src/Pure/meta_simplifier.ML
author wenzelm
Thu May 31 23:47:36 2007 +0200 (2007-05-31 ago)
changeset 23178 07ba6b58b3d2
parent 22902 ac833b4bb7ee
child 23221 f032bdc3eff4
permissions -rw-r--r--
simplified/unified list fold;
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(*  Title:      Pure/meta_simplifier.ML
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    ID:         $Id$
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    Author:     Tobias Nipkow and Stefan Berghofer
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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 debug_simp: bool ref
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  val trace_simp: bool ref
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  val simp_depth_limit: int ref
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  val trace_simp_depth_limit: int ref
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  type rrule
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  val eq_rrule: rrule * rrule -> bool
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  type cong
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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 rep_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 ref option,
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    context: Proof.context option} *
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   {congs: (string * cong) list * string list,
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    procs: proc Net.net,
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    mk_rews:
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     {mk: thm -> thm list,
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      mk_cong: thm -> thm,
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      mk_sym: thm -> thm option,
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      mk_eq_True: 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 print_ss: simpset -> unit
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  val empty_ss: simpset
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  val merge_ss: simpset * simpset -> simpset
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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 setmksimps: simpset * (thm -> thm list) -> simpset
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  val setmkcong: simpset * (thm -> thm) -> simpset
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  val setmksym: simpset * (thm -> thm option) -> simpset
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  val setmkeqTrue: 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_tac: thm list -> 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_tac: thm list -> tactic
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  val fold_goals_tac: thm list -> tactic
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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 solver: simpset -> solver -> int -> tactic
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  val clear_ss: simpset -> simpset
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  exception SIMPROC_FAIL of string * exn
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  val simproc_i: theory -> string -> term list
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    -> (theory -> simpset -> term -> thm option) -> simproc
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  val simproc: 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 theory_context: theory  -> simpset -> simpset
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  val debug_bounds: bool 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 ->
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    (simpset -> thm -> thm option) -> simpset -> cterm -> thm
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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 norm_hhf: thm -> thm
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  val norm_hhf_protect: thm -> thm
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  val rewrite: bool -> thm list -> cterm -> thm
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  val simplify: bool -> thm list -> thm -> thm
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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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(* congruences *)
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type cong = {thm: thm, lhs: cterm};
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fun eq_cong ({thm = thm1, ...}: cong, {thm = thm2, ...}: cong) =
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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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type mk_rews =
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 {mk: thm -> thm list,
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  mk_cong: thm -> thm,
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  mk_sym: thm -> thm option,
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  mk_eq_True: thm -> thm option,
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  reorient: theory -> term list -> term -> term -> bool};
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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 ref option,
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    context: Proof.context option} *
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   {congs: (string * cong) list * string list,
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    procs: proc Net.net,
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    mk_rews: mk_rews,
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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 rep_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_simpset f (Simpset ({rules, prems, bounds, depth, context},
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    {congs, procs, mk_rews, termless, subgoal_tac, loop_tacs, solvers})) =
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  make_simpset (f ((rules, prems, bounds, depth, context),
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    (congs, procs, mk_rews, termless, subgoal_tac, loop_tacs, solvers)));
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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 = ref 100;
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val trace_simp_depth_limit = ref 1;
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fun trace_depth (Simpset ({depth = (depth, exceeded), ...}, _)) msg =
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  if depth > !trace_simp_depth_limit then
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    (case exceeded of
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      NONE => ()
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    | SOME r => if !r then () else (tracing "trace_simp_depth_limit exceeded!"; r := true))
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  else
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    (tracing (enclose "[" "]" (string_of_int depth) ^ msg);
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      (case exceeded of SOME r => r := 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, if depth = !trace_simp_depth_limit then SOME (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 debug_simp = ref false;
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val trace_simp = ref false;
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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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in
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fun print_term ss warn a thy t = prnt ss warn (a ^ "\n" ^
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  Sign.string_of_term thy (if ! debug_simp then t else show_bounds ss t));
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fun debug warn a ss = if ! debug_simp then prnt ss warn (a ()) else ();
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fun trace warn a ss = if ! trace_simp then prnt ss warn (a ()) else ();
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fun debug_term warn a ss thy t = if ! debug_simp then print_term ss warn (a ()) thy t else ();
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fun trace_term warn a ss thy t = if ! trace_simp then print_term ss warn (a ()) thy t else ();
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fun trace_cterm warn a ss ct =
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  if ! trace_simp then print_term ss warn (a ()) (Thm.theory_of_cterm ct) (Thm.term_of ct)
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  else ();
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fun trace_thm a ss th =
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  if ! trace_simp then print_term ss false (a ()) (Thm.theory_of_thm th) (Thm.full_prop_of th)
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  else ();
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fun trace_named_thm a ss (th, name) =
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  if ! trace_simp then
wenzelm@22892
   314
    print_term ss false (if name = "" then a () else a () ^ " " ^ quote name ^ ":")
wenzelm@16985
   315
      (Thm.theory_of_thm th) (Thm.full_prop_of th)
wenzelm@16985
   316
  else ();
wenzelm@16985
   317
wenzelm@22892
   318
fun warn_thm a ss th =
wenzelm@22892
   319
  print_term ss true a (Thm.theory_of_thm th) (Thm.full_prop_of th);
wenzelm@16985
   320
wenzelm@20028
   321
fun cond_warn_thm a (ss as Simpset ({context, ...}, _)) th =
wenzelm@20546
   322
  if is_some context then () else warn_thm a ss th;
wenzelm@20028
   323
wenzelm@16985
   324
end;
wenzelm@16985
   325
wenzelm@16985
   326
wenzelm@15023
   327
(* print simpsets *)
berghofe@10413
   328
wenzelm@15023
   329
fun print_ss ss =
wenzelm@15023
   330
  let
wenzelm@15034
   331
    val pretty_thms = map Display.pretty_thm;
wenzelm@15023
   332
haftmann@22221
   333
    fun pretty_cong (name, {thm, lhs}) =
haftmann@22221
   334
      Pretty.block [Pretty.str (name ^ ":"), Pretty.brk 1, Display.pretty_thm thm];
wenzelm@15023
   335
    fun pretty_proc (name, lhss) =
wenzelm@15023
   336
      Pretty.big_list (name ^ ":") (map Display.pretty_cterm lhss);
wenzelm@15034
   337
wenzelm@15034
   338
    val Simpset ({rules, ...}, {congs, procs, loop_tacs, solvers, ...}) = ss;
wenzelm@16807
   339
    val smps = map #thm (Net.entries rules);
wenzelm@16807
   340
    val prcs = Net.entries procs |>
wenzelm@16807
   341
      map (fn Proc {name, lhs, id, ...} => ((name, lhs), id))
wenzelm@22234
   342
      |> partition_eq (eq_snd eq_procid)
wenzelm@17756
   343
      |> map (fn ps => (fst (fst (hd ps)), map (snd o fst) ps))
wenzelm@17756
   344
      |> Library.sort_wrt fst;
wenzelm@15023
   345
  in
wenzelm@15034
   346
    [Pretty.big_list "simplification rules:" (pretty_thms smps),
wenzelm@15034
   347
      Pretty.big_list "simplification procedures:" (map pretty_proc prcs),
haftmann@22221
   348
      Pretty.big_list "congruences:" (map pretty_cong (fst congs)),
haftmann@21286
   349
      Pretty.strs ("loopers:" :: map (quote o fst) loop_tacs),
wenzelm@15088
   350
      Pretty.strs ("unsafe solvers:" :: map (quote o solver_name) (#1 solvers)),
wenzelm@15088
   351
      Pretty.strs ("safe solvers:" :: map (quote o solver_name) (#2 solvers))]
wenzelm@15023
   352
    |> Pretty.chunks |> Pretty.writeln
nipkow@13828
   353
  end;
berghofe@10413
   354
wenzelm@15023
   355
berghofe@10413
   356
berghofe@10413
   357
(** simpset operations **)
berghofe@10413
   358
wenzelm@17882
   359
(* context *)
berghofe@10413
   360
wenzelm@17614
   361
fun eq_bound (x: string, (y, _)) = x = y;
wenzelm@17614
   362
wenzelm@22892
   363
fun add_bound bound = map_simpset1 (fn (rules, prems, (count, bounds), depth, context) =>
wenzelm@22892
   364
  (rules, prems, (count + 1, bound :: bounds), depth, context));
wenzelm@17882
   365
wenzelm@22892
   366
fun add_prems ths = map_simpset1 (fn (rules, prems, bounds, depth, context) =>
wenzelm@22892
   367
  (rules, ths @ prems, bounds, depth, context));
wenzelm@17882
   368
wenzelm@22892
   369
fun inherit_context (Simpset ({bounds, depth, context, ...}, _)) =
wenzelm@22892
   370
  map_simpset1 (fn (rules, prems, _, _, _) => (rules, prems, bounds, depth, context));
wenzelm@16985
   371
wenzelm@17882
   372
fun the_context (Simpset ({context = SOME ctxt, ...}, _)) = ctxt
wenzelm@17882
   373
  | the_context _ = raise Fail "Simplifier: no proof context in simpset";
berghofe@10413
   374
wenzelm@17897
   375
fun context ctxt =
wenzelm@22892
   376
  map_simpset1 (fn (rules, prems, bounds, depth, _) => (rules, prems, bounds, depth, SOME ctxt));
wenzelm@17882
   377
wenzelm@21516
   378
val theory_context = context o ProofContext.init;
wenzelm@17897
   379
wenzelm@22008
   380
fun activate_context thy (ss as Simpset ({context = SOME ctxt, ...}, _)) =
wenzelm@22008
   381
      context (Context.transfer_proof (Theory.merge (thy, ProofContext.theory_of ctxt)) ctxt) ss
wenzelm@22008
   382
  | activate_context thy ss =
wenzelm@17882
   383
     (warning "Simplifier: no proof context in simpset -- fallback to theory context!";
wenzelm@17897
   384
      theory_context thy ss);
wenzelm@17897
   385
wenzelm@17897
   386
wenzelm@20028
   387
(* maintain simp rules *)
berghofe@10413
   388
wenzelm@20546
   389
(* FIXME: it seems that the conditions on extra variables are too liberal if
wenzelm@20546
   390
prems are nonempty: does solving the prems really guarantee instantiation of
wenzelm@20546
   391
all its Vars? Better: a dynamic check each time a rule is applied.
wenzelm@20546
   392
*)
wenzelm@20546
   393
fun rewrite_rule_extra_vars prems elhs erhs =
wenzelm@20546
   394
  let
wenzelm@20546
   395
    val elhss = elhs :: prems;
wenzelm@20546
   396
    val tvars = fold Term.add_tvars elhss [];
wenzelm@20546
   397
    val vars = fold Term.add_vars elhss [];
wenzelm@20546
   398
  in
wenzelm@20546
   399
    erhs |> Term.exists_type (Term.exists_subtype
wenzelm@20546
   400
      (fn TVar v => not (member (op =) tvars v) | _ => false)) orelse
wenzelm@20546
   401
    erhs |> Term.exists_subterm
wenzelm@20546
   402
      (fn Var v => not (member (op =) vars v) | _ => false)
wenzelm@20546
   403
  end;
wenzelm@20546
   404
wenzelm@20546
   405
fun rrule_extra_vars elhs thm =
wenzelm@20546
   406
  rewrite_rule_extra_vars [] (term_of elhs) (Thm.full_prop_of thm);
wenzelm@20546
   407
wenzelm@15023
   408
fun mk_rrule2 {thm, name, lhs, elhs, perm} =
wenzelm@15023
   409
  let
wenzelm@20546
   410
    val t = term_of elhs;
wenzelm@20546
   411
    val fo = Pattern.first_order t orelse not (Pattern.pattern t);
wenzelm@20546
   412
    val extra = rrule_extra_vars elhs thm;
wenzelm@20546
   413
  in {thm = thm, name = name, lhs = lhs, elhs = elhs, extra = extra, fo = fo, perm = perm} end;
berghofe@10413
   414
wenzelm@20028
   415
fun del_rrule (rrule as {thm, elhs, ...}) ss =
wenzelm@22892
   416
  ss |> map_simpset1 (fn (rules, prems, bounds, depth, context) =>
wenzelm@22892
   417
    (Net.delete_term eq_rrule (term_of elhs, rrule) rules, prems, bounds, depth, context))
wenzelm@20028
   418
  handle Net.DELETE => (cond_warn_thm "Rewrite rule not in simpset:" ss thm; ss);
wenzelm@20028
   419
wenzelm@20546
   420
fun insert_rrule (rrule as {thm, name, elhs, ...}) ss =
wenzelm@22254
   421
 (trace_named_thm (fn () => "Adding rewrite rule") ss (thm, name);
wenzelm@22892
   422
  ss |> map_simpset1 (fn (rules, prems, bounds, depth, context) =>
wenzelm@15023
   423
    let
wenzelm@15023
   424
      val rrule2 as {elhs, ...} = mk_rrule2 rrule;
wenzelm@16807
   425
      val rules' = Net.insert_term eq_rrule (term_of elhs, rrule2) rules;
wenzelm@22892
   426
    in (rules', prems, bounds, depth, context) end)
wenzelm@20028
   427
  handle Net.INSERT => (cond_warn_thm "Ignoring duplicate rewrite rule:" ss thm; ss));
berghofe@10413
   428
berghofe@10413
   429
fun vperm (Var _, Var _) = true
berghofe@10413
   430
  | vperm (Abs (_, _, s), Abs (_, _, t)) = vperm (s, t)
berghofe@10413
   431
  | vperm (t1 $ t2, u1 $ u2) = vperm (t1, u1) andalso vperm (t2, u2)
berghofe@10413
   432
  | vperm (t, u) = (t = u);
berghofe@10413
   433
berghofe@10413
   434
fun var_perm (t, u) =
wenzelm@20197
   435
  vperm (t, u) andalso gen_eq_set (op =) (Term.add_vars t [], Term.add_vars u []);
berghofe@10413
   436
wenzelm@15023
   437
(*simple test for looping rewrite rules and stupid orientations*)
wenzelm@18208
   438
fun default_reorient thy prems lhs rhs =
wenzelm@15023
   439
  rewrite_rule_extra_vars prems lhs rhs
wenzelm@15023
   440
    orelse
wenzelm@15023
   441
  is_Var (head_of lhs)
wenzelm@15023
   442
    orelse
nipkow@16305
   443
(* turns t = x around, which causes a headache if x is a local variable -
nipkow@16305
   444
   usually it is very useful :-(
nipkow@16305
   445
  is_Free rhs andalso not(is_Free lhs) andalso not(Logic.occs(rhs,lhs))
nipkow@16305
   446
  andalso not(exists_subterm is_Var lhs)
nipkow@16305
   447
    orelse
nipkow@16305
   448
*)
wenzelm@16842
   449
  exists (fn t => Logic.occs (lhs, t)) (rhs :: prems)
wenzelm@15023
   450
    orelse
wenzelm@17203
   451
  null prems andalso Pattern.matches thy (lhs, rhs)
berghofe@10413
   452
    (*the condition "null prems" is necessary because conditional rewrites
berghofe@10413
   453
      with extra variables in the conditions may terminate although
wenzelm@15023
   454
      the rhs is an instance of the lhs; example: ?m < ?n ==> f(?n) == f(?m)*)
wenzelm@15023
   455
    orelse
wenzelm@15023
   456
  is_Const lhs andalso not (is_Const rhs);
berghofe@10413
   457
berghofe@10413
   458
fun decomp_simp thm =
wenzelm@15023
   459
  let
wenzelm@16458
   460
    val {thy, prop, ...} = Thm.rep_thm thm;
wenzelm@15023
   461
    val prems = Logic.strip_imp_prems prop;
wenzelm@15023
   462
    val concl = Drule.strip_imp_concl (Thm.cprop_of thm);
wenzelm@22902
   463
    val (lhs, rhs) = Thm.dest_equals concl handle TERM _ =>
wenzelm@15023
   464
      raise SIMPLIFIER ("Rewrite rule not a meta-equality", thm);
wenzelm@20579
   465
    val elhs = Thm.dest_arg (Thm.cprop_of (Thm.eta_conversion lhs));
wenzelm@16665
   466
    val elhs = if term_of elhs aconv term_of lhs then lhs else elhs;  (*share identical copies*)
wenzelm@18929
   467
    val erhs = Envir.eta_contract (term_of rhs);
wenzelm@15023
   468
    val perm =
wenzelm@15023
   469
      var_perm (term_of elhs, erhs) andalso
wenzelm@15023
   470
      not (term_of elhs aconv erhs) andalso
wenzelm@15023
   471
      not (is_Var (term_of elhs));
wenzelm@16458
   472
  in (thy, prems, term_of lhs, elhs, term_of rhs, perm) end;
berghofe@10413
   473
wenzelm@12783
   474
fun decomp_simp' thm =
wenzelm@12979
   475
  let val (_, _, lhs, _, rhs, _) = decomp_simp thm in
wenzelm@12783
   476
    if Thm.nprems_of thm > 0 then raise SIMPLIFIER ("Bad conditional rewrite rule", thm)
wenzelm@12979
   477
    else (lhs, rhs)
wenzelm@12783
   478
  end;
wenzelm@12783
   479
wenzelm@15023
   480
fun mk_eq_True (Simpset (_, {mk_rews = {mk_eq_True, ...}, ...})) (thm, name) =
wenzelm@15023
   481
  (case mk_eq_True thm of
skalberg@15531
   482
    NONE => []
skalberg@15531
   483
  | SOME eq_True =>
wenzelm@20546
   484
      let
wenzelm@20546
   485
        val (_, _, lhs, elhs, _, _) = decomp_simp eq_True;
wenzelm@20546
   486
        val extra = rrule_extra_vars elhs eq_True;
wenzelm@15023
   487
      in [{thm = eq_True, name = name, lhs = lhs, elhs = elhs, perm = false}] end);
berghofe@10413
   488
wenzelm@15023
   489
(*create the rewrite rule and possibly also the eq_True variant,
wenzelm@15023
   490
  in case there are extra vars on the rhs*)
wenzelm@15023
   491
fun rrule_eq_True (thm, name, lhs, elhs, rhs, ss, thm2) =
wenzelm@15023
   492
  let val rrule = {thm = thm, name = name, lhs = lhs, elhs = elhs, perm = false} in
wenzelm@20546
   493
    if rewrite_rule_extra_vars [] lhs rhs then
wenzelm@20546
   494
      mk_eq_True ss (thm2, name) @ [rrule]
wenzelm@20546
   495
    else [rrule]
berghofe@10413
   496
  end;
berghofe@10413
   497
wenzelm@15023
   498
fun mk_rrule ss (thm, name) =
wenzelm@15023
   499
  let val (_, prems, lhs, elhs, rhs, perm) = decomp_simp thm in
wenzelm@15023
   500
    if perm then [{thm = thm, name = name, lhs = lhs, elhs = elhs, perm = true}]
wenzelm@15023
   501
    else
wenzelm@15023
   502
      (*weak test for loops*)
wenzelm@15023
   503
      if rewrite_rule_extra_vars prems lhs rhs orelse is_Var (term_of elhs)
wenzelm@15023
   504
      then mk_eq_True ss (thm, name)
wenzelm@15023
   505
      else rrule_eq_True (thm, name, lhs, elhs, rhs, ss, thm)
berghofe@10413
   506
  end;
berghofe@10413
   507
wenzelm@15023
   508
fun orient_rrule ss (thm, name) =
wenzelm@18208
   509
  let
wenzelm@18208
   510
    val (thy, prems, lhs, elhs, rhs, perm) = decomp_simp thm;
wenzelm@18208
   511
    val Simpset (_, {mk_rews = {reorient, mk_sym, ...}, ...}) = ss;
wenzelm@18208
   512
  in
wenzelm@15023
   513
    if perm then [{thm = thm, name = name, lhs = lhs, elhs = elhs, perm = true}]
wenzelm@16458
   514
    else if reorient thy prems lhs rhs then
wenzelm@16458
   515
      if reorient thy prems rhs lhs
wenzelm@15023
   516
      then mk_eq_True ss (thm, name)
wenzelm@15023
   517
      else
wenzelm@18208
   518
        (case mk_sym thm of
wenzelm@18208
   519
          NONE => []
wenzelm@18208
   520
        | SOME thm' =>
wenzelm@18208
   521
            let val (_, _, lhs', elhs', rhs', _) = decomp_simp thm'
wenzelm@18208
   522
            in rrule_eq_True (thm', name, lhs', elhs', rhs', ss, thm) end)
wenzelm@15023
   523
    else rrule_eq_True (thm, name, lhs, elhs, rhs, ss, thm)
berghofe@10413
   524
  end;
berghofe@10413
   525
nipkow@15199
   526
fun extract_rews (Simpset (_, {mk_rews = {mk, ...}, ...}), thms) =
wenzelm@21646
   527
  maps (fn thm => map (rpair (PureThy.get_name_hint thm)) (mk thm)) thms;
berghofe@10413
   528
wenzelm@15023
   529
fun extract_safe_rrules (ss, thm) =
wenzelm@19482
   530
  maps (orient_rrule ss) (extract_rews (ss, [thm]));
berghofe@10413
   531
berghofe@10413
   532
wenzelm@20028
   533
(* add/del rules explicitly *)
berghofe@10413
   534
wenzelm@20028
   535
fun comb_simps comb mk_rrule (ss, thms) =
wenzelm@20028
   536
  let
wenzelm@20028
   537
    val rews = extract_rews (ss, thms);
wenzelm@20028
   538
  in fold (fold comb o mk_rrule) rews ss end;
berghofe@10413
   539
wenzelm@20028
   540
fun ss addsimps thms =
wenzelm@20028
   541
  comb_simps insert_rrule (mk_rrule ss) (ss, thms);
berghofe@10413
   542
wenzelm@15023
   543
fun ss delsimps thms =
wenzelm@20028
   544
  comb_simps del_rrule (map mk_rrule2 o mk_rrule ss) (ss, thms);
wenzelm@15023
   545
wenzelm@15023
   546
wenzelm@15023
   547
(* congs *)
berghofe@10413
   548
skalberg@15531
   549
fun cong_name (Const (a, _)) = SOME a
skalberg@15531
   550
  | cong_name (Free (a, _)) = SOME ("Free: " ^ a)
skalberg@15531
   551
  | cong_name _ = NONE;
ballarin@13835
   552
wenzelm@15023
   553
local
wenzelm@15023
   554
wenzelm@15023
   555
fun is_full_cong_prems [] [] = true
wenzelm@15023
   556
  | is_full_cong_prems [] _ = false
wenzelm@15023
   557
  | is_full_cong_prems (p :: prems) varpairs =
wenzelm@15023
   558
      (case Logic.strip_assums_concl p of
wenzelm@15023
   559
        Const ("==", _) $ lhs $ rhs =>
wenzelm@15023
   560
          let val (x, xs) = strip_comb lhs and (y, ys) = strip_comb rhs in
wenzelm@15023
   561
            is_Var x andalso forall is_Bound xs andalso
haftmann@20972
   562
            not (has_duplicates (op =) xs) andalso xs = ys andalso
wenzelm@20671
   563
            member (op =) varpairs (x, y) andalso
wenzelm@19303
   564
            is_full_cong_prems prems (remove (op =) (x, y) varpairs)
wenzelm@15023
   565
          end
wenzelm@15023
   566
      | _ => false);
wenzelm@15023
   567
wenzelm@15023
   568
fun is_full_cong thm =
berghofe@10413
   569
  let
wenzelm@15023
   570
    val prems = prems_of thm and concl = concl_of thm;
wenzelm@15023
   571
    val (lhs, rhs) = Logic.dest_equals concl;
wenzelm@15023
   572
    val (f, xs) = strip_comb lhs and (g, ys) = strip_comb rhs;
berghofe@10413
   573
  in
haftmann@20972
   574
    f = g andalso not (has_duplicates (op =) (xs @ ys)) andalso length xs = length ys andalso
wenzelm@15023
   575
    is_full_cong_prems prems (xs ~~ ys)
berghofe@10413
   576
  end;
berghofe@10413
   577
wenzelm@15023
   578
fun add_cong (ss, thm) = ss |>
wenzelm@15023
   579
  map_simpset2 (fn (congs, procs, mk_rews, termless, subgoal_tac, loop_tacs, solvers) =>
wenzelm@15023
   580
    let
wenzelm@22902
   581
      val (lhs, _) = Thm.dest_equals (Drule.strip_imp_concl (Thm.cprop_of thm))
wenzelm@15023
   582
        handle TERM _ => raise SIMPLIFIER ("Congruence not a meta-equality", thm);
wenzelm@18929
   583
    (*val lhs = Envir.eta_contract lhs;*)
wenzelm@20057
   584
      val a = the (cong_name (head_of (term_of lhs))) handle Option.Option =>
wenzelm@15023
   585
        raise SIMPLIFIER ("Congruence must start with a constant or free variable", thm);
haftmann@22221
   586
      val (xs, weak) = congs;
haftmann@22221
   587
      val _ =  if AList.defined (op =) xs a
haftmann@22221
   588
        then warning ("Overwriting congruence rule for " ^ quote a)
haftmann@22221
   589
        else ();
haftmann@22221
   590
      val xs' = AList.update (op =) (a, {lhs = lhs, thm = thm}) xs;
haftmann@22221
   591
      val weak' = if is_full_cong thm then weak else a :: weak;
haftmann@22221
   592
    in ((xs', weak'), procs, mk_rews, termless, subgoal_tac, loop_tacs, solvers) end);
berghofe@10413
   593
wenzelm@15023
   594
fun del_cong (ss, thm) = ss |>
wenzelm@15023
   595
  map_simpset2 (fn (congs, procs, mk_rews, termless, subgoal_tac, loop_tacs, solvers) =>
wenzelm@15023
   596
    let
wenzelm@15023
   597
      val (lhs, _) = Logic.dest_equals (Thm.concl_of thm) handle TERM _ =>
wenzelm@15023
   598
        raise SIMPLIFIER ("Congruence not a meta-equality", thm);
wenzelm@18929
   599
    (*val lhs = Envir.eta_contract lhs;*)
wenzelm@20057
   600
      val a = the (cong_name (head_of lhs)) handle Option.Option =>
wenzelm@15023
   601
        raise SIMPLIFIER ("Congruence must start with a constant", thm);
haftmann@22221
   602
      val (xs, _) = congs;
haftmann@22221
   603
      val xs' = filter_out (fn (x : string, _) => x = a) xs;
haftmann@22221
   604
      val weak' = xs' |> map_filter (fn (a, {thm, ...}: cong) =>
skalberg@15531
   605
        if is_full_cong thm then NONE else SOME a);
haftmann@22221
   606
    in ((xs', weak'), procs, mk_rews, termless, subgoal_tac, loop_tacs, solvers) end);
berghofe@10413
   607
wenzelm@15023
   608
fun mk_cong (Simpset (_, {mk_rews = {mk_cong = f, ...}, ...})) = f;
wenzelm@15023
   609
wenzelm@15023
   610
in
wenzelm@15023
   611
skalberg@15570
   612
val (op addeqcongs) = Library.foldl add_cong;
skalberg@15570
   613
val (op deleqcongs) = Library.foldl del_cong;
wenzelm@15023
   614
wenzelm@15023
   615
fun ss addcongs congs = ss addeqcongs map (mk_cong ss) congs;
wenzelm@15023
   616
fun ss delcongs congs = ss deleqcongs map (mk_cong ss) congs;
wenzelm@15023
   617
wenzelm@15023
   618
end;
berghofe@10413
   619
berghofe@10413
   620
wenzelm@15023
   621
(* simprocs *)
wenzelm@15023
   622
wenzelm@22008
   623
exception SIMPROC_FAIL of string * exn;
wenzelm@22008
   624
wenzelm@22234
   625
datatype simproc =
wenzelm@22234
   626
  Simproc of
wenzelm@22234
   627
    {name: string,
wenzelm@22234
   628
     lhss: cterm list,
wenzelm@22234
   629
     proc: morphism -> simpset -> cterm -> thm option,
wenzelm@22234
   630
     id: stamp * thm list};
wenzelm@22234
   631
wenzelm@22234
   632
fun eq_simproc (Simproc {id = id1, ...}, Simproc {id = id2, ...}) = eq_procid (id1, id2);
wenzelm@22008
   633
wenzelm@22234
   634
fun morph_simproc phi (Simproc {name, lhss, proc, id = (s, ths)}) =
wenzelm@22234
   635
  Simproc
wenzelm@22234
   636
   {name = name,
wenzelm@22234
   637
    lhss = map (Morphism.cterm phi) lhss,
wenzelm@22669
   638
    proc = Morphism.transform phi proc,
wenzelm@22234
   639
    id = (s, Morphism.fact phi ths)};
wenzelm@22234
   640
wenzelm@22234
   641
fun make_simproc {name, lhss, proc, identifier} =
wenzelm@22234
   642
  Simproc {name = name, lhss = lhss, proc = proc, id = (stamp (), identifier)};
wenzelm@22008
   643
wenzelm@22008
   644
fun mk_simproc name lhss proc =
wenzelm@22234
   645
  make_simproc {name = name, lhss = lhss, proc = fn _ => fn ss => fn ct =>
wenzelm@22234
   646
    proc (ProofContext.theory_of (the_context ss)) ss (Thm.term_of ct), identifier = []};
wenzelm@22008
   647
wenzelm@22008
   648
(* FIXME avoid global thy and Logic.varify *)
wenzelm@22008
   649
fun simproc_i thy name = mk_simproc name o map (Thm.cterm_of thy o Logic.varify);
wenzelm@22008
   650
fun simproc thy name = simproc_i thy name o map (Sign.read_term thy);
wenzelm@22008
   651
wenzelm@22008
   652
wenzelm@15023
   653
local
berghofe@10413
   654
wenzelm@16985
   655
fun add_proc (proc as Proc {name, lhs, ...}) ss =
wenzelm@22254
   656
 (trace_cterm false (fn () => "Adding simplification procedure " ^ quote name ^ " for") ss lhs;
wenzelm@15023
   657
  map_simpset2 (fn (congs, procs, mk_rews, termless, subgoal_tac, loop_tacs, solvers) =>
wenzelm@16807
   658
    (congs, Net.insert_term eq_proc (term_of lhs, proc) procs,
wenzelm@15023
   659
      mk_rews, termless, subgoal_tac, loop_tacs, solvers)) ss
wenzelm@15023
   660
  handle Net.INSERT =>
wenzelm@15023
   661
    (warning ("Ignoring duplicate simplification procedure " ^ quote name); ss));
berghofe@10413
   662
wenzelm@16985
   663
fun del_proc (proc as Proc {name, lhs, ...}) ss =
wenzelm@15023
   664
  map_simpset2 (fn (congs, procs, mk_rews, termless, subgoal_tac, loop_tacs, solvers) =>
wenzelm@16807
   665
    (congs, Net.delete_term eq_proc (term_of lhs, proc) procs,
wenzelm@15023
   666
      mk_rews, termless, subgoal_tac, loop_tacs, solvers)) ss
wenzelm@15023
   667
  handle Net.DELETE =>
wenzelm@15023
   668
    (warning ("Simplification procedure " ^ quote name ^ " not in simpset"); ss);
berghofe@10413
   669
wenzelm@22234
   670
fun prep_procs (Simproc {name, lhss, proc, id}) =
wenzelm@22669
   671
  lhss |> map (fn lhs => Proc {name = name, lhs = lhs, proc = Morphism.form proc, id = id});
wenzelm@22234
   672
wenzelm@15023
   673
in
berghofe@10413
   674
wenzelm@22234
   675
fun ss addsimprocs ps = fold (fold add_proc o prep_procs) ps ss;
wenzelm@22234
   676
fun ss delsimprocs ps = fold (fold del_proc o prep_procs) ps ss;
berghofe@10413
   677
wenzelm@15023
   678
end;
berghofe@10413
   679
berghofe@10413
   680
berghofe@10413
   681
(* mk_rews *)
berghofe@10413
   682
wenzelm@15023
   683
local
wenzelm@15023
   684
wenzelm@18208
   685
fun map_mk_rews f = map_simpset2 (fn (congs, procs, {mk, mk_cong, mk_sym, mk_eq_True, reorient},
wenzelm@15023
   686
      termless, subgoal_tac, loop_tacs, solvers) =>
wenzelm@18208
   687
  let
wenzelm@18208
   688
    val (mk', mk_cong', mk_sym', mk_eq_True', reorient') =
wenzelm@18208
   689
      f (mk, mk_cong, mk_sym, mk_eq_True, reorient);
wenzelm@18208
   690
    val mk_rews' = {mk = mk', mk_cong = mk_cong', mk_sym = mk_sym', mk_eq_True = mk_eq_True',
wenzelm@18208
   691
      reorient = reorient'};
wenzelm@18208
   692
  in (congs, procs, mk_rews', termless, subgoal_tac, loop_tacs, solvers) end);
wenzelm@15023
   693
wenzelm@15023
   694
in
berghofe@10413
   695
wenzelm@18208
   696
fun ss setmksimps mk = ss |> map_mk_rews (fn (_, mk_cong, mk_sym, mk_eq_True, reorient) =>
wenzelm@18208
   697
  (mk, mk_cong, mk_sym, mk_eq_True, reorient));
wenzelm@15023
   698
wenzelm@18208
   699
fun ss setmkcong mk_cong = ss |> map_mk_rews (fn (mk, _, mk_sym, mk_eq_True, reorient) =>
wenzelm@18208
   700
  (mk, mk_cong, mk_sym, mk_eq_True, reorient));
berghofe@10413
   701
wenzelm@18208
   702
fun ss setmksym mk_sym = ss |> map_mk_rews (fn (mk, mk_cong, _, mk_eq_True, reorient) =>
wenzelm@18208
   703
  (mk, mk_cong, mk_sym, mk_eq_True, reorient));
berghofe@10413
   704
wenzelm@18208
   705
fun ss setmkeqTrue mk_eq_True = ss |> map_mk_rews (fn (mk, mk_cong, mk_sym, _, reorient) =>
wenzelm@18208
   706
  (mk, mk_cong, mk_sym, mk_eq_True, reorient));
wenzelm@18208
   707
wenzelm@18208
   708
fun set_reorient reorient = map_mk_rews (fn (mk, mk_cong, mk_sym, mk_eq_True, _) =>
wenzelm@18208
   709
  (mk, mk_cong, mk_sym, mk_eq_True, reorient));
wenzelm@15023
   710
wenzelm@15023
   711
end;
wenzelm@15023
   712
skalberg@14242
   713
berghofe@10413
   714
(* termless *)
berghofe@10413
   715
wenzelm@15023
   716
fun ss settermless termless = ss |>
wenzelm@15023
   717
  map_simpset2 (fn (congs, procs, mk_rews, _, subgoal_tac, loop_tacs, solvers) =>
wenzelm@15023
   718
   (congs, procs, mk_rews, termless, subgoal_tac, loop_tacs, solvers));
skalberg@15006
   719
skalberg@15006
   720
wenzelm@15023
   721
(* tactics *)
skalberg@15006
   722
wenzelm@15023
   723
fun ss setsubgoaler subgoal_tac = ss |>
wenzelm@15023
   724
  map_simpset2 (fn (congs, procs, mk_rews, termless, _, loop_tacs, solvers) =>
wenzelm@15023
   725
   (congs, procs, mk_rews, termless, subgoal_tac, loop_tacs, solvers));
skalberg@15006
   726
wenzelm@17882
   727
fun ss setloop' tac = ss |>
wenzelm@15023
   728
  map_simpset2 (fn (congs, procs, mk_rews, termless, subgoal_tac, _, solvers) =>
wenzelm@15023
   729
   (congs, procs, mk_rews, termless, subgoal_tac, [("", tac)], solvers));
skalberg@15006
   730
wenzelm@17882
   731
fun ss setloop tac = ss setloop' (K tac);
wenzelm@17882
   732
wenzelm@17882
   733
fun ss addloop' (name, tac) = ss |>
wenzelm@15023
   734
  map_simpset2 (fn (congs, procs, mk_rews, termless, subgoal_tac, loop_tacs, solvers) =>
wenzelm@15023
   735
    (congs, procs, mk_rews, termless, subgoal_tac,
haftmann@21286
   736
      (if AList.defined (op =) loop_tacs name
haftmann@21286
   737
        then warning ("Overwriting looper " ^ quote name)
haftmann@21286
   738
        else (); AList.update (op =) (name, tac) loop_tacs),
wenzelm@15023
   739
      solvers));
skalberg@15006
   740
wenzelm@17882
   741
fun ss addloop (name, tac) = ss addloop' (name, K tac);
wenzelm@17882
   742
wenzelm@15023
   743
fun ss delloop name = ss |>
wenzelm@15023
   744
  map_simpset2 (fn (congs, procs, mk_rews, termless, subgoal_tac, loop_tacs, solvers) =>
haftmann@21286
   745
    (congs, procs, mk_rews, termless, subgoal_tac,
haftmann@21286
   746
      (if AList.defined (op =) loop_tacs name
haftmann@21286
   747
        then ()
haftmann@21286
   748
        else warning ("No such looper in simpset: " ^ quote name);
haftmann@21286
   749
       AList.delete (op =) name loop_tacs), solvers));
skalberg@15006
   750
wenzelm@15023
   751
fun ss setSSolver solver = ss |> map_simpset2 (fn (congs, procs, mk_rews, termless,
wenzelm@15023
   752
  subgoal_tac, loop_tacs, (unsafe_solvers, _)) =>
wenzelm@15023
   753
    (congs, procs, mk_rews, termless, subgoal_tac, loop_tacs, (unsafe_solvers, [solver])));
skalberg@15006
   754
wenzelm@15023
   755
fun ss addSSolver solver = ss |> map_simpset2 (fn (congs, procs, mk_rews, termless,
wenzelm@15023
   756
  subgoal_tac, loop_tacs, (unsafe_solvers, solvers)) => (congs, procs, mk_rews, termless,
haftmann@22717
   757
    subgoal_tac, loop_tacs, (unsafe_solvers, insert eq_solver solver solvers)));
skalberg@15006
   758
wenzelm@15023
   759
fun ss setSolver solver = ss |> map_simpset2 (fn (congs, procs, mk_rews, termless,
wenzelm@15023
   760
  subgoal_tac, loop_tacs, (_, solvers)) => (congs, procs, mk_rews, termless,
wenzelm@15023
   761
    subgoal_tac, loop_tacs, ([solver], solvers)));
skalberg@15006
   762
wenzelm@15023
   763
fun ss addSolver solver = ss |> map_simpset2 (fn (congs, procs, mk_rews, termless,
wenzelm@15023
   764
  subgoal_tac, loop_tacs, (unsafe_solvers, solvers)) => (congs, procs, mk_rews, termless,
haftmann@22717
   765
    subgoal_tac, loop_tacs, (insert eq_solver solver unsafe_solvers, solvers)));
skalberg@15006
   766
wenzelm@15023
   767
fun set_solvers solvers = map_simpset2 (fn (congs, procs, mk_rews, termless,
wenzelm@15023
   768
  subgoal_tac, loop_tacs, _) => (congs, procs, mk_rews, termless,
wenzelm@15023
   769
  subgoal_tac, loop_tacs, (solvers, solvers)));
skalberg@15006
   770
skalberg@15006
   771
wenzelm@18208
   772
(* empty *)
wenzelm@18208
   773
wenzelm@18208
   774
fun init_ss mk_rews termless subgoal_tac solvers =
wenzelm@22892
   775
  make_simpset ((Net.empty, [], (0, []), (0, NONE), NONE),
wenzelm@18208
   776
    (([], []), Net.empty, mk_rews, termless, subgoal_tac, [], solvers));
wenzelm@18208
   777
wenzelm@18208
   778
fun clear_ss (ss as Simpset (_, {mk_rews, termless, subgoal_tac, solvers, ...})) =
wenzelm@18208
   779
  init_ss mk_rews termless subgoal_tac solvers
wenzelm@18208
   780
  |> inherit_context ss;
wenzelm@18208
   781
wenzelm@18208
   782
val basic_mk_rews: mk_rews =
wenzelm@18208
   783
 {mk = fn th => if can Logic.dest_equals (Thm.concl_of th) then [th] else [],
wenzelm@18208
   784
  mk_cong = I,
wenzelm@18208
   785
  mk_sym = SOME o Drule.symmetric_fun,
wenzelm@18208
   786
  mk_eq_True = K NONE,
wenzelm@18208
   787
  reorient = default_reorient};
wenzelm@18208
   788
wenzelm@18208
   789
val empty_ss = init_ss basic_mk_rews Term.termless (K (K no_tac)) ([], []);
wenzelm@18208
   790
wenzelm@18208
   791
wenzelm@18208
   792
(* merge *)  (*NOTE: ignores some fields of 2nd simpset*)
wenzelm@18208
   793
wenzelm@18208
   794
fun merge_ss (ss1, ss2) =
wenzelm@18208
   795
  let
wenzelm@22892
   796
    val Simpset ({rules = rules1, prems = prems1, bounds = bounds1, depth = depth1, context = _},
wenzelm@18208
   797
     {congs = (congs1, weak1), procs = procs1, mk_rews, termless, subgoal_tac,
wenzelm@18208
   798
      loop_tacs = loop_tacs1, solvers = (unsafe_solvers1, solvers1)}) = ss1;
wenzelm@22892
   799
    val Simpset ({rules = rules2, prems = prems2, bounds = bounds2, depth = depth2, context = _},
wenzelm@18208
   800
     {congs = (congs2, weak2), procs = procs2, mk_rews = _, termless = _, subgoal_tac = _,
wenzelm@18208
   801
      loop_tacs = loop_tacs2, solvers = (unsafe_solvers2, solvers2)}) = ss2;
wenzelm@18208
   802
wenzelm@18208
   803
    val rules' = Net.merge eq_rrule (rules1, rules2);
wenzelm@22360
   804
    val prems' = gen_merge_lists Thm.eq_thm_prop prems1 prems2;
wenzelm@18208
   805
    val bounds' = if #1 bounds1 < #1 bounds2 then bounds2 else bounds1;
wenzelm@22892
   806
    val depth' = if #1 depth1 < #1 depth2 then depth2 else depth1;
haftmann@22221
   807
    val congs' = merge (eq_cong o pairself #2) (congs1, congs2);
haftmann@22221
   808
    val weak' = merge (op =) (weak1, weak2);
wenzelm@18208
   809
    val procs' = Net.merge eq_proc (procs1, procs2);
haftmann@21286
   810
    val loop_tacs' = AList.merge (op =) (K true) (loop_tacs1, loop_tacs2);
haftmann@22717
   811
    val unsafe_solvers' = merge eq_solver (unsafe_solvers1, unsafe_solvers2);
haftmann@22717
   812
    val solvers' = merge eq_solver (solvers1, solvers2);
wenzelm@18208
   813
  in
wenzelm@22892
   814
    make_simpset ((rules', prems', bounds', depth', NONE), ((congs', weak'), procs',
wenzelm@18208
   815
      mk_rews, termless, subgoal_tac, loop_tacs', (unsafe_solvers', solvers')))
wenzelm@18208
   816
  end;
wenzelm@18208
   817
wenzelm@18208
   818
skalberg@15006
   819
berghofe@10413
   820
(** rewriting **)
berghofe@10413
   821
berghofe@10413
   822
(*
berghofe@10413
   823
  Uses conversions, see:
berghofe@10413
   824
    L C Paulson, A higher-order implementation of rewriting,
berghofe@10413
   825
    Science of Computer Programming 3 (1983), pages 119-149.
berghofe@10413
   826
*)
berghofe@10413
   827
wenzelm@16985
   828
fun check_conv msg ss thm thm' =
berghofe@10413
   829
  let
berghofe@10413
   830
    val thm'' = transitive thm (transitive
wenzelm@22902
   831
      (symmetric (Drule.beta_eta_conversion (Thm.lhs_of thm'))) thm')
wenzelm@22254
   832
  in if msg then trace_thm (fn () => "SUCCEEDED") ss thm' else (); SOME thm'' end
berghofe@10413
   833
  handle THM _ =>
wenzelm@16458
   834
    let val {thy, prop = _ $ _ $ prop0, ...} = Thm.rep_thm thm in
wenzelm@22254
   835
      trace_thm (fn () => "Proved wrong thm (Check subgoaler?)") ss thm';
wenzelm@22254
   836
      trace_term false (fn () => "Should have proved:") ss thy prop0;
skalberg@15531
   837
      NONE
berghofe@10413
   838
    end;
berghofe@10413
   839
berghofe@10413
   840
berghofe@10413
   841
(* mk_procrule *)
berghofe@10413
   842
wenzelm@16985
   843
fun mk_procrule ss thm =
wenzelm@15023
   844
  let val (_, prems, lhs, elhs, rhs, _) = decomp_simp thm in
wenzelm@15023
   845
    if rewrite_rule_extra_vars prems lhs rhs
wenzelm@16985
   846
    then (warn_thm "Extra vars on rhs:" ss thm; [])
wenzelm@15023
   847
    else [mk_rrule2 {thm = thm, name = "", lhs = lhs, elhs = elhs, perm = false}]
berghofe@10413
   848
  end;
berghofe@10413
   849
berghofe@10413
   850
wenzelm@15023
   851
(* rewritec: conversion to apply the meta simpset to a term *)
berghofe@10413
   852
wenzelm@15023
   853
(*Since the rewriting strategy is bottom-up, we avoid re-normalizing already
wenzelm@15023
   854
  normalized terms by carrying around the rhs of the rewrite rule just
wenzelm@15023
   855
  applied. This is called the `skeleton'. It is decomposed in parallel
wenzelm@15023
   856
  with the term. Once a Var is encountered, the corresponding term is
wenzelm@15023
   857
  already in normal form.
wenzelm@15023
   858
  skel0 is a dummy skeleton that is to enforce complete normalization.*)
wenzelm@15023
   859
berghofe@10413
   860
val skel0 = Bound 0;
berghofe@10413
   861
wenzelm@15023
   862
(*Use rhs as skeleton only if the lhs does not contain unnormalized bits.
wenzelm@15023
   863
  The latter may happen iff there are weak congruence rules for constants
wenzelm@15023
   864
  in the lhs.*)
berghofe@10413
   865
wenzelm@15023
   866
fun uncond_skel ((_, weak), (lhs, rhs)) =
wenzelm@15023
   867
  if null weak then rhs  (*optimization*)
wenzelm@20671
   868
  else if exists_Const (member (op =) weak o #1) lhs then skel0
wenzelm@15023
   869
  else rhs;
wenzelm@15023
   870
wenzelm@15023
   871
(*Behaves like unconditional rule if rhs does not contain vars not in the lhs.
wenzelm@15023
   872
  Otherwise those vars may become instantiated with unnormalized terms
wenzelm@15023
   873
  while the premises are solved.*)
wenzelm@15023
   874
wenzelm@15023
   875
fun cond_skel (args as (congs, (lhs, rhs))) =
wenzelm@20197
   876
  if Term.add_vars rhs [] subset Term.add_vars lhs [] then uncond_skel args
berghofe@10413
   877
  else skel0;
berghofe@10413
   878
berghofe@10413
   879
(*
wenzelm@15023
   880
  Rewriting -- we try in order:
berghofe@10413
   881
    (1) beta reduction
berghofe@10413
   882
    (2) unconditional rewrite rules
berghofe@10413
   883
    (3) conditional rewrite rules
berghofe@10413
   884
    (4) simplification procedures
berghofe@10413
   885
berghofe@10413
   886
  IMPORTANT: rewrite rules must not introduce new Vars or TVars!
berghofe@10413
   887
*)
berghofe@10413
   888
wenzelm@16458
   889
fun rewritec (prover, thyt, maxt) ss t =
berghofe@10413
   890
  let
wenzelm@15023
   891
    val Simpset ({rules, ...}, {congs, procs, termless, ...}) = ss;
berghofe@10413
   892
    val eta_thm = Thm.eta_conversion t;
wenzelm@22902
   893
    val eta_t' = Thm.rhs_of eta_thm;
berghofe@10413
   894
    val eta_t = term_of eta_t';
wenzelm@20546
   895
    fun rew {thm, name, lhs, elhs, extra, fo, perm} =
berghofe@10413
   896
      let
wenzelm@16458
   897
        val {thy, prop, maxidx, ...} = rep_thm thm;
wenzelm@20546
   898
        val (rthm, elhs') =
wenzelm@20546
   899
          if maxt = ~1 orelse not extra then (thm, elhs)
wenzelm@22902
   900
          else (Thm.incr_indexes (maxt + 1) thm, Thm.incr_indexes_cterm (maxt + 1) elhs);
wenzelm@22902
   901
        val insts =
wenzelm@22902
   902
          if fo then Thm.first_order_match (elhs', eta_t')
wenzelm@22902
   903
          else Thm.match (elhs', eta_t');
berghofe@10413
   904
        val thm' = Thm.instantiate insts (Thm.rename_boundvars lhs eta_t rthm);
wenzelm@14643
   905
        val prop' = Thm.prop_of thm';
wenzelm@21576
   906
        val unconditional = (Logic.count_prems prop' = 0);
berghofe@10413
   907
        val (lhs', rhs') = Logic.dest_equals (Logic.strip_imp_concl prop')
berghofe@10413
   908
      in
nipkow@11295
   909
        if perm andalso not (termless (rhs', lhs'))
wenzelm@22254
   910
        then (trace_named_thm (fn () => "Cannot apply permutative rewrite rule") ss (thm, name);
wenzelm@22254
   911
              trace_thm (fn () => "Term does not become smaller:") ss thm'; NONE)
wenzelm@22254
   912
        else (trace_named_thm (fn () => "Applying instance of rewrite rule") ss (thm, name);
berghofe@10413
   913
           if unconditional
berghofe@10413
   914
           then
wenzelm@22254
   915
             (trace_thm (fn () => "Rewriting:") ss thm';
berghofe@10413
   916
              let val lr = Logic.dest_equals prop;
wenzelm@16985
   917
                  val SOME thm'' = check_conv false ss eta_thm thm'
skalberg@15531
   918
              in SOME (thm'', uncond_skel (congs, lr)) end)
berghofe@10413
   919
           else
wenzelm@22254
   920
             (trace_thm (fn () => "Trying to rewrite:") ss thm';
wenzelm@22892
   921
              if simp_depth ss > ! simp_depth_limit
nipkow@16042
   922
              then let val s = "simp_depth_limit exceeded - giving up"
wenzelm@22892
   923
                   in trace false (fn () => s) ss; warning s; NONE end
nipkow@16042
   924
              else
nipkow@16042
   925
              case prover ss thm' of
wenzelm@22254
   926
                NONE => (trace_thm (fn () => "FAILED") ss thm'; NONE)
skalberg@15531
   927
              | SOME thm2 =>
wenzelm@16985
   928
                  (case check_conv true ss eta_thm thm2 of
skalberg@15531
   929
                     NONE => NONE |
skalberg@15531
   930
                     SOME thm2' =>
berghofe@10413
   931
                       let val concl = Logic.strip_imp_concl prop
berghofe@10413
   932
                           val lr = Logic.dest_equals concl
nipkow@16042
   933
                       in SOME (thm2', cond_skel (congs, lr)) end)))
berghofe@10413
   934
      end
berghofe@10413
   935
skalberg@15531
   936
    fun rews [] = NONE
berghofe@10413
   937
      | rews (rrule :: rrules) =
skalberg@15531
   938
          let val opt = rew rrule handle Pattern.MATCH => NONE
skalberg@15531
   939
          in case opt of NONE => rews rrules | some => some end;
berghofe@10413
   940
berghofe@10413
   941
    fun sort_rrules rrs = let
wenzelm@14643
   942
      fun is_simple({thm, ...}:rrule) = case Thm.prop_of thm of
berghofe@10413
   943
                                      Const("==",_) $ _ $ _ => true
wenzelm@12603
   944
                                      | _                   => false
berghofe@10413
   945
      fun sort []        (re1,re2) = re1 @ re2
wenzelm@12603
   946
        | sort (rr::rrs) (re1,re2) = if is_simple rr
berghofe@10413
   947
                                     then sort rrs (rr::re1,re2)
berghofe@10413
   948
                                     else sort rrs (re1,rr::re2)
berghofe@10413
   949
    in sort rrs ([],[]) end
berghofe@10413
   950
skalberg@15531
   951
    fun proc_rews [] = NONE
wenzelm@15023
   952
      | proc_rews (Proc {name, proc, lhs, ...} :: ps) =
wenzelm@17203
   953
          if Pattern.matches thyt (Thm.term_of lhs, Thm.term_of t) then
wenzelm@22254
   954
            (debug_term false (fn () => "Trying procedure " ^ quote name ^ " on:") ss thyt eta_t;
wenzelm@13486
   955
             case transform_failure (curry SIMPROC_FAIL name)
wenzelm@22008
   956
                 (fn () => proc ss eta_t') () of
wenzelm@22892
   957
               NONE => (debug false (fn () => "FAILED") ss; proc_rews ps)
skalberg@15531
   958
             | SOME raw_thm =>
wenzelm@22254
   959
                 (trace_thm (fn () => "Procedure " ^ quote name ^ " produced rewrite rule:")
wenzelm@22254
   960
                   ss raw_thm;
wenzelm@16985
   961
                  (case rews (mk_procrule ss raw_thm) of
wenzelm@22254
   962
                    NONE => (trace_cterm true (fn () => "IGNORED result of simproc " ^ quote name ^
wenzelm@16985
   963
                      " -- does not match") ss t; proc_rews ps)
berghofe@10413
   964
                  | some => some)))
berghofe@10413
   965
          else proc_rews ps;
berghofe@10413
   966
  in case eta_t of
skalberg@15531
   967
       Abs _ $ _ => SOME (transitive eta_thm
berghofe@12155
   968
         (beta_conversion false eta_t'), skel0)
berghofe@10413
   969
     | _ => (case rews (sort_rrules (Net.match_term rules eta_t)) of
skalberg@15531
   970
               NONE => proc_rews (Net.match_term procs eta_t)
berghofe@10413
   971
             | some => some)
berghofe@10413
   972
  end;
berghofe@10413
   973
berghofe@10413
   974
berghofe@10413
   975
(* conversion to apply a congruence rule to a term *)
berghofe@10413
   976
wenzelm@16985
   977
fun congc prover ss maxt {thm=cong,lhs=lhs} t =
wenzelm@22902
   978
  let val rthm = Thm.incr_indexes (maxt + 1) cong;
wenzelm@22902
   979
      val rlhs = fst (Thm.dest_equals (Drule.strip_imp_concl (cprop_of rthm)));
wenzelm@22902
   980
      val insts = Thm.match (rlhs, t)
wenzelm@22902
   981
      (* Thm.match can raise Pattern.MATCH;
berghofe@10413
   982
         is handled when congc is called *)
berghofe@10413
   983
      val thm' = Thm.instantiate insts (Thm.rename_boundvars (term_of rlhs) (term_of t) rthm);
wenzelm@22254
   984
      val unit = trace_thm (fn () => "Applying congruence rule:") ss thm';
wenzelm@22254
   985
      fun err (msg, thm) = (trace_thm (fn () => msg) ss thm; NONE)
berghofe@10413
   986
  in case prover thm' of
skalberg@15531
   987
       NONE => err ("Congruence proof failed.  Could not prove", thm')
wenzelm@16985
   988
     | SOME thm2 => (case check_conv true ss (Drule.beta_eta_conversion t) thm2 of
skalberg@15531
   989
          NONE => err ("Congruence proof failed.  Should not have proved", thm2)
skalberg@15531
   990
        | SOME thm2' =>
wenzelm@22902
   991
            if op aconv (pairself term_of (Thm.dest_equals (cprop_of thm2')))
skalberg@15531
   992
            then NONE else SOME thm2')
berghofe@10413
   993
  end;
berghofe@10413
   994
berghofe@10413
   995
val (cA, (cB, cC)) =
wenzelm@22902
   996
  apsnd Thm.dest_equals (Thm.dest_implies (hd (cprems_of Drule.imp_cong)));
berghofe@10413
   997
skalberg@15531
   998
fun transitive1 NONE NONE = NONE
skalberg@15531
   999
  | transitive1 (SOME thm1) NONE = SOME thm1
skalberg@15531
  1000
  | transitive1 NONE (SOME thm2) = SOME thm2
skalberg@15531
  1001
  | transitive1 (SOME thm1) (SOME thm2) = SOME (transitive thm1 thm2)
berghofe@10413
  1002
skalberg@15531
  1003
fun transitive2 thm = transitive1 (SOME thm);
skalberg@15531
  1004
fun transitive3 thm = transitive1 thm o SOME;
berghofe@13607
  1005
wenzelm@16458
  1006
fun bottomc ((simprem, useprem, mutsimp), prover, thy, maxidx) =
berghofe@10413
  1007
  let
wenzelm@15023
  1008
    fun botc skel ss t =
skalberg@15531
  1009
          if is_Var skel then NONE
berghofe@10413
  1010
          else
wenzelm@15023
  1011
          (case subc skel ss t of
skalberg@15531
  1012
             some as SOME thm1 =>
wenzelm@22902
  1013
               (case rewritec (prover, thy, maxidx) ss (Thm.rhs_of thm1) of
skalberg@15531
  1014
                  SOME (thm2, skel2) =>
berghofe@13607
  1015
                    transitive2 (transitive thm1 thm2)
wenzelm@22902
  1016
                      (botc skel2 ss (Thm.rhs_of thm2))
skalberg@15531
  1017
                | NONE => some)
skalberg@15531
  1018
           | NONE =>
wenzelm@16458
  1019
               (case rewritec (prover, thy, maxidx) ss t of
skalberg@15531
  1020
                  SOME (thm2, skel2) => transitive2 thm2
wenzelm@22902
  1021
                    (botc skel2 ss (Thm.rhs_of thm2))
skalberg@15531
  1022
                | NONE => NONE))
berghofe@10413
  1023
wenzelm@15023
  1024
    and try_botc ss t =
wenzelm@15023
  1025
          (case botc skel0 ss t of
skalberg@15531
  1026
             SOME trec1 => trec1 | NONE => (reflexive t))
berghofe@10413
  1027
wenzelm@15023
  1028
    and subc skel (ss as Simpset ({bounds, ...}, {congs, ...})) t0 =
berghofe@10413
  1029
       (case term_of t0 of
berghofe@10413
  1030
           Abs (a, T, t) =>
wenzelm@15023
  1031
             let
wenzelm@20079
  1032
                 val b = Name.bound (#1 bounds);
wenzelm@16985
  1033
                 val (v, t') = Thm.dest_abs (SOME b) t0;
wenzelm@16985
  1034
                 val b' = #1 (Term.dest_Free (Thm.term_of v));
wenzelm@21962
  1035
                 val _ =
wenzelm@21962
  1036
                   if b <> b' then
wenzelm@21962
  1037
                     warning ("Simplifier: renamed bound variable " ^ quote b ^ " to " ^ quote b')
wenzelm@21962
  1038
                   else ();
wenzelm@17614
  1039
                 val ss' = add_bound ((b', T), a) ss;
wenzelm@15023
  1040
                 val skel' = case skel of Abs (_, _, sk) => sk | _ => skel0;
wenzelm@15023
  1041
             in case botc skel' ss' t' of
skalberg@15531
  1042
                  SOME thm => SOME (abstract_rule a v thm)
skalberg@15531
  1043
                | NONE => NONE
berghofe@10413
  1044
             end
berghofe@10413
  1045
         | t $ _ => (case t of
wenzelm@15023
  1046
             Const ("==>", _) $ _  => impc t0 ss
berghofe@10413
  1047
           | Abs _ =>
berghofe@10413
  1048
               let val thm = beta_conversion false t0
wenzelm@22902
  1049
               in case subc skel0 ss (Thm.rhs_of thm) of
skalberg@15531
  1050
                    NONE => SOME thm
skalberg@15531
  1051
                  | SOME thm' => SOME (transitive thm thm')
berghofe@10413
  1052
               end
berghofe@10413
  1053
           | _  =>
berghofe@10413
  1054
               let fun appc () =
berghofe@10413
  1055
                     let
berghofe@10413
  1056
                       val (tskel, uskel) = case skel of
berghofe@10413
  1057
                           tskel $ uskel => (tskel, uskel)
berghofe@10413
  1058
                         | _ => (skel0, skel0);
wenzelm@10767
  1059
                       val (ct, cu) = Thm.dest_comb t0
berghofe@10413
  1060
                     in
wenzelm@15023
  1061
                     (case botc tskel ss ct of
skalberg@15531
  1062
                        SOME thm1 =>
wenzelm@15023
  1063
                          (case botc uskel ss cu of
skalberg@15531
  1064
                             SOME thm2 => SOME (combination thm1 thm2)
skalberg@15531
  1065
                           | NONE => SOME (combination thm1 (reflexive cu)))
skalberg@15531
  1066
                      | NONE =>
wenzelm@15023
  1067
                          (case botc uskel ss cu of
skalberg@15531
  1068
                             SOME thm1 => SOME (combination (reflexive ct) thm1)
skalberg@15531
  1069
                           | NONE => NONE))
berghofe@10413
  1070
                     end
berghofe@10413
  1071
                   val (h, ts) = strip_comb t
ballarin@13835
  1072
               in case cong_name h of
skalberg@15531
  1073
                    SOME a =>
haftmann@17232
  1074
                      (case AList.lookup (op =) (fst congs) a of
skalberg@15531
  1075
                         NONE => appc ()
skalberg@15531
  1076
                       | SOME cong =>
wenzelm@15023
  1077
  (*post processing: some partial applications h t1 ... tj, j <= length ts,
wenzelm@15023
  1078
    may be a redex. Example: map (%x. x) = (%xs. xs) wrt map_cong*)
berghofe@10413
  1079
                          (let
wenzelm@16985
  1080
                             val thm = congc (prover ss) ss maxidx cong t0;
wenzelm@22902
  1081
                             val t = the_default t0 (Option.map Thm.rhs_of thm);
wenzelm@10767
  1082
                             val (cl, cr) = Thm.dest_comb t
berghofe@10413
  1083
                             val dVar = Var(("", 0), dummyT)
berghofe@10413
  1084
                             val skel =
berghofe@10413
  1085
                               list_comb (h, replicate (length ts) dVar)
wenzelm@15023
  1086
                           in case botc skel ss cl of
skalberg@15531
  1087
                                NONE => thm
skalberg@15531
  1088
                              | SOME thm' => transitive3 thm
berghofe@12155
  1089
                                  (combination thm' (reflexive cr))
wenzelm@20057
  1090
                           end handle Pattern.MATCH => appc ()))
berghofe@10413
  1091
                  | _ => appc ()
berghofe@10413
  1092
               end)
skalberg@15531
  1093
         | _ => NONE)
berghofe@10413
  1094
wenzelm@15023
  1095
    and impc ct ss =
wenzelm@15023
  1096
      if mutsimp then mut_impc0 [] ct [] [] ss else nonmut_impc ct ss
berghofe@10413
  1097
wenzelm@15023
  1098
    and rules_of_prem ss prem =
berghofe@13607
  1099
      if maxidx_of_term (term_of prem) <> ~1
berghofe@13607
  1100
      then (trace_cterm true
wenzelm@22254
  1101
        (fn () => "Cannot add premise as rewrite rule because it contains (type) unknowns:")
wenzelm@22254
  1102
          ss prem; ([], NONE))
berghofe@13607
  1103
      else
berghofe@13607
  1104
        let val asm = assume prem
skalberg@15531
  1105
        in (extract_safe_rrules (ss, asm), SOME asm) end
berghofe@10413
  1106
wenzelm@15023
  1107
    and add_rrules (rrss, asms) ss =
wenzelm@20028
  1108
      (fold o fold) insert_rrule rrss ss |> add_prems (map_filter I asms)
berghofe@10413
  1109
wenzelm@23178
  1110
    and disch r prem eq =
berghofe@13607
  1111
      let
wenzelm@22902
  1112
        val (lhs, rhs) = Thm.dest_equals (Thm.cprop_of eq);
berghofe@13607
  1113
        val eq' = implies_elim (Thm.instantiate
berghofe@13607
  1114
          ([], [(cA, prem), (cB, lhs), (cC, rhs)]) Drule.imp_cong)
berghofe@13607
  1115
          (implies_intr prem eq)
berghofe@13607
  1116
      in if not r then eq' else
berghofe@10413
  1117
        let
wenzelm@22902
  1118
          val (prem', concl) = Thm.dest_implies lhs;
wenzelm@22902
  1119
          val (prem'', _) = Thm.dest_implies rhs
berghofe@13607
  1120
        in transitive (transitive
berghofe@13607
  1121
          (Thm.instantiate ([], [(cA, prem'), (cB, prem), (cC, concl)])
berghofe@13607
  1122
             Drule.swap_prems_eq) eq')
berghofe@13607
  1123
          (Thm.instantiate ([], [(cA, prem), (cB, prem''), (cC, concl)])
berghofe@13607
  1124
             Drule.swap_prems_eq)
berghofe@10413
  1125
        end
berghofe@10413
  1126
      end
berghofe@10413
  1127
berghofe@13607
  1128
    and rebuild [] _ _ _ _ eq = eq
wenzelm@15023
  1129
      | rebuild (prem :: prems) concl (rrs :: rrss) (asm :: asms) ss eq =
berghofe@13607
  1130
          let
wenzelm@15023
  1131
            val ss' = add_rrules (rev rrss, rev asms) ss;
berghofe@13607
  1132
            val concl' =
wenzelm@22902
  1133
              Drule.mk_implies (prem, the_default concl (Option.map Thm.rhs_of eq));
wenzelm@23178
  1134
            val dprem = Option.map (disch false prem)
wenzelm@16458
  1135
          in case rewritec (prover, thy, maxidx) ss' concl' of
skalberg@15531
  1136
              NONE => rebuild prems concl' rrss asms ss (dprem eq)
wenzelm@23178
  1137
            | SOME (eq', _) => transitive2 (fold (disch false)
wenzelm@23178
  1138
                  prems (the (transitive3 (dprem eq) eq')))
wenzelm@22902
  1139
                (mut_impc0 (rev prems) (Thm.rhs_of eq') (rev rrss) (rev asms) ss)
berghofe@13607
  1140
          end
wenzelm@15023
  1141
wenzelm@15023
  1142
    and mut_impc0 prems concl rrss asms ss =
berghofe@13607
  1143
      let
berghofe@13607
  1144
        val prems' = strip_imp_prems concl;
wenzelm@15023
  1145
        val (rrss', asms') = split_list (map (rules_of_prem ss) prems')
berghofe@13607
  1146
      in mut_impc (prems @ prems') (strip_imp_concl concl) (rrss @ rrss')
wenzelm@15023
  1147
        (asms @ asms') [] [] [] [] ss ~1 ~1
berghofe@13607
  1148
      end
wenzelm@15023
  1149
wenzelm@15023
  1150
    and mut_impc [] concl [] [] prems' rrss' asms' eqns ss changed k =
skalberg@15570
  1151
        transitive1 (Library.foldl (fn (eq2, (eq1, prem)) => transitive1 eq1
wenzelm@23178
  1152
            (Option.map (disch false prem) eq2)) (NONE, eqns ~~ prems'))
berghofe@13607
  1153
          (if changed > 0 then
berghofe@13607
  1154
             mut_impc (rev prems') concl (rev rrss') (rev asms')
wenzelm@15023
  1155
               [] [] [] [] ss ~1 changed
wenzelm@15023
  1156
           else rebuild prems' concl rrss' asms' ss
wenzelm@15023
  1157
             (botc skel0 (add_rrules (rev rrss', rev asms') ss) concl))
berghofe@13607
  1158
berghofe@13607
  1159
      | mut_impc (prem :: prems) concl (rrs :: rrss) (asm :: asms)
wenzelm@15023
  1160
          prems' rrss' asms' eqns ss changed k =
skalberg@15531
  1161
        case (if k = 0 then NONE else botc skel0 (add_rrules
wenzelm@15023
  1162
          (rev rrss' @ rrss, rev asms' @ asms) ss) prem) of
skalberg@15531
  1163
            NONE => mut_impc prems concl rrss asms (prem :: prems')
skalberg@15531
  1164
              (rrs :: rrss') (asm :: asms') (NONE :: eqns) ss changed
berghofe@13607
  1165
              (if k = 0 then 0 else k - 1)
skalberg@15531
  1166
          | SOME eqn =>
berghofe@13607
  1167
            let
wenzelm@22902
  1168
              val prem' = Thm.rhs_of eqn;
berghofe@13607
  1169
              val tprems = map term_of prems;
skalberg@15570
  1170
              val i = 1 + Library.foldl Int.max (~1, map (fn p =>
wenzelm@19618
  1171
                find_index (fn q => q aconv p) tprems) (#hyps (rep_thm eqn)));
wenzelm@15023
  1172
              val (rrs', asm') = rules_of_prem ss prem'
berghofe@13607
  1173
            in mut_impc prems concl rrss asms (prem' :: prems')
wenzelm@23178
  1174
              (rrs' :: rrss') (asm' :: asms') (SOME (fold_rev (disch true)
wenzelm@23178
  1175
                (Library.take (i, prems))
wenzelm@18470
  1176
                (Drule.imp_cong_rule eqn (reflexive (Drule.list_implies
wenzelm@23178
  1177
                  (Library.drop (i, prems), concl))))) :: eqns)
wenzelm@20671
  1178
                  ss (length prems') ~1
berghofe@13607
  1179
            end
berghofe@13607
  1180
wenzelm@15023
  1181
     (*legacy code - only for backwards compatibility*)
wenzelm@15023
  1182
     and nonmut_impc ct ss =
wenzelm@22902
  1183
       let val (prem, conc) = Thm.dest_implies ct;
skalberg@15531
  1184
           val thm1 = if simprem then botc skel0 ss prem else NONE;
wenzelm@22902
  1185
           val prem1 = the_default prem (Option.map Thm.rhs_of thm1);
wenzelm@15023
  1186
           val ss1 = if not useprem then ss else add_rrules
wenzelm@15023
  1187
             (apsnd single (apfst single (rules_of_prem ss prem1))) ss
wenzelm@15023
  1188
       in (case botc skel0 ss1 conc of
skalberg@15531
  1189
           NONE => (case thm1 of
skalberg@15531
  1190
               NONE => NONE
wenzelm@18470
  1191
             | SOME thm1' => SOME (Drule.imp_cong_rule thm1' (reflexive conc)))
skalberg@15531
  1192
         | SOME thm2 =>
wenzelm@23178
  1193
           let val thm2' = disch false prem1 thm2
berghofe@10413
  1194
           in (case thm1 of
skalberg@15531
  1195
               NONE => SOME thm2'
skalberg@15531
  1196
             | SOME thm1' =>
wenzelm@18470
  1197
                 SOME (transitive (Drule.imp_cong_rule thm1' (reflexive conc)) thm2'))
berghofe@10413
  1198
           end)
berghofe@10413
  1199
       end
berghofe@10413
  1200
wenzelm@15023
  1201
 in try_botc end;
berghofe@10413
  1202
berghofe@10413
  1203
wenzelm@15023
  1204
(* Meta-rewriting: rewrites t to u and returns the theorem t==u *)
berghofe@10413
  1205
berghofe@10413
  1206
(*
berghofe@10413
  1207
  Parameters:
berghofe@10413
  1208
    mode = (simplify A,
berghofe@10413
  1209
            use A in simplifying B,
berghofe@10413
  1210
            use prems of B (if B is again a meta-impl.) to simplify A)
berghofe@10413
  1211
           when simplifying A ==> B
berghofe@10413
  1212
    prover: how to solve premises in conditional rewrites and congruences
berghofe@10413
  1213
*)
berghofe@10413
  1214
wenzelm@17705
  1215
val debug_bounds = ref false;
wenzelm@17705
  1216
wenzelm@21962
  1217
fun check_bounds ss ct =
wenzelm@21962
  1218
  if ! debug_bounds then
wenzelm@21962
  1219
    let
wenzelm@21962
  1220
      val Simpset ({bounds = (_, bounds), ...}, _) = ss;
wenzelm@21962
  1221
      val bs = fold_aterms (fn Free (x, _) =>
wenzelm@21962
  1222
          if Name.is_bound x andalso not (AList.defined eq_bound bounds x)
wenzelm@21962
  1223
          then insert (op =) x else I
wenzelm@21962
  1224
        | _ => I) (term_of ct) [];
wenzelm@21962
  1225
    in
wenzelm@21962
  1226
      if null bs then ()
wenzelm@22892
  1227
      else print_term ss true ("Simplifier: term contains loose bounds: " ^ commas_quote bs)
wenzelm@21962
  1228
        (Thm.theory_of_cterm ct) (Thm.term_of ct)
wenzelm@21962
  1229
    end
wenzelm@21962
  1230
  else ();
wenzelm@17614
  1231
wenzelm@19052
  1232
fun rewrite_cterm mode prover raw_ss raw_ct =
wenzelm@17882
  1233
  let
wenzelm@20260
  1234
    val ct = Thm.adjust_maxidx_cterm ~1 raw_ct;
wenzelm@17882
  1235
    val {thy, t, maxidx, ...} = Thm.rep_cterm ct;
wenzelm@22892
  1236
    val ss = inc_simp_depth (activate_context thy raw_ss);
wenzelm@22892
  1237
    val depth = simp_depth ss;
wenzelm@21962
  1238
    val _ =
wenzelm@22892
  1239
      if depth mod 20 = 0 then
wenzelm@22892
  1240
        warning ("Simplification depth " ^ string_of_int depth)
wenzelm@21962
  1241
      else ();
wenzelm@22254
  1242
    val _ = trace_cterm false (fn () => "SIMPLIFIER INVOKED ON THE FOLLOWING TERM:") ss ct;
wenzelm@17882
  1243
    val _ = check_bounds ss ct;
wenzelm@22892
  1244
  in bottomc (mode, Option.map Drule.flexflex_unique oo prover, thy, maxidx) ss ct end;
berghofe@10413
  1245
wenzelm@21708
  1246
val simple_prover =
wenzelm@21708
  1247
  SINGLE o (fn ss => ALLGOALS (resolve_tac (prems_of_ss ss)));
wenzelm@21708
  1248
wenzelm@11760
  1249
(*Rewrite a cterm*)
wenzelm@21708
  1250
fun rewrite _ [] ct = Thm.reflexive ct
wenzelm@21708
  1251
  | rewrite full thms ct =
wenzelm@21708
  1252
      rewrite_cterm (full, false, false) simple_prover
wenzelm@21708
  1253
        (theory_context (Thm.theory_of_cterm ct) empty_ss addsimps thms) ct;
wenzelm@11672
  1254
berghofe@10413
  1255
(*Rewrite a theorem*)
wenzelm@21708
  1256
fun simplify _ [] th = th
wenzelm@21708
  1257
  | simplify full thms th =
wenzelm@22902
  1258
      Conv.fconv_rule (rewrite_cterm (full, false, false) simple_prover
wenzelm@17897
  1259
        (theory_context (Thm.theory_of_thm th) empty_ss addsimps thms)) th;
berghofe@10413
  1260
wenzelm@21708
  1261
val rewrite_rule = simplify true;
wenzelm@21708
  1262
wenzelm@15023
  1263
(*simple term rewriting -- no proof*)
wenzelm@16458
  1264
fun rewrite_term thy rules procs =
wenzelm@17203
  1265
  Pattern.rewrite_term thy (map decomp_simp' rules) procs;
wenzelm@15023
  1266
wenzelm@22902
  1267
fun rewrite_thm mode prover ss = Conv.fconv_rule (rewrite_cterm mode prover ss);
berghofe@10413
  1268
berghofe@10413
  1269
(*Rewrite the subgoals of a proof state (represented by a theorem) *)
wenzelm@21708
  1270
fun rewrite_goals_rule thms th =
wenzelm@22902
  1271
  Conv.fconv_rule (Conv.goals_conv (K true) (rewrite_cterm (true, true, true) simple_prover
wenzelm@19142
  1272
    (theory_context (Thm.theory_of_thm th) empty_ss addsimps thms))) th;
berghofe@10413
  1273
wenzelm@15023
  1274
(*Rewrite the subgoal of a proof state (represented by a theorem)*)
skalberg@15011
  1275
fun rewrite_goal_rule mode prover ss i thm =
berghofe@10413
  1276
  if 0 < i  andalso  i <= nprems_of thm
wenzelm@22902
  1277
  then Conv.fconv_rule (Conv.goals_conv (fn j => j=i) (rewrite_cterm mode prover ss)) thm
wenzelm@22234
  1278
  else raise THM("rewrite_goal_rule", i, [thm]);
berghofe@10413
  1279
wenzelm@20228
  1280
wenzelm@21708
  1281
(** meta-rewriting tactics **)
wenzelm@21708
  1282
wenzelm@21708
  1283
(*Rewrite throughout proof state. *)
wenzelm@21708
  1284
fun rewrite_tac defs = PRIMITIVE(rewrite_rule defs);
wenzelm@21708
  1285
wenzelm@21708
  1286
(*Rewrite subgoals only, not main goal. *)
wenzelm@21708
  1287
fun rewrite_goals_tac defs = PRIMITIVE (rewrite_goals_rule defs);
wenzelm@21708
  1288
fun rewtac def = rewrite_goals_tac [def];
wenzelm@21708
  1289
wenzelm@21708
  1290
(*Prunes all redundant parameters from the proof state by rewriting.
wenzelm@21708
  1291
  DOES NOT rewrite main goal, where quantification over an unused bound
wenzelm@21708
  1292
    variable is sometimes done to avoid the need for cut_facts_tac.*)
wenzelm@21708
  1293
val prune_params_tac = rewrite_goals_tac [triv_forall_equality];
wenzelm@21708
  1294
wenzelm@21708
  1295
wenzelm@21708
  1296
(* for folding definitions, handling critical pairs *)
wenzelm@21708
  1297
wenzelm@21708
  1298
(*The depth of nesting in a term*)
wenzelm@21708
  1299
fun term_depth (Abs(a,T,t)) = 1 + term_depth t
wenzelm@21708
  1300
  | term_depth (f$t) = 1 + Int.max(term_depth f, term_depth t)
wenzelm@21708
  1301
  | term_depth _ = 0;
wenzelm@21708
  1302
wenzelm@21708
  1303
val lhs_of_thm = #1 o Logic.dest_equals o prop_of;
wenzelm@21708
  1304
wenzelm@21708
  1305
(*folding should handle critical pairs!  E.g. K == Inl(0),  S == Inr(Inl(0))
wenzelm@21708
  1306
  Returns longest lhs first to avoid folding its subexpressions.*)
wenzelm@21708
  1307
fun sort_lhs_depths defs =
wenzelm@21708
  1308
  let val keylist = AList.make (term_depth o lhs_of_thm) defs
wenzelm@21708
  1309
      val keys = sort_distinct (rev_order o int_ord) (map #2 keylist)
wenzelm@21708
  1310
  in map (AList.find (op =) keylist) keys end;
wenzelm@21708
  1311
wenzelm@21708
  1312
val rev_defs = sort_lhs_depths o map symmetric;
wenzelm@21708
  1313
wenzelm@21708
  1314
fun fold_rule defs = fold rewrite_rule (rev_defs defs);
wenzelm@21708
  1315
fun fold_tac defs = EVERY (map rewrite_tac (rev_defs defs));
wenzelm@21708
  1316
fun fold_goals_tac defs = EVERY (map rewrite_goals_tac (rev_defs defs));
wenzelm@21708
  1317
wenzelm@21708
  1318
wenzelm@20228
  1319
(* HHF normal form: !! before ==>, outermost !! generalized *)
wenzelm@20228
  1320
wenzelm@20228
  1321
local
wenzelm@20228
  1322
wenzelm@21565
  1323
fun gen_norm_hhf ss th =
wenzelm@21565
  1324
  (if Drule.is_norm_hhf (Thm.prop_of th) then th
wenzelm@22902
  1325
   else Conv.fconv_rule (rewrite_cterm (true, false, false) (K (K NONE)) ss) th)
wenzelm@21565
  1326
  |> Thm.adjust_maxidx_thm ~1
wenzelm@21565
  1327
  |> Drule.gen_all;
wenzelm@20228
  1328
wenzelm@20228
  1329
val ss = theory_context ProtoPure.thy empty_ss addsimps [Drule.norm_hhf_eq];
wenzelm@20228
  1330
wenzelm@20228
  1331
in
wenzelm@20228
  1332
wenzelm@20228
  1333
val norm_hhf = gen_norm_hhf ss;
wenzelm@20228
  1334
val norm_hhf_protect = gen_norm_hhf (ss addeqcongs [Drule.protect_cong]);
wenzelm@20228
  1335
wenzelm@20228
  1336
end;
wenzelm@20228
  1337
berghofe@10413
  1338
end;
berghofe@10413
  1339
wenzelm@11672
  1340
structure BasicMetaSimplifier: BASIC_META_SIMPLIFIER = MetaSimplifier;
wenzelm@11672
  1341
open BasicMetaSimplifier;