src/Pure/raw_simplifier.ML
author wenzelm
Fri Jan 10 21:37:28 2014 +0100 (2014-01-10)
changeset 54984 da70ab8531f4
parent 54982 b327bf0dabfb
child 54997 811c35e81ac5
permissions -rw-r--r--
more elementary management of declared hyps, below structure Assumption;
Goal.prove: insist in declared hyps;
Simplifier: declare hyps via Thm.assume_hyps;
more accurate tool context in some boundary cases;
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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
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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 debug_bounds: bool Unsynchronized.ref
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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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    bounds: maximal index of bound variables already used
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      (for generating new names when rewriting under lambda abstractions);
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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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    bounds: int * ((string * typ) * string) 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, bounds, depth) =
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  {rules = rules, prems = prems, bounds = bounds, depth = depth};
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fun map_ss1 f {rules, prems, bounds, depth} =
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  make_ss1 (f (rules, prems, bounds, 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))
wenzelm@51717
   309
    |> partition_eq (eq_snd eq_procid)
wenzelm@51717
   310
    |> map (fn ps => (fst (fst (hd ps)), map (snd o fst) ps)),
wenzelm@51717
   311
  congs = #1 congs,
wenzelm@51717
   312
  weak_congs = #2 congs,
wenzelm@51717
   313
  loopers = map fst loop_tacs,
wenzelm@51717
   314
  unsafe_solvers = map solver_name (#1 solvers),
wenzelm@51717
   315
  safe_solvers = map solver_name (#2 solvers)};
wenzelm@51717
   316
wenzelm@51717
   317
wenzelm@51717
   318
(* empty *)
wenzelm@51717
   319
wenzelm@54731
   320
fun init_ss mk_rews termless subgoal_tac solvers =
wenzelm@51717
   321
  make_simpset ((Net.empty, [], (0, []), (0, Unsynchronized.ref false)),
wenzelm@54731
   322
    (([], []), Net.empty, mk_rews, termless, subgoal_tac, [], solvers));
wenzelm@51717
   323
wenzelm@51717
   324
fun default_mk_sym _ th = SOME (th RS Drule.symmetric_thm);
wenzelm@51717
   325
wenzelm@51717
   326
val empty_ss =
wenzelm@51717
   327
  init_ss
wenzelm@51717
   328
    {mk = fn _ => fn th => if can Logic.dest_equals (Thm.concl_of th) then [th] else [],
wenzelm@51717
   329
      mk_cong = K I,
wenzelm@51717
   330
      mk_sym = default_mk_sym,
wenzelm@51717
   331
      mk_eq_True = K (K NONE),
wenzelm@51717
   332
      reorient = default_reorient}
wenzelm@54731
   333
    Term_Ord.termless (K (K no_tac)) ([], []);
wenzelm@51717
   334
wenzelm@51717
   335
wenzelm@51717
   336
(* merge *)  (*NOTE: ignores some fields of 2nd simpset*)
wenzelm@51717
   337
wenzelm@51717
   338
fun merge_ss (ss1, ss2) =
wenzelm@51717
   339
  if pointer_eq (ss1, ss2) then ss1
wenzelm@51717
   340
  else
wenzelm@51717
   341
    let
wenzelm@51717
   342
      val Simpset ({rules = rules1, prems = prems1, bounds = bounds1, depth = depth1},
wenzelm@51717
   343
       {congs = (congs1, weak1), procs = procs1, mk_rews, termless, subgoal_tac,
wenzelm@54731
   344
        loop_tacs = loop_tacs1, solvers = (unsafe_solvers1, solvers1)}) = ss1;
wenzelm@51717
   345
      val Simpset ({rules = rules2, prems = prems2, bounds = bounds2, depth = depth2},
wenzelm@51717
   346
       {congs = (congs2, weak2), procs = procs2, mk_rews = _, termless = _, subgoal_tac = _,
wenzelm@54731
   347
        loop_tacs = loop_tacs2, solvers = (unsafe_solvers2, solvers2)}) = ss2;
wenzelm@51717
   348
wenzelm@51717
   349
      val rules' = Net.merge eq_rrule (rules1, rules2);
wenzelm@51717
   350
      val prems' = Thm.merge_thms (prems1, prems2);
wenzelm@51717
   351
      val bounds' = if #1 bounds1 < #1 bounds2 then bounds2 else bounds1;
wenzelm@51717
   352
      val depth' = if #1 depth1 < #1 depth2 then depth2 else depth1;
wenzelm@51717
   353
      val congs' = merge (Thm.eq_thm_prop o pairself #2) (congs1, congs2);
wenzelm@51717
   354
      val weak' = merge (op =) (weak1, weak2);
wenzelm@51717
   355
      val procs' = Net.merge eq_proc (procs1, procs2);
wenzelm@51717
   356
      val loop_tacs' = AList.merge (op =) (K true) (loop_tacs1, loop_tacs2);
wenzelm@51717
   357
      val unsafe_solvers' = merge eq_solver (unsafe_solvers1, unsafe_solvers2);
wenzelm@51717
   358
      val solvers' = merge eq_solver (solvers1, solvers2);
wenzelm@51717
   359
    in
wenzelm@51717
   360
      make_simpset ((rules', prems', bounds', depth'), ((congs', weak'), procs',
wenzelm@54731
   361
        mk_rews, termless, subgoal_tac, loop_tacs', (unsafe_solvers', solvers')))
wenzelm@51717
   362
    end;
wenzelm@51717
   363
wenzelm@51717
   364
wenzelm@51717
   365
wenzelm@51717
   366
(** context data **)
wenzelm@51717
   367
wenzelm@51717
   368
structure Simpset = Generic_Data
wenzelm@51717
   369
(
wenzelm@51717
   370
  type T = simpset;
wenzelm@51717
   371
  val empty = empty_ss;
wenzelm@51717
   372
  val extend = I;
wenzelm@51717
   373
  val merge = merge_ss;
wenzelm@51717
   374
);
wenzelm@51717
   375
wenzelm@51717
   376
val simpset_of = Simpset.get o Context.Proof;
wenzelm@51717
   377
wenzelm@51717
   378
fun map_simpset f = Context.proof_map (Simpset.map f);
wenzelm@51717
   379
fun map_simpset1 f = map_simpset (fn Simpset (ss1, ss2) => Simpset (map_ss1 f ss1, ss2));
wenzelm@51717
   380
fun map_simpset2 f = map_simpset (fn Simpset (ss1, ss2) => Simpset (ss1, map_ss2 f ss2));
wenzelm@51717
   381
wenzelm@51717
   382
fun simpset_map ctxt f ss = ctxt |> map_simpset (K ss) |> f |> Context.Proof |> Simpset.get;
wenzelm@51717
   383
wenzelm@54729
   384
fun put_simpset ss = map_simpset (fn context_ss =>
wenzelm@54729
   385
  let
wenzelm@54731
   386
    val Simpset ({rules, prems, ...}, ss2) = ss;  (* FIXME prems from context (!?) *)
wenzelm@54731
   387
    val Simpset ({bounds, depth, ...}, _) = context_ss;
wenzelm@54731
   388
  in Simpset (make_ss1 (rules, prems, bounds, depth), ss2) end);
wenzelm@51717
   389
wenzelm@51717
   390
val empty_simpset = put_simpset empty_ss;
wenzelm@51717
   391
wenzelm@51717
   392
fun map_theory_simpset f thy =
wenzelm@51717
   393
  let
wenzelm@51717
   394
    val ctxt' = f (Proof_Context.init_global thy);
wenzelm@51717
   395
    val thy' = Proof_Context.theory_of ctxt';
wenzelm@51717
   396
  in Context.theory_map (Simpset.map (K (simpset_of ctxt'))) thy' end;
wenzelm@51717
   397
wenzelm@51717
   398
fun map_ss f = Context.mapping (map_theory_simpset f) f;
wenzelm@51717
   399
wenzelm@51717
   400
val clear_simpset =
wenzelm@54731
   401
  map_simpset (fn Simpset (_, {mk_rews, termless, subgoal_tac, solvers, ...}) =>
wenzelm@54731
   402
    init_ss mk_rews termless subgoal_tac solvers);
wenzelm@51717
   403
wenzelm@51717
   404
wenzelm@51717
   405
(* simp depth *)
wenzelm@51717
   406
wenzelm@51717
   407
val simp_depth_limit_raw = Config.declare "simp_depth_limit" (K (Config.Int 100));
wenzelm@51717
   408
val simp_depth_limit = Config.int simp_depth_limit_raw;
wenzelm@51717
   409
wenzelm@51717
   410
val simp_trace_depth_limit_default = Unsynchronized.ref 1;
wenzelm@51717
   411
val simp_trace_depth_limit_raw = Config.declare "simp_trace_depth_limit"
wenzelm@51717
   412
  (fn _ => Config.Int (! simp_trace_depth_limit_default));
wenzelm@51717
   413
val simp_trace_depth_limit = Config.int simp_trace_depth_limit_raw;
wenzelm@51717
   414
wenzelm@51717
   415
fun trace_depth ctxt msg =
wenzelm@51717
   416
  let
wenzelm@51717
   417
    val Simpset ({depth = (depth, exceeded), ...}, _) = simpset_of ctxt;
wenzelm@51717
   418
    val depth_limit = Config.get ctxt simp_trace_depth_limit;
wenzelm@51717
   419
  in
wenzelm@51717
   420
    if depth > depth_limit then
wenzelm@51717
   421
      if ! exceeded then () else (tracing "simp_trace_depth_limit exceeded!"; exceeded := true)
wenzelm@51717
   422
    else (tracing (enclose "[" "]" (string_of_int depth) ^ msg); exceeded := false)
wenzelm@51717
   423
  end;
wenzelm@51717
   424
wenzelm@51717
   425
fun inc_simp_depth ctxt =
wenzelm@51717
   426
  ctxt |> map_simpset1 (fn (rules, prems, bounds, (depth, exceeded)) =>
wenzelm@51717
   427
    (rules, prems, bounds,
wenzelm@51717
   428
      (depth + 1,
wenzelm@51717
   429
        if depth = Config.get ctxt simp_trace_depth_limit
wenzelm@51717
   430
        then Unsynchronized.ref false else exceeded)));
wenzelm@51717
   431
wenzelm@51717
   432
fun simp_depth ctxt =
wenzelm@51717
   433
  let val Simpset ({depth = (depth, _), ...}, _) = simpset_of ctxt
wenzelm@51717
   434
  in depth end;
wenzelm@51717
   435
wenzelm@51717
   436
wenzelm@51717
   437
(* diagnostics *)
wenzelm@51717
   438
wenzelm@51717
   439
exception SIMPLIFIER of string * thm;
wenzelm@51717
   440
wenzelm@51717
   441
val simp_debug_raw = Config.declare "simp_debug" (K (Config.Bool false));
wenzelm@51717
   442
val simp_debug = Config.bool simp_debug_raw;
wenzelm@51717
   443
wenzelm@51717
   444
val simp_trace_default = Unsynchronized.ref false;
wenzelm@51717
   445
val simp_trace_raw = Config.declare "simp_trace" (fn _ => Config.Bool (! simp_trace_default));
wenzelm@51717
   446
val simp_trace = Config.bool simp_trace_raw;
wenzelm@51717
   447
wenzelm@51717
   448
fun if_enabled ctxt flag f = if Config.get ctxt flag then f ctxt else ();
wenzelm@51717
   449
wenzelm@51717
   450
local
wenzelm@51717
   451
wenzelm@51717
   452
fun prnt ctxt warn a = if warn then warning a else trace_depth ctxt a;
wenzelm@51717
   453
wenzelm@51717
   454
fun show_bounds ctxt t =
wenzelm@51717
   455
  let
wenzelm@51717
   456
    val Simpset ({bounds = (_, bs), ...}, _) = simpset_of ctxt;
wenzelm@51717
   457
    val names = Term.declare_term_names t Name.context;
wenzelm@51717
   458
    val xs = rev (#1 (fold_map Name.variant (rev (map #2 bs)) names));
wenzelm@51717
   459
    fun subst (((b, T), _), x') = (Free (b, T), Syntax_Trans.mark_bound_abs (x', T));
wenzelm@51717
   460
  in Term.subst_atomic (ListPair.map subst (bs, xs)) t end;
wenzelm@51717
   461
wenzelm@51717
   462
in
wenzelm@51717
   463
wenzelm@51717
   464
fun print_term ctxt warn a t =
wenzelm@51717
   465
  prnt ctxt warn (a () ^ "\n" ^
wenzelm@51717
   466
    Syntax.string_of_term ctxt (if Config.get ctxt simp_debug then t else show_bounds ctxt t));
wenzelm@51717
   467
wenzelm@51717
   468
fun debug ctxt warn a = if_enabled ctxt simp_debug (fn _ => prnt ctxt warn (a ()));
wenzelm@51717
   469
fun trace ctxt warn a = if_enabled ctxt simp_trace (fn _ => prnt ctxt warn (a ()));
wenzelm@51717
   470
wenzelm@51717
   471
fun debug_term ctxt warn a t = if_enabled ctxt simp_debug (fn _ => print_term ctxt warn a t);
wenzelm@51717
   472
fun trace_term ctxt warn a t = if_enabled ctxt simp_trace (fn _ => print_term ctxt warn a t);
wenzelm@51717
   473
wenzelm@51717
   474
fun trace_cterm ctxt warn a ct =
wenzelm@51717
   475
  if_enabled ctxt simp_trace (fn _ => print_term ctxt warn a (Thm.term_of ct));
wenzelm@51717
   476
wenzelm@51717
   477
fun trace_thm ctxt a th =
wenzelm@51717
   478
  if_enabled ctxt simp_trace (fn _ => print_term ctxt false a (Thm.full_prop_of th));
wenzelm@51717
   479
wenzelm@51717
   480
fun trace_named_thm ctxt a (th, name) =
wenzelm@51717
   481
  if_enabled ctxt simp_trace (fn _ =>
wenzelm@51717
   482
    print_term ctxt false
wenzelm@51717
   483
      (fn () => if name = "" then a () else a () ^ " " ^ quote name ^ ":")
wenzelm@51717
   484
      (Thm.full_prop_of th));
wenzelm@51717
   485
wenzelm@51717
   486
fun warn_thm ctxt a th = print_term ctxt true a (Thm.full_prop_of th);
wenzelm@51717
   487
fun cond_warn_thm ctxt a th = Context_Position.if_visible ctxt (fn () => warn_thm ctxt a th) ();
wenzelm@51717
   488
wenzelm@51717
   489
end;
wenzelm@51717
   490
wenzelm@51717
   491
wenzelm@51717
   492
wenzelm@51717
   493
(** simpset operations **)
wenzelm@51717
   494
wenzelm@51717
   495
(* context *)
wenzelm@51717
   496
wenzelm@51717
   497
fun eq_bound (x: string, (y, _)) = x = y;
wenzelm@51717
   498
wenzelm@51717
   499
fun add_bound bound =
wenzelm@51717
   500
  map_simpset1 (fn (rules, prems, (count, bounds), depth) =>
wenzelm@51717
   501
    (rules, prems, (count + 1, bound :: bounds), depth));
wenzelm@51717
   502
wenzelm@51717
   503
fun prems_of ctxt =
wenzelm@51717
   504
  let val Simpset ({prems, ...}, _) = simpset_of ctxt in prems end;
wenzelm@51717
   505
wenzelm@51717
   506
fun add_prems ths =
wenzelm@51717
   507
  map_simpset1 (fn (rules, prems, bounds, depth) => (rules, ths @ prems, bounds, depth));
wenzelm@51717
   508
wenzelm@51717
   509
wenzelm@51717
   510
(* maintain simp rules *)
wenzelm@51717
   511
wenzelm@51717
   512
fun del_rrule (rrule as {thm, elhs, ...}) ctxt =
wenzelm@51717
   513
  ctxt |> map_simpset1 (fn (rules, prems, bounds, depth) =>
wenzelm@51717
   514
    (Net.delete_term eq_rrule (term_of elhs, rrule) rules, prems, bounds, depth))
wenzelm@51717
   515
  handle Net.DELETE => (cond_warn_thm ctxt (fn () => "Rewrite rule not in simpset:") thm; ctxt);
wenzelm@51717
   516
wenzelm@51717
   517
fun insert_rrule (rrule as {thm, name, ...}) ctxt =
wenzelm@51717
   518
 (trace_named_thm ctxt (fn () => "Adding rewrite rule") (thm, name);
wenzelm@51717
   519
  ctxt |> map_simpset1 (fn (rules, prems, bounds, depth) =>
wenzelm@51717
   520
    let
wenzelm@51717
   521
      val rrule2 as {elhs, ...} = mk_rrule2 rrule;
wenzelm@51717
   522
      val rules' = Net.insert_term eq_rrule (term_of elhs, rrule2) rules;
wenzelm@51717
   523
    in (rules', prems, bounds, depth) end)
wenzelm@51717
   524
  handle Net.INSERT => (cond_warn_thm ctxt (fn () => "Ignoring duplicate rewrite rule:") thm; ctxt));
wenzelm@51717
   525
wenzelm@51717
   526
local
wenzelm@51717
   527
wenzelm@51717
   528
fun vperm (Var _, Var _) = true
wenzelm@51717
   529
  | vperm (Abs (_, _, s), Abs (_, _, t)) = vperm (s, t)
wenzelm@51717
   530
  | vperm (t1 $ t2, u1 $ u2) = vperm (t1, u1) andalso vperm (t2, u2)
wenzelm@51717
   531
  | vperm (t, u) = (t = u);
wenzelm@51717
   532
wenzelm@51717
   533
fun var_perm (t, u) =
wenzelm@51717
   534
  vperm (t, u) andalso eq_set (op =) (Term.add_vars t [], Term.add_vars u []);
wenzelm@51717
   535
wenzelm@51717
   536
in
wenzelm@51717
   537
berghofe@10413
   538
fun decomp_simp thm =
wenzelm@15023
   539
  let
wenzelm@26626
   540
    val prop = Thm.prop_of thm;
wenzelm@15023
   541
    val prems = Logic.strip_imp_prems prop;
wenzelm@15023
   542
    val concl = Drule.strip_imp_concl (Thm.cprop_of thm);
wenzelm@22902
   543
    val (lhs, rhs) = Thm.dest_equals concl handle TERM _ =>
wenzelm@15023
   544
      raise SIMPLIFIER ("Rewrite rule not a meta-equality", thm);
wenzelm@20579
   545
    val elhs = Thm.dest_arg (Thm.cprop_of (Thm.eta_conversion lhs));
wenzelm@18929
   546
    val erhs = Envir.eta_contract (term_of rhs);
wenzelm@15023
   547
    val perm =
wenzelm@15023
   548
      var_perm (term_of elhs, erhs) andalso
wenzelm@15023
   549
      not (term_of elhs aconv erhs) andalso
wenzelm@15023
   550
      not (is_Var (term_of elhs));
wenzelm@52091
   551
  in (prems, term_of lhs, elhs, term_of rhs, perm) end;
berghofe@10413
   552
wenzelm@51717
   553
end;
wenzelm@51717
   554
wenzelm@12783
   555
fun decomp_simp' thm =
wenzelm@52091
   556
  let val (_, lhs, _, rhs, _) = decomp_simp thm in
wenzelm@12783
   557
    if Thm.nprems_of thm > 0 then raise SIMPLIFIER ("Bad conditional rewrite rule", thm)
wenzelm@12979
   558
    else (lhs, rhs)
wenzelm@12783
   559
  end;
wenzelm@12783
   560
wenzelm@51717
   561
fun mk_eq_True ctxt (thm, name) =
wenzelm@51717
   562
  let val Simpset (_, {mk_rews = {mk_eq_True, ...}, ...}) = simpset_of ctxt in
wenzelm@51717
   563
    (case mk_eq_True ctxt thm of
wenzelm@51717
   564
      NONE => []
wenzelm@51717
   565
    | SOME eq_True =>
wenzelm@52091
   566
        let val (_, lhs, elhs, _, _) = decomp_simp eq_True;
wenzelm@51717
   567
        in [{thm = eq_True, name = name, lhs = lhs, elhs = elhs, perm = false}] end)
wenzelm@51717
   568
  end;
berghofe@10413
   569
wenzelm@15023
   570
(*create the rewrite rule and possibly also the eq_True variant,
wenzelm@15023
   571
  in case there are extra vars on the rhs*)
wenzelm@52082
   572
fun rrule_eq_True ctxt thm name lhs elhs rhs thm2 =
wenzelm@15023
   573
  let val rrule = {thm = thm, name = name, lhs = lhs, elhs = elhs, perm = false} in
wenzelm@20546
   574
    if rewrite_rule_extra_vars [] lhs rhs then
wenzelm@51717
   575
      mk_eq_True ctxt (thm2, name) @ [rrule]
wenzelm@20546
   576
    else [rrule]
berghofe@10413
   577
  end;
berghofe@10413
   578
wenzelm@51717
   579
fun mk_rrule ctxt (thm, name) =
wenzelm@52091
   580
  let val (prems, lhs, elhs, rhs, perm) = decomp_simp thm in
wenzelm@15023
   581
    if perm then [{thm = thm, name = name, lhs = lhs, elhs = elhs, perm = true}]
wenzelm@15023
   582
    else
wenzelm@15023
   583
      (*weak test for loops*)
wenzelm@15023
   584
      if rewrite_rule_extra_vars prems lhs rhs orelse is_Var (term_of elhs)
wenzelm@51717
   585
      then mk_eq_True ctxt (thm, name)
wenzelm@52082
   586
      else rrule_eq_True ctxt thm name lhs elhs rhs thm
berghofe@10413
   587
  end;
berghofe@10413
   588
wenzelm@51717
   589
fun orient_rrule ctxt (thm, name) =
wenzelm@18208
   590
  let
wenzelm@52091
   591
    val (prems, lhs, elhs, rhs, perm) = decomp_simp thm;
wenzelm@51717
   592
    val Simpset (_, {mk_rews = {reorient, mk_sym, ...}, ...}) = simpset_of ctxt;
wenzelm@18208
   593
  in
wenzelm@15023
   594
    if perm then [{thm = thm, name = name, lhs = lhs, elhs = elhs, perm = true}]
wenzelm@51717
   595
    else if reorient ctxt prems lhs rhs then
wenzelm@51717
   596
      if reorient ctxt prems rhs lhs
wenzelm@51717
   597
      then mk_eq_True ctxt (thm, name)
wenzelm@15023
   598
      else
wenzelm@51717
   599
        (case mk_sym ctxt thm of
wenzelm@18208
   600
          NONE => []
wenzelm@18208
   601
        | SOME thm' =>
wenzelm@52091
   602
            let val (_, lhs', elhs', rhs', _) = decomp_simp thm'
wenzelm@52082
   603
            in rrule_eq_True ctxt thm' name lhs' elhs' rhs' thm end)
wenzelm@52082
   604
    else rrule_eq_True ctxt thm name lhs elhs rhs thm
berghofe@10413
   605
  end;
berghofe@10413
   606
wenzelm@54982
   607
fun extract_rews ctxt thms =
wenzelm@51717
   608
  let val Simpset (_, {mk_rews = {mk, ...}, ...}) = simpset_of ctxt
wenzelm@51717
   609
  in maps (fn thm => map (rpair (Thm.get_name_hint thm)) (mk ctxt thm)) thms end;
berghofe@10413
   610
wenzelm@54982
   611
fun extract_safe_rrules ctxt thm =
wenzelm@54982
   612
  maps (orient_rrule ctxt) (extract_rews ctxt [thm]);
berghofe@10413
   613
berghofe@10413
   614
wenzelm@20028
   615
(* add/del rules explicitly *)
berghofe@10413
   616
wenzelm@54982
   617
fun comb_simps ctxt comb mk_rrule thms =
wenzelm@20028
   618
  let
wenzelm@54982
   619
    val rews = extract_rews ctxt thms;
wenzelm@51717
   620
  in fold (fold comb o mk_rrule) rews ctxt end;
berghofe@10413
   621
wenzelm@51717
   622
fun ctxt addsimps thms =
wenzelm@54982
   623
  comb_simps ctxt insert_rrule (mk_rrule ctxt) thms;
berghofe@10413
   624
wenzelm@51717
   625
fun ctxt delsimps thms =
wenzelm@54982
   626
  comb_simps ctxt del_rrule (map mk_rrule2 o mk_rrule ctxt) thms;
wenzelm@15023
   627
wenzelm@51717
   628
fun add_simp thm ctxt = ctxt addsimps [thm];
wenzelm@51717
   629
fun del_simp thm ctxt = ctxt delsimps [thm];
wenzelm@15023
   630
wenzelm@30318
   631
wenzelm@15023
   632
(* congs *)
berghofe@10413
   633
wenzelm@15023
   634
local
wenzelm@15023
   635
wenzelm@15023
   636
fun is_full_cong_prems [] [] = true
wenzelm@15023
   637
  | is_full_cong_prems [] _ = false
wenzelm@15023
   638
  | is_full_cong_prems (p :: prems) varpairs =
wenzelm@15023
   639
      (case Logic.strip_assums_concl p of
wenzelm@15023
   640
        Const ("==", _) $ lhs $ rhs =>
wenzelm@15023
   641
          let val (x, xs) = strip_comb lhs and (y, ys) = strip_comb rhs in
wenzelm@15023
   642
            is_Var x andalso forall is_Bound xs andalso
haftmann@20972
   643
            not (has_duplicates (op =) xs) andalso xs = ys andalso
wenzelm@20671
   644
            member (op =) varpairs (x, y) andalso
wenzelm@19303
   645
            is_full_cong_prems prems (remove (op =) (x, y) varpairs)
wenzelm@15023
   646
          end
wenzelm@15023
   647
      | _ => false);
wenzelm@15023
   648
wenzelm@15023
   649
fun is_full_cong thm =
berghofe@10413
   650
  let
wenzelm@43597
   651
    val prems = Thm.prems_of thm and concl = Thm.concl_of thm;
wenzelm@15023
   652
    val (lhs, rhs) = Logic.dest_equals concl;
wenzelm@15023
   653
    val (f, xs) = strip_comb lhs and (g, ys) = strip_comb rhs;
berghofe@10413
   654
  in
haftmann@20972
   655
    f = g andalso not (has_duplicates (op =) (xs @ ys)) andalso length xs = length ys andalso
wenzelm@15023
   656
    is_full_cong_prems prems (xs ~~ ys)
berghofe@10413
   657
  end;
berghofe@10413
   658
wenzelm@51717
   659
fun mk_cong ctxt =
wenzelm@51717
   660
  let val Simpset (_, {mk_rews = {mk_cong = f, ...}, ...}) = simpset_of ctxt
wenzelm@51717
   661
  in f ctxt end;
wenzelm@45620
   662
wenzelm@45620
   663
in
wenzelm@45620
   664
wenzelm@54729
   665
fun add_eqcong thm ctxt = ctxt |> map_simpset2
wenzelm@54731
   666
  (fn (congs, procs, mk_rews, termless, subgoal_tac, loop_tacs, solvers) =>
wenzelm@15023
   667
    let
wenzelm@45621
   668
      val (lhs, _) = Logic.dest_equals (Thm.concl_of thm)
wenzelm@15023
   669
        handle TERM _ => raise SIMPLIFIER ("Congruence not a meta-equality", thm);
wenzelm@18929
   670
    (*val lhs = Envir.eta_contract lhs;*)
wenzelm@45621
   671
      val a = the (cong_name (head_of lhs)) handle Option.Option =>
wenzelm@15023
   672
        raise SIMPLIFIER ("Congruence must start with a constant or free variable", thm);
haftmann@22221
   673
      val (xs, weak) = congs;
wenzelm@38834
   674
      val _ =
wenzelm@51717
   675
        if AList.defined (op =) xs a then
wenzelm@51717
   676
          Context_Position.if_visible ctxt
wenzelm@51717
   677
            warning ("Overwriting congruence rule for " ^ quote (#2 a))
haftmann@22221
   678
        else ();
krauss@30908
   679
      val xs' = AList.update (op =) (a, thm) xs;
haftmann@22221
   680
      val weak' = if is_full_cong thm then weak else a :: weak;
wenzelm@54731
   681
    in ((xs', weak'), procs, mk_rews, termless, subgoal_tac, loop_tacs, solvers) end);
berghofe@10413
   682
wenzelm@54729
   683
fun del_eqcong thm ctxt = ctxt |> map_simpset2
wenzelm@54731
   684
  (fn (congs, procs, mk_rews, termless, subgoal_tac, loop_tacs, solvers) =>
wenzelm@15023
   685
    let
wenzelm@45621
   686
      val (lhs, _) = Logic.dest_equals (Thm.concl_of thm)
wenzelm@45621
   687
        handle TERM _ => raise SIMPLIFIER ("Congruence not a meta-equality", thm);
wenzelm@18929
   688
    (*val lhs = Envir.eta_contract lhs;*)
wenzelm@20057
   689
      val a = the (cong_name (head_of lhs)) handle Option.Option =>
wenzelm@15023
   690
        raise SIMPLIFIER ("Congruence must start with a constant", thm);
haftmann@22221
   691
      val (xs, _) = congs;
wenzelm@51590
   692
      val xs' = filter_out (fn (x : cong_name, _) => x = a) xs;
krauss@30908
   693
      val weak' = xs' |> map_filter (fn (a, thm) =>
skalberg@15531
   694
        if is_full_cong thm then NONE else SOME a);
wenzelm@54731
   695
    in ((xs', weak'), procs, mk_rews, termless, subgoal_tac, loop_tacs, solvers) end);
berghofe@10413
   696
wenzelm@51717
   697
fun add_cong thm ctxt = add_eqcong (mk_cong ctxt thm) ctxt;
wenzelm@51717
   698
fun del_cong thm ctxt = del_eqcong (mk_cong ctxt thm) ctxt;
wenzelm@15023
   699
wenzelm@15023
   700
end;
berghofe@10413
   701
berghofe@10413
   702
wenzelm@15023
   703
(* simprocs *)
wenzelm@15023
   704
wenzelm@22234
   705
datatype simproc =
wenzelm@22234
   706
  Simproc of
wenzelm@22234
   707
    {name: string,
wenzelm@22234
   708
     lhss: cterm list,
wenzelm@51717
   709
     proc: morphism -> Proof.context -> cterm -> thm option,
wenzelm@22234
   710
     id: stamp * thm list};
wenzelm@22234
   711
wenzelm@22234
   712
fun eq_simproc (Simproc {id = id1, ...}, Simproc {id = id2, ...}) = eq_procid (id1, id2);
wenzelm@22008
   713
wenzelm@45290
   714
fun transform_simproc phi (Simproc {name, lhss, proc, id = (s, ths)}) =
wenzelm@22234
   715
  Simproc
wenzelm@22234
   716
   {name = name,
wenzelm@22234
   717
    lhss = map (Morphism.cterm phi) lhss,
wenzelm@22669
   718
    proc = Morphism.transform phi proc,
wenzelm@22234
   719
    id = (s, Morphism.fact phi ths)};
wenzelm@22234
   720
wenzelm@22234
   721
fun make_simproc {name, lhss, proc, identifier} =
wenzelm@22234
   722
  Simproc {name = name, lhss = lhss, proc = proc, id = (stamp (), identifier)};
wenzelm@22008
   723
wenzelm@22008
   724
fun mk_simproc name lhss proc =
wenzelm@51717
   725
  make_simproc {name = name, lhss = lhss, proc = fn _ => fn ctxt => fn ct =>
wenzelm@51717
   726
    proc ctxt (Thm.term_of ct), identifier = []};
wenzelm@22008
   727
wenzelm@35845
   728
(* FIXME avoid global thy and Logic.varify_global *)
wenzelm@38715
   729
fun simproc_global_i thy name = mk_simproc name o map (Thm.cterm_of thy o Logic.varify_global);
wenzelm@38715
   730
fun simproc_global thy name = simproc_global_i thy name o map (Syntax.read_term_global thy);
wenzelm@22008
   731
wenzelm@22008
   732
wenzelm@15023
   733
local
berghofe@10413
   734
wenzelm@51717
   735
fun add_proc (proc as Proc {name, lhs, ...}) ctxt =
wenzelm@51717
   736
 (trace_cterm ctxt false (fn () => "Adding simplification procedure " ^ quote name ^ " for") lhs;
wenzelm@54729
   737
  ctxt |> map_simpset2
wenzelm@54731
   738
    (fn (congs, procs, mk_rews, termless, subgoal_tac, loop_tacs, solvers) =>
wenzelm@54729
   739
      (congs, Net.insert_term eq_proc (term_of lhs, proc) procs,
wenzelm@54731
   740
        mk_rews, termless, subgoal_tac, loop_tacs, solvers))
wenzelm@15023
   741
  handle Net.INSERT =>
wenzelm@51717
   742
    (Context_Position.if_visible ctxt
wenzelm@51717
   743
      warning ("Ignoring duplicate simplification procedure " ^ quote name); ctxt));
berghofe@10413
   744
wenzelm@51717
   745
fun del_proc (proc as Proc {name, lhs, ...}) ctxt =
wenzelm@54729
   746
  ctxt |> map_simpset2
wenzelm@54731
   747
    (fn (congs, procs, mk_rews, termless, subgoal_tac, loop_tacs, solvers) =>
wenzelm@54729
   748
      (congs, Net.delete_term eq_proc (term_of lhs, proc) procs,
wenzelm@54731
   749
        mk_rews, termless, subgoal_tac, loop_tacs, solvers))
wenzelm@15023
   750
  handle Net.DELETE =>
wenzelm@51717
   751
    (Context_Position.if_visible ctxt
wenzelm@51717
   752
      warning ("Simplification procedure " ^ quote name ^ " not in simpset"); ctxt);
berghofe@10413
   753
wenzelm@22234
   754
fun prep_procs (Simproc {name, lhss, proc, id}) =
wenzelm@22669
   755
  lhss |> map (fn lhs => Proc {name = name, lhs = lhs, proc = Morphism.form proc, id = id});
wenzelm@22234
   756
wenzelm@15023
   757
in
berghofe@10413
   758
wenzelm@51717
   759
fun ctxt addsimprocs ps = fold (fold add_proc o prep_procs) ps ctxt;
wenzelm@51717
   760
fun ctxt delsimprocs ps = fold (fold del_proc o prep_procs) ps ctxt;
berghofe@10413
   761
wenzelm@15023
   762
end;
berghofe@10413
   763
berghofe@10413
   764
berghofe@10413
   765
(* mk_rews *)
berghofe@10413
   766
wenzelm@15023
   767
local
wenzelm@15023
   768
wenzelm@54729
   769
fun map_mk_rews f =
wenzelm@54731
   770
  map_simpset2 (fn (congs, procs, mk_rews, termless, subgoal_tac, loop_tacs, solvers) =>
wenzelm@54729
   771
    let
wenzelm@54729
   772
      val {mk, mk_cong, mk_sym, mk_eq_True, reorient} = mk_rews;
wenzelm@54729
   773
      val (mk', mk_cong', mk_sym', mk_eq_True', reorient') =
wenzelm@54729
   774
        f (mk, mk_cong, mk_sym, mk_eq_True, reorient);
wenzelm@54729
   775
      val mk_rews' = {mk = mk', mk_cong = mk_cong', mk_sym = mk_sym', mk_eq_True = mk_eq_True',
wenzelm@54729
   776
        reorient = reorient'};
wenzelm@54731
   777
    in (congs, procs, mk_rews', termless, subgoal_tac, loop_tacs, solvers) end);
wenzelm@15023
   778
wenzelm@15023
   779
in
berghofe@10413
   780
wenzelm@51717
   781
fun mksimps ctxt =
wenzelm@51717
   782
  let val Simpset (_, {mk_rews = {mk, ...}, ...}) = simpset_of ctxt
wenzelm@51717
   783
  in mk ctxt end;
wenzelm@30318
   784
wenzelm@45625
   785
fun set_mksimps mk = map_mk_rews (fn (_, mk_cong, mk_sym, mk_eq_True, reorient) =>
wenzelm@18208
   786
  (mk, mk_cong, mk_sym, mk_eq_True, reorient));
wenzelm@15023
   787
wenzelm@45625
   788
fun set_mkcong mk_cong = map_mk_rews (fn (mk, _, mk_sym, mk_eq_True, reorient) =>
wenzelm@18208
   789
  (mk, mk_cong, mk_sym, mk_eq_True, reorient));
berghofe@10413
   790
wenzelm@45625
   791
fun set_mksym mk_sym = map_mk_rews (fn (mk, mk_cong, _, mk_eq_True, reorient) =>
wenzelm@18208
   792
  (mk, mk_cong, mk_sym, mk_eq_True, reorient));
berghofe@10413
   793
wenzelm@45625
   794
fun set_mkeqTrue mk_eq_True = map_mk_rews (fn (mk, mk_cong, mk_sym, _, reorient) =>
wenzelm@18208
   795
  (mk, mk_cong, mk_sym, mk_eq_True, reorient));
wenzelm@18208
   796
wenzelm@18208
   797
fun set_reorient reorient = map_mk_rews (fn (mk, mk_cong, mk_sym, mk_eq_True, _) =>
wenzelm@18208
   798
  (mk, mk_cong, mk_sym, mk_eq_True, reorient));
wenzelm@15023
   799
wenzelm@15023
   800
end;
wenzelm@15023
   801
skalberg@14242
   802
berghofe@10413
   803
(* termless *)
berghofe@10413
   804
wenzelm@45625
   805
fun set_termless termless =
wenzelm@54731
   806
  map_simpset2 (fn (congs, procs, mk_rews, _, subgoal_tac, loop_tacs, solvers) =>
wenzelm@54731
   807
   (congs, procs, mk_rews, termless, subgoal_tac, loop_tacs, solvers));
skalberg@15006
   808
skalberg@15006
   809
wenzelm@15023
   810
(* tactics *)
skalberg@15006
   811
wenzelm@45625
   812
fun set_subgoaler subgoal_tac =
wenzelm@54731
   813
  map_simpset2 (fn (congs, procs, mk_rews, termless, _, loop_tacs, solvers) =>
wenzelm@54731
   814
   (congs, procs, mk_rews, termless, subgoal_tac, loop_tacs, solvers));
skalberg@15006
   815
wenzelm@52037
   816
fun ctxt setloop tac = ctxt |>
wenzelm@54731
   817
  map_simpset2 (fn (congs, procs, mk_rews, termless, subgoal_tac, _, solvers) =>
wenzelm@54731
   818
   (congs, procs, mk_rews, termless, subgoal_tac, [("", tac)], solvers));
skalberg@15006
   819
wenzelm@52037
   820
fun ctxt addloop (name, tac) = ctxt |>
wenzelm@54731
   821
  map_simpset2 (fn (congs, procs, mk_rews, termless, subgoal_tac, loop_tacs, solvers) =>
wenzelm@15023
   822
    (congs, procs, mk_rews, termless, subgoal_tac,
wenzelm@54731
   823
     AList.update (op =) (name, tac) loop_tacs, solvers));
skalberg@15006
   824
wenzelm@51717
   825
fun ctxt delloop name = ctxt |>
wenzelm@54731
   826
  map_simpset2 (fn (congs, procs, mk_rews, termless, subgoal_tac, loop_tacs, solvers) =>
haftmann@21286
   827
    (congs, procs, mk_rews, termless, subgoal_tac,
wenzelm@38834
   828
     (if AList.defined (op =) loop_tacs name then ()
wenzelm@51717
   829
      else
wenzelm@51717
   830
        Context_Position.if_visible ctxt
wenzelm@51717
   831
          warning ("No such looper in simpset: " ^ quote name);
wenzelm@54731
   832
        AList.delete (op =) name loop_tacs), solvers));
skalberg@15006
   833
wenzelm@54729
   834
fun ctxt setSSolver solver = ctxt |> map_simpset2
wenzelm@54731
   835
  (fn (congs, procs, mk_rews, termless, subgoal_tac, loop_tacs, (unsafe_solvers, _)) =>
wenzelm@54731
   836
    (congs, procs, mk_rews, termless, subgoal_tac, loop_tacs, (unsafe_solvers, [solver])));
skalberg@15006
   837
wenzelm@51717
   838
fun ctxt addSSolver solver = ctxt |> map_simpset2 (fn (congs, procs, mk_rews, termless,
wenzelm@54731
   839
  subgoal_tac, loop_tacs, (unsafe_solvers, solvers)) => (congs, procs, mk_rews, termless,
wenzelm@54731
   840
    subgoal_tac, loop_tacs, (unsafe_solvers, insert eq_solver solver solvers)));
skalberg@15006
   841
wenzelm@51717
   842
fun ctxt setSolver solver = ctxt |> map_simpset2 (fn (congs, procs, mk_rews, termless,
wenzelm@54731
   843
  subgoal_tac, loop_tacs, (_, solvers)) => (congs, procs, mk_rews, termless,
wenzelm@54731
   844
    subgoal_tac, loop_tacs, ([solver], solvers)));
skalberg@15006
   845
wenzelm@51717
   846
fun ctxt addSolver solver = ctxt |> map_simpset2 (fn (congs, procs, mk_rews, termless,
wenzelm@54731
   847
  subgoal_tac, loop_tacs, (unsafe_solvers, solvers)) => (congs, procs, mk_rews, termless,
wenzelm@54731
   848
    subgoal_tac, loop_tacs, (insert eq_solver solver unsafe_solvers, solvers)));
skalberg@15006
   849
wenzelm@15023
   850
fun set_solvers solvers = map_simpset2 (fn (congs, procs, mk_rews, termless,
wenzelm@54731
   851
  subgoal_tac, loop_tacs, _) => (congs, procs, mk_rews, termless,
wenzelm@54731
   852
  subgoal_tac, loop_tacs, (solvers, solvers)));
wenzelm@54729
   853
wenzelm@54729
   854
wenzelm@54729
   855
(* trace operations *)
wenzelm@54729
   856
wenzelm@54731
   857
type trace_ops =
wenzelm@54731
   858
 {trace_invoke: {depth: int, term: term} -> Proof.context -> Proof.context,
wenzelm@54731
   859
  trace_apply: {unconditional: bool, term: term, thm: thm, name: string} ->
wenzelm@54731
   860
    Proof.context -> (Proof.context -> (thm * term) option) -> (thm * term) option};
wenzelm@54729
   861
wenzelm@54731
   862
structure Trace_Ops = Theory_Data
wenzelm@54731
   863
(
wenzelm@54731
   864
  type T = trace_ops;
wenzelm@54731
   865
  val empty: T =
wenzelm@54731
   866
   {trace_invoke = fn _ => fn ctxt => ctxt,
wenzelm@54731
   867
    trace_apply = fn _ => fn ctxt => fn cont => cont ctxt};
wenzelm@54731
   868
  val extend = I;
wenzelm@54731
   869
  fun merge (trace_ops, _) = trace_ops;
wenzelm@54731
   870
);
wenzelm@54731
   871
wenzelm@54731
   872
val set_trace_ops = Trace_Ops.put;
wenzelm@54731
   873
wenzelm@54731
   874
val trace_ops = Trace_Ops.get o Proof_Context.theory_of;
wenzelm@54729
   875
fun trace_invoke args ctxt = #trace_invoke (trace_ops ctxt) args ctxt;
wenzelm@54729
   876
fun trace_apply args ctxt = #trace_apply (trace_ops ctxt) args ctxt;
skalberg@15006
   877
skalberg@15006
   878
skalberg@15006
   879
berghofe@10413
   880
(** rewriting **)
berghofe@10413
   881
berghofe@10413
   882
(*
berghofe@10413
   883
  Uses conversions, see:
berghofe@10413
   884
    L C Paulson, A higher-order implementation of rewriting,
berghofe@10413
   885
    Science of Computer Programming 3 (1983), pages 119-149.
berghofe@10413
   886
*)
berghofe@10413
   887
wenzelm@51717
   888
fun check_conv ctxt msg thm thm' =
berghofe@10413
   889
  let
wenzelm@36944
   890
    val thm'' = Thm.transitive thm thm' handle THM _ =>
wenzelm@36944
   891
     Thm.transitive thm (Thm.transitive
wenzelm@36944
   892
       (Thm.symmetric (Drule.beta_eta_conversion (Thm.lhs_of thm'))) thm')
wenzelm@51717
   893
  in if msg then trace_thm ctxt (fn () => "SUCCEEDED") thm' else (); SOME thm'' end
berghofe@10413
   894
  handle THM _ =>
wenzelm@26626
   895
    let
wenzelm@26626
   896
      val _ $ _ $ prop0 = Thm.prop_of thm;
wenzelm@26626
   897
    in
wenzelm@51717
   898
      trace_thm ctxt (fn () => "Proved wrong thm (Check subgoaler?)") thm';
wenzelm@51717
   899
      trace_term ctxt false (fn () => "Should have proved:") prop0;
skalberg@15531
   900
      NONE
berghofe@10413
   901
    end;
berghofe@10413
   902
berghofe@10413
   903
berghofe@10413
   904
(* mk_procrule *)
berghofe@10413
   905
wenzelm@51717
   906
fun mk_procrule ctxt thm =
wenzelm@52091
   907
  let val (prems, lhs, elhs, rhs, _) = decomp_simp thm in
wenzelm@15023
   908
    if rewrite_rule_extra_vars prems lhs rhs
wenzelm@51717
   909
    then (cond_warn_thm ctxt (fn () => "Extra vars on rhs:") thm; [])
wenzelm@15023
   910
    else [mk_rrule2 {thm = thm, name = "", lhs = lhs, elhs = elhs, perm = false}]
berghofe@10413
   911
  end;
berghofe@10413
   912
berghofe@10413
   913
wenzelm@15023
   914
(* rewritec: conversion to apply the meta simpset to a term *)
berghofe@10413
   915
wenzelm@15023
   916
(*Since the rewriting strategy is bottom-up, we avoid re-normalizing already
wenzelm@15023
   917
  normalized terms by carrying around the rhs of the rewrite rule just
wenzelm@15023
   918
  applied. This is called the `skeleton'. It is decomposed in parallel
wenzelm@15023
   919
  with the term. Once a Var is encountered, the corresponding term is
wenzelm@15023
   920
  already in normal form.
wenzelm@15023
   921
  skel0 is a dummy skeleton that is to enforce complete normalization.*)
wenzelm@15023
   922
berghofe@10413
   923
val skel0 = Bound 0;
berghofe@10413
   924
wenzelm@15023
   925
(*Use rhs as skeleton only if the lhs does not contain unnormalized bits.
wenzelm@15023
   926
  The latter may happen iff there are weak congruence rules for constants
wenzelm@15023
   927
  in the lhs.*)
berghofe@10413
   928
wenzelm@15023
   929
fun uncond_skel ((_, weak), (lhs, rhs)) =
wenzelm@15023
   930
  if null weak then rhs  (*optimization*)
wenzelm@51591
   931
  else if exists_subterm
wenzelm@51591
   932
    (fn Const (a, _) => member (op =) weak (true, a)
wenzelm@51591
   933
      | Free (a, _) => member (op =) weak (false, a)
wenzelm@51591
   934
      | _ => false) lhs then skel0
wenzelm@15023
   935
  else rhs;
wenzelm@15023
   936
wenzelm@15023
   937
(*Behaves like unconditional rule if rhs does not contain vars not in the lhs.
wenzelm@15023
   938
  Otherwise those vars may become instantiated with unnormalized terms
wenzelm@15023
   939
  while the premises are solved.*)
wenzelm@15023
   940
wenzelm@32797
   941
fun cond_skel (args as (_, (lhs, rhs))) =
haftmann@33038
   942
  if subset (op =) (Term.add_vars rhs [], Term.add_vars lhs []) then uncond_skel args
berghofe@10413
   943
  else skel0;
berghofe@10413
   944
berghofe@10413
   945
(*
wenzelm@15023
   946
  Rewriting -- we try in order:
berghofe@10413
   947
    (1) beta reduction
berghofe@10413
   948
    (2) unconditional rewrite rules
berghofe@10413
   949
    (3) conditional rewrite rules
berghofe@10413
   950
    (4) simplification procedures
berghofe@10413
   951
berghofe@10413
   952
  IMPORTANT: rewrite rules must not introduce new Vars or TVars!
berghofe@10413
   953
*)
berghofe@10413
   954
wenzelm@52091
   955
fun rewritec (prover, maxt) ctxt t =
berghofe@10413
   956
  let
wenzelm@51717
   957
    val Simpset ({rules, ...}, {congs, procs, termless, ...}) = simpset_of ctxt;
berghofe@10413
   958
    val eta_thm = Thm.eta_conversion t;
wenzelm@22902
   959
    val eta_t' = Thm.rhs_of eta_thm;
berghofe@10413
   960
    val eta_t = term_of eta_t';
wenzelm@20546
   961
    fun rew {thm, name, lhs, elhs, extra, fo, perm} =
berghofe@10413
   962
      let
wenzelm@32797
   963
        val prop = Thm.prop_of thm;
wenzelm@20546
   964
        val (rthm, elhs') =
wenzelm@20546
   965
          if maxt = ~1 orelse not extra then (thm, elhs)
wenzelm@22902
   966
          else (Thm.incr_indexes (maxt + 1) thm, Thm.incr_indexes_cterm (maxt + 1) elhs);
wenzelm@22902
   967
        val insts =
wenzelm@22902
   968
          if fo then Thm.first_order_match (elhs', eta_t')
wenzelm@22902
   969
          else Thm.match (elhs', eta_t');
berghofe@10413
   970
        val thm' = Thm.instantiate insts (Thm.rename_boundvars lhs eta_t rthm);
wenzelm@14643
   971
        val prop' = Thm.prop_of thm';
wenzelm@21576
   972
        val unconditional = (Logic.count_prems prop' = 0);
wenzelm@54725
   973
        val (lhs', rhs') = Logic.dest_equals (Logic.strip_imp_concl prop');
wenzelm@54729
   974
        val trace_args = {unconditional = unconditional, term = eta_t, thm = thm', name = name};
berghofe@10413
   975
      in
nipkow@11295
   976
        if perm andalso not (termless (rhs', lhs'))
wenzelm@54725
   977
        then
wenzelm@54725
   978
         (trace_named_thm ctxt (fn () => "Cannot apply permutative rewrite rule") (thm, name);
wenzelm@54725
   979
          trace_thm ctxt (fn () => "Term does not become smaller:") thm';
wenzelm@54725
   980
          NONE)
wenzelm@54725
   981
        else
wenzelm@54725
   982
         (trace_named_thm ctxt (fn () => "Applying instance of rewrite rule") (thm, name);
wenzelm@54725
   983
          if unconditional
wenzelm@54725
   984
          then
wenzelm@54725
   985
           (trace_thm ctxt (fn () => "Rewriting:") thm';
wenzelm@54729
   986
            trace_apply trace_args ctxt (fn ctxt' =>
wenzelm@54729
   987
              let
wenzelm@54729
   988
                val lr = Logic.dest_equals prop;
wenzelm@54729
   989
                val SOME thm'' = check_conv ctxt' false eta_thm thm';
wenzelm@54729
   990
              in SOME (thm'', uncond_skel (congs, lr)) end))
wenzelm@54725
   991
          else
wenzelm@54725
   992
           (trace_thm ctxt (fn () => "Trying to rewrite:") thm';
wenzelm@54725
   993
            if simp_depth ctxt > Config.get ctxt simp_depth_limit
wenzelm@54725
   994
            then
wenzelm@38834
   995
              let
wenzelm@54725
   996
                val s = "simp_depth_limit exceeded - giving up";
wenzelm@54725
   997
                val _ = trace ctxt false (fn () => s);
wenzelm@54725
   998
                val _ = Context_Position.if_visible ctxt warning s;
wenzelm@54725
   999
              in NONE end
wenzelm@54725
  1000
            else
wenzelm@54729
  1001
              trace_apply trace_args ctxt (fn ctxt' =>
wenzelm@54729
  1002
                (case prover ctxt' thm' of
wenzelm@54729
  1003
                  NONE => (trace_thm ctxt' (fn () => "FAILED") thm'; NONE)
wenzelm@54729
  1004
                | SOME thm2 =>
wenzelm@54729
  1005
                    (case check_conv ctxt' true eta_thm thm2 of
wenzelm@54729
  1006
                      NONE => NONE
wenzelm@54729
  1007
                    | SOME thm2' =>
wenzelm@54729
  1008
                        let
wenzelm@54729
  1009
                          val concl = Logic.strip_imp_concl prop;
wenzelm@54729
  1010
                          val lr = Logic.dest_equals concl;
wenzelm@54729
  1011
                        in SOME (thm2', cond_skel (congs, lr)) end)))))
wenzelm@51717
  1012
      end;
berghofe@10413
  1013
skalberg@15531
  1014
    fun rews [] = NONE
berghofe@10413
  1015
      | rews (rrule :: rrules) =
skalberg@15531
  1016
          let val opt = rew rrule handle Pattern.MATCH => NONE
wenzelm@54725
  1017
          in (case opt of NONE => rews rrules | some => some) end;
berghofe@10413
  1018
wenzelm@38834
  1019
    fun sort_rrules rrs =
wenzelm@38834
  1020
      let
wenzelm@38834
  1021
        fun is_simple ({thm, ...}: rrule) =
wenzelm@38834
  1022
          (case Thm.prop_of thm of
wenzelm@38834
  1023
            Const ("==", _) $ _ $ _ => true
wenzelm@38834
  1024
          | _ => false);
wenzelm@38834
  1025
        fun sort [] (re1, re2) = re1 @ re2
wenzelm@38834
  1026
          | sort (rr :: rrs) (re1, re2) =
wenzelm@38834
  1027
              if is_simple rr
wenzelm@38834
  1028
              then sort rrs (rr :: re1, re2)
wenzelm@38834
  1029
              else sort rrs (re1, rr :: re2);
wenzelm@38834
  1030
      in sort rrs ([], []) end;
berghofe@10413
  1031
skalberg@15531
  1032
    fun proc_rews [] = NONE
wenzelm@15023
  1033
      | proc_rews (Proc {name, proc, lhs, ...} :: ps) =
wenzelm@52091
  1034
          if Pattern.matches (Proof_Context.theory_of ctxt) (Thm.term_of lhs, Thm.term_of t) then
wenzelm@51717
  1035
            (debug_term ctxt false (fn () => "Trying procedure " ^ quote name ^ " on:") eta_t;
wenzelm@54725
  1036
             (case proc ctxt eta_t' of
wenzelm@51717
  1037
               NONE => (debug ctxt false (fn () => "FAILED"); proc_rews ps)
skalberg@15531
  1038
             | SOME raw_thm =>
wenzelm@51717
  1039
                 (trace_thm ctxt (fn () => "Procedure " ^ quote name ^ " produced rewrite rule:")
wenzelm@51717
  1040
                   raw_thm;
wenzelm@51717
  1041
                  (case rews (mk_procrule ctxt raw_thm) of
wenzelm@51717
  1042
                    NONE => (trace_cterm ctxt true (fn () => "IGNORED result of simproc " ^ quote name ^
wenzelm@51717
  1043
                      " -- does not match") t; proc_rews ps)
wenzelm@54725
  1044
                  | some => some))))
berghofe@10413
  1045
          else proc_rews ps;
wenzelm@38834
  1046
  in
wenzelm@38834
  1047
    (case eta_t of
wenzelm@38834
  1048
      Abs _ $ _ => SOME (Thm.transitive eta_thm (Thm.beta_conversion false eta_t'), skel0)
wenzelm@38834
  1049
    | _ =>
wenzelm@38834
  1050
      (case rews (sort_rrules (Net.match_term rules eta_t)) of
wenzelm@38834
  1051
        NONE => proc_rews (Net.match_term procs eta_t)
wenzelm@38834
  1052
      | some => some))
berghofe@10413
  1053
  end;
berghofe@10413
  1054
berghofe@10413
  1055
berghofe@10413
  1056
(* conversion to apply a congruence rule to a term *)
berghofe@10413
  1057
wenzelm@51717
  1058
fun congc prover ctxt maxt cong t =
wenzelm@51717
  1059
  let
wenzelm@51717
  1060
    val rthm = Thm.incr_indexes (maxt + 1) cong;
wenzelm@51717
  1061
    val rlhs = fst (Thm.dest_equals (Drule.strip_imp_concl (cprop_of rthm)));
wenzelm@51717
  1062
    val insts = Thm.match (rlhs, t)
wenzelm@51717
  1063
    (* Thm.match can raise Pattern.MATCH;
wenzelm@51717
  1064
       is handled when congc is called *)
wenzelm@51717
  1065
    val thm' = Thm.instantiate insts (Thm.rename_boundvars (term_of rlhs) (term_of t) rthm);
wenzelm@51717
  1066
    val _ = trace_thm ctxt (fn () => "Applying congruence rule:") thm';
wenzelm@51717
  1067
    fun err (msg, thm) = (trace_thm ctxt (fn () => msg) thm; NONE);
wenzelm@38834
  1068
  in
wenzelm@38834
  1069
    (case prover thm' of
wenzelm@38834
  1070
      NONE => err ("Congruence proof failed.  Could not prove", thm')
wenzelm@38834
  1071
    | SOME thm2 =>
wenzelm@51717
  1072
        (case check_conv ctxt true (Drule.beta_eta_conversion t) thm2 of
skalberg@15531
  1073
          NONE => err ("Congruence proof failed.  Should not have proved", thm2)
skalberg@15531
  1074
        | SOME thm2' =>
wenzelm@22902
  1075
            if op aconv (pairself term_of (Thm.dest_equals (cprop_of thm2')))
wenzelm@38834
  1076
            then NONE else SOME thm2'))
berghofe@10413
  1077
  end;
berghofe@10413
  1078
berghofe@10413
  1079
val (cA, (cB, cC)) =
wenzelm@22902
  1080
  apsnd Thm.dest_equals (Thm.dest_implies (hd (cprems_of Drule.imp_cong)));
berghofe@10413
  1081
skalberg@15531
  1082
fun transitive1 NONE NONE = NONE
skalberg@15531
  1083
  | transitive1 (SOME thm1) NONE = SOME thm1
skalberg@15531
  1084
  | transitive1 NONE (SOME thm2) = SOME thm2
wenzelm@54725
  1085
  | transitive1 (SOME thm1) (SOME thm2) = SOME (Thm.transitive thm1 thm2);
berghofe@10413
  1086
skalberg@15531
  1087
fun transitive2 thm = transitive1 (SOME thm);
skalberg@15531
  1088
fun transitive3 thm = transitive1 thm o SOME;
berghofe@13607
  1089
wenzelm@52091
  1090
fun bottomc ((simprem, useprem, mutsimp), prover, maxidx) =
berghofe@10413
  1091
  let
wenzelm@51717
  1092
    fun botc skel ctxt t =
wenzelm@54725
  1093
      if is_Var skel then NONE
wenzelm@54725
  1094
      else
wenzelm@54725
  1095
        (case subc skel ctxt t of
wenzelm@54725
  1096
           some as SOME thm1 =>
wenzelm@54725
  1097
             (case rewritec (prover, maxidx) ctxt (Thm.rhs_of thm1) of
wenzelm@54725
  1098
                SOME (thm2, skel2) =>
wenzelm@54725
  1099
                  transitive2 (Thm.transitive thm1 thm2)
wenzelm@51717
  1100
                    (botc skel2 ctxt (Thm.rhs_of thm2))
wenzelm@54725
  1101
              | NONE => some)
wenzelm@54725
  1102
         | NONE =>
wenzelm@54725
  1103
             (case rewritec (prover, maxidx) ctxt t of
wenzelm@54725
  1104
                SOME (thm2, skel2) => transitive2 thm2
wenzelm@54725
  1105
                  (botc skel2 ctxt (Thm.rhs_of thm2))
wenzelm@54725
  1106
              | NONE => NONE))
berghofe@10413
  1107
wenzelm@51717
  1108
    and try_botc ctxt t =
wenzelm@54725
  1109
      (case botc skel0 ctxt t of
wenzelm@54725
  1110
        SOME trec1 => trec1
wenzelm@54725
  1111
      | NONE => Thm.reflexive t)
berghofe@10413
  1112
wenzelm@51717
  1113
    and subc skel ctxt t0 =
wenzelm@51717
  1114
        let val Simpset ({bounds, ...}, {congs, ...}) = simpset_of ctxt in
wenzelm@51717
  1115
          (case term_of t0 of
wenzelm@51717
  1116
              Abs (a, T, _) =>
wenzelm@51717
  1117
                let
wenzelm@51717
  1118
                    val b = Name.bound (#1 bounds);
wenzelm@51717
  1119
                    val (v, t') = Thm.dest_abs (SOME b) t0;
wenzelm@51717
  1120
                    val b' = #1 (Term.dest_Free (Thm.term_of v));
wenzelm@51717
  1121
                    val _ =
wenzelm@51717
  1122
                      if b <> b' then
wenzelm@51717
  1123
                        warning ("Simplifier: renamed bound variable " ^
wenzelm@51717
  1124
                          quote b ^ " to " ^ quote b' ^ Position.here (Position.thread_data ()))
wenzelm@51717
  1125
                      else ();
wenzelm@51717
  1126
                    val ctxt' = add_bound ((b', T), a) ctxt;
wenzelm@54725
  1127
                    val skel' = (case skel of Abs (_, _, sk) => sk | _ => skel0);
wenzelm@51717
  1128
                in
wenzelm@51717
  1129
                  (case botc skel' ctxt' t' of
wenzelm@51717
  1130
                    SOME thm => SOME (Thm.abstract_rule a v thm)
wenzelm@51717
  1131
                  | NONE => NONE)
wenzelm@51717
  1132
                end
wenzelm@54725
  1133
            | t $ _ =>
wenzelm@54725
  1134
              (case t of
wenzelm@51717
  1135
                Const ("==>", _) $ _  => impc t0 ctxt
wenzelm@51717
  1136
              | Abs _ =>
wenzelm@51717
  1137
                  let val thm = Thm.beta_conversion false t0
wenzelm@54725
  1138
                  in
wenzelm@54725
  1139
                    (case subc skel0 ctxt (Thm.rhs_of thm) of
wenzelm@54725
  1140
                      NONE => SOME thm
wenzelm@54725
  1141
                    | SOME thm' => SOME (Thm.transitive thm thm'))
wenzelm@51717
  1142
                  end
wenzelm@51717
  1143
              | _  =>
wenzelm@54727
  1144
                  let
wenzelm@54727
  1145
                    fun appc () =
wenzelm@54727
  1146
                      let
wenzelm@54727
  1147
                        val (tskel, uskel) =
wenzelm@54727
  1148
                          (case skel of
wenzelm@54727
  1149
                            tskel $ uskel => (tskel, uskel)
wenzelm@54727
  1150
                          | _ => (skel0, skel0));
wenzelm@54727
  1151
                        val (ct, cu) = Thm.dest_comb t0;
wenzelm@54727
  1152
                      in
wenzelm@54727
  1153
                        (case botc tskel ctxt ct of
wenzelm@54727
  1154
                          SOME thm1 =>
wenzelm@54727
  1155
                            (case botc uskel ctxt cu of
wenzelm@54727
  1156
                              SOME thm2 => SOME (Thm.combination thm1 thm2)
wenzelm@54727
  1157
                            | NONE => SOME (Thm.combination thm1 (Thm.reflexive cu)))
wenzelm@54727
  1158
                        | NONE =>
wenzelm@54727
  1159
                            (case botc uskel ctxt cu of
wenzelm@54727
  1160
                              SOME thm1 => SOME (Thm.combination (Thm.reflexive ct) thm1)
wenzelm@54727
  1161
                            | NONE => NONE))
wenzelm@54727
  1162
                      end;
wenzelm@54727
  1163
                    val (h, ts) = strip_comb t;
wenzelm@54725
  1164
                  in
wenzelm@54725
  1165
                    (case cong_name h of
wenzelm@54725
  1166
                      SOME a =>
wenzelm@54725
  1167
                        (case AList.lookup (op =) (fst congs) a of
wenzelm@54725
  1168
                           NONE => appc ()
wenzelm@54725
  1169
                        | SOME cong =>
wenzelm@51717
  1170
     (*post processing: some partial applications h t1 ... tj, j <= length ts,
wenzelm@51717
  1171
       may be a redex. Example: map (%x. x) = (%xs. xs) wrt map_cong*)
wenzelm@54725
  1172
                           (let
wenzelm@54725
  1173
                              val thm = congc (prover ctxt) ctxt maxidx cong t0;
wenzelm@54725
  1174
                              val t = the_default t0 (Option.map Thm.rhs_of thm);
wenzelm@54725
  1175
                              val (cl, cr) = Thm.dest_comb t
wenzelm@54725
  1176
                              val dVar = Var(("", 0), dummyT)
wenzelm@54725
  1177
                              val skel =
wenzelm@54725
  1178
                                list_comb (h, replicate (length ts) dVar)
wenzelm@54725
  1179
                            in
wenzelm@54725
  1180
                              (case botc skel ctxt cl of
wenzelm@54725
  1181
                                NONE => thm
wenzelm@54725
  1182
                              | SOME thm' =>
wenzelm@54725
  1183
                                  transitive3 thm (Thm.combination thm' (Thm.reflexive cr)))
wenzelm@54725
  1184
                            end handle Pattern.MATCH => appc ()))
wenzelm@54725
  1185
                     | _ => appc ())
wenzelm@51717
  1186
                  end)
wenzelm@51717
  1187
            | _ => NONE)
wenzelm@51717
  1188
        end
wenzelm@51717
  1189
    and impc ct ctxt =
wenzelm@54725
  1190
      if mutsimp then mut_impc0 [] ct [] [] ctxt
wenzelm@54725
  1191
      else nonmut_impc ct ctxt
berghofe@10413
  1192
wenzelm@54984
  1193
    and rules_of_prem prem ctxt =
berghofe@13607
  1194
      if maxidx_of_term (term_of prem) <> ~1
wenzelm@51717
  1195
      then (trace_cterm ctxt true
wenzelm@22254
  1196
        (fn () => "Cannot add premise as rewrite rule because it contains (type) unknowns:")
wenzelm@54984
  1197
        prem; (([], NONE), ctxt))
berghofe@13607
  1198
      else
wenzelm@54984
  1199
        let val (asm, ctxt') = Thm.assume_hyps prem ctxt
wenzelm@54984
  1200
        in ((extract_safe_rrules ctxt' asm, SOME asm), ctxt') end
berghofe@10413
  1201
wenzelm@51717
  1202
    and add_rrules (rrss, asms) ctxt =
wenzelm@51717
  1203
      (fold o fold) insert_rrule rrss ctxt |> add_prems (map_filter I asms)
berghofe@10413
  1204
wenzelm@23178
  1205
    and disch r prem eq =
berghofe@13607
  1206
      let
wenzelm@22902
  1207
        val (lhs, rhs) = Thm.dest_equals (Thm.cprop_of eq);
wenzelm@54727
  1208
        val eq' =
wenzelm@54727
  1209
          Thm.implies_elim
wenzelm@54727
  1210
            (Thm.instantiate ([], [(cA, prem), (cB, lhs), (cC, rhs)]) Drule.imp_cong)
wenzelm@54727
  1211
            (Thm.implies_intr prem eq);
wenzelm@54725
  1212
      in
wenzelm@54725
  1213
        if not r then eq'
wenzelm@54725
  1214
        else
wenzelm@54725
  1215
          let
wenzelm@54725
  1216
            val (prem', concl) = Thm.dest_implies lhs;
wenzelm@54727
  1217
            val (prem'', _) = Thm.dest_implies rhs;
wenzelm@54727
  1218
          in
wenzelm@54727
  1219
            Thm.transitive
wenzelm@54727
  1220
              (Thm.transitive
wenzelm@54727
  1221
                (Thm.instantiate ([], [(cA, prem'), (cB, prem), (cC, concl)]) Drule.swap_prems_eq)
wenzelm@54727
  1222
                eq')
wenzelm@54727
  1223
              (Thm.instantiate ([], [(cA, prem), (cB, prem''), (cC, concl)]) Drule.swap_prems_eq)
wenzelm@54725
  1224
          end
berghofe@10413
  1225
      end
berghofe@10413
  1226
berghofe@13607
  1227
    and rebuild [] _ _ _ _ eq = eq
wenzelm@51717
  1228
      | rebuild (prem :: prems) concl (_ :: rrss) (_ :: asms) ctxt eq =
berghofe@13607
  1229
          let
wenzelm@51717
  1230
            val ctxt' = add_rrules (rev rrss, rev asms) ctxt;
berghofe@13607
  1231
            val concl' =
wenzelm@22902
  1232
              Drule.mk_implies (prem, the_default concl (Option.map Thm.rhs_of eq));
wenzelm@54727
  1233
            val dprem = Option.map (disch false prem);
wenzelm@38834
  1234
          in
wenzelm@52091
  1235
            (case rewritec (prover, maxidx) ctxt' concl' of
wenzelm@51717
  1236
              NONE => rebuild prems concl' rrss asms ctxt (dprem eq)
wenzelm@54727
  1237
            | SOME (eq', _) =>
wenzelm@54727
  1238
                transitive2 (fold (disch false) prems (the (transitive3 (dprem eq) eq')))
wenzelm@54727
  1239
                  (mut_impc0 (rev prems) (Thm.rhs_of eq') (rev rrss) (rev asms) ctxt))
berghofe@13607
  1240
          end
wenzelm@15023
  1241
wenzelm@51717
  1242
    and mut_impc0 prems concl rrss asms ctxt =
berghofe@13607
  1243
      let
berghofe@13607
  1244
        val prems' = strip_imp_prems concl;
wenzelm@54984
  1245
        val ((rrss', asms'), ctxt') = fold_map rules_of_prem prems' ctxt |>> split_list;
wenzelm@38834
  1246
      in
wenzelm@38834
  1247
        mut_impc (prems @ prems') (strip_imp_concl concl) (rrss @ rrss')
wenzelm@54984
  1248
          (asms @ asms') [] [] [] [] ctxt' ~1 ~1
berghofe@13607
  1249
      end
wenzelm@15023
  1250
wenzelm@51717
  1251
    and mut_impc [] concl [] [] prems' rrss' asms' eqns ctxt changed k =
wenzelm@33245
  1252
        transitive1 (fold (fn (eq1, prem) => fn eq2 => transitive1 eq1
wenzelm@33245
  1253
            (Option.map (disch false prem) eq2)) (eqns ~~ prems') NONE)
berghofe@13607
  1254
          (if changed > 0 then
berghofe@13607
  1255
             mut_impc (rev prems') concl (rev rrss') (rev asms')
wenzelm@51717
  1256
               [] [] [] [] ctxt ~1 changed
wenzelm@51717
  1257
           else rebuild prems' concl rrss' asms' ctxt
wenzelm@51717
  1258
             (botc skel0 (add_rrules (rev rrss', rev asms') ctxt) concl))
berghofe@13607
  1259
berghofe@13607
  1260
      | mut_impc (prem :: prems) concl (rrs :: rrss) (asm :: asms)
wenzelm@51717
  1261
          prems' rrss' asms' eqns ctxt changed k =
wenzelm@54725
  1262
        (case (if k = 0 then NONE else botc skel0 (add_rrules
wenzelm@51717
  1263
          (rev rrss' @ rrss, rev asms' @ asms) ctxt) prem) of
skalberg@15531
  1264
            NONE => mut_impc prems concl rrss asms (prem :: prems')
wenzelm@51717
  1265
              (rrs :: rrss') (asm :: asms') (NONE :: eqns) ctxt changed
berghofe@13607
  1266
              (if k = 0 then 0 else k - 1)
wenzelm@54725
  1267
        | SOME eqn =>
berghofe@13607
  1268
            let
wenzelm@22902
  1269
              val prem' = Thm.rhs_of eqn;
berghofe@13607
  1270
              val tprems = map term_of prems;
wenzelm@33029
  1271
              val i = 1 + fold Integer.max (map (fn p =>
wenzelm@44058
  1272
                find_index (fn q => q aconv p) tprems) (Thm.hyps_of eqn)) ~1;
wenzelm@54984
  1273
              val ((rrs', asm'), ctxt') = rules_of_prem prem' ctxt;
wenzelm@54725
  1274
            in
wenzelm@54725
  1275
              mut_impc prems concl rrss asms (prem' :: prems')
wenzelm@54725
  1276
                (rrs' :: rrss') (asm' :: asms')
wenzelm@54725
  1277
                (SOME (fold_rev (disch true)
wenzelm@54725
  1278
                  (take i prems)
wenzelm@54725
  1279
                  (Drule.imp_cong_rule eqn (Thm.reflexive (Drule.list_implies
wenzelm@54725
  1280
                    (drop i prems, concl))))) :: eqns)
wenzelm@54984
  1281
                ctxt' (length prems') ~1
wenzelm@54725
  1282
            end)
berghofe@13607
  1283
wenzelm@54725
  1284
    (*legacy code -- only for backwards compatibility*)
wenzelm@51717
  1285
    and nonmut_impc ct ctxt =
wenzelm@38834
  1286
      let
wenzelm@38834
  1287
        val (prem, conc) = Thm.dest_implies ct;
wenzelm@51717
  1288
        val thm1 = if simprem then botc skel0 ctxt prem else NONE;
wenzelm@38834
  1289
        val prem1 = the_default prem (Option.map Thm.rhs_of thm1);
wenzelm@51717
  1290
        val ctxt1 =
wenzelm@51717
  1291
          if not useprem then ctxt
wenzelm@54984
  1292
          else
wenzelm@54984
  1293
            let val ((rrs, asm), ctxt') = rules_of_prem prem1 ctxt
wenzelm@54984
  1294
            in add_rrules ([rrs], [asm]) ctxt' end;
wenzelm@38834
  1295
      in
wenzelm@51717
  1296
        (case botc skel0 ctxt1 conc of
wenzelm@38834
  1297
          NONE =>
wenzelm@38834
  1298
            (case thm1 of
wenzelm@38834
  1299
              NONE => NONE
wenzelm@38834
  1300
            | SOME thm1' => SOME (Drule.imp_cong_rule thm1' (Thm.reflexive conc)))
wenzelm@38834
  1301
        | SOME thm2 =>
wenzelm@38834
  1302
            let val thm2' = disch false prem1 thm2 in
wenzelm@38834
  1303
              (case thm1 of
wenzelm@38834
  1304
                NONE => SOME thm2'
wenzelm@38834
  1305
              | SOME thm1' =>
wenzelm@36944
  1306
                 SOME (Thm.transitive (Drule.imp_cong_rule thm1' (Thm.reflexive conc)) thm2'))
wenzelm@38834
  1307
            end)
wenzelm@54725
  1308
      end;
berghofe@10413
  1309
wenzelm@54725
  1310
  in try_botc end;
berghofe@10413
  1311
berghofe@10413
  1312
wenzelm@15023
  1313
(* Meta-rewriting: rewrites t to u and returns the theorem t==u *)
berghofe@10413
  1314
berghofe@10413
  1315
(*
berghofe@10413
  1316
  Parameters:
berghofe@10413
  1317
    mode = (simplify A,
berghofe@10413
  1318
            use A in simplifying B,
berghofe@10413
  1319
            use prems of B (if B is again a meta-impl.) to simplify A)
berghofe@10413
  1320
           when simplifying A ==> B
berghofe@10413
  1321
    prover: how to solve premises in conditional rewrites and congruences
berghofe@10413
  1322
*)
berghofe@10413
  1323
wenzelm@32738
  1324
val debug_bounds = Unsynchronized.ref false;
wenzelm@17705
  1325
wenzelm@51717
  1326
fun check_bounds ctxt ct =
wenzelm@21962
  1327
  if ! debug_bounds then
wenzelm@21962
  1328
    let
wenzelm@51717
  1329
      val Simpset ({bounds = (_, bounds), ...}, _) = simpset_of ctxt;
wenzelm@51717
  1330
      val bs =
wenzelm@51717
  1331
        fold_aterms
wenzelm@51717
  1332
          (fn Free (x, _) =>
wenzelm@51717
  1333
            if Name.is_bound x andalso not (AList.defined eq_bound bounds x)
wenzelm@51717
  1334
            then insert (op =) x else I
wenzelm@51717
  1335
          | _ => I) (term_of ct) [];
wenzelm@21962
  1336
    in
wenzelm@21962
  1337
      if null bs then ()
wenzelm@51717
  1338
      else
wenzelm@51717
  1339
        print_term ctxt true
wenzelm@51717
  1340
          (fn () => "Simplifier: term contains loose bounds: " ^ commas_quote bs)
wenzelm@51717
  1341
          (Thm.term_of ct)
wenzelm@21962
  1342
    end
wenzelm@21962
  1343
  else ();
wenzelm@17614
  1344
wenzelm@51717
  1345
fun rewrite_cterm mode prover raw_ctxt raw_ct =
wenzelm@17882
  1346
  let
wenzelm@54729
  1347
    val thy = Proof_Context.theory_of raw_ctxt;
wenzelm@52091
  1348
wenzelm@20260
  1349
    val ct = Thm.adjust_maxidx_cterm ~1 raw_ct;
wenzelm@32797
  1350
    val {maxidx, ...} = Thm.rep_cterm ct;
wenzelm@52091
  1351
    val _ =
wenzelm@52091
  1352
      Theory.subthy (theory_of_cterm ct, thy) orelse
wenzelm@52091
  1353
        raise CTERM ("rewrite_cterm: bad background theory", [ct]);
wenzelm@52091
  1354
wenzelm@54729
  1355
    val ctxt =
wenzelm@54729
  1356
      raw_ctxt
wenzelm@54729
  1357
      |> Context_Position.set_visible false
wenzelm@54729
  1358
      |> inc_simp_depth
wenzelm@54729
  1359
      |> (fn ctxt => trace_invoke {depth = simp_depth ctxt, term = Thm.term_of ct} ctxt);
wenzelm@54729
  1360
wenzelm@51717
  1361
    val _ = trace_cterm ctxt false (fn () => "SIMPLIFIER INVOKED ON THE FOLLOWING TERM:") ct;
wenzelm@51717
  1362
    val _ = check_bounds ctxt ct;
wenzelm@52091
  1363
  in bottomc (mode, Option.map Drule.flexflex_unique oo prover, maxidx) ctxt ct end;
berghofe@10413
  1364
wenzelm@21708
  1365
val simple_prover =
wenzelm@51717
  1366
  SINGLE o (fn ctxt => ALLGOALS (resolve_tac (prems_of ctxt)));
wenzelm@21708
  1367
wenzelm@54742
  1368
fun rewrite _ _ [] = Thm.reflexive
wenzelm@54742
  1369
  | rewrite ctxt full thms =
wenzelm@51717
  1370
      rewrite_cterm (full, false, false) simple_prover
wenzelm@54742
  1371
        (empty_simpset ctxt addsimps thms);
wenzelm@11672
  1372
wenzelm@54742
  1373
fun rewrite_rule ctxt = Conv.fconv_rule o rewrite ctxt true;
wenzelm@21708
  1374
wenzelm@15023
  1375
(*simple term rewriting -- no proof*)
wenzelm@16458
  1376
fun rewrite_term thy rules procs =
wenzelm@17203
  1377
  Pattern.rewrite_term thy (map decomp_simp' rules) procs;
wenzelm@15023
  1378
wenzelm@51717
  1379
fun rewrite_thm mode prover ctxt = Conv.fconv_rule (rewrite_cterm mode prover ctxt);
berghofe@10413
  1380
wenzelm@23536
  1381
(*Rewrite the subgoals of a proof state (represented by a theorem)*)
wenzelm@54742
  1382
fun rewrite_goals_rule ctxt thms th =
wenzelm@23584
  1383
  Conv.fconv_rule (Conv.prems_conv ~1 (rewrite_cterm (true, true, true) simple_prover
wenzelm@54742
  1384
    (empty_simpset ctxt addsimps thms))) th;
berghofe@10413
  1385
wenzelm@20228
  1386
wenzelm@21708
  1387
(** meta-rewriting tactics **)
wenzelm@21708
  1388
wenzelm@28839
  1389
(*Rewrite all subgoals*)
wenzelm@54742
  1390
fun rewrite_goals_tac ctxt defs = PRIMITIVE (rewrite_goals_rule ctxt defs);
wenzelm@21708
  1391
wenzelm@28839
  1392
(*Rewrite one subgoal*)
wenzelm@51717
  1393
fun generic_rewrite_goal_tac mode prover_tac ctxt i thm =
wenzelm@25203
  1394
  if 0 < i andalso i <= Thm.nprems_of thm then
wenzelm@51717
  1395
    Seq.single (Conv.gconv_rule (rewrite_cterm mode (SINGLE o prover_tac) ctxt) i thm)
wenzelm@25203
  1396
  else Seq.empty;
wenzelm@23536
  1397
wenzelm@54742
  1398
fun rewrite_goal_tac ctxt rews =
wenzelm@51717
  1399
  generic_rewrite_goal_tac (true, false, false) (K no_tac)
wenzelm@54742
  1400
    (empty_simpset ctxt addsimps rews);
wenzelm@23536
  1401
wenzelm@46707
  1402
(*Prunes all redundant parameters from the proof state by rewriting.*)
wenzelm@54742
  1403
fun prune_params_tac ctxt = rewrite_goals_tac ctxt [Drule.triv_forall_equality];
wenzelm@21708
  1404
wenzelm@21708
  1405
wenzelm@21708
  1406
(* for folding definitions, handling critical pairs *)
wenzelm@21708
  1407
wenzelm@21708
  1408
(*The depth of nesting in a term*)
wenzelm@32797
  1409
fun term_depth (Abs (_, _, t)) = 1 + term_depth t
wenzelm@32797
  1410
  | term_depth (f $ t) = 1 + Int.max (term_depth f, term_depth t)
wenzelm@21708
  1411
  | term_depth _ = 0;
wenzelm@21708
  1412
wenzelm@21708
  1413
val lhs_of_thm = #1 o Logic.dest_equals o prop_of;
wenzelm@21708
  1414
wenzelm@21708
  1415
(*folding should handle critical pairs!  E.g. K == Inl(0),  S == Inr(Inl(0))
wenzelm@21708
  1416
  Returns longest lhs first to avoid folding its subexpressions.*)
wenzelm@21708
  1417
fun sort_lhs_depths defs =
wenzelm@21708
  1418
  let val keylist = AList.make (term_depth o lhs_of_thm) defs
wenzelm@21708
  1419
      val keys = sort_distinct (rev_order o int_ord) (map #2 keylist)
wenzelm@21708
  1420
  in map (AList.find (op =) keylist) keys end;
wenzelm@21708
  1421
wenzelm@36944
  1422
val rev_defs = sort_lhs_depths o map Thm.symmetric;
wenzelm@21708
  1423
wenzelm@54742
  1424
fun fold_rule ctxt defs = fold (rewrite_rule ctxt) (rev_defs defs);
wenzelm@54742
  1425
fun fold_goals_tac ctxt defs = EVERY (map (rewrite_goals_tac ctxt) (rev_defs defs));
wenzelm@21708
  1426
wenzelm@21708
  1427
wenzelm@20228
  1428
(* HHF normal form: !! before ==>, outermost !! generalized *)
wenzelm@20228
  1429
wenzelm@20228
  1430
local
wenzelm@20228
  1431
wenzelm@54883
  1432
fun gen_norm_hhf ss ctxt th =
wenzelm@21565
  1433
  (if Drule.is_norm_hhf (Thm.prop_of th) then th
wenzelm@51717
  1434
   else
wenzelm@51717
  1435
    Conv.fconv_rule
wenzelm@54883
  1436
      (rewrite_cterm (true, false, false) (K (K NONE)) (put_simpset ss ctxt)) th)
wenzelm@21565
  1437
  |> Thm.adjust_maxidx_thm ~1
wenzelm@21565
  1438
  |> Drule.gen_all;
wenzelm@20228
  1439
wenzelm@51717
  1440
val hhf_ss =
wenzelm@51717
  1441
  simpset_of (empty_simpset (Context.proof_of (Context.the_thread_data ()))
wenzelm@51717
  1442
    addsimps Drule.norm_hhf_eqs);
wenzelm@51717
  1443
wenzelm@51717
  1444
val hhf_protect_ss =
wenzelm@51717
  1445
  simpset_of (empty_simpset (Context.proof_of (Context.the_thread_data ()))
wenzelm@51717
  1446
    addsimps Drule.norm_hhf_eqs |> add_eqcong Drule.protect_cong);
wenzelm@20228
  1447
wenzelm@20228
  1448
in
wenzelm@20228
  1449
wenzelm@26424
  1450
val norm_hhf = gen_norm_hhf hhf_ss;
wenzelm@51717
  1451
val norm_hhf_protect = gen_norm_hhf hhf_protect_ss;
wenzelm@20228
  1452
wenzelm@20228
  1453
end;
wenzelm@20228
  1454
berghofe@10413
  1455
end;
berghofe@10413
  1456
wenzelm@41228
  1457
structure Basic_Meta_Simplifier: BASIC_RAW_SIMPLIFIER = Raw_Simplifier;
wenzelm@32738
  1458
open Basic_Meta_Simplifier;