctxt end;
wenzelm@45620
   622
wenzelm@45620
   623
in
wenzelm@45620
   624
wenzelm@54729
   625
fun add_eqcong thm ctxt = ctxt |> map_simpset2
wenzelm@54731
   626
  (fn (congs, procs, mk_rews, termless, subgoal_tac, loop_tacs, solvers) =>
wenzelm@15023
   627
    let
wenzelm@45621
   628
      val (lhs, _) = Logic.dest_equals (Thm.concl_of thm)
wenzelm@54997
   629
        handle TERM _ => raise SIMPLIFIER ("Congruence not a meta-equality", [thm]);
wenzelm@18929
   630
    (*val lhs = Envir.eta_contract lhs;*)
wenzelm@45621
   631
      val a = the (cong_name (head_of lhs)) handle Option.Option =>
wenzelm@54997
   632
        raise SIMPLIFIER ("Congruence must start with a constant or free variable", [thm]);
haftmann@22221
   633
      val (xs, weak) = congs;
wenzelm@38834
   634
      val _ =
wenzelm@51717
   635
        if AList.defined (op =) xs a then
wenzelm@55028
   636
          cond_warning ctxt (fn () => "Overwriting congruence rule for " ^ quote (#2 a))
haftmann@22221
   637
        else ();
krauss@30908
   638
      val xs' = AList.update (op =) (a, thm) xs;
haftmann@22221
   639
      val weak' = if is_full_cong thm then weak else a :: weak;
wenzelm@54731
   640
    in ((xs', weak'), procs, mk_rews, termless, subgoal_tac, loop_tacs, solvers) end);
berghofe@10413
   641
wenzelm@54729
   642
fun del_eqcong thm ctxt = ctxt |> map_simpset2
wenzelm@54731
   643
  (fn (congs, procs, mk_rews, termless, subgoal_tac, loop_tacs, solvers) =>
wenzelm@15023
   644
    let
wenzelm@45621
   645
      val (lhs, _) = Logic.dest_equals (Thm.concl_of thm)
wenzelm@54997
   646
        handle TERM _ => raise SIMPLIFIER ("Congruence not a meta-equality", [thm]);
wenzelm@18929
   647
    (*val lhs = Envir.eta_contract lhs;*)
wenzelm@20057
   648
      val a = the (cong_name (head_of lhs)) handle Option.Option =>
wenzelm@54997
   649
        raise SIMPLIFIER ("Congruence must start with a constant", [thm]);
haftmann@22221
   650
      val (xs, _) = congs;
wenzelm@51590
   651
      val xs' = filter_out (fn (x : cong_name, _) => x = a) xs;
krauss@30908
   652
      val weak' = xs' |> map_filter (fn (a, thm) =>
skalberg@15531
   653
        if is_full_cong thm then NONE else SOME a);
wenzelm@54731
   654
    in ((xs', weak'), procs, mk_rews, termless, subgoal_tac, loop_tacs, solvers) end);
berghofe@10413
   655
wenzelm@51717
   656
fun add_cong thm ctxt = add_eqcong (mk_cong ctxt thm) ctxt;
wenzelm@51717
   657
fun del_cong thm ctxt = del_eqcong (mk_cong ctxt thm) ctxt;
wenzelm@15023
   658
wenzelm@15023
   659
end;
berghofe@10413
   660
berghofe@10413
   661
wenzelm@15023
   662
(* simprocs *)
wenzelm@15023
   663
wenzelm@22234
   664
datatype simproc =
wenzelm@22234
   665
  Simproc of
wenzelm@22234
   666
    {name: string,
wenzelm@22234
   667
     lhss: cterm list,
wenzelm@51717
   668
     proc: morphism -> Proof.context -> cterm -> thm option,
wenzelm@22234
   669
     id: stamp * thm list};
wenzelm@22234
   670
wenzelm@22234
   671
fun eq_simproc (Simproc {id = id1, ...}, Simproc {id = id2, ...}) = eq_procid (id1, id2);
wenzelm@22008
   672
wenzelm@45290
   673
fun transform_simproc phi (Simproc {name, lhss, proc, id = (s, ths)}) =
wenzelm@22234
   674
  Simproc
wenzelm@22234
   675
   {name = name,
wenzelm@22234
   676
    lhss = map (Morphism.cterm phi) lhss,
wenzelm@22669
   677
    proc = Morphism.transform phi proc,
wenzelm@22234
   678
    id = (s, Morphism.fact phi ths)};
wenzelm@22234
   679
wenzelm@22234
   680
fun make_simproc {name, lhss, proc, identifier} =
wenzelm@22234
   681
  Simproc {name = name, lhss = lhss, proc = proc, id = (stamp (), identifier)};
wenzelm@22008
   682
wenzelm@22008
   683
fun mk_simproc name lhss proc =
wenzelm@51717
   684
  make_simproc {name = name, lhss = lhss, proc = fn _ => fn ctxt => fn ct =>
wenzelm@55028
   685
    proc ctxt (term_of ct), identifier = []};
wenzelm@22008
   686
wenzelm@35845
   687
(* FIXME avoid global thy and Logic.varify_global *)
wenzelm@38715
   688
fun simproc_global_i thy name = mk_simproc name o map (Thm.cterm_of thy o Logic.varify_global);
wenzelm@38715
   689
fun simproc_global thy name = simproc_global_i thy name o map (Syntax.read_term_global thy);
wenzelm@22008
   690
wenzelm@22008
   691
wenzelm@15023
   692
local
berghofe@10413
   693
wenzelm@51717
   694
fun add_proc (proc as Proc {name, lhs, ...}) ctxt =
wenzelm@55031
   695
 (cond_tracing ctxt (fn () =>
wenzelm@55028
   696
    print_term ctxt ("Adding simplification procedure " ^ quote name ^ " for") (term_of lhs));
wenzelm@54729
   697
  ctxt |> map_simpset2
wenzelm@54731
   698
    (fn (congs, procs, mk_rews, termless, subgoal_tac, loop_tacs, solvers) =>
wenzelm@54729
   699
      (congs, Net.insert_term eq_proc (term_of lhs, proc) procs,
wenzelm@54731
   700
        mk_rews, termless, subgoal_tac, loop_tacs, solvers))
wenzelm@15023
   701
  handle Net.INSERT =>
wenzelm@55028
   702
    (cond_warning ctxt (fn () => "Ignoring duplicate simplification procedure " ^ quote name);
wenzelm@55028
   703
      ctxt));
berghofe@10413
   704
wenzelm@51717
   705
fun del_proc (proc as Proc {name, lhs, ...}) ctxt =
wenzelm@54729
   706
  ctxt |> map_simpset2
wenzelm@54731
   707
    (fn (congs, procs, mk_rews, termless, subgoal_tac, loop_tacs, solvers) =>
wenzelm@54729
   708
      (congs, Net.delete_term eq_proc (term_of lhs, proc) procs,
wenzelm@54731
   709
        mk_rews, termless, subgoal_tac, loop_tacs, solvers))
wenzelm@15023
   710
  handle Net.DELETE =>
wenzelm@55028
   711
    (cond_warning ctxt (fn () => "Simplification procedure " ^ quote name ^ " not in simpset");
wenzelm@55028
   712
      ctxt);
berghofe@10413
   713
wenzelm@22234
   714
fun prep_procs (Simproc {name, lhss, proc, id}) =
wenzelm@22669
   715
  lhss |> map (fn lhs => Proc {name = name, lhs = lhs, proc = Morphism.form proc, id = id});
wenzelm@22234
   716
wenzelm@15023
   717
in
berghofe@10413
   718
wenzelm@51717
   719
fun ctxt addsimprocs ps = fold (fold add_proc o prep_procs) ps ctxt;
wenzelm@51717
   720
fun ctxt delsimprocs ps = fold (fold del_proc o prep_procs) ps ctxt;
berghofe@10413
   721
wenzelm@15023
   722
end;
berghofe@10413
   723
berghofe@10413
   724
berghofe@10413
   725
(* mk_rews *)
berghofe@10413
   726
wenzelm@15023
   727
local
wenzelm@15023
   728
wenzelm@54729
   729
fun map_mk_rews f =
wenzelm@54731
   730
  map_simpset2 (fn (congs, procs, mk_rews, termless, subgoal_tac, loop_tacs, solvers) =>
wenzelm@54729
   731
    let
wenzelm@54729
   732
      val {mk, mk_cong, mk_sym, mk_eq_True, reorient} = mk_rews;
wenzelm@54729
   733
      val (mk', mk_cong', mk_sym', mk_eq_True', reorient') =
wenzelm@54729
   734
        f (mk, mk_cong, mk_sym, mk_eq_True, reorient);
wenzelm@54729
   735
      val mk_rews' = {mk = mk', mk_cong = mk_cong', mk_sym = mk_sym', mk_eq_True = mk_eq_True',
wenzelm@54729
   736
        reorient = reorient'};
wenzelm@54731
   737
    in (congs, procs, mk_rews', termless, subgoal_tac, loop_tacs, solvers) end);
wenzelm@15023
   738
wenzelm@15023
   739
in
berghofe@10413
   740
wenzelm@51717
   741
fun mksimps ctxt =
wenzelm@51717
   742
  let val Simpset (_, {mk_rews = {mk, ...}, ...}) = simpset_of ctxt
wenzelm@51717
   743
  in mk ctxt end;
wenzelm@30318
   744
wenzelm@45625
   745
fun set_mksimps mk = map_mk_rews (fn (_, mk_cong, mk_sym, mk_eq_True, reorient) =>
wenzelm@18208
   746
  (mk, mk_cong, mk_sym, mk_eq_True, reorient));
wenzelm@15023
   747
wenzelm@45625
   748
fun set_mkcong mk_cong = map_mk_rews (fn (mk, _, mk_sym, mk_eq_True, reorient) =>
wenzelm@18208
   749
  (mk, mk_cong, mk_sym, mk_eq_True, reorient));
berghofe@10413
   750
wenzelm@45625
   751
fun set_mksym mk_sym = map_mk_rews (fn (mk, mk_cong, _, mk_eq_True, reorient) =>
wenzelm@18208
   752
  (mk, mk_cong, mk_sym, mk_eq_True, reorient));
berghofe@10413
   753
wenzelm@45625
   754
fun set_mkeqTrue mk_eq_True = map_mk_rews (fn (mk, mk_cong, mk_sym, _, reorient) =>
wenzelm@18208
   755
  (mk, mk_cong, mk_sym, mk_eq_True, reorient));
wenzelm@18208
   756
wenzelm@18208
   757
fun set_reorient reorient = map_mk_rews (fn (mk, mk_cong, mk_sym, mk_eq_True, _) =>
wenzelm@18208
   758
  (mk, mk_cong, mk_sym, mk_eq_True, reorient));
wenzelm@15023
   759
wenzelm@15023
   760
end;
wenzelm@15023
   761
skalberg@14242
   762
berghofe@10413
   763
(* termless *)
berghofe@10413
   764
wenzelm@45625
   765
fun set_termless termless =
wenzelm@54731
   766
  map_simpset2 (fn (congs, procs, mk_rews, _, subgoal_tac, loop_tacs, solvers) =>
wenzelm@54731
   767
   (congs, procs, mk_rews, termless, subgoal_tac, loop_tacs, solvers));
skalberg@15006
   768
skalberg@15006
   769
wenzelm@15023
   770
(* tactics *)
skalberg@15006
   771
wenzelm@45625
   772
fun set_subgoaler subgoal_tac =
wenzelm@54731
   773
  map_simpset2 (fn (congs, procs, mk_rews, termless, _, loop_tacs, solvers) =>
wenzelm@54731
   774
   (congs, procs, mk_rews, termless, subgoal_tac, loop_tacs, solvers));
skalberg@15006
   775
wenzelm@52037
   776
fun ctxt setloop tac = ctxt |>
wenzelm@54731
   777
  map_simpset2 (fn (congs, procs, mk_rews, termless, subgoal_tac, _, solvers) =>
wenzelm@54731
   778
   (congs, procs, mk_rews, termless, subgoal_tac, [("", tac)], solvers));
skalberg@15006
   779
wenzelm@52037
   780
fun ctxt addloop (name, tac) = ctxt |>
wenzelm@54731
   781
  map_simpset2 (fn (congs, procs, mk_rews, termless, subgoal_tac, loop_tacs, solvers) =>
wenzelm@15023
   782
    (congs, procs, mk_rews, termless, subgoal_tac,
wenzelm@54731
   783
     AList.update (op =) (name, tac) loop_tacs, solvers));
skalberg@15006
   784
wenzelm@51717
   785
fun ctxt delloop name = ctxt |>
wenzelm@54731
   786
  map_simpset2 (fn (congs, procs, mk_rews, termless, subgoal_tac, loop_tacs, solvers) =>
haftmann@21286
   787
    (congs, procs, mk_rews, termless, subgoal_tac,
wenzelm@38834
   788
     (if AList.defined (op =) loop_tacs name then ()
wenzelm@55028
   789
      else cond_warning ctxt (fn () => "No such looper in simpset: " ^ quote name);
wenzelm@55028
   790
      AList.delete (op =) name loop_tacs), solvers));
skalberg@15006
   791
wenzelm@54729
   792
fun ctxt setSSolver solver = ctxt |> map_simpset2
wenzelm@54731
   793
  (fn (congs, procs, mk_rews, termless, subgoal_tac, loop_tacs, (unsafe_solvers, _)) =>
wenzelm@54731
   794
    (congs, procs, mk_rews, termless, subgoal_tac, loop_tacs, (unsafe_solvers, [solver])));
skalberg@15006
   795
wenzelm@51717
   796
fun ctxt addSSolver solver = ctxt |> map_simpset2 (fn (congs, procs, mk_rews, termless,
wenzelm@54731
   797
  subgoal_tac, loop_tacs, (unsafe_solvers, solvers)) => (congs, procs, mk_rews, termless,
wenzelm@54731
   798
    subgoal_tac, loop_tacs, (unsafe_solvers, insert eq_solver solver solvers)));
skalberg@15006
   799
wenzelm@51717
   800
fun ctxt setSolver solver = ctxt |> map_simpset2 (fn (congs, procs, mk_rews, termless,
wenzelm@54731
   801
  subgoal_tac, loop_tacs, (_, solvers)) => (congs, procs, mk_rews, termless,
wenzelm@54731
   802
    subgoal_tac, loop_tacs, ([solver], solvers)));
skalberg@15006
   803
wenzelm@51717
   804
fun ctxt addSolver solver = ctxt |> map_simpset2 (fn (congs, procs, mk_rews, termless,
wenzelm@54731
   805
  subgoal_tac, loop_tacs, (unsafe_solvers, solvers)) => (congs, procs, mk_rews, termless,
wenzelm@54731
   806
    subgoal_tac, loop_tacs, (insert eq_solver solver unsafe_solvers, solvers)));
skalberg@15006
   807
wenzelm@15023
   808
fun set_solvers solvers = map_simpset2 (fn (congs, procs, mk_rews, termless,
wenzelm@54731
   809
  subgoal_tac, loop_tacs, _) => (congs, procs, mk_rews, termless,
wenzelm@54731
   810
  subgoal_tac, loop_tacs, (solvers, solvers)));
wenzelm@54729
   811
wenzelm@54729
   812
wenzelm@54729
   813
(* trace operations *)
wenzelm@54729
   814
wenzelm@54731
   815
type trace_ops =
wenzelm@54731
   816
 {trace_invoke: {depth: int, term: term} -> Proof.context -> Proof.context,
wenzelm@54731
   817
  trace_apply: {unconditional: bool, term: term, thm: thm, name: string} ->
wenzelm@54731
   818
    Proof.context -> (Proof.context -> (thm * term) option) -> (thm * term) option};
wenzelm@54729
   819
wenzelm@54731
   820
structure Trace_Ops = Theory_Data
wenzelm@54731
   821
(
wenzelm@54731
   822
  type T = trace_ops;
wenzelm@54731
   823
  val empty: T =
wenzelm@54731
   824
   {trace_invoke = fn _ => fn ctxt => ctxt,
wenzelm@54731
   825
    trace_apply = fn _ => fn ctxt => fn cont => cont ctxt};
wenzelm@54731
   826
  val extend = I;
wenzelm@54731
   827
  fun merge (trace_ops, _) = trace_ops;
wenzelm@54731
   828
);
wenzelm@54731
   829
wenzelm@54731
   830
val set_trace_ops = Trace_Ops.put;
wenzelm@54731
   831
wenzelm@54731
   832
val trace_ops = Trace_Ops.get o Proof_Context.theory_of;
wenzelm@54729
   833
fun trace_invoke args ctxt = #trace_invoke (trace_ops ctxt) args ctxt;
wenzelm@54729
   834
fun trace_apply args ctxt = #trace_apply (trace_ops ctxt) args ctxt;
skalberg@15006
   835
skalberg@15006
   836
skalberg@15006
   837
berghofe@10413
   838
(** rewriting **)
berghofe@10413
   839
berghofe@10413
   840
(*
berghofe@10413
   841
  Uses conversions, see:
berghofe@10413
   842
    L C Paulson, A higher-order implementation of rewriting,
berghofe@10413
   843
    Science of Computer Programming 3 (1983), pages 119-149.
berghofe@10413
   844
*)
berghofe@10413
   845
wenzelm@51717
   846
fun check_conv ctxt msg thm thm' =
berghofe@10413
   847
  let
wenzelm@36944
   848
    val thm'' = Thm.transitive thm thm' handle THM _ =>
wenzelm@36944
   849
     Thm.transitive thm (Thm.transitive
wenzelm@36944
   850
       (Thm.symmetric (Drule.beta_eta_conversion (Thm.lhs_of thm'))) thm')
wenzelm@55028
   851
    val _ =
wenzelm@55031
   852
      if msg then cond_tracing ctxt (fn () => print_thm ctxt "SUCCEEDED" ("", thm'))
wenzelm@55028
   853
      else ();
wenzelm@55028
   854
  in SOME thm'' end
berghofe@10413
   855
  handle THM _ =>
wenzelm@26626
   856
    let
wenzelm@26626
   857
      val _ $ _ $ prop0 = Thm.prop_of thm;
wenzelm@55028
   858
      val _ =
wenzelm@55032
   859
        cond_tracing ctxt (fn () =>
wenzelm@55032
   860
          print_thm ctxt "Proved wrong theorem (bad subgoaler?)" ("", thm') ^ "\n" ^
wenzelm@55028
   861
          print_term ctxt "Should have proved:" prop0);
wenzelm@55028
   862
    in NONE end;
berghofe@10413
   863
berghofe@10413
   864
berghofe@10413
   865
(* mk_procrule *)
berghofe@10413
   866
wenzelm@51717
   867
fun mk_procrule ctxt thm =
wenzelm@52091
   868
  let val (prems, lhs, elhs, rhs, _) = decomp_simp thm in
wenzelm@15023
   869
    if rewrite_rule_extra_vars prems lhs rhs
wenzelm@55028
   870
    then (cond_warning ctxt (fn () => print_thm ctxt "Extra vars on rhs:" ("", thm)); [])
wenzelm@15023
   871
    else [mk_rrule2 {thm = thm, name = "", lhs = lhs, elhs = elhs, perm = false}]
berghofe@10413
   872
  end;
berghofe@10413
   873
berghofe@10413
   874
wenzelm@15023
   875
(* rewritec: conversion to apply the meta simpset to a term *)
berghofe@10413
   876
wenzelm@15023
   877
(*Since the rewriting strategy is bottom-up, we avoid re-normalizing already
wenzelm@15023
   878
  normalized terms by carrying around the rhs of the rewrite rule just
wenzelm@15023
   879
  applied. This is called the `skeleton'. It is decomposed in parallel
wenzelm@15023
   880
  with the term. Once a Var is encountered, the corresponding term is
wenzelm@15023
   881
  already in normal form.
wenzelm@15023
   882
  skel0 is a dummy skeleton that is to enforce complete normalization.*)
wenzelm@15023
   883
berghofe@10413
   884
val skel0 = Bound 0;
berghofe@10413
   885
wenzelm@15023
   886
(*Use rhs as skeleton only if the lhs does not contain unnormalized bits.
wenzelm@15023
   887
  The latter may happen iff there are weak congruence rules for constants
wenzelm@15023
   888
  in the lhs.*)
berghofe@10413
   889
wenzelm@15023
   890
fun uncond_skel ((_, weak), (lhs, rhs)) =
wenzelm@15023
   891
  if null weak then rhs  (*optimization*)
wenzelm@51591
   892
  else if exists_subterm
wenzelm@51591
   893
    (fn Const (a, _) => member (op =) weak (true, a)
wenzelm@51591
   894
      | Free (a, _) => member (op =) weak (false, a)
wenzelm@51591
   895
      | _ => false) lhs then skel0
wenzelm@15023
   896
  else rhs;
wenzelm@15023
   897
wenzelm@15023
   898
(*Behaves like unconditional rule if rhs does not contain vars not in the lhs.
wenzelm@15023
   899
  Otherwise those vars may become instantiated with unnormalized terms
wenzelm@15023
   900
  while the premises are solved.*)
wenzelm@15023
   901
wenzelm@32797
   902
fun cond_skel (args as (_, (lhs, rhs))) =
haftmann@33038
   903
  if subset (op =) (Term.add_vars rhs [], Term.add_vars lhs []) then uncond_skel args
berghofe@10413
   904
  else skel0;
berghofe@10413
   905
berghofe@10413
   906
(*
wenzelm@15023
   907
  Rewriting -- we try in order:
berghofe@10413
   908
    (1) beta reduction
berghofe@10413
   909
    (2) unconditional rewrite rules
berghofe@10413
   910
    (3) conditional rewrite rules
berghofe@10413
   911
    (4) simplification procedures
berghofe@10413
   912
berghofe@10413
   913
  IMPORTANT: rewrite rules must not introduce new Vars or TVars!
berghofe@10413
   914
*)
berghofe@10413
   915
wenzelm@52091
   916
fun rewritec (prover, maxt) ctxt t =
berghofe@10413
   917
  let
wenzelm@51717
   918
    val Simpset ({rules, ...}, {congs, procs, termless, ...}) = simpset_of ctxt;
berghofe@10413
   919
    val eta_thm = Thm.eta_conversion t;
wenzelm@22902
   920
    val eta_t' = Thm.rhs_of eta_thm;
berghofe@10413
   921
    val eta_t = term_of eta_t';
wenzelm@20546
   922
    fun rew {thm, name, lhs, elhs, extra, fo, perm} =
berghofe@10413
   923
      let
wenzelm@32797
   924
        val prop = Thm.prop_of thm;
wenzelm@20546
   925
        val (rthm, elhs') =
wenzelm@20546
   926
          if maxt = ~1 orelse not extra then (thm, elhs)
wenzelm@22902
   927
          else (Thm.incr_indexes (maxt + 1) thm, Thm.incr_indexes_cterm (maxt + 1) elhs);
wenzelm@22902
   928
        val insts =
wenzelm@22902
   929
          if fo then Thm.first_order_match (elhs', eta_t')
wenzelm@22902
   930
          else Thm.match (elhs', eta_t');
berghofe@10413
   931
        val thm' = Thm.instantiate insts (Thm.rename_boundvars lhs eta_t rthm);
wenzelm@14643
   932
        val prop' = Thm.prop_of thm';
wenzelm@21576
   933
        val unconditional = (Logic.count_prems prop' = 0);
wenzelm@54725
   934
        val (lhs', rhs') = Logic.dest_equals (Logic.strip_imp_concl prop');
wenzelm@54729
   935
        val trace_args = {unconditional = unconditional, term = eta_t, thm = thm', name = name};
berghofe@10413
   936
      in
nipkow@11295
   937
        if perm andalso not (termless (rhs', lhs'))
wenzelm@54725
   938
        then
wenzelm@55031
   939
         (cond_tracing ctxt (fn () =>
wenzelm@55028
   940
            print_thm ctxt "Cannot apply permutative rewrite rule" (name, thm) ^ "\n" ^
wenzelm@55028
   941
            print_thm ctxt "Term does not become smaller:" ("", thm'));
wenzelm@54725
   942
          NONE)
wenzelm@54725
   943
        else
wenzelm@55031
   944
         (cond_tracing ctxt (fn () =>
wenzelm@55028
   945
            print_thm ctxt "Applying instance of rewrite rule" (name, thm));
wenzelm@54725
   946
          if unconditional
wenzelm@54725
   947
          then
wenzelm@55031
   948
           (cond_tracing ctxt (fn () => print_thm ctxt "Rewriting:" ("", thm'));
wenzelm@54729
   949
            trace_apply trace_args ctxt (fn ctxt' =>
wenzelm@54729
   950
              let
wenzelm@54729
   951
                val lr = Logic.dest_equals prop;
wenzelm@54729
   952
                val SOME thm'' = check_conv ctxt' false eta_thm thm';
wenzelm@54729
   953
              in SOME (thm'', uncond_skel (congs, lr)) end))
wenzelm@54725
   954
          else
wenzelm@55031
   955
           (cond_tracing ctxt (fn () => print_thm ctxt "Trying to rewrite:" ("", thm'));
wenzelm@54725
   956
            if simp_depth ctxt > Config.get ctxt simp_depth_limit
wenzelm@55031
   957
            then (cond_tracing ctxt (fn () => "simp_depth_limit exceeded - giving up"); NONE)
wenzelm@54725
   958
            else
wenzelm@54729
   959
              trace_apply trace_args ctxt (fn ctxt' =>
wenzelm@54729
   960
                (case prover ctxt' thm' of
wenzelm@55031
   961
                  NONE => (cond_tracing ctxt' (fn () => print_thm ctxt' "FAILED" ("", thm')); NONE)
wenzelm@54729
   962
                | SOME thm2 =>
wenzelm@54729
   963
                    (case check_conv ctxt' true eta_thm thm2 of
wenzelm@54729
   964
                      NONE => NONE
wenzelm@54729
   965
                    | SOME thm2' =>
wenzelm@54729
   966
                        let
wenzelm@54729
   967
                          val concl = Logic.strip_imp_concl prop;
wenzelm@54729
   968
                          val lr = Logic.dest_equals concl;
wenzelm@54729
   969
                        in SOME (thm2', cond_skel (congs, lr)) end)))))
wenzelm@51717
   970
      end;
berghofe@10413
   971
skalberg@15531
   972
    fun rews [] = NONE
berghofe@10413
   973
      | rews (rrule :: rrules) =
skalberg@15531
   974
          let val opt = rew rrule handle Pattern.MATCH => NONE
wenzelm@54725
   975
          in (case opt of NONE => rews rrules | some => some) end;
berghofe@10413
   976
wenzelm@38834
   977
    fun sort_rrules rrs =
wenzelm@38834
   978
      let
wenzelm@38834
   979
        fun is_simple ({thm, ...}: rrule) =
wenzelm@38834
   980
          (case Thm.prop_of thm of
wenzelm@38834
   981
            Const ("==", _) $ _ $ _ => true
wenzelm@38834
   982
          | _ => false);
wenzelm@38834
   983
        fun sort [] (re1, re2) = re1 @ re2
wenzelm@38834
   984
          | sort (rr :: rrs) (re1, re2) =
wenzelm@38834
   985
              if is_simple rr
wenzelm@38834
   986
              then sort rrs (rr :: re1, re2)
wenzelm@38834
   987
              else sort rrs (re1, rr :: re2);
wenzelm@38834
   988
      in sort rrs ([], []) end;
berghofe@10413
   989
skalberg@15531
   990
    fun proc_rews [] = NONE
wenzelm@15023
   991
      | proc_rews (Proc {name, proc, lhs, ...} :: ps) =
wenzelm@55028
   992
          if Pattern.matches (Proof_Context.theory_of ctxt) (term_of lhs, term_of t) then
wenzelm@55031
   993
            (cond_tracing' ctxt simp_debug (fn () =>
wenzelm@55028
   994
              print_term ctxt ("Trying procedure " ^ quote name ^ " on:") eta_t);
wenzelm@54725
   995
             (case proc ctxt eta_t' of
wenzelm@55031
   996
               NONE => (cond_tracing' ctxt simp_debug (fn () => "FAILED"); proc_rews ps)
skalberg@15531
   997
             | SOME raw_thm =>
wenzelm@55031
   998
                 (cond_tracing ctxt (fn () =>
wenzelm@55028
   999
                    print_thm ctxt ("Procedure " ^ quote name ^ " produced rewrite rule:")
wenzelm@55028
  1000
                      ("", raw_thm));
wenzelm@51717
  1001
                  (case rews (mk_procrule ctxt raw_thm) of
wenzelm@55028
  1002
                    NONE =>
wenzelm@55031
  1003
                     (cond_tracing ctxt (fn () =>
wenzelm@55028
  1004
                        print_term ctxt ("IGNORED result of simproc " ^ quote name ^
wenzelm@55028
  1005
                            " -- does not match") (Thm.term_of t));
wenzelm@55028
  1006
                      proc_rews ps)
wenzelm@54725
  1007
                  | some => some))))
berghofe@10413
  1008
          else proc_rews ps;
wenzelm@38834
  1009
  in
wenzelm@38834
  1010
    (case eta_t of
wenzelm@38834
  1011
      Abs _ $ _ => SOME (Thm.transitive eta_thm (Thm.beta_conversion false eta_t'), skel0)
wenzelm@38834
  1012
    | _ =>
wenzelm@38834
  1013
      (case rews (sort_rrules (Net.match_term rules eta_t)) of
wenzelm@38834
  1014
        NONE => proc_rews (Net.match_term procs eta_t)
wenzelm@38834
  1015
      | some => some))
berghofe@10413
  1016
  end;
berghofe@10413
  1017
berghofe@10413
  1018
berghofe@10413
  1019
(* conversion to apply a congruence rule to a term *)
berghofe@10413
  1020
wenzelm@51717
  1021
fun congc prover ctxt maxt cong t =
wenzelm@51717
  1022
  let
wenzelm@51717
  1023
    val rthm = Thm.incr_indexes (maxt + 1) cong;
wenzelm@51717
  1024
    val rlhs = fst (Thm.dest_equals (Drule.strip_imp_concl (cprop_of rthm)));
wenzelm@51717
  1025
    val insts = Thm.match (rlhs, t)
wenzelm@51717
  1026
    (* Thm.match can raise Pattern.MATCH;
wenzelm@51717
  1027
       is handled when congc is called *)
wenzelm@51717
  1028
    val thm' = Thm.instantiate insts (Thm.rename_boundvars (term_of rlhs) (term_of t) rthm);
wenzelm@55028
  1029
    val _ =
wenzelm@55031
  1030
      cond_tracing ctxt (fn () => print_thm ctxt "Applying congruence rule:" ("", thm'));
wenzelm@55031
  1031
    fun err (msg, thm) = (cond_tracing ctxt (fn () => print_thm ctxt msg ("", thm)); NONE);
wenzelm@38834
  1032
  in
wenzelm@38834
  1033
    (case prover thm' of
wenzelm@38834
  1034
      NONE => err ("Congruence proof failed.  Could not prove", thm')
wenzelm@38834
  1035
    | SOME thm2 =>
wenzelm@51717
  1036
        (case check_conv ctxt true (Drule.beta_eta_conversion t) thm2 of
skalberg@15531
  1037
          NONE => err ("Congruence proof failed.  Should not have proved", thm2)
skalberg@15531
  1038
        | SOME thm2' =>
wenzelm@22902
  1039
            if op aconv (pairself term_of (Thm.dest_equals (cprop_of thm2')))
wenzelm@38834
  1040
            then NONE else SOME thm2'))
berghofe@10413
  1041
  end;
berghofe@10413
  1042
berghofe@10413
  1043
val (cA, (cB, cC)) =
wenzelm@22902
  1044
  apsnd Thm.dest_equals (Thm.dest_implies (hd (cprems_of Drule.imp_cong)));
berghofe@10413
  1045
skalberg@15531
  1046
fun transitive1 NONE NONE = NONE
skalberg@15531
  1047
  | transitive1 (SOME thm1) NONE = SOME thm1
skalberg@15531
  1048
  | transitive1 NONE (SOME thm2) = SOME thm2
wenzelm@54725
  1049
  | transitive1 (SOME thm1) (SOME thm2) = SOME (Thm.transitive thm1 thm2);
berghofe@10413
  1050
skalberg@15531
  1051
fun transitive2 thm = transitive1 (SOME thm);
skalberg@15531
  1052
fun transitive3 thm = transitive1 thm o SOME;
berghofe@13607
  1053
wenzelm@52091
  1054
fun bottomc ((simprem, useprem, mutsimp), prover, maxidx) =
berghofe@10413
  1055
  let
wenzelm@51717
  1056
    fun botc skel ctxt t =
wenzelm@54725
  1057
      if is_Var skel then NONE
wenzelm@54725
  1058
      else
wenzelm@54725
  1059
        (case subc skel ctxt t of
wenzelm@54725
  1060
           some as SOME thm1 =>
wenzelm@54725
  1061
             (case rewritec (prover, maxidx) ctxt (Thm.rhs_of thm1) of
wenzelm@54725
  1062
                SOME (thm2, skel2) =>
wenzelm@54725
  1063
                  transitive2 (Thm.transitive thm1 thm2)
wenzelm@51717
  1064
                    (botc skel2 ctxt (Thm.rhs_of thm2))
wenzelm@54725
  1065
              | NONE => some)
wenzelm@54725
  1066
         | NONE =>
wenzelm@54725
  1067
             (case rewritec (prover, maxidx) ctxt t of
wenzelm@54725
  1068
                SOME (thm2, skel2) => transitive2 thm2
wenzelm@54725
  1069
                  (botc skel2 ctxt (Thm.rhs_of thm2))
wenzelm@54725
  1070
              | NONE => NONE))
berghofe@10413
  1071
wenzelm@51717
  1072
    and try_botc ctxt t =
wenzelm@54725
  1073
      (case botc skel0 ctxt t of
wenzelm@54725
  1074
        SOME trec1 => trec1
wenzelm@54725
  1075
      | NONE => Thm.reflexive t)
berghofe@10413
  1076
wenzelm@51717
  1077
    and subc skel ctxt t0 =
wenzelm@55014
  1078
        let val Simpset (_, {congs, ...}) = simpset_of ctxt in
wenzelm@51717
  1079
          (case term_of t0 of
wenzelm@51717
  1080
              Abs (a, T, _) =>
wenzelm@51717
  1081
                let
wenzelm@55014
  1082
                    val (b, ctxt') = Variable.next_bound (a, T) ctxt;
wenzelm@51717
  1083
                    val (v, t') = Thm.dest_abs (SOME b) t0;
wenzelm@55028
  1084
                    val b' = #1 (Term.dest_Free (term_of v));
wenzelm@51717
  1085
                    val _ =
wenzelm@51717
  1086
                      if b <> b' then
wenzelm@51717
  1087
                        warning ("Simplifier: renamed bound variable " ^
wenzelm@51717
  1088
                          quote b ^ " to " ^ quote b' ^ Position.here (Position.thread_data ()))
wenzelm@51717
  1089
                      else ();
wenzelm@54725
  1090
                    val skel' = (case skel of Abs (_, _, sk) => sk | _ => skel0);
wenzelm@51717
  1091
                in
wenzelm@51717
  1092
                  (case botc skel' ctxt' t' of
wenzelm@51717
  1093
                    SOME thm => SOME (Thm.abstract_rule a v thm)
wenzelm@51717
  1094
                  | NONE => NONE)
wenzelm@51717
  1095
                end
wenzelm@54725
  1096
            | t $ _ =>
wenzelm@54725
  1097
              (case t of
wenzelm@51717
  1098
                Const ("==>", _) $ _  => impc t0 ctxt
wenzelm@51717
  1099
              | Abs _ =>
wenzelm@51717
  1100
                  let val thm = Thm.beta_conversion false t0
wenzelm@54725
  1101
                  in
wenzelm@54725
  1102
                    (case subc skel0 ctxt (Thm.rhs_of thm) of
wenzelm@54725
  1103
                      NONE => SOME thm
wenzelm@54725
  1104
                    | SOME thm' => SOME (Thm.transitive thm thm'))
wenzelm@51717
  1105
                  end
wenzelm@51717
  1106
              | _  =>
wenzelm@54727
  1107
                  let
wenzelm@54727
  1108
                    fun appc () =
wenzelm@54727
  1109
                      let
wenzelm@54727
  1110
                        val (tskel, uskel) =
wenzelm@54727
  1111
                          (case skel of
wenzelm@54727
  1112
                            tskel $ uskel => (tskel, uskel)
wenzelm@54727
  1113
                          | _ => (skel0, skel0));
wenzelm@54727
  1114
                        val (ct, cu) = Thm.dest_comb t0;
wenzelm@54727
  1115
                      in
wenzelm@54727
  1116
                        (case botc tskel ctxt ct of
wenzelm@54727
  1117
                          SOME thm1 =>
wenzelm@54727
  1118
                            (case botc uskel ctxt cu of
wenzelm@54727
  1119
                              SOME thm2 => SOME (Thm.combination thm1 thm2)
wenzelm@54727
  1120
                            | NONE => SOME (Thm.combination thm1 (Thm.reflexive cu)))
wenzelm@54727
  1121
                        | NONE =>
wenzelm@54727
  1122
                            (case botc uskel ctxt cu of
wenzelm@54727
  1123
                              SOME thm1 => SOME (Thm.combination (Thm.reflexive ct) thm1)
wenzelm@54727
  1124
                            | NONE => NONE))
wenzelm@54727
  1125
                      end;
wenzelm@54727
  1126
                    val (h, ts) = strip_comb t;
wenzelm@54725
  1127
                  in
wenzelm@54725
  1128
                    (case cong_name h of
wenzelm@54725
  1129
                      SOME a =>
wenzelm@54725
  1130
                        (case AList.lookup (op =) (fst congs) a of
wenzelm@54725
  1131
                           NONE => appc ()
wenzelm@54725
  1132
                        | SOME cong =>
wenzelm@51717
  1133
     (*post processing: some partial applications h t1 ... tj, j <= length ts,
wenzelm@51717
  1134
       may be a redex. Example: map (%x. x) = (%xs. xs) wrt map_cong*)
wenzelm@54725
  1135
                           (let
wenzelm@54725
  1136
                              val thm = congc (prover ctxt) ctxt maxidx cong t0;
wenzelm@54725
  1137
                              val t = the_default t0 (Option.map Thm.rhs_of thm);
wenzelm@54725
  1138
                              val (cl, cr) = Thm.dest_comb t
wenzelm@54725
  1139
                              val dVar = Var(("", 0), dummyT)
wenzelm@54725
  1140
                              val skel =
wenzelm@54725
  1141
                                list_comb (h, replicate (length ts) dVar)
wenzelm@54725
  1142
                            in
wenzelm@54725
  1143
                              (case botc skel ctxt cl of
wenzelm@54725
  1144
                                NONE => thm
wenzelm@54725
  1145
                              | SOME thm' =>
wenzelm@54725
  1146
                                  transitive3 thm (Thm.combination thm' (Thm.reflexive cr)))
wenzelm@54725
  1147
                            end handle Pattern.MATCH => appc ()))
wenzelm@54725
  1148
                     | _ => appc ())
wenzelm@51717
  1149
                  end)
wenzelm@51717
  1150
            | _ => NONE)
wenzelm@51717
  1151
        end
wenzelm@51717
  1152
    and impc ct ctxt =
wenzelm@54725
  1153
      if mutsimp then mut_impc0 [] ct [] [] ctxt
wenzelm@54725
  1154
      else nonmut_impc ct ctxt
berghofe@10413
  1155
wenzelm@54984
  1156
    and rules_of_prem prem ctxt =
berghofe@13607
  1157
      if maxidx_of_term (term_of prem) <> ~1
wenzelm@55028
  1158
      then
wenzelm@55031
  1159
       (cond_tracing ctxt (fn () =>
wenzelm@55028
  1160
          print_term ctxt "Cannot add premise as rewrite rule because it contains (type) unknowns:"
wenzelm@55028
  1161
            (term_of prem));
wenzelm@55028
  1162
        (([], NONE), ctxt))
berghofe@13607
  1163
      else
wenzelm@54984
  1164
        let val (asm, ctxt') = Thm.assume_hyps prem ctxt
wenzelm@54984
  1165
        in ((extract_safe_rrules ctxt' asm, SOME asm), ctxt') end
berghofe@10413
  1166
wenzelm@51717
  1167
    and add_rrules (rrss, asms) ctxt =
wenzelm@51717
  1168
      (fold o fold) insert_rrule rrss ctxt |> add_prems (map_filter I asms)
berghofe@10413
  1169
wenzelm@23178
  1170
    and disch r prem eq =
berghofe@13607
  1171
      let
wenzelm@22902
  1172
        val (lhs, rhs) = Thm.dest_equals (Thm.cprop_of eq);
wenzelm@54727
  1173
        val eq' =
wenzelm@54727
  1174
          Thm.implies_elim
wenzelm@54727
  1175
            (Thm.instantiate ([], [(cA, prem), (cB, lhs), (cC, rhs)]) Drule.imp_cong)
wenzelm@54727
  1176
            (Thm.implies_intr prem eq);
wenzelm@54725
  1177
      in
wenzelm@54725
  1178
        if not r then eq'
wenzelm@54725
  1179
        else
wenzelm@54725
  1180
          let
wenzelm@54725
  1181
            val (prem', concl) = Thm.dest_implies lhs;
wenzelm@54727
  1182
            val (prem'', _) = Thm.dest_implies rhs;
wenzelm@54727
  1183
          in
wenzelm@54727
  1184
            Thm.transitive
wenzelm@54727
  1185
              (Thm.transitive
wenzelm@54727
  1186
                (Thm.instantiate ([], [(cA, prem'), (cB, prem), (cC, concl)]) Drule.swap_prems_eq)
wenzelm@54727
  1187
                eq')
wenzelm@54727
  1188
              (Thm.instantiate ([], [(cA, prem), (cB, prem''), (cC, concl)]) Drule.swap_prems_eq)
wenzelm@54725
  1189
          end
berghofe@10413
  1190
      end
berghofe@10413
  1191
berghofe@13607
  1192
    and rebuild [] _ _ _ _ eq = eq
wenzelm@51717
  1193
      | rebuild (prem :: prems) concl (_ :: rrss) (_ :: asms) ctxt eq =
berghofe@13607
  1194
          let
wenzelm@51717
  1195
            val ctxt' = add_rrules (rev rrss, rev asms) ctxt;
berghofe@13607
  1196
            val concl' =
wenzelm@22902
  1197
              Drule.mk_implies (prem, the_default concl (Option.map Thm.rhs_of eq));
wenzelm@54727
  1198
            val dprem = Option.map (disch false prem);
wenzelm@38834
  1199
          in
wenzelm@52091
  1200
            (case rewritec (prover, maxidx) ctxt' concl' of
wenzelm@51717
  1201
              NONE => rebuild prems concl' rrss asms ctxt (dprem eq)
wenzelm@54727
  1202
            | SOME (eq', _) =>
wenzelm@54727
  1203
                transitive2 (fold (disch false) prems (the (transitive3 (dprem eq) eq')))
wenzelm@54727
  1204
                  (mut_impc0 (rev prems) (Thm.rhs_of eq') (rev rrss) (rev asms) ctxt))
berghofe@13607
  1205
          end
wenzelm@15023
  1206
wenzelm@51717
  1207
    and mut_impc0 prems concl rrss asms ctxt =
berghofe@13607
  1208
      let
berghofe@13607
  1209
        val prems' = strip_imp_prems concl;
wenzelm@54984
  1210
        val ((rrss', asms'), ctxt') = fold_map rules_of_prem prems' ctxt |>> split_list;
wenzelm@38834
  1211
      in
wenzelm@38834
  1212
        mut_impc (prems @ prems') (strip_imp_concl concl) (rrss @ rrss')
wenzelm@54984
  1213
          (asms @ asms') [] [] [] [] ctxt' ~1 ~1
berghofe@13607
  1214
      end
wenzelm@15023
  1215
wenzelm@51717
  1216
    and mut_impc [] concl [] [] prems' rrss' asms' eqns ctxt changed k =
wenzelm@33245
  1217
        transitive1 (fold (fn (eq1, prem) => fn eq2 => transitive1 eq1
wenzelm@33245
  1218
            (Option.map (disch false prem) eq2)) (eqns ~~ prems') NONE)
berghofe@13607
  1219
          (if changed > 0 then
berghofe@13607
  1220
             mut_impc (rev prems') concl (rev rrss') (rev asms')
wenzelm@51717
  1221
               [] [] [] [] ctxt ~1 changed
wenzelm@51717
  1222
           else rebuild prems' concl rrss' asms' ctxt
wenzelm@51717
  1223
             (botc skel0 (add_rrules (rev rrss', rev asms') ctxt) concl))
berghofe@13607
  1224
berghofe@13607
  1225
      | mut_impc (prem :: prems) concl (rrs :: rrss) (asm :: asms)
wenzelm@51717
  1226
          prems' rrss' asms' eqns ctxt changed k =
wenzelm@54725
  1227
        (case (if k = 0 then NONE else botc skel0 (add_rrules
wenzelm@51717
  1228
          (rev rrss' @ rrss, rev asms' @ asms) ctxt) prem) of
skalberg@15531
  1229
            NONE => mut_impc prems concl rrss asms (prem :: prems')
wenzelm@51717
  1230
              (rrs :: rrss') (asm :: asms') (NONE :: eqns) ctxt changed
berghofe@13607
  1231
              (if k = 0 then 0 else k - 1)
wenzelm@54725
  1232
        | SOME eqn =>
berghofe@13607
  1233
            let
wenzelm@22902
  1234
              val prem' = Thm.rhs_of eqn;
berghofe@13607
  1235
              val tprems = map term_of prems;
wenzelm@33029
  1236
              val i = 1 + fold Integer.max (map (fn p =>
wenzelm@44058
  1237
                find_index (fn q => q aconv p) tprems) (Thm.hyps_of eqn)) ~1;
wenzelm@54984
  1238
              val ((rrs', asm'), ctxt') = rules_of_prem prem' ctxt;
wenzelm@54725
  1239
            in
wenzelm@54725
  1240
              mut_impc prems concl rrss asms (prem' :: prems')
wenzelm@54725
  1241
                (rrs' :: rrss') (asm' :: asms')
wenzelm@54725
  1242
                (SOME (fold_rev (disch true)
wenzelm@54725
  1243
                  (take i prems)
wenzelm@54725
  1244
                  (Drule.imp_cong_rule eqn (Thm.reflexive (Drule.list_implies
wenzelm@54725
  1245
                    (drop i prems, concl))))) :: eqns)
wenzelm@54984
  1246
                ctxt' (length prems') ~1
wenzelm@54725
  1247
            end)
berghofe@13607
  1248
wenzelm@54725
  1249
    (*legacy code -- only for backwards compatibility*)
wenzelm@51717
  1250
    and nonmut_impc ct ctxt =
wenzelm@38834
  1251
      let
wenzelm@38834
  1252
        val (prem, conc) = Thm.dest_implies ct;
wenzelm@51717
  1253
        val thm1 = if simprem then botc skel0 ctxt prem else NONE;
wenzelm@38834
  1254
        val prem1 = the_default prem (Option.map Thm.rhs_of thm1);
wenzelm@51717
  1255
        val ctxt1 =
wenzelm@51717
  1256
          if not useprem then ctxt
wenzelm@54984
  1257
          else
wenzelm@54984
  1258
            let val ((rrs, asm), ctxt') = rules_of_prem prem1 ctxt
wenzelm@54984
  1259
            in add_rrules ([rrs], [asm]) ctxt' end;
wenzelm@38834
  1260
      in
wenzelm@51717
  1261
        (case botc skel0 ctxt1 conc of
wenzelm@38834
  1262
          NONE =>
wenzelm@38834
  1263
            (case thm1 of
wenzelm@38834
  1264
              NONE => NONE
wenzelm@38834
  1265
            | SOME thm1' => SOME (Drule.imp_cong_rule thm1' (Thm.reflexive conc)))
wenzelm@38834
  1266
        | SOME thm2 =>
wenzelm@38834
  1267
            let val thm2' = disch false prem1 thm2 in
wenzelm@38834
  1268
              (case thm1 of
wenzelm@38834
  1269
                NONE => SOME thm2'
wenzelm@38834
  1270
              | SOME thm1' =>
wenzelm@36944
  1271
                 SOME (Thm.transitive (Drule.imp_cong_rule thm1' (Thm.reflexive conc)) thm2'))
wenzelm@38834
  1272
            end)
wenzelm@54725
  1273
      end;
berghofe@10413
  1274
wenzelm@54725
  1275
  in try_botc end;
berghofe@10413
  1276
berghofe@10413
  1277
wenzelm@15023
  1278
(* Meta-rewriting: rewrites t to u and returns the theorem t==u *)
berghofe@10413
  1279
berghofe@10413
  1280
(*
berghofe@10413
  1281
  Parameters:
berghofe@10413
  1282
    mode = (simplify A,
berghofe@10413
  1283
            use A in simplifying B,
berghofe@10413
  1284
            use prems of B (if B is again a meta-impl.) to simplify A)
berghofe@10413
  1285
           when simplifying A ==> B
berghofe@10413
  1286
    prover: how to solve premises in conditional rewrites and congruences
berghofe@10413
  1287
*)
berghofe@10413
  1288
wenzelm@51717
  1289
fun rewrite_cterm mode prover raw_ctxt raw_ct =
wenzelm@17882
  1290
  let
wenzelm@54729
  1291
    val thy = Proof_Context.theory_of raw_ctxt;
wenzelm@52091
  1292
wenzelm@20260
  1293
    val ct = Thm.adjust_maxidx_cterm ~1 raw_ct;
wenzelm@32797
  1294
    val {maxidx, ...} = Thm.rep_cterm ct;
wenzelm@52091
  1295
    val _ =
wenzelm@52091
  1296
      Theory.subthy (theory_of_cterm ct, thy) orelse
wenzelm@52091
  1297
        raise CTERM ("rewrite_cterm: bad background theory", [ct]);
wenzelm@52091
  1298
wenzelm@54729
  1299
    val ctxt =
wenzelm@54729
  1300
      raw_ctxt
wenzelm@54729
  1301
      |> Context_Position.set_visible false
wenzelm@54729
  1302
      |> inc_simp_depth
wenzelm@55028
  1303
      |> (fn ctxt => trace_invoke {depth = simp_depth ctxt, term = term_of ct} ctxt);
wenzelm@54729
  1304
wenzelm@55028
  1305
    val _ =
wenzelm@55031
  1306
      cond_tracing ctxt (fn () =>
wenzelm@55028
  1307
        print_term ctxt "SIMPLIFIER INVOKED ON THE FOLLOWING TERM:" (term_of ct));
wenzelm@52091
  1308
  in bottomc (mode, Option.map Drule.flexflex_unique oo prover, maxidx) ctxt ct end;
berghofe@10413
  1309
wenzelm@21708
  1310
val simple_prover =
wenzelm@51717
  1311
  SINGLE o (fn ctxt => ALLGOALS (resolve_tac (prems_of ctxt)));
wenzelm@21708
  1312
wenzelm@54742
  1313
fun rewrite _ _ [] = Thm.reflexive
wenzelm@54742
  1314
  | rewrite ctxt full thms =
wenzelm@51717
  1315
      rewrite_cterm (full, false, false) simple_prover
wenzelm@54742
  1316
        (empty_simpset ctxt addsimps thms);
wenzelm@11672
  1317
wenzelm@54742
  1318
fun rewrite_rule ctxt = Conv.fconv_rule o rewrite ctxt true;
wenzelm@21708
  1319
wenzelm@15023
  1320
(*simple term rewriting -- no proof*)
wenzelm@16458
  1321
fun rewrite_term thy rules procs =
wenzelm@17203
  1322
  Pattern.rewrite_term thy (map decomp_simp' rules) procs;
wenzelm@15023
  1323
wenzelm@51717
  1324
fun rewrite_thm mode prover ctxt = Conv.fconv_rule (rewrite_cterm mode prover ctxt);
berghofe@10413
  1325
wenzelm@23536
  1326
(*Rewrite the subgoals of a proof state (represented by a theorem)*)
wenzelm@54742
  1327
fun rewrite_goals_rule ctxt thms th =
wenzelm@23584
  1328
  Conv.fconv_rule (Conv.prems_conv ~1 (rewrite_cterm (true, true, true) simple_prover
wenzelm@54742
  1329
    (empty_simpset ctxt addsimps thms))) th;
berghofe@10413
  1330
wenzelm@20228
  1331
wenzelm@21708
  1332
(** meta-rewriting tactics **)
wenzelm@21708
  1333
wenzelm@28839
  1334
(*Rewrite all subgoals*)
wenzelm@54742
  1335
fun rewrite_goals_tac ctxt defs = PRIMITIVE (rewrite_goals_rule ctxt defs);
wenzelm@21708
  1336
wenzelm@28839
  1337
(*Rewrite one subgoal*)
wenzelm@51717
  1338
fun generic_rewrite_goal_tac mode prover_tac ctxt i thm =
wenzelm@25203
  1339
  if 0 < i andalso i <= Thm.nprems_of thm then
wenzelm@51717
  1340
    Seq.single (Conv.gconv_rule (rewrite_cterm mode (SINGLE o prover_tac) ctxt) i thm)
wenzelm@25203
  1341
  else Seq.empty;
wenzelm@23536
  1342
wenzelm@54742
  1343
fun rewrite_goal_tac ctxt rews =
wenzelm@51717
  1344
  generic_rewrite_goal_tac (true, false, false) (K no_tac)
wenzelm@54742
  1345
    (empty_simpset ctxt addsimps rews);
wenzelm@23536
  1346
wenzelm@46707
  1347
(*Prunes all redundant parameters from the proof state by rewriting.*)
wenzelm@54742
  1348
fun prune_params_tac ctxt = rewrite_goals_tac ctxt [Drule.triv_forall_equality];
wenzelm@21708
  1349
wenzelm@21708
  1350
wenzelm@21708
  1351
(* for folding definitions, handling critical pairs *)
wenzelm@21708
  1352
wenzelm@21708
  1353
(*The depth of nesting in a term*)
wenzelm@32797
  1354
fun term_depth (Abs (_, _, t)) = 1 + term_depth t
wenzelm@32797
  1355
  | term_depth (f $ t) = 1 + Int.max (term_depth f, term_depth t)
wenzelm@21708
  1356
  | term_depth _ = 0;
wenzelm@21708
  1357
wenzelm@21708
  1358
val lhs_of_thm = #1 o Logic.dest_equals o prop_of;
wenzelm@21708
  1359
wenzelm@21708
  1360
(*folding should handle critical pairs!  E.g. K == Inl(0),  S == Inr(Inl(0))
wenzelm@21708
  1361
  Returns longest lhs first to avoid folding its subexpressions.*)
wenzelm@21708
  1362
fun sort_lhs_depths defs =
wenzelm@21708
  1363
  let val keylist = AList.make (term_depth o lhs_of_thm) defs
wenzelm@21708
  1364
      val keys = sort_distinct (rev_order o int_ord) (map #2 keylist)
wenzelm@21708
  1365
  in map (AList.find (op =) keylist) keys end;
wenzelm@21708
  1366
wenzelm@36944
  1367
val rev_defs = sort_lhs_depths o map Thm.symmetric;
wenzelm@21708
  1368
wenzelm@54742
  1369
fun fold_rule ctxt defs = fold (rewrite_rule ctxt) (rev_defs defs);
wenzelm@54742
  1370
fun fold_goals_tac ctxt defs = EVERY (map (rewrite_goals_tac ctxt) (rev_defs defs));
wenzelm@21708
  1371
wenzelm@21708
  1372
wenzelm@20228
  1373
(* HHF normal form: !! before ==>, outermost !! generalized *)
wenzelm@20228
  1374
wenzelm@20228
  1375
local
wenzelm@20228
  1376
wenzelm@54883
  1377
fun gen_norm_hhf ss ctxt th =
wenzelm@21565
  1378
  (if Drule.is_norm_hhf (Thm.prop_of th) then th
wenzelm@51717
  1379
   else
wenzelm@51717
  1380
    Conv.fconv_rule
wenzelm@54883
  1381
      (rewrite_cterm (true, false, false) (K (K NONE)) (put_simpset ss ctxt)) th)
wenzelm@21565
  1382
  |> Thm.adjust_maxidx_thm ~1
wenzelm@21565
  1383
  |> Drule.gen_all;
wenzelm@20228
  1384
wenzelm@51717
  1385
val hhf_ss =
wenzelm@51717
  1386
  simpset_of (empty_simpset (Context.proof_of (Context.the_thread_data ()))
wenzelm@51717
  1387
    addsimps Drule.norm_hhf_eqs);
wenzelm@51717
  1388
wenzelm@51717
  1389
val hhf_protect_ss =
wenzelm@51717
  1390
  simpset_of (empty_simpset (Context.proof_of (Context.the_thread_data ()))
wenzelm@51717
  1391
    addsimps Drule.norm_hhf_eqs |> add_eqcong Drule.protect_cong);
wenzelm@20228
  1392
wenzelm@20228
  1393
in
wenzelm@20228
  1394
wenzelm@26424
  1395
val norm_hhf = gen_norm_hhf hhf_ss;
wenzelm@51717
  1396
val norm_hhf_protect = gen_norm_hhf hhf_protect_ss;
wenzelm@20228
  1397
wenzelm@20228
  1398
end;
wenzelm@20228
  1399
berghofe@10413
  1400
end;
berghofe@10413
  1401
wenzelm@41228
  1402
structure Basic_Meta_Simplifier: BASIC_RAW_SIMPLIFIER = Raw_Simplifier;
wenzelm@32738
  1403
open Basic_Meta_Simplifier;