src/Pure/meta_simplifier.ML
author wenzelm
Thu Dec 02 16:04:22 2010 +0100 (2010-12-02)
changeset 40878 7695e4de4d86
parent 39163 4d701c0388c3
child 41183 e20f0d0e2af3
permissions -rw-r--r--
renamed trace_simp to simp_trace, and debug_simp to simp_debug;
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(*  Title:      Pure/meta_simplifier.ML
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    Author:     Tobias Nipkow and Stefan Berghofer, TU Muenchen
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Meta-level Simplification.
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*)
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infix 4
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  addsimps delsimps addeqcongs deleqcongs addcongs delcongs addsimprocs delsimprocs
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  setmksimps setmkcong setmksym setmkeqTrue settermless setsubgoaler
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  setloop' setloop addloop addloop' delloop setSSolver addSSolver setSolver addSolver;
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signature BASIC_META_SIMPLIFIER =
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sig
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  val simp_debug: bool Config.T
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  val simp_debug_raw: Config.raw
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  val simp_trace: bool Config.T
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  val simp_trace_raw: Config.raw
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  val simp_trace_default: bool Unsynchronized.ref
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  val simp_trace_depth_limit: int Unsynchronized.ref
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  type rrule
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  val eq_rrule: rrule * rrule -> bool
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  type simpset
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  type proc
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  type solver
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  val mk_solver': string -> (simpset -> int -> tactic) -> solver
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  val mk_solver: string -> (thm list -> int -> tactic) -> solver
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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: (string * thm) list,
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    weak_congs: string 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 morph_simproc: morphism -> simproc -> simproc
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  val make_simproc: {name: string, lhss: cterm list,
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    proc: morphism -> simpset -> cterm -> thm option, identifier: thm list} -> simproc
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  val mk_simproc: string -> cterm list -> (theory -> simpset -> term -> thm option) -> simproc
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  val add_prems: thm list -> simpset -> simpset
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  val prems_of_ss: simpset -> thm list
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  val addsimps: simpset * thm list -> simpset
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  val delsimps: simpset * thm list -> simpset
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  val addeqcongs: simpset * thm list -> simpset
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  val deleqcongs: simpset * thm list -> simpset
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  val addcongs: simpset * thm list -> simpset
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  val delcongs: simpset * thm list -> simpset
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  val addsimprocs: simpset * simproc list -> simpset
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  val delsimprocs: simpset * simproc list -> simpset
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  val mksimps: simpset -> thm -> thm list
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  val setmksimps: simpset * (simpset -> thm -> thm list) -> simpset
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  val setmkcong: simpset * (simpset -> thm -> thm) -> simpset
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  val setmksym: simpset * (simpset -> thm -> thm option) -> simpset
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  val setmkeqTrue: simpset * (simpset -> thm -> thm option) -> simpset
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  val settermless: simpset * (term * term -> bool) -> simpset
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  val setsubgoaler: simpset * (simpset -> int -> tactic) -> simpset
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  val setloop': simpset * (simpset -> int -> tactic) -> simpset
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  val setloop: simpset * (int -> tactic) -> simpset
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  val addloop': simpset * (string * (simpset -> int -> tactic)) -> simpset
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  val addloop: simpset * (string * (int -> tactic)) -> simpset
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  val delloop: simpset * string -> simpset
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  val setSSolver: simpset * solver -> simpset
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  val addSSolver: simpset * solver -> simpset
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  val setSolver: simpset * solver -> simpset
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  val addSolver: simpset * solver -> simpset
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  val rewrite_rule: thm list -> thm -> thm
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  val rewrite_goals_rule: thm list -> thm -> thm
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  val rewrite_goals_tac: thm list -> tactic
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  val rewrite_goal_tac: thm list -> int -> tactic
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  val rewtac: thm -> tactic
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  val prune_params_tac: tactic
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  val fold_rule: thm list -> thm -> thm
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  val fold_goals_tac: thm list -> tactic
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  val norm_hhf: thm -> thm
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  val norm_hhf_protect: thm -> thm
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end;
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signature META_SIMPLIFIER =
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sig
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  include BASIC_META_SIMPLIFIER
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  exception SIMPLIFIER of string * thm
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  val internal_ss: simpset ->
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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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    context: Proof.context option} *
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   {congs: (string * thm) list * string list,
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    procs: proc Net.net,
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    mk_rews:
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     {mk: simpset -> thm -> thm list,
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      mk_cong: simpset -> thm -> thm,
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      mk_sym: simpset -> thm -> thm option,
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      mk_eq_True: simpset -> thm -> thm option,
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      reorient: theory -> term list -> term -> term -> bool},
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    termless: term * term -> bool,
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    subgoal_tac: simpset -> int -> tactic,
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    loop_tacs: (string * (simpset -> int -> tactic)) list,
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    solvers: solver list * solver list}
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  val add_simp: thm -> simpset -> simpset
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  val del_simp: thm -> simpset -> simpset
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  val solver: simpset -> solver -> int -> tactic
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  val simp_depth_limit_raw: Config.raw
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  val simp_depth_limit: int Config.T
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  val clear_ss: simpset -> simpset
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  val simproc_global_i: theory -> string -> term list
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    -> (theory -> simpset -> term -> thm option) -> simproc
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  val simproc_global: theory -> string -> string list
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    -> (theory -> simpset -> term -> thm option) -> simproc
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  val inherit_context: simpset -> simpset -> simpset
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  val the_context: simpset -> Proof.context
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  val context: Proof.context -> simpset -> simpset
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  val global_context: theory  -> simpset -> simpset
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  val with_context: Proof.context -> (simpset -> simpset) -> simpset -> simpset
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  val debug_bounds: bool Unsynchronized.ref
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  val set_reorient: (theory -> term list -> term -> term -> bool) -> simpset -> simpset
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  val set_solvers: solver list -> simpset -> simpset
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  val rewrite_cterm: bool * bool * bool -> (simpset -> thm -> thm option) -> simpset -> 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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    (simpset -> thm -> thm option) -> simpset -> thm -> thm
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  val rewrite_goal_rule: bool * bool * bool ->
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    (simpset -> thm -> thm option) -> simpset -> int -> thm -> thm
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  val asm_rewrite_goal_tac: bool * bool * bool ->
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    (simpset -> tactic) -> simpset -> int -> tactic
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  val rewrite: bool -> thm list -> conv
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  val simplify: bool -> thm list -> thm -> thm
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end;
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structure MetaSimplifier: META_SIMPLIFIER =
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struct
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(** datatype simpset **)
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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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(* simplification sets, procedures, and solvers *)
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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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    context: Proof.context option} *
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   {congs: (string * thm) list * string list,
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    procs: proc Net.net,
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    mk_rews:
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     {mk: simpset -> thm -> thm list,
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      mk_cong: simpset -> thm -> thm,
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      mk_sym: simpset -> thm -> thm option,
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      mk_eq_True: simpset -> thm -> thm option,
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      reorient: theory -> term list -> term -> term -> bool},
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    termless: term * term -> bool,
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    subgoal_tac: simpset -> int -> tactic,
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    loop_tacs: (string * (simpset -> int -> tactic)) list,
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    solvers: solver list * solver list}
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and proc =
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  Proc of
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   {name: string,
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    lhs: cterm,
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    proc: simpset -> cterm -> thm option,
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    id: stamp * thm list}
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and solver =
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  Solver of
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   {name: string,
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    solver: simpset -> int -> tactic,
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    id: stamp};
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fun internal_ss (Simpset args) = args;
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fun make_ss1 (rules, prems, bounds, depth, context) =
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  {rules = rules, prems = prems, bounds = bounds, depth = depth, context = context};
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fun map_ss1 f {rules, prems, bounds, depth, context} =
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  make_ss1 (f (rules, prems, bounds, depth, context));
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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 map_simpset1 f (Simpset (r1, r2)) = Simpset (map_ss1 f r1, r2);
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fun map_simpset2 f (Simpset (r1, r2)) = Simpset (r1, map_ss2 f r2);
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fun prems_of_ss (Simpset ({prems, ...}, _)) = prems;
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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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fun mk_solver' name solver = Solver {name = name, solver = solver, id = stamp ()};
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fun mk_solver name solver = mk_solver' name (solver o prems_of_ss);
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fun solver_name (Solver {name, ...}) = name;
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fun solver ss (Solver {solver = tac, ...}) = tac ss;
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fun eq_solver (Solver {id = id1, ...}, Solver {id = id2, ...}) = (id1 = id2);
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(* simp depth *)
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val simp_depth_limit_raw = Config.declare "simp_depth_limit" (K (Config.Int 100));
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val simp_depth_limit = Config.int simp_depth_limit_raw;
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val simp_trace_depth_limit = Unsynchronized.ref 1;
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fun trace_depth (Simpset ({depth = (depth, exceeded), ...}, _)) msg =
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  if depth > ! simp_trace_depth_limit then
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    if ! exceeded then () else (tracing "simp_trace_depth_limit exceeded!"; exceeded := true)
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  else
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    (tracing (enclose "[" "]" (string_of_int depth) ^ msg); exceeded := false);
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val inc_simp_depth = map_simpset1 (fn (rules, prems, bounds, (depth, exceeded), context) =>
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  (rules, prems, bounds,
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    (depth + 1,
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      if depth = ! simp_trace_depth_limit then Unsynchronized.ref false else exceeded), context));
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fun simp_depth (Simpset ({depth = (depth, _), ...}, _)) = depth;
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(* diagnostics *)
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exception SIMPLIFIER of string * thm;
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val simp_debug_raw = Config.declare "simp_debug" (K (Config.Bool false));
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val simp_debug = Config.bool simp_debug_raw;
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val simp_trace_default = Unsynchronized.ref false;
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val simp_trace_raw = Config.declare "simp_trace" (fn _ => Config.Bool (! simp_trace_default));
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val simp_trace = Config.bool simp_trace_raw;
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fun if_enabled (Simpset ({context, ...}, _)) flag f =
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  (case context of
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    SOME ctxt => if Config.get ctxt flag then f ctxt else ()
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  | NONE => ())
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fun if_visible (Simpset ({context, ...}, _)) f x =
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  (case context of
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    SOME ctxt => if Context_Position.is_visible ctxt then f x else ()
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  | NONE => ());
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local
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fun prnt ss warn a = if warn then warning a else trace_depth ss a;
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fun show_bounds (Simpset ({bounds = (_, bs), ...}, _)) t =
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  let
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    val names = Term.declare_term_names t Name.context;
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    val xs = rev (#1 (Name.variants (rev (map #2 bs)) names));
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    fun subst (((b, T), _), x') = (Free (b, T), Syntax.mark_boundT (x', T));
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  in Term.subst_atomic (ListPair.map subst (bs, xs)) t end;
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fun print_term ss warn a t ctxt = prnt ss warn (a () ^ "\n" ^
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  Syntax.string_of_term ctxt
wenzelm@40878
   306
    (if Config.get ctxt simp_debug then t else show_bounds ss t));
boehmes@35979
   307
wenzelm@17705
   308
in
wenzelm@17705
   309
boehmes@35979
   310
fun print_term_global ss warn a thy t =
wenzelm@36610
   311
  print_term ss warn (K a) t (ProofContext.init_global thy);
wenzelm@16985
   312
wenzelm@40878
   313
fun debug warn a ss = if_enabled ss simp_debug (fn _ => prnt ss warn (a ()));
wenzelm@40878
   314
fun trace warn a ss = if_enabled ss simp_trace (fn _ => prnt ss warn (a ()));
boehmes@35979
   315
wenzelm@40878
   316
fun debug_term warn a ss t = if_enabled ss simp_debug (print_term ss warn a t);
wenzelm@40878
   317
fun trace_term warn a ss t = if_enabled ss simp_trace (print_term ss warn a t);
wenzelm@16985
   318
wenzelm@16985
   319
fun trace_cterm warn a ss ct =
wenzelm@40878
   320
  if_enabled ss simp_trace (print_term ss warn a (Thm.term_of ct));
wenzelm@16985
   321
wenzelm@16985
   322
fun trace_thm a ss th =
wenzelm@40878
   323
  if_enabled ss simp_trace (print_term ss false a (Thm.full_prop_of th));
wenzelm@16985
   324
wenzelm@16985
   325
fun trace_named_thm a ss (th, name) =
wenzelm@40878
   326
  if_enabled ss simp_trace (print_term ss false
boehmes@35979
   327
    (fn () => if name = "" then a () else a () ^ " " ^ quote name ^ ":")
boehmes@35979
   328
    (Thm.full_prop_of th));
wenzelm@16985
   329
wenzelm@22892
   330
fun warn_thm a ss th =
boehmes@35979
   331
  print_term_global ss true a (Thm.theory_of_thm th) (Thm.full_prop_of th);
wenzelm@16985
   332
wenzelm@38834
   333
fun cond_warn_thm a ss th = if_visible ss (fn () => warn_thm a ss th) ();
wenzelm@20028
   334
wenzelm@16985
   335
end;
wenzelm@16985
   336
wenzelm@16985
   337
berghofe@10413
   338
berghofe@10413
   339
(** simpset operations **)
berghofe@10413
   340
wenzelm@17882
   341
(* context *)
berghofe@10413
   342
wenzelm@17614
   343
fun eq_bound (x: string, (y, _)) = x = y;
wenzelm@17614
   344
wenzelm@22892
   345
fun add_bound bound = map_simpset1 (fn (rules, prems, (count, bounds), depth, context) =>
wenzelm@22892
   346
  (rules, prems, (count + 1, bound :: bounds), depth, context));
wenzelm@17882
   347
wenzelm@22892
   348
fun add_prems ths = map_simpset1 (fn (rules, prems, bounds, depth, context) =>
wenzelm@22892
   349
  (rules, ths @ prems, bounds, depth, context));
wenzelm@17882
   350
wenzelm@22892
   351
fun inherit_context (Simpset ({bounds, depth, context, ...}, _)) =
wenzelm@22892
   352
  map_simpset1 (fn (rules, prems, _, _, _) => (rules, prems, bounds, depth, context));
wenzelm@16985
   353
wenzelm@17882
   354
fun the_context (Simpset ({context = SOME ctxt, ...}, _)) = ctxt
wenzelm@17882
   355
  | the_context _ = raise Fail "Simplifier: no proof context in simpset";
berghofe@10413
   356
wenzelm@17897
   357
fun context ctxt =
wenzelm@22892
   358
  map_simpset1 (fn (rules, prems, bounds, depth, _) => (rules, prems, bounds, depth, SOME ctxt));
wenzelm@17882
   359
wenzelm@36610
   360
val global_context = context o ProofContext.init_global;
wenzelm@17897
   361
wenzelm@27312
   362
fun activate_context thy ss =
wenzelm@27312
   363
  let
wenzelm@27312
   364
    val ctxt = the_context ss;
wenzelm@36545
   365
    val ctxt' = ctxt
wenzelm@36545
   366
      |> Context.raw_transfer (Theory.merge (thy, ProofContext.theory_of ctxt))
wenzelm@36545
   367
      |> Context_Position.set_visible false;
wenzelm@27312
   368
  in context ctxt' ss end;
wenzelm@17897
   369
wenzelm@36545
   370
fun with_context ctxt f ss = inherit_context ss (f (context ctxt ss));
wenzelm@36545
   371
wenzelm@17897
   372
wenzelm@20028
   373
(* maintain simp rules *)
berghofe@10413
   374
wenzelm@20546
   375
(* FIXME: it seems that the conditions on extra variables are too liberal if
wenzelm@20546
   376
prems are nonempty: does solving the prems really guarantee instantiation of
wenzelm@20546
   377
all its Vars? Better: a dynamic check each time a rule is applied.
wenzelm@20546
   378
*)
wenzelm@20546
   379
fun rewrite_rule_extra_vars prems elhs erhs =
wenzelm@20546
   380
  let
wenzelm@20546
   381
    val elhss = elhs :: prems;
wenzelm@20546
   382
    val tvars = fold Term.add_tvars elhss [];
wenzelm@20546
   383
    val vars = fold Term.add_vars elhss [];
wenzelm@20546
   384
  in
wenzelm@20546
   385
    erhs |> Term.exists_type (Term.exists_subtype
wenzelm@20546
   386
      (fn TVar v => not (member (op =) tvars v) | _ => false)) orelse
wenzelm@20546
   387
    erhs |> Term.exists_subterm
wenzelm@20546
   388
      (fn Var v => not (member (op =) vars v) | _ => false)
wenzelm@20546
   389
  end;
wenzelm@20546
   390
wenzelm@20546
   391
fun rrule_extra_vars elhs thm =
wenzelm@20546
   392
  rewrite_rule_extra_vars [] (term_of elhs) (Thm.full_prop_of thm);
wenzelm@20546
   393
wenzelm@15023
   394
fun mk_rrule2 {thm, name, lhs, elhs, perm} =
wenzelm@15023
   395
  let
wenzelm@20546
   396
    val t = term_of elhs;
wenzelm@20546
   397
    val fo = Pattern.first_order t orelse not (Pattern.pattern t);
wenzelm@20546
   398
    val extra = rrule_extra_vars elhs thm;
wenzelm@20546
   399
  in {thm = thm, name = name, lhs = lhs, elhs = elhs, extra = extra, fo = fo, perm = perm} end;
berghofe@10413
   400
wenzelm@20028
   401
fun del_rrule (rrule as {thm, elhs, ...}) ss =
wenzelm@22892
   402
  ss |> map_simpset1 (fn (rules, prems, bounds, depth, context) =>
wenzelm@22892
   403
    (Net.delete_term eq_rrule (term_of elhs, rrule) rules, prems, bounds, depth, context))
wenzelm@20028
   404
  handle Net.DELETE => (cond_warn_thm "Rewrite rule not in simpset:" ss thm; ss);
wenzelm@20028
   405
wenzelm@32797
   406
fun insert_rrule (rrule as {thm, name, ...}) ss =
wenzelm@22254
   407
 (trace_named_thm (fn () => "Adding rewrite rule") ss (thm, name);
wenzelm@22892
   408
  ss |> map_simpset1 (fn (rules, prems, bounds, depth, context) =>
wenzelm@15023
   409
    let
wenzelm@15023
   410
      val rrule2 as {elhs, ...} = mk_rrule2 rrule;
wenzelm@16807
   411
      val rules' = Net.insert_term eq_rrule (term_of elhs, rrule2) rules;
wenzelm@22892
   412
    in (rules', prems, bounds, depth, context) end)
wenzelm@20028
   413
  handle Net.INSERT => (cond_warn_thm "Ignoring duplicate rewrite rule:" ss thm; ss));
berghofe@10413
   414
berghofe@10413
   415
fun vperm (Var _, Var _) = true
berghofe@10413
   416
  | vperm (Abs (_, _, s), Abs (_, _, t)) = vperm (s, t)
berghofe@10413
   417
  | vperm (t1 $ t2, u1 $ u2) = vperm (t1, u1) andalso vperm (t2, u2)
berghofe@10413
   418
  | vperm (t, u) = (t = u);
berghofe@10413
   419
berghofe@10413
   420
fun var_perm (t, u) =
haftmann@33038
   421
  vperm (t, u) andalso eq_set (op =) (Term.add_vars t [], Term.add_vars u []);
berghofe@10413
   422
wenzelm@15023
   423
(*simple test for looping rewrite rules and stupid orientations*)
wenzelm@18208
   424
fun default_reorient thy prems lhs rhs =
wenzelm@15023
   425
  rewrite_rule_extra_vars prems lhs rhs
wenzelm@15023
   426
    orelse
wenzelm@15023
   427
  is_Var (head_of lhs)
wenzelm@15023
   428
    orelse
nipkow@16305
   429
(* turns t = x around, which causes a headache if x is a local variable -
nipkow@16305
   430
   usually it is very useful :-(
nipkow@16305
   431
  is_Free rhs andalso not(is_Free lhs) andalso not(Logic.occs(rhs,lhs))
nipkow@16305
   432
  andalso not(exists_subterm is_Var lhs)
nipkow@16305
   433
    orelse
nipkow@16305
   434
*)
wenzelm@16842
   435
  exists (fn t => Logic.occs (lhs, t)) (rhs :: prems)
wenzelm@15023
   436
    orelse
wenzelm@17203
   437
  null prems andalso Pattern.matches thy (lhs, rhs)
berghofe@10413
   438
    (*the condition "null prems" is necessary because conditional rewrites
berghofe@10413
   439
      with extra variables in the conditions may terminate although
wenzelm@15023
   440
      the rhs is an instance of the lhs; example: ?m < ?n ==> f(?n) == f(?m)*)
wenzelm@15023
   441
    orelse
wenzelm@15023
   442
  is_Const lhs andalso not (is_Const rhs);
berghofe@10413
   443
berghofe@10413
   444
fun decomp_simp thm =
wenzelm@15023
   445
  let
wenzelm@26626
   446
    val thy = Thm.theory_of_thm thm;
wenzelm@26626
   447
    val prop = Thm.prop_of thm;
wenzelm@15023
   448
    val prems = Logic.strip_imp_prems prop;
wenzelm@15023
   449
    val concl = Drule.strip_imp_concl (Thm.cprop_of thm);
wenzelm@22902
   450
    val (lhs, rhs) = Thm.dest_equals concl handle TERM _ =>
wenzelm@15023
   451
      raise SIMPLIFIER ("Rewrite rule not a meta-equality", thm);
wenzelm@20579
   452
    val elhs = Thm.dest_arg (Thm.cprop_of (Thm.eta_conversion lhs));
wenzelm@16665
   453
    val elhs = if term_of elhs aconv term_of lhs then lhs else elhs;  (*share identical copies*)
wenzelm@18929
   454
    val erhs = Envir.eta_contract (term_of rhs);
wenzelm@15023
   455
    val perm =
wenzelm@15023
   456
      var_perm (term_of elhs, erhs) andalso
wenzelm@15023
   457
      not (term_of elhs aconv erhs) andalso
wenzelm@15023
   458
      not (is_Var (term_of elhs));
wenzelm@16458
   459
  in (thy, prems, term_of lhs, elhs, term_of rhs, perm) end;
berghofe@10413
   460
wenzelm@12783
   461
fun decomp_simp' thm =
wenzelm@12979
   462
  let val (_, _, lhs, _, rhs, _) = decomp_simp thm in
wenzelm@12783
   463
    if Thm.nprems_of thm > 0 then raise SIMPLIFIER ("Bad conditional rewrite rule", thm)
wenzelm@12979
   464
    else (lhs, rhs)
wenzelm@12783
   465
  end;
wenzelm@12783
   466
wenzelm@36543
   467
fun mk_eq_True (ss as Simpset (_, {mk_rews = {mk_eq_True, ...}, ...})) (thm, name) =
wenzelm@36543
   468
  (case mk_eq_True ss thm of
skalberg@15531
   469
    NONE => []
skalberg@15531
   470
  | SOME eq_True =>
wenzelm@20546
   471
      let
wenzelm@20546
   472
        val (_, _, lhs, elhs, _, _) = decomp_simp eq_True;
wenzelm@15023
   473
      in [{thm = eq_True, name = name, lhs = lhs, elhs = elhs, perm = false}] end);
berghofe@10413
   474
wenzelm@15023
   475
(*create the rewrite rule and possibly also the eq_True variant,
wenzelm@15023
   476
  in case there are extra vars on the rhs*)
wenzelm@15023
   477
fun rrule_eq_True (thm, name, lhs, elhs, rhs, ss, thm2) =
wenzelm@15023
   478
  let val rrule = {thm = thm, name = name, lhs = lhs, elhs = elhs, perm = false} in
wenzelm@20546
   479
    if rewrite_rule_extra_vars [] lhs rhs then
wenzelm@20546
   480
      mk_eq_True ss (thm2, name) @ [rrule]
wenzelm@20546
   481
    else [rrule]
berghofe@10413
   482
  end;
berghofe@10413
   483
wenzelm@15023
   484
fun mk_rrule ss (thm, name) =
wenzelm@15023
   485
  let val (_, prems, lhs, elhs, rhs, perm) = decomp_simp thm in
wenzelm@15023
   486
    if perm then [{thm = thm, name = name, lhs = lhs, elhs = elhs, perm = true}]
wenzelm@15023
   487
    else
wenzelm@15023
   488
      (*weak test for loops*)
wenzelm@15023
   489
      if rewrite_rule_extra_vars prems lhs rhs orelse is_Var (term_of elhs)
wenzelm@15023
   490
      then mk_eq_True ss (thm, name)
wenzelm@15023
   491
      else rrule_eq_True (thm, name, lhs, elhs, rhs, ss, thm)
berghofe@10413
   492
  end;
berghofe@10413
   493
wenzelm@15023
   494
fun orient_rrule ss (thm, name) =
wenzelm@18208
   495
  let
wenzelm@18208
   496
    val (thy, prems, lhs, elhs, rhs, perm) = decomp_simp thm;
wenzelm@18208
   497
    val Simpset (_, {mk_rews = {reorient, mk_sym, ...}, ...}) = ss;
wenzelm@18208
   498
  in
wenzelm@15023
   499
    if perm then [{thm = thm, name = name, lhs = lhs, elhs = elhs, perm = true}]
wenzelm@16458
   500
    else if reorient thy prems lhs rhs then
wenzelm@16458
   501
      if reorient thy prems rhs lhs
wenzelm@15023
   502
      then mk_eq_True ss (thm, name)
wenzelm@15023
   503
      else
wenzelm@36543
   504
        (case mk_sym ss thm of
wenzelm@18208
   505
          NONE => []
wenzelm@18208
   506
        | SOME thm' =>
wenzelm@18208
   507
            let val (_, _, lhs', elhs', rhs', _) = decomp_simp thm'
wenzelm@18208
   508
            in rrule_eq_True (thm', name, lhs', elhs', rhs', ss, thm) end)
wenzelm@15023
   509
    else rrule_eq_True (thm, name, lhs, elhs, rhs, ss, thm)
berghofe@10413
   510
  end;
berghofe@10413
   511
wenzelm@36543
   512
fun extract_rews (ss as Simpset (_, {mk_rews = {mk, ...}, ...}), thms) =
wenzelm@36543
   513
  maps (fn thm => map (rpair (Thm.get_name_hint thm)) (mk ss thm)) thms;
berghofe@10413
   514
wenzelm@15023
   515
fun extract_safe_rrules (ss, thm) =
wenzelm@19482
   516
  maps (orient_rrule ss) (extract_rews (ss, [thm]));
berghofe@10413
   517
berghofe@10413
   518
wenzelm@20028
   519
(* add/del rules explicitly *)
berghofe@10413
   520
wenzelm@20028
   521
fun comb_simps comb mk_rrule (ss, thms) =
wenzelm@20028
   522
  let
wenzelm@20028
   523
    val rews = extract_rews (ss, thms);
wenzelm@20028
   524
  in fold (fold comb o mk_rrule) rews ss end;
berghofe@10413
   525
wenzelm@20028
   526
fun ss addsimps thms =
wenzelm@20028
   527
  comb_simps insert_rrule (mk_rrule ss) (ss, thms);
berghofe@10413
   528
wenzelm@15023
   529
fun ss delsimps thms =
wenzelm@20028
   530
  comb_simps del_rrule (map mk_rrule2 o mk_rrule ss) (ss, thms);
wenzelm@15023
   531
haftmann@27558
   532
fun add_simp thm ss = ss addsimps [thm];
haftmann@27558
   533
fun del_simp thm ss = ss delsimps [thm];
wenzelm@15023
   534
wenzelm@30318
   535
wenzelm@15023
   536
(* congs *)
berghofe@10413
   537
skalberg@15531
   538
fun cong_name (Const (a, _)) = SOME a
skalberg@15531
   539
  | cong_name (Free (a, _)) = SOME ("Free: " ^ a)
skalberg@15531
   540
  | cong_name _ = NONE;
ballarin@13835
   541
wenzelm@15023
   542
local
wenzelm@15023
   543
wenzelm@15023
   544
fun is_full_cong_prems [] [] = true
wenzelm@15023
   545
  | is_full_cong_prems [] _ = false
wenzelm@15023
   546
  | is_full_cong_prems (p :: prems) varpairs =
wenzelm@15023
   547
      (case Logic.strip_assums_concl p of
wenzelm@15023
   548
        Const ("==", _) $ lhs $ rhs =>
wenzelm@15023
   549
          let val (x, xs) = strip_comb lhs and (y, ys) = strip_comb rhs in
wenzelm@15023
   550
            is_Var x andalso forall is_Bound xs andalso
haftmann@20972
   551
            not (has_duplicates (op =) xs) andalso xs = ys andalso
wenzelm@20671
   552
            member (op =) varpairs (x, y) andalso
wenzelm@19303
   553
            is_full_cong_prems prems (remove (op =) (x, y) varpairs)
wenzelm@15023
   554
          end
wenzelm@15023
   555
      | _ => false);
wenzelm@15023
   556
wenzelm@15023
   557
fun is_full_cong thm =
berghofe@10413
   558
  let
wenzelm@15023
   559
    val prems = prems_of thm and concl = concl_of thm;
wenzelm@15023
   560
    val (lhs, rhs) = Logic.dest_equals concl;
wenzelm@15023
   561
    val (f, xs) = strip_comb lhs and (g, ys) = strip_comb rhs;
berghofe@10413
   562
  in
haftmann@20972
   563
    f = g andalso not (has_duplicates (op =) (xs @ ys)) andalso length xs = length ys andalso
wenzelm@15023
   564
    is_full_cong_prems prems (xs ~~ ys)
berghofe@10413
   565
  end;
berghofe@10413
   566
wenzelm@15023
   567
fun add_cong (ss, thm) = ss |>
wenzelm@15023
   568
  map_simpset2 (fn (congs, procs, mk_rews, termless, subgoal_tac, loop_tacs, solvers) =>
wenzelm@15023
   569
    let
wenzelm@22902
   570
      val (lhs, _) = Thm.dest_equals (Drule.strip_imp_concl (Thm.cprop_of thm))
wenzelm@15023
   571
        handle TERM _ => raise SIMPLIFIER ("Congruence not a meta-equality", thm);
wenzelm@18929
   572
    (*val lhs = Envir.eta_contract lhs;*)
wenzelm@20057
   573
      val a = the (cong_name (head_of (term_of lhs))) handle Option.Option =>
wenzelm@15023
   574
        raise SIMPLIFIER ("Congruence must start with a constant or free variable", thm);
haftmann@22221
   575
      val (xs, weak) = congs;
wenzelm@38834
   576
      val _ =
wenzelm@38834
   577
        if AList.defined (op =) xs a
wenzelm@38834
   578
        then if_visible ss warning ("Overwriting congruence rule for " ^ quote a)
haftmann@22221
   579
        else ();
krauss@30908
   580
      val xs' = AList.update (op =) (a, thm) xs;
haftmann@22221
   581
      val weak' = if is_full_cong thm then weak else a :: weak;
haftmann@22221
   582
    in ((xs', weak'), procs, mk_rews, termless, subgoal_tac, loop_tacs, solvers) end);
berghofe@10413
   583
wenzelm@15023
   584
fun del_cong (ss, thm) = ss |>
wenzelm@15023
   585
  map_simpset2 (fn (congs, procs, mk_rews, termless, subgoal_tac, loop_tacs, solvers) =>
wenzelm@15023
   586
    let
wenzelm@15023
   587
      val (lhs, _) = Logic.dest_equals (Thm.concl_of thm) handle TERM _ =>
wenzelm@15023
   588
        raise SIMPLIFIER ("Congruence not a meta-equality", thm);
wenzelm@18929
   589
    (*val lhs = Envir.eta_contract lhs;*)
wenzelm@20057
   590
      val a = the (cong_name (head_of lhs)) handle Option.Option =>
wenzelm@15023
   591
        raise SIMPLIFIER ("Congruence must start with a constant", thm);
haftmann@22221
   592
      val (xs, _) = congs;
haftmann@22221
   593
      val xs' = filter_out (fn (x : string, _) => x = a) xs;
krauss@30908
   594
      val weak' = xs' |> map_filter (fn (a, thm) =>
skalberg@15531
   595
        if is_full_cong thm then NONE else SOME a);
haftmann@22221
   596
    in ((xs', weak'), procs, mk_rews, termless, subgoal_tac, loop_tacs, solvers) end);
berghofe@10413
   597
wenzelm@36543
   598
fun mk_cong (ss as Simpset (_, {mk_rews = {mk_cong = f, ...}, ...})) = f ss;
wenzelm@15023
   599
wenzelm@15023
   600
in
wenzelm@15023
   601
skalberg@15570
   602
val (op addeqcongs) = Library.foldl add_cong;
skalberg@15570
   603
val (op deleqcongs) = Library.foldl del_cong;
wenzelm@15023
   604
wenzelm@15023
   605
fun ss addcongs congs = ss addeqcongs map (mk_cong ss) congs;
wenzelm@15023
   606
fun ss delcongs congs = ss deleqcongs map (mk_cong ss) congs;
wenzelm@15023
   607
wenzelm@15023
   608
end;
berghofe@10413
   609
berghofe@10413
   610
wenzelm@15023
   611
(* simprocs *)
wenzelm@15023
   612
wenzelm@22234
   613
datatype simproc =
wenzelm@22234
   614
  Simproc of
wenzelm@22234
   615
    {name: string,
wenzelm@22234
   616
     lhss: cterm list,
wenzelm@22234
   617
     proc: morphism -> simpset -> cterm -> thm option,
wenzelm@22234
   618
     id: stamp * thm list};
wenzelm@22234
   619
wenzelm@22234
   620
fun eq_simproc (Simproc {id = id1, ...}, Simproc {id = id2, ...}) = eq_procid (id1, id2);
wenzelm@22008
   621
wenzelm@22234
   622
fun morph_simproc phi (Simproc {name, lhss, proc, id = (s, ths)}) =
wenzelm@22234
   623
  Simproc
wenzelm@22234
   624
   {name = name,
wenzelm@22234
   625
    lhss = map (Morphism.cterm phi) lhss,
wenzelm@22669
   626
    proc = Morphism.transform phi proc,
wenzelm@22234
   627
    id = (s, Morphism.fact phi ths)};
wenzelm@22234
   628
wenzelm@22234
   629
fun make_simproc {name, lhss, proc, identifier} =
wenzelm@22234
   630
  Simproc {name = name, lhss = lhss, proc = proc, id = (stamp (), identifier)};
wenzelm@22008
   631
wenzelm@22008
   632
fun mk_simproc name lhss proc =
wenzelm@22234
   633
  make_simproc {name = name, lhss = lhss, proc = fn _ => fn ss => fn ct =>
wenzelm@22234
   634
    proc (ProofContext.theory_of (the_context ss)) ss (Thm.term_of ct), identifier = []};
wenzelm@22008
   635
wenzelm@35845
   636
(* FIXME avoid global thy and Logic.varify_global *)
wenzelm@38715
   637
fun simproc_global_i thy name = mk_simproc name o map (Thm.cterm_of thy o Logic.varify_global);
wenzelm@38715
   638
fun simproc_global thy name = simproc_global_i thy name o map (Syntax.read_term_global thy);
wenzelm@22008
   639
wenzelm@22008
   640
wenzelm@15023
   641
local
berghofe@10413
   642
wenzelm@16985
   643
fun add_proc (proc as Proc {name, lhs, ...}) ss =
wenzelm@22254
   644
 (trace_cterm false (fn () => "Adding simplification procedure " ^ quote name ^ " for") ss lhs;
wenzelm@15023
   645
  map_simpset2 (fn (congs, procs, mk_rews, termless, subgoal_tac, loop_tacs, solvers) =>
wenzelm@16807
   646
    (congs, Net.insert_term eq_proc (term_of lhs, proc) procs,
wenzelm@15023
   647
      mk_rews, termless, subgoal_tac, loop_tacs, solvers)) ss
wenzelm@15023
   648
  handle Net.INSERT =>
wenzelm@38834
   649
    (if_visible ss warning ("Ignoring duplicate simplification procedure " ^ quote name); ss));
berghofe@10413
   650
wenzelm@16985
   651
fun del_proc (proc as Proc {name, lhs, ...}) ss =
wenzelm@15023
   652
  map_simpset2 (fn (congs, procs, mk_rews, termless, subgoal_tac, loop_tacs, solvers) =>
wenzelm@16807
   653
    (congs, Net.delete_term eq_proc (term_of lhs, proc) procs,
wenzelm@15023
   654
      mk_rews, termless, subgoal_tac, loop_tacs, solvers)) ss
wenzelm@15023
   655
  handle Net.DELETE =>
wenzelm@38834
   656
    (if_visible ss warning ("Simplification procedure " ^ quote name ^ " not in simpset"); ss);
berghofe@10413
   657
wenzelm@22234
   658
fun prep_procs (Simproc {name, lhss, proc, id}) =
wenzelm@22669
   659
  lhss |> map (fn lhs => Proc {name = name, lhs = lhs, proc = Morphism.form proc, id = id});
wenzelm@22234
   660
wenzelm@15023
   661
in
berghofe@10413
   662
wenzelm@22234
   663
fun ss addsimprocs ps = fold (fold add_proc o prep_procs) ps ss;
wenzelm@22234
   664
fun ss delsimprocs ps = fold (fold del_proc o prep_procs) ps ss;
berghofe@10413
   665
wenzelm@15023
   666
end;
berghofe@10413
   667
berghofe@10413
   668
berghofe@10413
   669
(* mk_rews *)
berghofe@10413
   670
wenzelm@15023
   671
local
wenzelm@15023
   672
wenzelm@18208
   673
fun map_mk_rews f = map_simpset2 (fn (congs, procs, {mk, mk_cong, mk_sym, mk_eq_True, reorient},
wenzelm@15023
   674
      termless, subgoal_tac, loop_tacs, solvers) =>
wenzelm@18208
   675
  let
wenzelm@18208
   676
    val (mk', mk_cong', mk_sym', mk_eq_True', reorient') =
wenzelm@18208
   677
      f (mk, mk_cong, mk_sym, mk_eq_True, reorient);
wenzelm@18208
   678
    val mk_rews' = {mk = mk', mk_cong = mk_cong', mk_sym = mk_sym', mk_eq_True = mk_eq_True',
wenzelm@18208
   679
      reorient = reorient'};
wenzelm@18208
   680
  in (congs, procs, mk_rews', termless, subgoal_tac, loop_tacs, solvers) end);
wenzelm@15023
   681
wenzelm@15023
   682
in
berghofe@10413
   683
wenzelm@36543
   684
fun mksimps (ss as Simpset (_, {mk_rews = {mk, ...}, ...})) = mk ss;
wenzelm@30318
   685
wenzelm@18208
   686
fun ss setmksimps mk = ss |> map_mk_rews (fn (_, mk_cong, mk_sym, mk_eq_True, reorient) =>
wenzelm@18208
   687
  (mk, mk_cong, mk_sym, mk_eq_True, reorient));
wenzelm@15023
   688
wenzelm@18208
   689
fun ss setmkcong mk_cong = ss |> map_mk_rews (fn (mk, _, mk_sym, mk_eq_True, reorient) =>
wenzelm@18208
   690
  (mk, mk_cong, mk_sym, mk_eq_True, reorient));
berghofe@10413
   691
wenzelm@18208
   692
fun ss setmksym mk_sym = ss |> map_mk_rews (fn (mk, mk_cong, _, mk_eq_True, reorient) =>
wenzelm@18208
   693
  (mk, mk_cong, mk_sym, mk_eq_True, reorient));
berghofe@10413
   694
wenzelm@18208
   695
fun ss setmkeqTrue mk_eq_True = ss |> map_mk_rews (fn (mk, mk_cong, mk_sym, _, reorient) =>
wenzelm@18208
   696
  (mk, mk_cong, mk_sym, mk_eq_True, reorient));
wenzelm@18208
   697
wenzelm@18208
   698
fun set_reorient reorient = map_mk_rews (fn (mk, mk_cong, mk_sym, mk_eq_True, _) =>
wenzelm@18208
   699
  (mk, mk_cong, mk_sym, mk_eq_True, reorient));
wenzelm@15023
   700
wenzelm@15023
   701
end;
wenzelm@15023
   702
skalberg@14242
   703
berghofe@10413
   704
(* termless *)
berghofe@10413
   705
wenzelm@15023
   706
fun ss settermless termless = ss |>
wenzelm@15023
   707
  map_simpset2 (fn (congs, procs, mk_rews, _, subgoal_tac, loop_tacs, solvers) =>
wenzelm@15023
   708
   (congs, procs, mk_rews, termless, subgoal_tac, loop_tacs, solvers));
skalberg@15006
   709
skalberg@15006
   710
wenzelm@15023
   711
(* tactics *)
skalberg@15006
   712
wenzelm@15023
   713
fun ss setsubgoaler subgoal_tac = ss |>
wenzelm@15023
   714
  map_simpset2 (fn (congs, procs, mk_rews, termless, _, loop_tacs, solvers) =>
wenzelm@15023
   715
   (congs, procs, mk_rews, termless, subgoal_tac, loop_tacs, solvers));
skalberg@15006
   716
wenzelm@17882
   717
fun ss setloop' tac = ss |>
wenzelm@15023
   718
  map_simpset2 (fn (congs, procs, mk_rews, termless, subgoal_tac, _, solvers) =>
wenzelm@15023
   719
   (congs, procs, mk_rews, termless, subgoal_tac, [("", tac)], solvers));
skalberg@15006
   720
wenzelm@17882
   721
fun ss setloop tac = ss setloop' (K tac);
wenzelm@17882
   722
wenzelm@17882
   723
fun ss addloop' (name, tac) = ss |>
wenzelm@15023
   724
  map_simpset2 (fn (congs, procs, mk_rews, termless, subgoal_tac, loop_tacs, solvers) =>
wenzelm@15023
   725
    (congs, procs, mk_rews, termless, subgoal_tac,
wenzelm@38834
   726
     (if AList.defined (op =) loop_tacs name
wenzelm@38834
   727
      then if_visible ss warning ("Overwriting looper " ^ quote name)
wenzelm@38834
   728
      else (); AList.update (op =) (name, tac) loop_tacs), solvers));
skalberg@15006
   729
wenzelm@17882
   730
fun ss addloop (name, tac) = ss addloop' (name, K tac);
wenzelm@17882
   731
wenzelm@15023
   732
fun ss delloop name = ss |>
wenzelm@15023
   733
  map_simpset2 (fn (congs, procs, mk_rews, termless, subgoal_tac, loop_tacs, solvers) =>
haftmann@21286
   734
    (congs, procs, mk_rews, termless, subgoal_tac,
wenzelm@38834
   735
     (if AList.defined (op =) loop_tacs name then ()
wenzelm@38834
   736
      else if_visible ss warning ("No such looper in simpset: " ^ quote name);
wenzelm@38834
   737
      AList.delete (op =) name loop_tacs), solvers));
skalberg@15006
   738
wenzelm@15023
   739
fun ss setSSolver solver = ss |> map_simpset2 (fn (congs, procs, mk_rews, termless,
wenzelm@15023
   740
  subgoal_tac, loop_tacs, (unsafe_solvers, _)) =>
wenzelm@15023
   741
    (congs, procs, mk_rews, termless, subgoal_tac, loop_tacs, (unsafe_solvers, [solver])));
skalberg@15006
   742
wenzelm@15023
   743
fun ss addSSolver solver = ss |> map_simpset2 (fn (congs, procs, mk_rews, termless,
wenzelm@15023
   744
  subgoal_tac, loop_tacs, (unsafe_solvers, solvers)) => (congs, procs, mk_rews, termless,
haftmann@22717
   745
    subgoal_tac, loop_tacs, (unsafe_solvers, insert eq_solver solver solvers)));
skalberg@15006
   746
wenzelm@15023
   747
fun ss setSolver solver = ss |> map_simpset2 (fn (congs, procs, mk_rews, termless,
wenzelm@15023
   748
  subgoal_tac, loop_tacs, (_, solvers)) => (congs, procs, mk_rews, termless,
wenzelm@15023
   749
    subgoal_tac, loop_tacs, ([solver], solvers)));
skalberg@15006
   750
wenzelm@15023
   751
fun ss addSolver solver = ss |> map_simpset2 (fn (congs, procs, mk_rews, termless,
wenzelm@15023
   752
  subgoal_tac, loop_tacs, (unsafe_solvers, solvers)) => (congs, procs, mk_rews, termless,
haftmann@22717
   753
    subgoal_tac, loop_tacs, (insert eq_solver solver unsafe_solvers, solvers)));
skalberg@15006
   754
wenzelm@15023
   755
fun set_solvers solvers = map_simpset2 (fn (congs, procs, mk_rews, termless,
wenzelm@15023
   756
  subgoal_tac, loop_tacs, _) => (congs, procs, mk_rews, termless,
wenzelm@15023
   757
  subgoal_tac, loop_tacs, (solvers, solvers)));
skalberg@15006
   758
skalberg@15006
   759
wenzelm@18208
   760
(* empty *)
wenzelm@18208
   761
wenzelm@18208
   762
fun init_ss mk_rews termless subgoal_tac solvers =
wenzelm@32738
   763
  make_simpset ((Net.empty, [], (0, []), (0, Unsynchronized.ref false), NONE),
wenzelm@18208
   764
    (([], []), Net.empty, mk_rews, termless, subgoal_tac, [], solvers));
wenzelm@18208
   765
wenzelm@18208
   766
fun clear_ss (ss as Simpset (_, {mk_rews, termless, subgoal_tac, solvers, ...})) =
wenzelm@18208
   767
  init_ss mk_rews termless subgoal_tac solvers
wenzelm@18208
   768
  |> inherit_context ss;
wenzelm@18208
   769
wenzelm@36543
   770
val empty_ss =
wenzelm@36543
   771
  init_ss
wenzelm@36543
   772
    {mk = fn _ => fn th => if can Logic.dest_equals (Thm.concl_of th) then [th] else [],
wenzelm@36543
   773
      mk_cong = K I,
wenzelm@36543
   774
      mk_sym = K (SOME o Drule.symmetric_fun),
wenzelm@36543
   775
      mk_eq_True = K (K NONE),
wenzelm@36543
   776
      reorient = default_reorient}
wenzelm@36543
   777
    Term_Ord.termless (K (K no_tac)) ([], []);
wenzelm@18208
   778
wenzelm@18208
   779
wenzelm@18208
   780
(* merge *)  (*NOTE: ignores some fields of 2nd simpset*)
wenzelm@18208
   781
wenzelm@18208
   782
fun merge_ss (ss1, ss2) =
wenzelm@24358
   783
  if pointer_eq (ss1, ss2) then ss1
wenzelm@24358
   784
  else
wenzelm@24358
   785
    let
wenzelm@24358
   786
      val Simpset ({rules = rules1, prems = prems1, bounds = bounds1, depth = depth1, context = _},
wenzelm@24358
   787
       {congs = (congs1, weak1), procs = procs1, mk_rews, termless, subgoal_tac,
wenzelm@24358
   788
        loop_tacs = loop_tacs1, solvers = (unsafe_solvers1, solvers1)}) = ss1;
wenzelm@24358
   789
      val Simpset ({rules = rules2, prems = prems2, bounds = bounds2, depth = depth2, context = _},
wenzelm@24358
   790
       {congs = (congs2, weak2), procs = procs2, mk_rews = _, termless = _, subgoal_tac = _,
wenzelm@24358
   791
        loop_tacs = loop_tacs2, solvers = (unsafe_solvers2, solvers2)}) = ss2;
wenzelm@30356
   792
wenzelm@24358
   793
      val rules' = Net.merge eq_rrule (rules1, rules2);
wenzelm@33520
   794
      val prems' = Thm.merge_thms (prems1, prems2);
wenzelm@24358
   795
      val bounds' = if #1 bounds1 < #1 bounds2 then bounds2 else bounds1;
wenzelm@24358
   796
      val depth' = if #1 depth1 < #1 depth2 then depth2 else depth1;
wenzelm@31298
   797
      val congs' = merge (Thm.eq_thm_prop o pairself #2) (congs1, congs2);
wenzelm@24358
   798
      val weak' = merge (op =) (weak1, weak2);
wenzelm@24358
   799
      val procs' = Net.merge eq_proc (procs1, procs2);
wenzelm@24358
   800
      val loop_tacs' = AList.merge (op =) (K true) (loop_tacs1, loop_tacs2);
wenzelm@24358
   801
      val unsafe_solvers' = merge eq_solver (unsafe_solvers1, unsafe_solvers2);
wenzelm@24358
   802
      val solvers' = merge eq_solver (solvers1, solvers2);
wenzelm@24358
   803
    in
wenzelm@24358
   804
      make_simpset ((rules', prems', bounds', depth', NONE), ((congs', weak'), procs',
wenzelm@24358
   805
        mk_rews, termless, subgoal_tac, loop_tacs', (unsafe_solvers', solvers')))
wenzelm@24358
   806
    end;
wenzelm@18208
   807
wenzelm@18208
   808
wenzelm@30356
   809
(* dest_ss *)
wenzelm@30356
   810
wenzelm@30356
   811
fun dest_ss (Simpset ({rules, ...}, {congs, procs, loop_tacs, solvers, ...})) =
wenzelm@30356
   812
 {simps = Net.entries rules
wenzelm@30356
   813
    |> map (fn {name, thm, ...} => (name, thm)),
wenzelm@30356
   814
  procs = Net.entries procs
wenzelm@30356
   815
    |> map (fn Proc {name, lhs, id, ...} => ((name, lhs), id))
wenzelm@30356
   816
    |> partition_eq (eq_snd eq_procid)
wenzelm@30356
   817
    |> map (fn ps => (fst (fst (hd ps)), map (snd o fst) ps)),
krauss@30908
   818
  congs = #1 congs,
wenzelm@30356
   819
  weak_congs = #2 congs,
wenzelm@30356
   820
  loopers = map fst loop_tacs,
wenzelm@30356
   821
  unsafe_solvers = map solver_name (#1 solvers),
wenzelm@30356
   822
  safe_solvers = map solver_name (#2 solvers)};
wenzelm@30356
   823
wenzelm@30356
   824
skalberg@15006
   825
berghofe@10413
   826
(** rewriting **)
berghofe@10413
   827
berghofe@10413
   828
(*
berghofe@10413
   829
  Uses conversions, see:
berghofe@10413
   830
    L C Paulson, A higher-order implementation of rewriting,
berghofe@10413
   831
    Science of Computer Programming 3 (1983), pages 119-149.
berghofe@10413
   832
*)
berghofe@10413
   833
wenzelm@16985
   834
fun check_conv msg ss thm thm' =
berghofe@10413
   835
  let
wenzelm@36944
   836
    val thm'' = Thm.transitive thm thm' handle THM _ =>
wenzelm@36944
   837
     Thm.transitive thm (Thm.transitive
wenzelm@36944
   838
       (Thm.symmetric (Drule.beta_eta_conversion (Thm.lhs_of thm'))) thm')
wenzelm@22254
   839
  in if msg then trace_thm (fn () => "SUCCEEDED") ss thm' else (); SOME thm'' end
berghofe@10413
   840
  handle THM _ =>
wenzelm@26626
   841
    let
wenzelm@26626
   842
      val _ $ _ $ prop0 = Thm.prop_of thm;
wenzelm@26626
   843
    in
wenzelm@22254
   844
      trace_thm (fn () => "Proved wrong thm (Check subgoaler?)") ss thm';
boehmes@35979
   845
      trace_term false (fn () => "Should have proved:") ss prop0;
skalberg@15531
   846
      NONE
berghofe@10413
   847
    end;
berghofe@10413
   848
berghofe@10413
   849
berghofe@10413
   850
(* mk_procrule *)
berghofe@10413
   851
wenzelm@16985
   852
fun mk_procrule ss thm =
wenzelm@15023
   853
  let val (_, prems, lhs, elhs, rhs, _) = decomp_simp thm in
wenzelm@15023
   854
    if rewrite_rule_extra_vars prems lhs rhs
wenzelm@38834
   855
    then (cond_warn_thm "Extra vars on rhs:" ss thm; [])
wenzelm@15023
   856
    else [mk_rrule2 {thm = thm, name = "", lhs = lhs, elhs = elhs, perm = false}]
berghofe@10413
   857
  end;
berghofe@10413
   858
berghofe@10413
   859
wenzelm@15023
   860
(* rewritec: conversion to apply the meta simpset to a term *)
berghofe@10413
   861
wenzelm@15023
   862
(*Since the rewriting strategy is bottom-up, we avoid re-normalizing already
wenzelm@15023
   863
  normalized terms by carrying around the rhs of the rewrite rule just
wenzelm@15023
   864
  applied. This is called the `skeleton'. It is decomposed in parallel
wenzelm@15023
   865
  with the term. Once a Var is encountered, the corresponding term is
wenzelm@15023
   866
  already in normal form.
wenzelm@15023
   867
  skel0 is a dummy skeleton that is to enforce complete normalization.*)
wenzelm@15023
   868
berghofe@10413
   869
val skel0 = Bound 0;
berghofe@10413
   870
wenzelm@15023
   871
(*Use rhs as skeleton only if the lhs does not contain unnormalized bits.
wenzelm@15023
   872
  The latter may happen iff there are weak congruence rules for constants
wenzelm@15023
   873
  in the lhs.*)
berghofe@10413
   874
wenzelm@15023
   875
fun uncond_skel ((_, weak), (lhs, rhs)) =
wenzelm@15023
   876
  if null weak then rhs  (*optimization*)
wenzelm@20671
   877
  else if exists_Const (member (op =) weak o #1) lhs then skel0
wenzelm@15023
   878
  else rhs;
wenzelm@15023
   879
wenzelm@15023
   880
(*Behaves like unconditional rule if rhs does not contain vars not in the lhs.
wenzelm@15023
   881
  Otherwise those vars may become instantiated with unnormalized terms
wenzelm@15023
   882
  while the premises are solved.*)
wenzelm@15023
   883
wenzelm@32797
   884
fun cond_skel (args as (_, (lhs, rhs))) =
haftmann@33038
   885
  if subset (op =) (Term.add_vars rhs [], Term.add_vars lhs []) then uncond_skel args
berghofe@10413
   886
  else skel0;
berghofe@10413
   887
berghofe@10413
   888
(*
wenzelm@15023
   889
  Rewriting -- we try in order:
berghofe@10413
   890
    (1) beta reduction
berghofe@10413
   891
    (2) unconditional rewrite rules
berghofe@10413
   892
    (3) conditional rewrite rules
berghofe@10413
   893
    (4) simplification procedures
berghofe@10413
   894
berghofe@10413
   895
  IMPORTANT: rewrite rules must not introduce new Vars or TVars!
berghofe@10413
   896
*)
berghofe@10413
   897
wenzelm@16458
   898
fun rewritec (prover, thyt, maxt) ss t =
berghofe@10413
   899
  let
wenzelm@24124
   900
    val ctxt = the_context ss;
wenzelm@15023
   901
    val Simpset ({rules, ...}, {congs, procs, termless, ...}) = ss;
berghofe@10413
   902
    val eta_thm = Thm.eta_conversion t;
wenzelm@22902
   903
    val eta_t' = Thm.rhs_of eta_thm;
berghofe@10413
   904
    val eta_t = term_of eta_t';
wenzelm@20546
   905
    fun rew {thm, name, lhs, elhs, extra, fo, perm} =
berghofe@10413
   906
      let
wenzelm@32797
   907
        val prop = Thm.prop_of thm;
wenzelm@20546
   908
        val (rthm, elhs') =
wenzelm@20546
   909
          if maxt = ~1 orelse not extra then (thm, elhs)
wenzelm@22902
   910
          else (Thm.incr_indexes (maxt + 1) thm, Thm.incr_indexes_cterm (maxt + 1) elhs);
wenzelm@22902
   911
        val insts =
wenzelm@22902
   912
          if fo then Thm.first_order_match (elhs', eta_t')
wenzelm@22902
   913
          else Thm.match (elhs', eta_t');
berghofe@10413
   914
        val thm' = Thm.instantiate insts (Thm.rename_boundvars lhs eta_t rthm);
wenzelm@14643
   915
        val prop' = Thm.prop_of thm';
wenzelm@21576
   916
        val unconditional = (Logic.count_prems prop' = 0);
berghofe@10413
   917
        val (lhs', rhs') = Logic.dest_equals (Logic.strip_imp_concl prop')
berghofe@10413
   918
      in
nipkow@11295
   919
        if perm andalso not (termless (rhs', lhs'))
wenzelm@22254
   920
        then (trace_named_thm (fn () => "Cannot apply permutative rewrite rule") ss (thm, name);
wenzelm@22254
   921
              trace_thm (fn () => "Term does not become smaller:") ss thm'; NONE)
wenzelm@22254
   922
        else (trace_named_thm (fn () => "Applying instance of rewrite rule") ss (thm, name);
berghofe@10413
   923
           if unconditional
berghofe@10413
   924
           then
wenzelm@22254
   925
             (trace_thm (fn () => "Rewriting:") ss thm';
wenzelm@38834
   926
              let
wenzelm@38834
   927
                val lr = Logic.dest_equals prop;
wenzelm@38834
   928
                val SOME thm'' = check_conv false ss eta_thm thm';
skalberg@15531
   929
              in SOME (thm'', uncond_skel (congs, lr)) end)
berghofe@10413
   930
           else
wenzelm@22254
   931
             (trace_thm (fn () => "Trying to rewrite:") ss thm';
wenzelm@24124
   932
              if simp_depth ss > Config.get ctxt simp_depth_limit
wenzelm@38834
   933
              then
wenzelm@38834
   934
                let
wenzelm@38834
   935
                  val s = "simp_depth_limit exceeded - giving up";
wenzelm@38834
   936
                  val _ = trace false (fn () => s) ss;
wenzelm@38834
   937
                  val _ = if_visible ss warning s;
wenzelm@38834
   938
                in NONE end
nipkow@16042
   939
              else
nipkow@16042
   940
              case prover ss thm' of
wenzelm@22254
   941
                NONE => (trace_thm (fn () => "FAILED") ss thm'; NONE)
skalberg@15531
   942
              | SOME thm2 =>
wenzelm@16985
   943
                  (case check_conv true ss eta_thm thm2 of
skalberg@15531
   944
                     NONE => NONE |
skalberg@15531
   945
                     SOME thm2' =>
berghofe@10413
   946
                       let val concl = Logic.strip_imp_concl prop
berghofe@10413
   947
                           val lr = Logic.dest_equals concl
nipkow@16042
   948
                       in SOME (thm2', cond_skel (congs, lr)) end)))
berghofe@10413
   949
      end
berghofe@10413
   950
skalberg@15531
   951
    fun rews [] = NONE
berghofe@10413
   952
      | rews (rrule :: rrules) =
skalberg@15531
   953
          let val opt = rew rrule handle Pattern.MATCH => NONE
skalberg@15531
   954
          in case opt of NONE => rews rrules | some => some end;
berghofe@10413
   955
wenzelm@38834
   956
    fun sort_rrules rrs =
wenzelm@38834
   957
      let
wenzelm@38834
   958
        fun is_simple ({thm, ...}: rrule) =
wenzelm@38834
   959
          (case Thm.prop_of thm of
wenzelm@38834
   960
            Const ("==", _) $ _ $ _ => true
wenzelm@38834
   961
          | _ => false);
wenzelm@38834
   962
        fun sort [] (re1, re2) = re1 @ re2
wenzelm@38834
   963
          | sort (rr :: rrs) (re1, re2) =
wenzelm@38834
   964
              if is_simple rr
wenzelm@38834
   965
              then sort rrs (rr :: re1, re2)
wenzelm@38834
   966
              else sort rrs (re1, rr :: re2);
wenzelm@38834
   967
      in sort rrs ([], []) end;
berghofe@10413
   968
skalberg@15531
   969
    fun proc_rews [] = NONE
wenzelm@15023
   970
      | proc_rews (Proc {name, proc, lhs, ...} :: ps) =
wenzelm@17203
   971
          if Pattern.matches thyt (Thm.term_of lhs, Thm.term_of t) then
boehmes@35979
   972
            (debug_term false (fn () => "Trying procedure " ^ quote name ^ " on:") ss eta_t;
wenzelm@23938
   973
             case proc ss eta_t' of
wenzelm@22892
   974
               NONE => (debug false (fn () => "FAILED") ss; proc_rews ps)
skalberg@15531
   975
             | SOME raw_thm =>
wenzelm@22254
   976
                 (trace_thm (fn () => "Procedure " ^ quote name ^ " produced rewrite rule:")
wenzelm@22254
   977
                   ss raw_thm;
wenzelm@16985
   978
                  (case rews (mk_procrule ss raw_thm) of
wenzelm@22254
   979
                    NONE => (trace_cterm true (fn () => "IGNORED result of simproc " ^ quote name ^
wenzelm@16985
   980
                      " -- does not match") ss t; proc_rews ps)
berghofe@10413
   981
                  | some => some)))
berghofe@10413
   982
          else proc_rews ps;
wenzelm@38834
   983
  in
wenzelm@38834
   984
    (case eta_t of
wenzelm@38834
   985
      Abs _ $ _ => SOME (Thm.transitive eta_thm (Thm.beta_conversion false eta_t'), skel0)
wenzelm@38834
   986
    | _ =>
wenzelm@38834
   987
      (case rews (sort_rrules (Net.match_term rules eta_t)) of
wenzelm@38834
   988
        NONE => proc_rews (Net.match_term procs eta_t)
wenzelm@38834
   989
      | some => some))
berghofe@10413
   990
  end;
berghofe@10413
   991
berghofe@10413
   992
berghofe@10413
   993
(* conversion to apply a congruence rule to a term *)
berghofe@10413
   994
krauss@30908
   995
fun congc prover ss maxt cong t =
wenzelm@22902
   996
  let val rthm = Thm.incr_indexes (maxt + 1) cong;
wenzelm@22902
   997
      val rlhs = fst (Thm.dest_equals (Drule.strip_imp_concl (cprop_of rthm)));
wenzelm@22902
   998
      val insts = Thm.match (rlhs, t)
wenzelm@22902
   999
      (* Thm.match can raise Pattern.MATCH;
berghofe@10413
  1000
         is handled when congc is called *)
berghofe@10413
  1001
      val thm' = Thm.instantiate insts (Thm.rename_boundvars (term_of rlhs) (term_of t) rthm);
wenzelm@32797
  1002
      val _ = trace_thm (fn () => "Applying congruence rule:") ss thm';
wenzelm@22254
  1003
      fun err (msg, thm) = (trace_thm (fn () => msg) ss thm; NONE)
wenzelm@38834
  1004
  in
wenzelm@38834
  1005
    (case prover thm' of
wenzelm@38834
  1006
      NONE => err ("Congruence proof failed.  Could not prove", thm')
wenzelm@38834
  1007
    | SOME thm2 =>
wenzelm@38834
  1008
        (case check_conv true ss (Drule.beta_eta_conversion t) thm2 of
skalberg@15531
  1009
          NONE => err ("Congruence proof failed.  Should not have proved", thm2)
skalberg@15531
  1010
        | SOME thm2' =>
wenzelm@22902
  1011
            if op aconv (pairself term_of (Thm.dest_equals (cprop_of thm2')))
wenzelm@38834
  1012
            then NONE else SOME thm2'))
berghofe@10413
  1013
  end;
berghofe@10413
  1014
berghofe@10413
  1015
val (cA, (cB, cC)) =
wenzelm@22902
  1016
  apsnd Thm.dest_equals (Thm.dest_implies (hd (cprems_of Drule.imp_cong)));
berghofe@10413
  1017
skalberg@15531
  1018
fun transitive1 NONE NONE = NONE
skalberg@15531
  1019
  | transitive1 (SOME thm1) NONE = SOME thm1
skalberg@15531
  1020
  | transitive1 NONE (SOME thm2) = SOME thm2
wenzelm@36944
  1021
  | transitive1 (SOME thm1) (SOME thm2) = SOME (Thm.transitive thm1 thm2)
berghofe@10413
  1022
skalberg@15531
  1023
fun transitive2 thm = transitive1 (SOME thm);
skalberg@15531
  1024
fun transitive3 thm = transitive1 thm o SOME;
berghofe@13607
  1025
wenzelm@16458
  1026
fun bottomc ((simprem, useprem, mutsimp), prover, thy, maxidx) =
berghofe@10413
  1027
  let
wenzelm@15023
  1028
    fun botc skel ss t =
skalberg@15531
  1029
          if is_Var skel then NONE
berghofe@10413
  1030
          else
wenzelm@15023
  1031
          (case subc skel ss t of
skalberg@15531
  1032
             some as SOME thm1 =>
wenzelm@22902
  1033
               (case rewritec (prover, thy, maxidx) ss (Thm.rhs_of thm1) of
skalberg@15531
  1034
                  SOME (thm2, skel2) =>
wenzelm@36944
  1035
                    transitive2 (Thm.transitive thm1 thm2)
wenzelm@22902
  1036
                      (botc skel2 ss (Thm.rhs_of thm2))
skalberg@15531
  1037
                | NONE => some)
skalberg@15531
  1038
           | NONE =>
wenzelm@16458
  1039
               (case rewritec (prover, thy, maxidx) ss t of
skalberg@15531
  1040
                  SOME (thm2, skel2) => transitive2 thm2
wenzelm@22902
  1041
                    (botc skel2 ss (Thm.rhs_of thm2))
skalberg@15531
  1042
                | NONE => NONE))
berghofe@10413
  1043
wenzelm@15023
  1044
    and try_botc ss t =
wenzelm@15023
  1045
          (case botc skel0 ss t of
wenzelm@36944
  1046
             SOME trec1 => trec1 | NONE => (Thm.reflexive t))
berghofe@10413
  1047
wenzelm@15023
  1048
    and subc skel (ss as Simpset ({bounds, ...}, {congs, ...})) t0 =
berghofe@10413
  1049
       (case term_of t0 of
wenzelm@32797
  1050
           Abs (a, T, _) =>
wenzelm@15023
  1051
             let
wenzelm@20079
  1052
                 val b = Name.bound (#1 bounds);
wenzelm@16985
  1053
                 val (v, t') = Thm.dest_abs (SOME b) t0;
wenzelm@16985
  1054
                 val b' = #1 (Term.dest_Free (Thm.term_of v));
wenzelm@21962
  1055
                 val _ =
wenzelm@21962
  1056
                   if b <> b' then
wenzelm@35231
  1057
                     warning ("Simplifier: renamed bound variable " ^
wenzelm@35231
  1058
                       quote b ^ " to " ^ quote b' ^ Position.str_of (Position.thread_data ()))
wenzelm@21962
  1059
                   else ();
wenzelm@17614
  1060
                 val ss' = add_bound ((b', T), a) ss;
wenzelm@15023
  1061
                 val skel' = case skel of Abs (_, _, sk) => sk | _ => skel0;
wenzelm@15023
  1062
             in case botc skel' ss' t' of
wenzelm@36944
  1063
                  SOME thm => SOME (Thm.abstract_rule a v thm)
skalberg@15531
  1064
                | NONE => NONE
berghofe@10413
  1065
             end
berghofe@10413
  1066
         | t $ _ => (case t of
wenzelm@15023
  1067
             Const ("==>", _) $ _  => impc t0 ss
berghofe@10413
  1068
           | Abs _ =>
wenzelm@36944
  1069
               let val thm = Thm.beta_conversion false t0
wenzelm@22902
  1070
               in case subc skel0 ss (Thm.rhs_of thm) of
skalberg@15531
  1071
                    NONE => SOME thm
wenzelm@36944
  1072
                  | SOME thm' => SOME (Thm.transitive thm thm')
berghofe@10413
  1073
               end
berghofe@10413
  1074
           | _  =>
berghofe@10413
  1075
               let fun appc () =
berghofe@10413
  1076
                     let
berghofe@10413
  1077
                       val (tskel, uskel) = case skel of
berghofe@10413
  1078
                           tskel $ uskel => (tskel, uskel)
berghofe@10413
  1079
                         | _ => (skel0, skel0);
wenzelm@10767
  1080
                       val (ct, cu) = Thm.dest_comb t0
berghofe@10413
  1081
                     in
wenzelm@15023
  1082
                     (case botc tskel ss ct of
skalberg@15531
  1083
                        SOME thm1 =>
wenzelm@15023
  1084
                          (case botc uskel ss cu of
wenzelm@36944
  1085
                             SOME thm2 => SOME (Thm.combination thm1 thm2)
wenzelm@36944
  1086
                           | NONE => SOME (Thm.combination thm1 (Thm.reflexive cu)))
skalberg@15531
  1087
                      | NONE =>
wenzelm@15023
  1088
                          (case botc uskel ss cu of
wenzelm@36944
  1089
                             SOME thm1 => SOME (Thm.combination (Thm.reflexive ct) thm1)
skalberg@15531
  1090
                           | NONE => NONE))
berghofe@10413
  1091
                     end
berghofe@10413
  1092
                   val (h, ts) = strip_comb t
ballarin@13835
  1093
               in case cong_name h of
skalberg@15531
  1094
                    SOME a =>
haftmann@17232
  1095
                      (case AList.lookup (op =) (fst congs) a of
skalberg@15531
  1096
                         NONE => appc ()
skalberg@15531
  1097
                       | SOME cong =>
wenzelm@15023
  1098
  (*post processing: some partial applications h t1 ... tj, j <= length ts,
wenzelm@15023
  1099
    may be a redex. Example: map (%x. x) = (%xs. xs) wrt map_cong*)
berghofe@10413
  1100
                          (let
wenzelm@16985
  1101
                             val thm = congc (prover ss) ss maxidx cong t0;
wenzelm@22902
  1102
                             val t = the_default t0 (Option.map Thm.rhs_of thm);
wenzelm@10767
  1103
                             val (cl, cr) = Thm.dest_comb t
berghofe@10413
  1104
                             val dVar = Var(("", 0), dummyT)
berghofe@10413
  1105
                             val skel =
berghofe@10413
  1106
                               list_comb (h, replicate (length ts) dVar)
wenzelm@15023
  1107
                           in case botc skel ss cl of
skalberg@15531
  1108
                                NONE => thm
skalberg@15531
  1109
                              | SOME thm' => transitive3 thm
wenzelm@36944
  1110
                                  (Thm.combination thm' (Thm.reflexive cr))
wenzelm@20057
  1111
                           end handle Pattern.MATCH => appc ()))
berghofe@10413
  1112
                  | _ => appc ()
berghofe@10413
  1113
               end)
skalberg@15531
  1114
         | _ => NONE)
berghofe@10413
  1115
wenzelm@15023
  1116
    and impc ct ss =
wenzelm@15023
  1117
      if mutsimp then mut_impc0 [] ct [] [] ss else nonmut_impc ct ss
berghofe@10413
  1118
wenzelm@15023
  1119
    and rules_of_prem ss prem =
berghofe@13607
  1120
      if maxidx_of_term (term_of prem) <> ~1
berghofe@13607
  1121
      then (trace_cterm true
wenzelm@22254
  1122
        (fn () => "Cannot add premise as rewrite rule because it contains (type) unknowns:")
wenzelm@22254
  1123
          ss prem; ([], NONE))
berghofe@13607
  1124
      else
wenzelm@36944
  1125
        let val asm = Thm.assume prem
skalberg@15531
  1126
        in (extract_safe_rrules (ss, asm), SOME asm) end
berghofe@10413
  1127
wenzelm@15023
  1128
    and add_rrules (rrss, asms) ss =
wenzelm@20028
  1129
      (fold o fold) insert_rrule rrss ss |> add_prems (map_filter I asms)
berghofe@10413
  1130
wenzelm@23178
  1131
    and disch r prem eq =
berghofe@13607
  1132
      let
wenzelm@22902
  1133
        val (lhs, rhs) = Thm.dest_equals (Thm.cprop_of eq);
wenzelm@36944
  1134
        val eq' = Thm.implies_elim (Thm.instantiate
berghofe@13607
  1135
          ([], [(cA, prem), (cB, lhs), (cC, rhs)]) Drule.imp_cong)
wenzelm@36944
  1136
          (Thm.implies_intr prem eq)
berghofe@13607
  1137
      in if not r then eq' else
berghofe@10413
  1138
        let
wenzelm@22902
  1139
          val (prem', concl) = Thm.dest_implies lhs;
wenzelm@22902
  1140
          val (prem'', _) = Thm.dest_implies rhs
wenzelm@36944
  1141
        in Thm.transitive (Thm.transitive
berghofe@13607
  1142
          (Thm.instantiate ([], [(cA, prem'), (cB, prem), (cC, concl)])
berghofe@13607
  1143
             Drule.swap_prems_eq) eq')
berghofe@13607
  1144
          (Thm.instantiate ([], [(cA, prem), (cB, prem''), (cC, concl)])
berghofe@13607
  1145
             Drule.swap_prems_eq)
berghofe@10413
  1146
        end
berghofe@10413
  1147
      end
berghofe@10413
  1148
berghofe@13607
  1149
    and rebuild [] _ _ _ _ eq = eq
wenzelm@32797
  1150
      | rebuild (prem :: prems) concl (_ :: rrss) (_ :: asms) ss eq =
berghofe@13607
  1151
          let
wenzelm@15023
  1152
            val ss' = add_rrules (rev rrss, rev asms) ss;
berghofe@13607
  1153
            val concl' =
wenzelm@22902
  1154
              Drule.mk_implies (prem, the_default concl (Option.map Thm.rhs_of eq));
wenzelm@23178
  1155
            val dprem = Option.map (disch false prem)
wenzelm@38834
  1156
          in
wenzelm@38834
  1157
            (case rewritec (prover, thy, maxidx) ss' concl' of
skalberg@15531
  1158
              NONE => rebuild prems concl' rrss asms ss (dprem eq)
wenzelm@23178
  1159
            | SOME (eq', _) => transitive2 (fold (disch false)
wenzelm@23178
  1160
                  prems (the (transitive3 (dprem eq) eq')))
wenzelm@38834
  1161
                (mut_impc0 (rev prems) (Thm.rhs_of eq') (rev rrss) (rev asms) ss))
berghofe@13607
  1162
          end
wenzelm@15023
  1163
wenzelm@15023
  1164
    and mut_impc0 prems concl rrss asms ss =
berghofe@13607
  1165
      let
berghofe@13607
  1166
        val prems' = strip_imp_prems concl;
wenzelm@15023
  1167
        val (rrss', asms') = split_list (map (rules_of_prem ss) prems')
wenzelm@38834
  1168
      in
wenzelm@38834
  1169
        mut_impc (prems @ prems') (strip_imp_concl concl) (rrss @ rrss')
wenzelm@38834
  1170
          (asms @ asms') [] [] [] [] ss ~1 ~1
berghofe@13607
  1171
      end
wenzelm@15023
  1172
wenzelm@15023
  1173
    and mut_impc [] concl [] [] prems' rrss' asms' eqns ss changed k =
wenzelm@33245
  1174
        transitive1 (fold (fn (eq1, prem) => fn eq2 => transitive1 eq1
wenzelm@33245
  1175
            (Option.map (disch false prem) eq2)) (eqns ~~ prems') NONE)
berghofe@13607
  1176
          (if changed > 0 then
berghofe@13607
  1177
             mut_impc (rev prems') concl (rev rrss') (rev asms')
wenzelm@15023
  1178
               [] [] [] [] ss ~1 changed
wenzelm@15023
  1179
           else rebuild prems' concl rrss' asms' ss
wenzelm@15023
  1180
             (botc skel0 (add_rrules (rev rrss', rev asms') ss) concl))
berghofe@13607
  1181
berghofe@13607
  1182
      | mut_impc (prem :: prems) concl (rrs :: rrss) (asm :: asms)
wenzelm@15023
  1183
          prems' rrss' asms' eqns ss changed k =
skalberg@15531
  1184
        case (if k = 0 then NONE else botc skel0 (add_rrules
wenzelm@15023
  1185
          (rev rrss' @ rrss, rev asms' @ asms) ss) prem) of
skalberg@15531
  1186
            NONE => mut_impc prems concl rrss asms (prem :: prems')
skalberg@15531
  1187
              (rrs :: rrss') (asm :: asms') (NONE :: eqns) ss changed
berghofe@13607
  1188
              (if k = 0 then 0 else k - 1)
skalberg@15531
  1189
          | SOME eqn =>
berghofe@13607
  1190
            let
wenzelm@22902
  1191
              val prem' = Thm.rhs_of eqn;
berghofe@13607
  1192
              val tprems = map term_of prems;
wenzelm@33029
  1193
              val i = 1 + fold Integer.max (map (fn p =>
wenzelm@33029
  1194
                find_index (fn q => q aconv p) tprems) (#hyps (rep_thm eqn))) ~1;
wenzelm@15023
  1195
              val (rrs', asm') = rules_of_prem ss prem'
berghofe@13607
  1196
            in mut_impc prems concl rrss asms (prem' :: prems')
wenzelm@23178
  1197
              (rrs' :: rrss') (asm' :: asms') (SOME (fold_rev (disch true)
haftmann@33957
  1198
                (take i prems)
wenzelm@36944
  1199
                (Drule.imp_cong_rule eqn (Thm.reflexive (Drule.list_implies
haftmann@33957
  1200
                  (drop i prems, concl))))) :: eqns)
wenzelm@20671
  1201
                  ss (length prems') ~1
berghofe@13607
  1202
            end
berghofe@13607
  1203
wenzelm@15023
  1204
     (*legacy code - only for backwards compatibility*)
wenzelm@38834
  1205
    and nonmut_impc ct ss =
wenzelm@38834
  1206
      let
wenzelm@38834
  1207
        val (prem, conc) = Thm.dest_implies ct;
wenzelm@38834
  1208
        val thm1 = if simprem then botc skel0 ss prem else NONE;
wenzelm@38834
  1209
        val prem1 = the_default prem (Option.map Thm.rhs_of thm1);
wenzelm@38834
  1210
        val ss1 =
wenzelm@38834
  1211
          if not useprem then ss
wenzelm@38834
  1212
          else add_rrules (apsnd single (apfst single (rules_of_prem ss prem1))) ss
wenzelm@38834
  1213
      in
wenzelm@38834
  1214
        (case botc skel0 ss1 conc of
wenzelm@38834
  1215
          NONE =>
wenzelm@38834
  1216
            (case thm1 of
wenzelm@38834
  1217
              NONE => NONE
wenzelm@38834
  1218
            | SOME thm1' => SOME (Drule.imp_cong_rule thm1' (Thm.reflexive conc)))
wenzelm@38834
  1219
        | SOME thm2 =>
wenzelm@38834
  1220
            let val thm2' = disch false prem1 thm2 in
wenzelm@38834
  1221
              (case thm1 of
wenzelm@38834
  1222
                NONE => SOME thm2'
wenzelm@38834
  1223
              | SOME thm1' =>
wenzelm@36944
  1224
                 SOME (Thm.transitive (Drule.imp_cong_rule thm1' (Thm.reflexive conc)) thm2'))
wenzelm@38834
  1225
            end)
wenzelm@38834
  1226
      end
berghofe@10413
  1227
wenzelm@15023
  1228
 in try_botc end;
berghofe@10413
  1229
berghofe@10413
  1230
wenzelm@15023
  1231
(* Meta-rewriting: rewrites t to u and returns the theorem t==u *)
berghofe@10413
  1232
berghofe@10413
  1233
(*
berghofe@10413
  1234
  Parameters:
berghofe@10413
  1235
    mode = (simplify A,
berghofe@10413
  1236
            use A in simplifying B,
berghofe@10413
  1237
            use prems of B (if B is again a meta-impl.) to simplify A)
berghofe@10413
  1238
           when simplifying A ==> B
berghofe@10413
  1239
    prover: how to solve premises in conditional rewrites and congruences
berghofe@10413
  1240
*)
berghofe@10413
  1241
wenzelm@32738
  1242
val debug_bounds = Unsynchronized.ref false;
wenzelm@17705
  1243
wenzelm@21962
  1244
fun check_bounds ss ct =
wenzelm@21962
  1245
  if ! debug_bounds then
wenzelm@21962
  1246
    let
wenzelm@21962
  1247
      val Simpset ({bounds = (_, bounds), ...}, _) = ss;
wenzelm@21962
  1248
      val bs = fold_aterms (fn Free (x, _) =>
wenzelm@21962
  1249
          if Name.is_bound x andalso not (AList.defined eq_bound bounds x)
wenzelm@21962
  1250
          then insert (op =) x else I
wenzelm@21962
  1251
        | _ => I) (term_of ct) [];
wenzelm@21962
  1252
    in
wenzelm@21962
  1253
      if null bs then ()
boehmes@35979
  1254
      else print_term_global ss true ("Simplifier: term contains loose bounds: " ^ commas_quote bs)
wenzelm@21962
  1255
        (Thm.theory_of_cterm ct) (Thm.term_of ct)
wenzelm@21962
  1256
    end
wenzelm@21962
  1257
  else ();
wenzelm@17614
  1258
wenzelm@19052
  1259
fun rewrite_cterm mode prover raw_ss raw_ct =
wenzelm@17882
  1260
  let
wenzelm@26626
  1261
    val thy = Thm.theory_of_cterm raw_ct;
wenzelm@20260
  1262
    val ct = Thm.adjust_maxidx_cterm ~1 raw_ct;
wenzelm@32797
  1263
    val {maxidx, ...} = Thm.rep_cterm ct;
wenzelm@22892
  1264
    val ss = inc_simp_depth (activate_context thy raw_ss);
wenzelm@22892
  1265
    val depth = simp_depth ss;
wenzelm@21962
  1266
    val _ =
wenzelm@22892
  1267
      if depth mod 20 = 0 then
wenzelm@38834
  1268
        if_visible ss warning ("Simplification depth " ^ string_of_int depth)
wenzelm@21962
  1269
      else ();
wenzelm@22254
  1270
    val _ = trace_cterm false (fn () => "SIMPLIFIER INVOKED ON THE FOLLOWING TERM:") ss ct;
wenzelm@17882
  1271
    val _ = check_bounds ss ct;
wenzelm@22892
  1272
  in bottomc (mode, Option.map Drule.flexflex_unique oo prover, thy, maxidx) ss ct end;
berghofe@10413
  1273
wenzelm@21708
  1274
val simple_prover =
wenzelm@21708
  1275
  SINGLE o (fn ss => ALLGOALS (resolve_tac (prems_of_ss ss)));
wenzelm@21708
  1276
wenzelm@21708
  1277
fun rewrite _ [] ct = Thm.reflexive ct
haftmann@27582
  1278
  | rewrite full thms ct = rewrite_cterm (full, false, false) simple_prover
wenzelm@35232
  1279
      (global_context (Thm.theory_of_cterm ct) empty_ss addsimps thms) ct;
wenzelm@11672
  1280
wenzelm@23598
  1281
fun simplify full thms = Conv.fconv_rule (rewrite full thms);
wenzelm@21708
  1282
val rewrite_rule = simplify true;
wenzelm@21708
  1283
wenzelm@15023
  1284
(*simple term rewriting -- no proof*)
wenzelm@16458
  1285
fun rewrite_term thy rules procs =
wenzelm@17203
  1286
  Pattern.rewrite_term thy (map decomp_simp' rules) procs;
wenzelm@15023
  1287
wenzelm@22902
  1288
fun rewrite_thm mode prover ss = Conv.fconv_rule (rewrite_cterm mode prover ss);
berghofe@10413
  1289
wenzelm@23536
  1290
(*Rewrite the subgoals of a proof state (represented by a theorem)*)
wenzelm@21708
  1291
fun rewrite_goals_rule thms th =
wenzelm@23584
  1292
  Conv.fconv_rule (Conv.prems_conv ~1 (rewrite_cterm (true, true, true) simple_prover
wenzelm@35232
  1293
    (global_context (Thm.theory_of_thm th) empty_ss addsimps thms))) th;
berghofe@10413
  1294
wenzelm@15023
  1295
(*Rewrite the subgoal of a proof state (represented by a theorem)*)
skalberg@15011
  1296
fun rewrite_goal_rule mode prover ss i thm =
wenzelm@23536
  1297
  if 0 < i andalso i <= Thm.nprems_of thm
wenzelm@23584
  1298
  then Conv.gconv_rule (rewrite_cterm mode prover ss) i thm
wenzelm@23536
  1299
  else raise THM ("rewrite_goal_rule", i, [thm]);
berghofe@10413
  1300
wenzelm@20228
  1301
wenzelm@21708
  1302
(** meta-rewriting tactics **)
wenzelm@21708
  1303
wenzelm@28839
  1304
(*Rewrite all subgoals*)
wenzelm@21708
  1305
fun rewrite_goals_tac defs = PRIMITIVE (rewrite_goals_rule defs);
wenzelm@21708
  1306
fun rewtac def = rewrite_goals_tac [def];
wenzelm@21708
  1307
wenzelm@28839
  1308
(*Rewrite one subgoal*)
wenzelm@25203
  1309
fun asm_rewrite_goal_tac mode prover_tac ss i thm =
wenzelm@25203
  1310
  if 0 < i andalso i <= Thm.nprems_of thm then
wenzelm@25203
  1311
    Seq.single (Conv.gconv_rule (rewrite_cterm mode (SINGLE o prover_tac) ss) i thm)
wenzelm@25203
  1312
  else Seq.empty;
wenzelm@23536
  1313
wenzelm@23536
  1314
fun rewrite_goal_tac rews =
wenzelm@23536
  1315
  let val ss = empty_ss addsimps rews in
wenzelm@23536
  1316
    fn i => fn st => asm_rewrite_goal_tac (true, false, false) (K no_tac)
wenzelm@35232
  1317
      (global_context (Thm.theory_of_thm st) ss) i st
wenzelm@23536
  1318
  end;
wenzelm@23536
  1319
wenzelm@21708
  1320
(*Prunes all redundant parameters from the proof state by rewriting.
wenzelm@21708
  1321
  DOES NOT rewrite main goal, where quantification over an unused bound
wenzelm@21708
  1322
    variable is sometimes done to avoid the need for cut_facts_tac.*)
wenzelm@21708
  1323
val prune_params_tac = rewrite_goals_tac [triv_forall_equality];
wenzelm@21708
  1324
wenzelm@21708
  1325
wenzelm@21708
  1326
(* for folding definitions, handling critical pairs *)
wenzelm@21708
  1327
wenzelm@21708
  1328
(*The depth of nesting in a term*)
wenzelm@32797
  1329
fun term_depth (Abs (_, _, t)) = 1 + term_depth t
wenzelm@32797
  1330
  | term_depth (f $ t) = 1 + Int.max (term_depth f, term_depth t)
wenzelm@21708
  1331
  | term_depth _ = 0;
wenzelm@21708
  1332
wenzelm@21708
  1333
val lhs_of_thm = #1 o Logic.dest_equals o prop_of;
wenzelm@21708
  1334
wenzelm@21708
  1335
(*folding should handle critical pairs!  E.g. K == Inl(0),  S == Inr(Inl(0))
wenzelm@21708
  1336
  Returns longest lhs first to avoid folding its subexpressions.*)
wenzelm@21708
  1337
fun sort_lhs_depths defs =
wenzelm@21708
  1338
  let val keylist = AList.make (term_depth o lhs_of_thm) defs
wenzelm@21708
  1339
      val keys = sort_distinct (rev_order o int_ord) (map #2 keylist)
wenzelm@21708
  1340
  in map (AList.find (op =) keylist) keys end;
wenzelm@21708
  1341
wenzelm@36944
  1342
val rev_defs = sort_lhs_depths o map Thm.symmetric;
wenzelm@21708
  1343
wenzelm@21708
  1344
fun fold_rule defs = fold rewrite_rule (rev_defs defs);
wenzelm@21708
  1345
fun fold_goals_tac defs = EVERY (map rewrite_goals_tac (rev_defs defs));
wenzelm@21708
  1346
wenzelm@21708
  1347
wenzelm@20228
  1348
(* HHF normal form: !! before ==>, outermost !! generalized *)
wenzelm@20228
  1349
wenzelm@20228
  1350
local
wenzelm@20228
  1351
wenzelm@21565
  1352
fun gen_norm_hhf ss th =
wenzelm@21565
  1353
  (if Drule.is_norm_hhf (Thm.prop_of th) then th
wenzelm@26424
  1354
   else Conv.fconv_rule
wenzelm@35232
  1355
    (rewrite_cterm (true, false, false) (K (K NONE)) (global_context (Thm.theory_of_thm th) ss)) th)
wenzelm@21565
  1356
  |> Thm.adjust_maxidx_thm ~1
wenzelm@21565
  1357
  |> Drule.gen_all;
wenzelm@20228
  1358
wenzelm@28620
  1359
val hhf_ss = empty_ss addsimps Drule.norm_hhf_eqs;
wenzelm@20228
  1360
wenzelm@20228
  1361
in
wenzelm@20228
  1362
wenzelm@26424
  1363
val norm_hhf = gen_norm_hhf hhf_ss;
wenzelm@26424
  1364
val norm_hhf_protect = gen_norm_hhf (hhf_ss addeqcongs [Drule.protect_cong]);
wenzelm@20228
  1365
wenzelm@20228
  1366
end;
wenzelm@20228
  1367
berghofe@10413
  1368
end;
berghofe@10413
  1369
wenzelm@32738
  1370
structure Basic_Meta_Simplifier: BASIC_META_SIMPLIFIER = MetaSimplifier;
wenzelm@32738
  1371
open Basic_Meta_Simplifier;