src/Pure/meta_simplifier.ML
author nipkow
Sun Jun 12 08:53:41 2005 +0200 (2005-06-12)
changeset 16378 8af448f67cef
parent 16305 5e7b6731b004
child 16380 019ec70774ff
permissions -rw-r--r--
simp_depth now starts at -1 to make it start at 0 ;-)
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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 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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  type cong
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  type solver
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  val mk_solver: string -> (thm list -> int -> tactic) -> solver
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  type simpset
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  type proc
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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} *
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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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    termless: term * term -> bool,
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    subgoal_tac: simpset -> int -> tactic,
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    loop_tacs: (string * (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 mk_simproc: string -> cterm list ->
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    (Sign.sg -> 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 * (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 generic_simp_tac: bool -> bool * bool * bool -> simpset -> int -> 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 clear_ss: simpset -> simpset
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  exception SIMPROC_FAIL of string * exn
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  val simproc_i: Sign.sg -> string -> term list
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    -> (Sign.sg -> simpset -> term -> thm option) -> simproc
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  val simproc: Sign.sg -> string -> string list
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    -> (Sign.sg -> simpset -> term -> thm option) -> simproc
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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_aux: (simpset -> thm -> thm option) -> bool -> thm list -> cterm -> thm
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  val simplify_aux: (simpset -> thm -> thm option) -> bool -> thm list -> thm -> thm
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  val rewrite_term: Sign.sg -> 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_goals_rule_aux: (simpset -> thm -> thm option) -> thm list -> 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 simp_thm: bool * bool * bool -> simpset -> thm -> thm
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  val simp_cterm: bool * bool * bool -> simpset -> cterm -> thm
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end;
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structure MetaSimplifier: META_SIMPLIFIER =
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struct
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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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val simp_depth = ref (~1);
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val simp_depth_limit = ref 1000;
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val trace_simp_depth_limit = ref 1000;
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local
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fun println a =
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  if !simp_depth > !trace_simp_depth_limit then ()
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  else tracing (enclose "[" "]" (string_of_int(!simp_depth)) ^ a);
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fun prnt warn a = if warn then warning a else println a;
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fun prtm warn a sg t = prnt warn (a ^ "\n" ^ Sign.string_of_term sg t);
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fun prctm warn a t = prnt warn (a ^ "\n" ^ Display.string_of_cterm t);
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in
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fun debug warn a = if ! debug_simp then prnt warn a else ();
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fun trace warn a = if ! trace_simp then prnt warn a else ();
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fun debug_term warn a sign t = if ! debug_simp then prtm warn a sign t else ();
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fun trace_term warn a sign t = if ! trace_simp then prtm warn a sign t else ();
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fun trace_cterm warn a ct = if ! trace_simp then prctm warn a ct else ();
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fun trace_thm a th = if ! trace_simp then prctm false a (Thm.cprop_of th) else ();
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fun trace_named_thm a (thm, name) =
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  if ! trace_simp then
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    prctm false (if name = "" then a else a ^ " " ^ quote name ^ ":") (Thm.cprop_of thm)
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  else ();
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fun warn_thm a = prctm true a o Thm.cprop_of;
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end;
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(** datatype simpset **)
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(* rewrite rules *)
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type rrule = {thm: thm, name: string, lhs: term, elhs: cterm, fo: bool, perm: bool};
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(*thm: the rewrite rule;
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  name: name of theorem from which rewrite rule was extracted;
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  lhs: the left-hand side;
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  elhs: the etac-contracted lhs;
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  fo: use first-order matching;
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  perm: the rewrite rule is permutative;
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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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fun eq_rrule ({thm = thm1, ...}: rrule, {thm = thm2, ...}: rrule) =
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  Drule.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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  Drule.eq_thm_prop (thm1, thm2);
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(* solvers *)
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datatype solver =
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  Solver of
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   {name: string,
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    solver: thm list -> int -> tactic,
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    id: stamp};
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fun mk_solver name solver = Solver {name = name, solver = solver, id = stamp ()};
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fun solver_name (Solver {name, ...}) = name;
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fun solver ths (Solver {solver = tacf, ...}) = tacf ths;
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fun eq_solver (Solver {id = id1, ...}, Solver {id = id2, ...}) = (id1 = id2);
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val merge_solvers = gen_merge_lists eq_solver;
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(* simplification sets and procedures *)
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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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    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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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} *
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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 * (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: Sign.sg -> simpset -> term -> thm option,
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    id: stamp};
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fun eq_proc (Proc {id = id1, ...}, Proc {id = id2, ...}) = (id1 = id2);
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fun rep_ss (Simpset args) = args;
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fun make_ss1 (rules, prems, bounds) =
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  {rules = rules, prems = prems, bounds = bounds};
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fun map_ss1 f {rules, prems, bounds} =
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  make_ss1 (f (rules, prems, bounds));
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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},
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    {congs, procs, mk_rews, termless, subgoal_tac, loop_tacs, solvers})) =
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  make_simpset (f ((rules, prems, bounds),
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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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(* print simpsets *)
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fun print_ss ss =
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  let
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    val pretty_thms = map Display.pretty_thm;
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    fun pretty_cong (name, th) =
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      Pretty.block [Pretty.str (name ^ ":"), Pretty.brk 1, Display.pretty_thm th];
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    fun pretty_proc (name, lhss) =
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      Pretty.big_list (name ^ ":") (map Display.pretty_cterm lhss);
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    val Simpset ({rules, ...}, {congs, procs, loop_tacs, solvers, ...}) = ss;
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    val smps = map (#thm o #2) (Net.dest rules);
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    val cngs = map (fn (name, {thm, ...}) => (name, thm)) (#1 congs);
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    val prcs = Net.dest procs |>
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      map (fn (_, Proc {name, lhs, id, ...}) => ((name, lhs), id))
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      |> partition_eq eq_snd
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      |> map (fn ps => (#1 (#1 (hd ps)), map (#2 o #1) ps))
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      |> Library.sort_wrt #1;
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  in
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    [Pretty.big_list "simplification rules:" (pretty_thms smps),
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      Pretty.big_list "simplification procedures:" (map pretty_proc prcs),
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      Pretty.big_list "congruences:" (map pretty_cong cngs),
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      Pretty.strs ("loopers:" :: map (quote o #1) loop_tacs),
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      Pretty.strs ("unsafe solvers:" :: map (quote o solver_name) (#1 solvers)),
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      Pretty.strs ("safe solvers:" :: map (quote o solver_name) (#2 solvers))]
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    |> Pretty.chunks |> Pretty.writeln
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  end;
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(* empty simpsets *)
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local
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fun init_ss mk_rews termless subgoal_tac solvers =
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  make_simpset ((Net.empty, [], 0),
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    (([], []), Net.empty, mk_rews, termless, subgoal_tac, [], solvers));
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val basic_mk_rews: mk_rews =
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 {mk = fn th => if can Logic.dest_equals (Thm.concl_of th) then [th] else [],
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  mk_cong = I,
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  mk_sym = SOME o Drule.symmetric_fun,
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  mk_eq_True = K NONE};
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in
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val empty_ss = init_ss basic_mk_rews Term.termless (K (K no_tac)) ([], []);
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fun clear_ss (Simpset (_, {mk_rews, termless, subgoal_tac, solvers, ...})) =
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  init_ss mk_rews termless subgoal_tac solvers;
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end;
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(* merge simpsets *)            (*NOTE: ignores some fields of 2nd simpset*)
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fun merge_ss (ss1, ss2) =
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  let
nipkow@16042
   323
    val Simpset ({rules = rules1, prems = prems1, bounds = bounds1},
wenzelm@15023
   324
     {congs = (congs1, weak1), procs = procs1, mk_rews, termless, subgoal_tac,
wenzelm@15023
   325
      loop_tacs = loop_tacs1, solvers = (unsafe_solvers1, solvers1)}) = ss1;
nipkow@16042
   326
    val Simpset ({rules = rules2, prems = prems2, bounds = bounds2},
wenzelm@15023
   327
     {congs = (congs2, weak2), procs = procs2, mk_rews = _, termless = _, subgoal_tac = _,
wenzelm@15023
   328
      loop_tacs = loop_tacs2, solvers = (unsafe_solvers2, solvers2)}) = ss2;
skalberg@15011
   329
wenzelm@15023
   330
    val rules' = Net.merge (rules1, rules2, eq_rrule);
wenzelm@15023
   331
    val prems' = gen_merge_lists Drule.eq_thm_prop prems1 prems2;
berghofe@15249
   332
    val bounds' = Int.max (bounds1, bounds2);
wenzelm@15023
   333
    val congs' = gen_merge_lists (eq_cong o pairself #2) congs1 congs2;
wenzelm@15023
   334
    val weak' = merge_lists weak1 weak2;
wenzelm@15023
   335
    val procs' = Net.merge (procs1, procs2, eq_proc);
wenzelm@15023
   336
    val loop_tacs' = merge_alists loop_tacs1 loop_tacs2;
wenzelm@15023
   337
    val unsafe_solvers' = merge_solvers unsafe_solvers1 unsafe_solvers2;
wenzelm@15023
   338
    val solvers' = merge_solvers solvers1 solvers2;
wenzelm@15023
   339
  in
nipkow@16042
   340
    make_simpset ((rules', prems', bounds'), ((congs', weak'), procs',
wenzelm@15023
   341
      mk_rews, termless, subgoal_tac, loop_tacs', (unsafe_solvers', solvers')))
wenzelm@15023
   342
  end;
wenzelm@15023
   343
wenzelm@15023
   344
wenzelm@15023
   345
(* simprocs *)
wenzelm@15023
   346
wenzelm@15023
   347
exception SIMPROC_FAIL of string * exn;
wenzelm@15023
   348
wenzelm@15023
   349
datatype simproc = Simproc of proc list;
wenzelm@15023
   350
wenzelm@15023
   351
fun mk_simproc name lhss proc =
wenzelm@15023
   352
  let val id = stamp () in
wenzelm@15023
   353
    Simproc (lhss |> map (fn lhs =>
wenzelm@15023
   354
      Proc {name = name, lhs = lhs, proc = proc, id = id}))
wenzelm@15023
   355
  end;
wenzelm@15023
   356
wenzelm@15023
   357
fun simproc_i sg name = mk_simproc name o map (Thm.cterm_of sg o Logic.varify);
wenzelm@15023
   358
fun simproc sg name = simproc_i sg name o map (Sign.simple_read_term sg TypeInfer.logicT);
wenzelm@15023
   359
skalberg@15011
   360
berghofe@10413
   361
berghofe@10413
   362
(** simpset operations **)
berghofe@10413
   363
wenzelm@15023
   364
(* bounds and prems *)
berghofe@10413
   365
nipkow@16042
   366
val incr_bounds = map_simpset1 (fn (rules, prems, bounds) =>
nipkow@16042
   367
  (rules, prems, bounds + 1));
berghofe@10413
   368
nipkow@16042
   369
fun add_prems ths = map_simpset1 (fn (rules, prems, bounds) =>
nipkow@16042
   370
  (rules, ths @ prems, bounds));
wenzelm@15023
   371
wenzelm@15023
   372
fun prems_of_ss (Simpset ({prems, ...}, _)) = prems;
berghofe@10413
   373
berghofe@10413
   374
wenzelm@15023
   375
(* addsimps *)
berghofe@10413
   376
wenzelm@15023
   377
fun mk_rrule2 {thm, name, lhs, elhs, perm} =
wenzelm@15023
   378
  let
wenzelm@15023
   379
    val fo = Pattern.first_order (term_of elhs) orelse not (Pattern.pattern (term_of elhs))
wenzelm@15023
   380
  in {thm = thm, name = name, lhs = lhs, elhs = elhs, fo = fo, perm = perm} end;
berghofe@10413
   381
wenzelm@15023
   382
fun insert_rrule quiet (ss, rrule as {thm, name, lhs, elhs, perm}) =
wenzelm@15023
   383
 (trace_named_thm "Adding rewrite rule" (thm, name);
nipkow@16042
   384
  ss |> map_simpset1 (fn (rules, prems, bounds) =>
wenzelm@15023
   385
    let
wenzelm@15023
   386
      val rrule2 as {elhs, ...} = mk_rrule2 rrule;
wenzelm@15023
   387
      val rules' = Net.insert_term ((term_of elhs, rrule2), rules, eq_rrule);
nipkow@16042
   388
    in (rules', prems, bounds) end)
wenzelm@15023
   389
  handle Net.INSERT =>
wenzelm@15023
   390
    (if quiet then () else warn_thm "Ignoring duplicate rewrite rule:" thm; ss));
berghofe@10413
   391
berghofe@10413
   392
fun vperm (Var _, Var _) = true
berghofe@10413
   393
  | vperm (Abs (_, _, s), Abs (_, _, t)) = vperm (s, t)
berghofe@10413
   394
  | vperm (t1 $ t2, u1 $ u2) = vperm (t1, u1) andalso vperm (t2, u2)
berghofe@10413
   395
  | vperm (t, u) = (t = u);
berghofe@10413
   396
berghofe@10413
   397
fun var_perm (t, u) =
berghofe@10413
   398
  vperm (t, u) andalso eq_set (term_varnames t, term_varnames u);
berghofe@10413
   399
berghofe@10413
   400
(* FIXME: it seems that the conditions on extra variables are too liberal if
berghofe@10413
   401
prems are nonempty: does solving the prems really guarantee instantiation of
berghofe@10413
   402
all its Vars? Better: a dynamic check each time a rule is applied.
berghofe@10413
   403
*)
berghofe@10413
   404
fun rewrite_rule_extra_vars prems elhs erhs =
skalberg@15570
   405
  not (term_varnames erhs subset Library.foldl add_term_varnames (term_varnames elhs, prems))
berghofe@10413
   406
  orelse
wenzelm@15023
   407
  not (term_tvars erhs subset (term_tvars elhs union List.concat (map term_tvars prems)));
berghofe@10413
   408
wenzelm@15023
   409
(*simple test for looping rewrite rules and stupid orientations*)
berghofe@10413
   410
fun reorient sign prems lhs rhs =
wenzelm@15023
   411
  rewrite_rule_extra_vars prems lhs rhs
wenzelm@15023
   412
    orelse
wenzelm@15023
   413
  is_Var (head_of lhs)
wenzelm@15023
   414
    orelse
nipkow@16305
   415
(* turns t = x around, which causes a headache if x is a local variable -
nipkow@16305
   416
   usually it is very useful :-(
nipkow@16305
   417
  is_Free rhs andalso not(is_Free lhs) andalso not(Logic.occs(rhs,lhs))
nipkow@16305
   418
  andalso not(exists_subterm is_Var lhs)
nipkow@16305
   419
    orelse
nipkow@16305
   420
*)
wenzelm@15023
   421
  exists (apl (lhs, Logic.occs)) (rhs :: prems)
wenzelm@15023
   422
    orelse
wenzelm@15023
   423
  null prems andalso Pattern.matches (Sign.tsig_of sign) (lhs, rhs)
berghofe@10413
   424
    (*the condition "null prems" is necessary because conditional rewrites
berghofe@10413
   425
      with extra variables in the conditions may terminate although
wenzelm@15023
   426
      the rhs is an instance of the lhs; example: ?m < ?n ==> f(?n) == f(?m)*)
wenzelm@15023
   427
    orelse
wenzelm@15023
   428
  is_Const lhs andalso not (is_Const rhs);
berghofe@10413
   429
berghofe@10413
   430
fun decomp_simp thm =
wenzelm@15023
   431
  let
wenzelm@15023
   432
    val {sign, prop, ...} = Thm.rep_thm thm;
wenzelm@15023
   433
    val prems = Logic.strip_imp_prems prop;
wenzelm@15023
   434
    val concl = Drule.strip_imp_concl (Thm.cprop_of thm);
wenzelm@15023
   435
    val (lhs, rhs) = Drule.dest_equals concl handle TERM _ =>
wenzelm@15023
   436
      raise SIMPLIFIER ("Rewrite rule not a meta-equality", thm);
wenzelm@15023
   437
    val (_, elhs) = Drule.dest_equals (Thm.cprop_of (Thm.eta_conversion lhs));
wenzelm@15023
   438
    val elhs = if elhs = lhs then lhs else elhs;  (*share identical copies*)
wenzelm@15023
   439
    val erhs = Pattern.eta_contract (term_of rhs);
wenzelm@15023
   440
    val perm =
wenzelm@15023
   441
      var_perm (term_of elhs, erhs) andalso
wenzelm@15023
   442
      not (term_of elhs aconv erhs) andalso
wenzelm@15023
   443
      not (is_Var (term_of elhs));
berghofe@10413
   444
  in (sign, prems, term_of lhs, elhs, term_of rhs, perm) end;
berghofe@10413
   445
wenzelm@12783
   446
fun decomp_simp' thm =
wenzelm@12979
   447
  let val (_, _, lhs, _, rhs, _) = decomp_simp thm in
wenzelm@12783
   448
    if Thm.nprems_of thm > 0 then raise SIMPLIFIER ("Bad conditional rewrite rule", thm)
wenzelm@12979
   449
    else (lhs, rhs)
wenzelm@12783
   450
  end;
wenzelm@12783
   451
wenzelm@15023
   452
fun mk_eq_True (Simpset (_, {mk_rews = {mk_eq_True, ...}, ...})) (thm, name) =
wenzelm@15023
   453
  (case mk_eq_True thm of
skalberg@15531
   454
    NONE => []
skalberg@15531
   455
  | SOME eq_True =>
wenzelm@15023
   456
      let val (_, _, lhs, elhs, _, _) = decomp_simp eq_True
wenzelm@15023
   457
      in [{thm = eq_True, name = name, lhs = lhs, elhs = elhs, perm = false}] end);
berghofe@10413
   458
wenzelm@15023
   459
(*create the rewrite rule and possibly also the eq_True variant,
wenzelm@15023
   460
  in case there are extra vars on the rhs*)
wenzelm@15023
   461
fun rrule_eq_True (thm, name, lhs, elhs, rhs, ss, thm2) =
wenzelm@15023
   462
  let val rrule = {thm = thm, name = name, lhs = lhs, elhs = elhs, perm = false} in
wenzelm@15023
   463
    if term_varnames rhs subset term_varnames lhs andalso
wenzelm@15023
   464
      term_tvars rhs subset term_tvars lhs then [rrule]
wenzelm@15023
   465
    else mk_eq_True ss (thm2, name) @ [rrule]
berghofe@10413
   466
  end;
berghofe@10413
   467
wenzelm@15023
   468
fun mk_rrule ss (thm, name) =
wenzelm@15023
   469
  let val (_, prems, lhs, elhs, rhs, perm) = decomp_simp thm in
wenzelm@15023
   470
    if perm then [{thm = thm, name = name, lhs = lhs, elhs = elhs, perm = true}]
wenzelm@15023
   471
    else
wenzelm@15023
   472
      (*weak test for loops*)
wenzelm@15023
   473
      if rewrite_rule_extra_vars prems lhs rhs orelse is_Var (term_of elhs)
wenzelm@15023
   474
      then mk_eq_True ss (thm, name)
wenzelm@15023
   475
      else rrule_eq_True (thm, name, lhs, elhs, rhs, ss, thm)
berghofe@10413
   476
  end;
berghofe@10413
   477
wenzelm@15023
   478
fun orient_rrule ss (thm, name) =
wenzelm@15023
   479
  let val (sign, prems, lhs, elhs, rhs, perm) = decomp_simp thm in
wenzelm@15023
   480
    if perm then [{thm = thm, name = name, lhs = lhs, elhs = elhs, perm = true}]
wenzelm@15023
   481
    else if reorient sign prems lhs rhs then
wenzelm@15023
   482
      if reorient sign prems rhs lhs
wenzelm@15023
   483
      then mk_eq_True ss (thm, name)
wenzelm@15023
   484
      else
wenzelm@15023
   485
        let val Simpset (_, {mk_rews = {mk_sym, ...}, ...}) = ss in
wenzelm@15023
   486
          (case mk_sym thm of
skalberg@15531
   487
            NONE => []
skalberg@15531
   488
          | SOME thm' =>
wenzelm@15023
   489
              let val (_, _, lhs', elhs', rhs', _) = decomp_simp thm'
wenzelm@15023
   490
              in rrule_eq_True (thm', name, lhs', elhs', rhs', ss, thm) end)
wenzelm@15023
   491
        end
wenzelm@15023
   492
    else rrule_eq_True (thm, name, lhs, elhs, rhs, ss, thm)
berghofe@10413
   493
  end;
berghofe@10413
   494
nipkow@15199
   495
fun extract_rews (Simpset (_, {mk_rews = {mk, ...}, ...}), thms) =
skalberg@15570
   496
  List.concat (map (fn thm => map (rpair (Thm.name_of_thm thm)) (mk thm)) thms);
berghofe@10413
   497
wenzelm@15023
   498
fun orient_comb_simps comb mk_rrule (ss, thms) =
wenzelm@15023
   499
  let
wenzelm@15023
   500
    val rews = extract_rews (ss, thms);
skalberg@15570
   501
    val rrules = List.concat (map mk_rrule rews);
skalberg@15570
   502
  in Library.foldl comb (ss, rrules) end;
berghofe@10413
   503
wenzelm@15023
   504
fun extract_safe_rrules (ss, thm) =
skalberg@15570
   505
  List.concat (map (orient_rrule ss) (extract_rews (ss, [thm])));
berghofe@10413
   506
wenzelm@15023
   507
(*add rewrite rules explicitly; do not reorient!*)
wenzelm@15023
   508
fun ss addsimps thms =
wenzelm@15023
   509
  orient_comb_simps (insert_rrule false) (mk_rrule ss) (ss, thms);
berghofe@10413
   510
berghofe@10413
   511
wenzelm@15023
   512
(* delsimps *)
berghofe@10413
   513
wenzelm@15023
   514
fun del_rrule (ss, rrule as {thm, elhs, ...}) =
nipkow@16042
   515
  ss |> map_simpset1 (fn (rules, prems, bounds) =>
nipkow@16042
   516
    (Net.delete_term ((term_of elhs, rrule), rules, eq_rrule), prems, bounds))
wenzelm@15023
   517
  handle Net.DELETE => (warn_thm "Rewrite rule not in simpset:" thm; ss);
berghofe@10413
   518
wenzelm@15023
   519
fun ss delsimps thms =
wenzelm@15023
   520
  orient_comb_simps del_rrule (map mk_rrule2 o mk_rrule ss) (ss, thms);
wenzelm@15023
   521
wenzelm@15023
   522
wenzelm@15023
   523
(* congs *)
berghofe@10413
   524
skalberg@15531
   525
fun cong_name (Const (a, _)) = SOME a
skalberg@15531
   526
  | cong_name (Free (a, _)) = SOME ("Free: " ^ a)
skalberg@15531
   527
  | cong_name _ = NONE;
ballarin@13835
   528
wenzelm@15023
   529
local
wenzelm@15023
   530
wenzelm@15023
   531
fun is_full_cong_prems [] [] = true
wenzelm@15023
   532
  | is_full_cong_prems [] _ = false
wenzelm@15023
   533
  | is_full_cong_prems (p :: prems) varpairs =
wenzelm@15023
   534
      (case Logic.strip_assums_concl p of
wenzelm@15023
   535
        Const ("==", _) $ lhs $ rhs =>
wenzelm@15023
   536
          let val (x, xs) = strip_comb lhs and (y, ys) = strip_comb rhs in
wenzelm@15023
   537
            is_Var x andalso forall is_Bound xs andalso
wenzelm@15023
   538
            null (findrep xs) andalso xs = ys andalso
wenzelm@15023
   539
            (x, y) mem varpairs andalso
wenzelm@15023
   540
            is_full_cong_prems prems (varpairs \ (x, y))
wenzelm@15023
   541
          end
wenzelm@15023
   542
      | _ => false);
wenzelm@15023
   543
wenzelm@15023
   544
fun is_full_cong thm =
berghofe@10413
   545
  let
wenzelm@15023
   546
    val prems = prems_of thm and concl = concl_of thm;
wenzelm@15023
   547
    val (lhs, rhs) = Logic.dest_equals concl;
wenzelm@15023
   548
    val (f, xs) = strip_comb lhs and (g, ys) = strip_comb rhs;
berghofe@10413
   549
  in
wenzelm@15023
   550
    f = g andalso null (findrep (xs @ ys)) andalso length xs = length ys andalso
wenzelm@15023
   551
    is_full_cong_prems prems (xs ~~ ys)
berghofe@10413
   552
  end;
berghofe@10413
   553
wenzelm@15023
   554
fun add_cong (ss, thm) = ss |>
wenzelm@15023
   555
  map_simpset2 (fn (congs, procs, mk_rews, termless, subgoal_tac, loop_tacs, solvers) =>
wenzelm@15023
   556
    let
wenzelm@15023
   557
      val (lhs, _) = Drule.dest_equals (Drule.strip_imp_concl (Thm.cprop_of thm))
wenzelm@15023
   558
        handle TERM _ => raise SIMPLIFIER ("Congruence not a meta-equality", thm);
wenzelm@15023
   559
    (*val lhs = Pattern.eta_contract lhs;*)
skalberg@15570
   560
      val a = valOf (cong_name (head_of (term_of lhs))) handle Option =>
wenzelm@15023
   561
        raise SIMPLIFIER ("Congruence must start with a constant or free variable", thm);
wenzelm@15023
   562
      val (alist, weak) = congs;
wenzelm@15023
   563
      val alist2 = overwrite_warn (alist, (a, {lhs = lhs, thm = thm}))
wenzelm@15023
   564
        ("Overwriting congruence rule for " ^ quote a);
wenzelm@15023
   565
      val weak2 = if is_full_cong thm then weak else a :: weak;
wenzelm@15023
   566
    in ((alist2, weak2), procs, mk_rews, termless, subgoal_tac, loop_tacs, solvers) end);
berghofe@10413
   567
wenzelm@15023
   568
fun del_cong (ss, thm) = ss |>
wenzelm@15023
   569
  map_simpset2 (fn (congs, procs, mk_rews, termless, subgoal_tac, loop_tacs, solvers) =>
wenzelm@15023
   570
    let
wenzelm@15023
   571
      val (lhs, _) = Logic.dest_equals (Thm.concl_of thm) handle TERM _ =>
wenzelm@15023
   572
        raise SIMPLIFIER ("Congruence not a meta-equality", thm);
wenzelm@15023
   573
    (*val lhs = Pattern.eta_contract lhs;*)
skalberg@15570
   574
      val a = valOf (cong_name (head_of lhs)) handle Option =>
wenzelm@15023
   575
        raise SIMPLIFIER ("Congruence must start with a constant", thm);
wenzelm@15023
   576
      val (alist, _) = congs;
skalberg@15570
   577
      val alist2 = List.filter (fn (x, _) => x <> a) alist;
skalberg@15570
   578
      val weak2 = alist2 |> List.mapPartial (fn (a, {thm, ...}) =>
skalberg@15531
   579
        if is_full_cong thm then NONE else SOME a);
wenzelm@15023
   580
    in ((alist2, weak2), procs, mk_rews, termless, subgoal_tac, loop_tacs, solvers) end);
berghofe@10413
   581
wenzelm@15023
   582
fun mk_cong (Simpset (_, {mk_rews = {mk_cong = f, ...}, ...})) = f;
wenzelm@15023
   583
wenzelm@15023
   584
in
wenzelm@15023
   585
skalberg@15570
   586
val (op addeqcongs) = Library.foldl add_cong;
skalberg@15570
   587
val (op deleqcongs) = Library.foldl del_cong;
wenzelm@15023
   588
wenzelm@15023
   589
fun ss addcongs congs = ss addeqcongs map (mk_cong ss) congs;
wenzelm@15023
   590
fun ss delcongs congs = ss deleqcongs map (mk_cong ss) congs;
wenzelm@15023
   591
wenzelm@15023
   592
end;
berghofe@10413
   593
berghofe@10413
   594
wenzelm@15023
   595
(* simprocs *)
wenzelm@15023
   596
wenzelm@15023
   597
local
berghofe@10413
   598
wenzelm@15023
   599
fun add_proc (ss, proc as Proc {name, lhs, ...}) =
wenzelm@15023
   600
 (trace_cterm false ("Adding simplification procedure " ^ quote name ^ " for") lhs;
wenzelm@15023
   601
  map_simpset2 (fn (congs, procs, mk_rews, termless, subgoal_tac, loop_tacs, solvers) =>
wenzelm@15023
   602
    (congs, Net.insert_term ((term_of lhs, proc), procs, eq_proc),
wenzelm@15023
   603
      mk_rews, termless, subgoal_tac, loop_tacs, solvers)) ss
wenzelm@15023
   604
  handle Net.INSERT =>
wenzelm@15023
   605
    (warning ("Ignoring duplicate simplification procedure " ^ quote name); ss));
berghofe@10413
   606
wenzelm@15023
   607
fun del_proc (ss, proc as Proc {name, lhs, ...}) =
wenzelm@15023
   608
  map_simpset2 (fn (congs, procs, mk_rews, termless, subgoal_tac, loop_tacs, solvers) =>
wenzelm@15023
   609
    (congs, Net.delete_term ((term_of lhs, proc), procs, eq_proc),
wenzelm@15023
   610
      mk_rews, termless, subgoal_tac, loop_tacs, solvers)) ss
wenzelm@15023
   611
  handle Net.DELETE =>
wenzelm@15023
   612
    (warning ("Simplification procedure " ^ quote name ^ " not in simpset"); ss);
berghofe@10413
   613
wenzelm@15023
   614
in
berghofe@10413
   615
skalberg@15570
   616
val (op addsimprocs) = Library.foldl (fn (ss, Simproc procs) => Library.foldl add_proc (ss, procs));
skalberg@15570
   617
val (op delsimprocs) = Library.foldl (fn (ss, Simproc procs) => Library.foldl del_proc (ss, procs));
berghofe@10413
   618
wenzelm@15023
   619
end;
berghofe@10413
   620
berghofe@10413
   621
berghofe@10413
   622
(* mk_rews *)
berghofe@10413
   623
wenzelm@15023
   624
local
wenzelm@15023
   625
nipkow@15199
   626
fun map_mk_rews f = map_simpset2 (fn (congs, procs, {mk, mk_cong, mk_sym, mk_eq_True},
wenzelm@15023
   627
      termless, subgoal_tac, loop_tacs, solvers) =>
nipkow@15199
   628
  let val (mk', mk_cong', mk_sym', mk_eq_True') = f (mk, mk_cong, mk_sym, mk_eq_True) in
nipkow@15199
   629
    (congs, procs, {mk = mk', mk_cong = mk_cong', mk_sym = mk_sym', mk_eq_True = mk_eq_True'},
wenzelm@15023
   630
      termless, subgoal_tac, loop_tacs, solvers)
wenzelm@15023
   631
  end);
wenzelm@15023
   632
wenzelm@15023
   633
in
berghofe@10413
   634
nipkow@15199
   635
fun ss setmksimps mk = ss |> map_mk_rews (fn (_, mk_cong, mk_sym, mk_eq_True) =>
nipkow@15199
   636
  (mk, mk_cong, mk_sym, mk_eq_True));
wenzelm@15023
   637
nipkow@15199
   638
fun ss setmkcong mk_cong = ss |> map_mk_rews (fn (mk, _, mk_sym, mk_eq_True) =>
nipkow@15199
   639
  (mk, mk_cong, mk_sym, mk_eq_True));
berghofe@10413
   640
nipkow@15199
   641
fun ss setmksym mk_sym = ss |> map_mk_rews (fn (mk, mk_cong, _, mk_eq_True) =>
nipkow@15199
   642
  (mk, mk_cong, mk_sym, mk_eq_True));
berghofe@10413
   643
nipkow@15199
   644
fun ss setmkeqTrue mk_eq_True = ss |> map_mk_rews (fn (mk, mk_cong, mk_sym, _) =>
nipkow@15199
   645
  (mk, mk_cong, mk_sym, mk_eq_True));
wenzelm@15023
   646
wenzelm@15023
   647
end;
wenzelm@15023
   648
skalberg@14242
   649
berghofe@10413
   650
(* termless *)
berghofe@10413
   651
wenzelm@15023
   652
fun ss settermless termless = ss |>
wenzelm@15023
   653
  map_simpset2 (fn (congs, procs, mk_rews, _, subgoal_tac, loop_tacs, solvers) =>
wenzelm@15023
   654
   (congs, procs, mk_rews, termless, subgoal_tac, loop_tacs, solvers));
skalberg@15006
   655
skalberg@15006
   656
wenzelm@15023
   657
(* tactics *)
skalberg@15006
   658
wenzelm@15023
   659
fun ss setsubgoaler subgoal_tac = ss |>
wenzelm@15023
   660
  map_simpset2 (fn (congs, procs, mk_rews, termless, _, loop_tacs, solvers) =>
wenzelm@15023
   661
   (congs, procs, mk_rews, termless, subgoal_tac, loop_tacs, solvers));
skalberg@15006
   662
wenzelm@15023
   663
fun ss setloop tac = ss |>
wenzelm@15023
   664
  map_simpset2 (fn (congs, procs, mk_rews, termless, subgoal_tac, _, solvers) =>
wenzelm@15023
   665
   (congs, procs, mk_rews, termless, subgoal_tac, [("", tac)], solvers));
skalberg@15006
   666
wenzelm@15023
   667
fun ss addloop (name, tac) = ss |>
wenzelm@15023
   668
  map_simpset2 (fn (congs, procs, mk_rews, termless, subgoal_tac, loop_tacs, solvers) =>
wenzelm@15023
   669
    (congs, procs, mk_rews, termless, subgoal_tac,
wenzelm@15023
   670
      overwrite_warn (loop_tacs, (name, tac)) ("Overwriting looper " ^ quote name),
wenzelm@15023
   671
      solvers));
skalberg@15006
   672
wenzelm@15023
   673
fun ss delloop name = ss |>
wenzelm@15023
   674
  map_simpset2 (fn (congs, procs, mk_rews, termless, subgoal_tac, loop_tacs, solvers) =>
wenzelm@15034
   675
    let val loop_tacs' = filter_out (equal name o #1) loop_tacs in
wenzelm@15034
   676
      if length loop_tacs <> length loop_tacs' then ()
wenzelm@15034
   677
      else warning ("No such looper in simpset: " ^ quote name);
wenzelm@15034
   678
      (congs, procs, mk_rews, termless, subgoal_tac, loop_tacs', solvers)
wenzelm@15023
   679
    end);
skalberg@15006
   680
wenzelm@15023
   681
fun ss setSSolver solver = ss |> map_simpset2 (fn (congs, procs, mk_rews, termless,
wenzelm@15023
   682
  subgoal_tac, loop_tacs, (unsafe_solvers, _)) =>
wenzelm@15023
   683
    (congs, procs, mk_rews, termless, subgoal_tac, loop_tacs, (unsafe_solvers, [solver])));
skalberg@15006
   684
wenzelm@15023
   685
fun ss addSSolver solver = ss |> map_simpset2 (fn (congs, procs, mk_rews, termless,
wenzelm@15023
   686
  subgoal_tac, loop_tacs, (unsafe_solvers, solvers)) => (congs, procs, mk_rews, termless,
wenzelm@15023
   687
    subgoal_tac, loop_tacs, (unsafe_solvers, merge_solvers solvers [solver])));
skalberg@15006
   688
wenzelm@15023
   689
fun ss setSolver solver = ss |> map_simpset2 (fn (congs, procs, mk_rews, termless,
wenzelm@15023
   690
  subgoal_tac, loop_tacs, (_, solvers)) => (congs, procs, mk_rews, termless,
wenzelm@15023
   691
    subgoal_tac, loop_tacs, ([solver], solvers)));
skalberg@15006
   692
wenzelm@15023
   693
fun ss addSolver solver = ss |> map_simpset2 (fn (congs, procs, mk_rews, termless,
wenzelm@15023
   694
  subgoal_tac, loop_tacs, (unsafe_solvers, solvers)) => (congs, procs, mk_rews, termless,
wenzelm@15023
   695
    subgoal_tac, loop_tacs, (merge_solvers unsafe_solvers [solver], solvers)));
skalberg@15006
   696
wenzelm@15023
   697
fun set_solvers solvers = map_simpset2 (fn (congs, procs, mk_rews, termless,
wenzelm@15023
   698
  subgoal_tac, loop_tacs, _) => (congs, procs, mk_rews, termless,
wenzelm@15023
   699
  subgoal_tac, loop_tacs, (solvers, solvers)));
skalberg@15006
   700
skalberg@15006
   701
skalberg@15006
   702
berghofe@10413
   703
(** rewriting **)
berghofe@10413
   704
berghofe@10413
   705
(*
berghofe@10413
   706
  Uses conversions, see:
berghofe@10413
   707
    L C Paulson, A higher-order implementation of rewriting,
berghofe@10413
   708
    Science of Computer Programming 3 (1983), pages 119-149.
berghofe@10413
   709
*)
berghofe@10413
   710
wenzelm@15023
   711
val dest_eq = Drule.dest_equals o Thm.cprop_of;
wenzelm@15023
   712
val lhs_of = #1 o dest_eq;
wenzelm@15023
   713
val rhs_of = #2 o dest_eq;
berghofe@10413
   714
berghofe@10413
   715
fun check_conv msg thm thm' =
berghofe@10413
   716
  let
berghofe@10413
   717
    val thm'' = transitive thm (transitive
skalberg@15001
   718
      (symmetric (Drule.beta_eta_conversion (lhs_of thm'))) thm')
skalberg@15531
   719
  in if msg then trace_thm "SUCCEEDED" thm' else (); SOME thm'' end
berghofe@10413
   720
  handle THM _ =>
wenzelm@15023
   721
    let val {sign, prop = _ $ _ $ prop0, ...} = Thm.rep_thm thm in
wenzelm@15023
   722
      trace_thm "Proved wrong thm (Check subgoaler?)" thm';
wenzelm@15023
   723
      trace_term false "Should have proved:" sign prop0;
skalberg@15531
   724
      NONE
berghofe@10413
   725
    end;
berghofe@10413
   726
berghofe@10413
   727
berghofe@10413
   728
(* mk_procrule *)
berghofe@10413
   729
berghofe@10413
   730
fun mk_procrule thm =
wenzelm@15023
   731
  let val (_, prems, lhs, elhs, rhs, _) = decomp_simp thm in
wenzelm@15023
   732
    if rewrite_rule_extra_vars prems lhs rhs
wenzelm@15023
   733
    then (warn_thm "Extra vars on rhs:" thm; [])
wenzelm@15023
   734
    else [mk_rrule2 {thm = thm, name = "", lhs = lhs, elhs = elhs, perm = false}]
berghofe@10413
   735
  end;
berghofe@10413
   736
berghofe@10413
   737
wenzelm@15023
   738
(* rewritec: conversion to apply the meta simpset to a term *)
berghofe@10413
   739
wenzelm@15023
   740
(*Since the rewriting strategy is bottom-up, we avoid re-normalizing already
wenzelm@15023
   741
  normalized terms by carrying around the rhs of the rewrite rule just
wenzelm@15023
   742
  applied. This is called the `skeleton'. It is decomposed in parallel
wenzelm@15023
   743
  with the term. Once a Var is encountered, the corresponding term is
wenzelm@15023
   744
  already in normal form.
wenzelm@15023
   745
  skel0 is a dummy skeleton that is to enforce complete normalization.*)
wenzelm@15023
   746
berghofe@10413
   747
val skel0 = Bound 0;
berghofe@10413
   748
wenzelm@15023
   749
(*Use rhs as skeleton only if the lhs does not contain unnormalized bits.
wenzelm@15023
   750
  The latter may happen iff there are weak congruence rules for constants
wenzelm@15023
   751
  in the lhs.*)
berghofe@10413
   752
wenzelm@15023
   753
fun uncond_skel ((_, weak), (lhs, rhs)) =
wenzelm@15023
   754
  if null weak then rhs  (*optimization*)
wenzelm@15023
   755
  else if exists_Const (fn (c, _) => c mem weak) lhs then skel0
wenzelm@15023
   756
  else rhs;
wenzelm@15023
   757
wenzelm@15023
   758
(*Behaves like unconditional rule if rhs does not contain vars not in the lhs.
wenzelm@15023
   759
  Otherwise those vars may become instantiated with unnormalized terms
wenzelm@15023
   760
  while the premises are solved.*)
wenzelm@15023
   761
wenzelm@15023
   762
fun cond_skel (args as (congs, (lhs, rhs))) =
wenzelm@15023
   763
  if term_varnames rhs subset term_varnames lhs then uncond_skel args
berghofe@10413
   764
  else skel0;
berghofe@10413
   765
berghofe@10413
   766
(*
wenzelm@15023
   767
  Rewriting -- we try in order:
berghofe@10413
   768
    (1) beta reduction
berghofe@10413
   769
    (2) unconditional rewrite rules
berghofe@10413
   770
    (3) conditional rewrite rules
berghofe@10413
   771
    (4) simplification procedures
berghofe@10413
   772
berghofe@10413
   773
  IMPORTANT: rewrite rules must not introduce new Vars or TVars!
berghofe@10413
   774
*)
berghofe@10413
   775
wenzelm@15023
   776
fun rewritec (prover, signt, maxt) ss t =
berghofe@10413
   777
  let
wenzelm@15023
   778
    val Simpset ({rules, ...}, {congs, procs, termless, ...}) = ss;
berghofe@10413
   779
    val eta_thm = Thm.eta_conversion t;
berghofe@10413
   780
    val eta_t' = rhs_of eta_thm;
berghofe@10413
   781
    val eta_t = term_of eta_t';
berghofe@10413
   782
    val tsigt = Sign.tsig_of signt;
berghofe@13607
   783
    fun rew {thm, name, lhs, elhs, fo, perm} =
berghofe@10413
   784
      let
berghofe@10413
   785
        val {sign, prop, maxidx, ...} = rep_thm thm;
berghofe@10413
   786
        val (rthm, elhs') = if maxt = ~1 then (thm, elhs)
berghofe@10413
   787
          else (Thm.incr_indexes (maxt+1) thm, Thm.cterm_incr_indexes (maxt+1) elhs);
berghofe@10413
   788
        val insts = if fo then Thm.cterm_first_order_match (elhs', eta_t')
berghofe@10413
   789
                          else Thm.cterm_match (elhs', eta_t');
berghofe@10413
   790
        val thm' = Thm.instantiate insts (Thm.rename_boundvars lhs eta_t rthm);
wenzelm@14643
   791
        val prop' = Thm.prop_of thm';
berghofe@10413
   792
        val unconditional = (Logic.count_prems (prop',0) = 0);
berghofe@10413
   793
        val (lhs', rhs') = Logic.dest_equals (Logic.strip_imp_concl prop')
berghofe@10413
   794
      in
nipkow@11295
   795
        if perm andalso not (termless (rhs', lhs'))
berghofe@13607
   796
        then (trace_named_thm "Cannot apply permutative rewrite rule" (thm, name);
skalberg@15531
   797
              trace_thm "Term does not become smaller:" thm'; NONE)
berghofe@13607
   798
        else (trace_named_thm "Applying instance of rewrite rule" (thm, name);
berghofe@10413
   799
           if unconditional
berghofe@10413
   800
           then
nipkow@13569
   801
             (trace_thm "Rewriting:" thm';
berghofe@10413
   802
              let val lr = Logic.dest_equals prop;
skalberg@15531
   803
                  val SOME thm'' = check_conv false eta_thm thm'
skalberg@15531
   804
              in SOME (thm'', uncond_skel (congs, lr)) end)
berghofe@10413
   805
           else
nipkow@13569
   806
             (trace_thm "Trying to rewrite:" thm';
nipkow@16042
   807
              if !simp_depth > !simp_depth_limit
nipkow@16042
   808
              then let val s = "simp_depth_limit exceeded - giving up"
nipkow@16042
   809
                   in trace false s; warning s; NONE end
nipkow@16042
   810
              else
nipkow@16042
   811
              case prover ss thm' of
skalberg@15531
   812
                NONE => (trace_thm "FAILED" thm'; NONE)
skalberg@15531
   813
              | SOME thm2 =>
berghofe@10413
   814
                  (case check_conv true eta_thm thm2 of
skalberg@15531
   815
                     NONE => NONE |
skalberg@15531
   816
                     SOME thm2' =>
berghofe@10413
   817
                       let val concl = Logic.strip_imp_concl prop
berghofe@10413
   818
                           val lr = Logic.dest_equals concl
nipkow@16042
   819
                       in SOME (thm2', cond_skel (congs, lr)) end)))
berghofe@10413
   820
      end
berghofe@10413
   821
skalberg@15531
   822
    fun rews [] = NONE
berghofe@10413
   823
      | rews (rrule :: rrules) =
skalberg@15531
   824
          let val opt = rew rrule handle Pattern.MATCH => NONE
skalberg@15531
   825
          in case opt of NONE => rews rrules | some => some end;
berghofe@10413
   826
berghofe@10413
   827
    fun sort_rrules rrs = let
wenzelm@14643
   828
      fun is_simple({thm, ...}:rrule) = case Thm.prop_of thm of
berghofe@10413
   829
                                      Const("==",_) $ _ $ _ => true
wenzelm@12603
   830
                                      | _                   => false
berghofe@10413
   831
      fun sort []        (re1,re2) = re1 @ re2
wenzelm@12603
   832
        | sort (rr::rrs) (re1,re2) = if is_simple rr
berghofe@10413
   833
                                     then sort rrs (rr::re1,re2)
berghofe@10413
   834
                                     else sort rrs (re1,rr::re2)
berghofe@10413
   835
    in sort rrs ([],[]) end
berghofe@10413
   836
skalberg@15531
   837
    fun proc_rews [] = NONE
wenzelm@15023
   838
      | proc_rews (Proc {name, proc, lhs, ...} :: ps) =
wenzelm@15023
   839
          if Pattern.matches tsigt (Thm.term_of lhs, Thm.term_of t) then
berghofe@10413
   840
            (debug_term false ("Trying procedure " ^ quote name ^ " on:") signt eta_t;
wenzelm@13486
   841
             case transform_failure (curry SIMPROC_FAIL name)
wenzelm@15023
   842
                 (fn () => proc signt ss eta_t) () of
skalberg@15531
   843
               NONE => (debug false "FAILED"; proc_rews ps)
skalberg@15531
   844
             | SOME raw_thm =>
nipkow@13569
   845
                 (trace_thm ("Procedure " ^ quote name ^ " produced rewrite rule:") raw_thm;
berghofe@10413
   846
                  (case rews (mk_procrule raw_thm) of
skalberg@15531
   847
                    NONE => (trace_cterm true ("IGNORED result of simproc " ^ quote name ^
wenzelm@13486
   848
                      " -- does not match") t; proc_rews ps)
berghofe@10413
   849
                  | some => some)))
berghofe@10413
   850
          else proc_rews ps;
berghofe@10413
   851
  in case eta_t of
skalberg@15531
   852
       Abs _ $ _ => SOME (transitive eta_thm
berghofe@12155
   853
         (beta_conversion false eta_t'), skel0)
berghofe@10413
   854
     | _ => (case rews (sort_rrules (Net.match_term rules eta_t)) of
skalberg@15531
   855
               NONE => proc_rews (Net.match_term procs eta_t)
berghofe@10413
   856
             | some => some)
berghofe@10413
   857
  end;
berghofe@10413
   858
berghofe@10413
   859
berghofe@10413
   860
(* conversion to apply a congruence rule to a term *)
berghofe@10413
   861
berghofe@10413
   862
fun congc (prover,signt,maxt) {thm=cong,lhs=lhs} t =
wenzelm@14643
   863
  let val sign = Thm.sign_of_thm cong
berghofe@10413
   864
      val rthm = if maxt = ~1 then cong else Thm.incr_indexes (maxt+1) cong;
berghofe@10413
   865
      val rlhs = fst (Drule.dest_equals (Drule.strip_imp_concl (cprop_of rthm)));
berghofe@10413
   866
      val insts = Thm.cterm_match (rlhs, t)
berghofe@10413
   867
      (* Pattern.match can raise Pattern.MATCH;
berghofe@10413
   868
         is handled when congc is called *)
berghofe@10413
   869
      val thm' = Thm.instantiate insts (Thm.rename_boundvars (term_of rlhs) (term_of t) rthm);
nipkow@13569
   870
      val unit = trace_thm "Applying congruence rule:" thm';
skalberg@15531
   871
      fun err (msg, thm) = (trace_thm msg thm; NONE)
berghofe@10413
   872
  in case prover thm' of
skalberg@15531
   873
       NONE => err ("Congruence proof failed.  Could not prove", thm')
skalberg@15531
   874
     | SOME thm2 => (case check_conv true (Drule.beta_eta_conversion t) thm2 of
skalberg@15531
   875
          NONE => err ("Congruence proof failed.  Should not have proved", thm2)
skalberg@15531
   876
        | SOME thm2' =>
berghofe@12155
   877
            if op aconv (pairself term_of (dest_equals (cprop_of thm2')))
skalberg@15531
   878
            then NONE else SOME thm2')
berghofe@10413
   879
  end;
berghofe@10413
   880
berghofe@10413
   881
val (cA, (cB, cC)) =
berghofe@10413
   882
  apsnd dest_equals (dest_implies (hd (cprems_of Drule.imp_cong)));
berghofe@10413
   883
skalberg@15531
   884
fun transitive1 NONE NONE = NONE
skalberg@15531
   885
  | transitive1 (SOME thm1) NONE = SOME thm1
skalberg@15531
   886
  | transitive1 NONE (SOME thm2) = SOME thm2
skalberg@15531
   887
  | transitive1 (SOME thm1) (SOME thm2) = SOME (transitive thm1 thm2)
berghofe@10413
   888
skalberg@15531
   889
fun transitive2 thm = transitive1 (SOME thm);
skalberg@15531
   890
fun transitive3 thm = transitive1 thm o SOME;
berghofe@13607
   891
wenzelm@15023
   892
fun bottomc ((simprem, useprem, mutsimp), prover, sign, maxidx) =
berghofe@10413
   893
  let
wenzelm@15023
   894
    fun botc skel ss t =
skalberg@15531
   895
          if is_Var skel then NONE
berghofe@10413
   896
          else
wenzelm@15023
   897
          (case subc skel ss t of
skalberg@15531
   898
             some as SOME thm1 =>
wenzelm@15023
   899
               (case rewritec (prover, sign, maxidx) ss (rhs_of thm1) of
skalberg@15531
   900
                  SOME (thm2, skel2) =>
berghofe@13607
   901
                    transitive2 (transitive thm1 thm2)
wenzelm@15023
   902
                      (botc skel2 ss (rhs_of thm2))
skalberg@15531
   903
                | NONE => some)
skalberg@15531
   904
           | NONE =>
wenzelm@15023
   905
               (case rewritec (prover, sign, maxidx) ss t of
skalberg@15531
   906
                  SOME (thm2, skel2) => transitive2 thm2
wenzelm@15023
   907
                    (botc skel2 ss (rhs_of thm2))
skalberg@15531
   908
                | NONE => NONE))
berghofe@10413
   909
wenzelm@15023
   910
    and try_botc ss t =
wenzelm@15023
   911
          (case botc skel0 ss t of
skalberg@15531
   912
             SOME trec1 => trec1 | NONE => (reflexive t))
berghofe@10413
   913
wenzelm@15023
   914
    and subc skel (ss as Simpset ({bounds, ...}, {congs, ...})) t0 =
berghofe@10413
   915
       (case term_of t0 of
berghofe@10413
   916
           Abs (a, T, t) =>
wenzelm@15023
   917
             let
skalberg@15531
   918
                 val (v, t') = Thm.dest_abs (SOME ("." ^ a ^ "." ^ string_of_int bounds)) t0;
berghofe@15249
   919
                 val ss' = incr_bounds ss;
wenzelm@15023
   920
                 val skel' = case skel of Abs (_, _, sk) => sk | _ => skel0;
wenzelm@15023
   921
             in case botc skel' ss' t' of
skalberg@15531
   922
                  SOME thm => SOME (abstract_rule a v thm)
skalberg@15531
   923
                | NONE => NONE
berghofe@10413
   924
             end
berghofe@10413
   925
         | t $ _ => (case t of
wenzelm@15023
   926
             Const ("==>", _) $ _  => impc t0 ss
berghofe@10413
   927
           | Abs _ =>
berghofe@10413
   928
               let val thm = beta_conversion false t0
wenzelm@15023
   929
               in case subc skel0 ss (rhs_of thm) of
skalberg@15531
   930
                    NONE => SOME thm
skalberg@15531
   931
                  | SOME thm' => SOME (transitive thm thm')
berghofe@10413
   932
               end
berghofe@10413
   933
           | _  =>
berghofe@10413
   934
               let fun appc () =
berghofe@10413
   935
                     let
berghofe@10413
   936
                       val (tskel, uskel) = case skel of
berghofe@10413
   937
                           tskel $ uskel => (tskel, uskel)
berghofe@10413
   938
                         | _ => (skel0, skel0);
wenzelm@10767
   939
                       val (ct, cu) = Thm.dest_comb t0
berghofe@10413
   940
                     in
wenzelm@15023
   941
                     (case botc tskel ss ct of
skalberg@15531
   942
                        SOME thm1 =>
wenzelm@15023
   943
                          (case botc uskel ss cu of
skalberg@15531
   944
                             SOME thm2 => SOME (combination thm1 thm2)
skalberg@15531
   945
                           | NONE => SOME (combination thm1 (reflexive cu)))
skalberg@15531
   946
                      | NONE =>
wenzelm@15023
   947
                          (case botc uskel ss cu of
skalberg@15531
   948
                             SOME thm1 => SOME (combination (reflexive ct) thm1)
skalberg@15531
   949
                           | NONE => NONE))
berghofe@10413
   950
                     end
berghofe@10413
   951
                   val (h, ts) = strip_comb t
ballarin@13835
   952
               in case cong_name h of
skalberg@15531
   953
                    SOME a =>
berghofe@10413
   954
                      (case assoc_string (fst congs, a) of
skalberg@15531
   955
                         NONE => appc ()
skalberg@15531
   956
                       | SOME cong =>
wenzelm@15023
   957
  (*post processing: some partial applications h t1 ... tj, j <= length ts,
wenzelm@15023
   958
    may be a redex. Example: map (%x. x) = (%xs. xs) wrt map_cong*)
berghofe@10413
   959
                          (let
wenzelm@15023
   960
                             val thm = congc (prover ss, sign, maxidx) cong t0;
skalberg@15570
   961
                             val t = getOpt (Option.map rhs_of thm, t0);
wenzelm@10767
   962
                             val (cl, cr) = Thm.dest_comb t
berghofe@10413
   963
                             val dVar = Var(("", 0), dummyT)
berghofe@10413
   964
                             val skel =
berghofe@10413
   965
                               list_comb (h, replicate (length ts) dVar)
wenzelm@15023
   966
                           in case botc skel ss cl of
skalberg@15531
   967
                                NONE => thm
skalberg@15531
   968
                              | SOME thm' => transitive3 thm
berghofe@12155
   969
                                  (combination thm' (reflexive cr))
berghofe@10413
   970
                           end handle TERM _ => error "congc result"
berghofe@10413
   971
                                    | Pattern.MATCH => appc ()))
berghofe@10413
   972
                  | _ => appc ()
berghofe@10413
   973
               end)
skalberg@15531
   974
         | _ => NONE)
berghofe@10413
   975
wenzelm@15023
   976
    and impc ct ss =
wenzelm@15023
   977
      if mutsimp then mut_impc0 [] ct [] [] ss else nonmut_impc ct ss
berghofe@10413
   978
wenzelm@15023
   979
    and rules_of_prem ss prem =
berghofe@13607
   980
      if maxidx_of_term (term_of prem) <> ~1
berghofe@13607
   981
      then (trace_cterm true
skalberg@15531
   982
        "Cannot add premise as rewrite rule because it contains (type) unknowns:" prem; ([], NONE))
berghofe@13607
   983
      else
berghofe@13607
   984
        let val asm = assume prem
skalberg@15531
   985
        in (extract_safe_rrules (ss, asm), SOME asm) end
berghofe@10413
   986
wenzelm@15023
   987
    and add_rrules (rrss, asms) ss =
skalberg@15570
   988
      Library.foldl (insert_rrule true) (ss, List.concat rrss) |> add_prems (List.mapPartial I asms)
berghofe@10413
   989
berghofe@13607
   990
    and disch r (prem, eq) =
berghofe@13607
   991
      let
berghofe@13607
   992
        val (lhs, rhs) = dest_eq eq;
berghofe@13607
   993
        val eq' = implies_elim (Thm.instantiate
berghofe@13607
   994
          ([], [(cA, prem), (cB, lhs), (cC, rhs)]) Drule.imp_cong)
berghofe@13607
   995
          (implies_intr prem eq)
berghofe@13607
   996
      in if not r then eq' else
berghofe@10413
   997
        let
berghofe@13607
   998
          val (prem', concl) = dest_implies lhs;
berghofe@13607
   999
          val (prem'', _) = dest_implies rhs
berghofe@13607
  1000
        in transitive (transitive
berghofe@13607
  1001
          (Thm.instantiate ([], [(cA, prem'), (cB, prem), (cC, concl)])
berghofe@13607
  1002
             Drule.swap_prems_eq) eq')
berghofe@13607
  1003
          (Thm.instantiate ([], [(cA, prem), (cB, prem''), (cC, concl)])
berghofe@13607
  1004
             Drule.swap_prems_eq)
berghofe@10413
  1005
        end
berghofe@10413
  1006
      end
berghofe@10413
  1007
berghofe@13607
  1008
    and rebuild [] _ _ _ _ eq = eq
wenzelm@15023
  1009
      | rebuild (prem :: prems) concl (rrs :: rrss) (asm :: asms) ss eq =
berghofe@13607
  1010
          let
wenzelm@15023
  1011
            val ss' = add_rrules (rev rrss, rev asms) ss;
berghofe@13607
  1012
            val concl' =
skalberg@15570
  1013
              Drule.mk_implies (prem, getOpt (Option.map rhs_of eq, concl));
skalberg@15570
  1014
            val dprem = Option.map (curry (disch false) prem)
wenzelm@15023
  1015
          in case rewritec (prover, sign, maxidx) ss' concl' of
skalberg@15531
  1016
              NONE => rebuild prems concl' rrss asms ss (dprem eq)
skalberg@15570
  1017
            | SOME (eq', _) => transitive2 (Library.foldl (disch false o swap)
skalberg@15570
  1018
                  (valOf (transitive3 (dprem eq) eq'), prems))
wenzelm@15023
  1019
                (mut_impc0 (rev prems) (rhs_of eq') (rev rrss) (rev asms) ss)
berghofe@13607
  1020
          end
wenzelm@15023
  1021
wenzelm@15023
  1022
    and mut_impc0 prems concl rrss asms ss =
berghofe@13607
  1023
      let
berghofe@13607
  1024
        val prems' = strip_imp_prems concl;
wenzelm@15023
  1025
        val (rrss', asms') = split_list (map (rules_of_prem ss) prems')
berghofe@13607
  1026
      in mut_impc (prems @ prems') (strip_imp_concl concl) (rrss @ rrss')
wenzelm@15023
  1027
        (asms @ asms') [] [] [] [] ss ~1 ~1
berghofe@13607
  1028
      end
wenzelm@15023
  1029
wenzelm@15023
  1030
    and mut_impc [] concl [] [] prems' rrss' asms' eqns ss changed k =
skalberg@15570
  1031
        transitive1 (Library.foldl (fn (eq2, (eq1, prem)) => transitive1 eq1
skalberg@15570
  1032
            (Option.map (curry (disch false) prem) eq2)) (NONE, eqns ~~ prems'))
berghofe@13607
  1033
          (if changed > 0 then
berghofe@13607
  1034
             mut_impc (rev prems') concl (rev rrss') (rev asms')
wenzelm@15023
  1035
               [] [] [] [] ss ~1 changed
wenzelm@15023
  1036
           else rebuild prems' concl rrss' asms' ss
wenzelm@15023
  1037
             (botc skel0 (add_rrules (rev rrss', rev asms') ss) concl))
berghofe@13607
  1038
berghofe@13607
  1039
      | mut_impc (prem :: prems) concl (rrs :: rrss) (asm :: asms)
wenzelm@15023
  1040
          prems' rrss' asms' eqns ss changed k =
skalberg@15531
  1041
        case (if k = 0 then NONE else botc skel0 (add_rrules
wenzelm@15023
  1042
          (rev rrss' @ rrss, rev asms' @ asms) ss) prem) of
skalberg@15531
  1043
            NONE => mut_impc prems concl rrss asms (prem :: prems')
skalberg@15531
  1044
              (rrs :: rrss') (asm :: asms') (NONE :: eqns) ss changed
berghofe@13607
  1045
              (if k = 0 then 0 else k - 1)
skalberg@15531
  1046
          | SOME eqn =>
berghofe@13607
  1047
            let
berghofe@13607
  1048
              val prem' = rhs_of eqn;
berghofe@13607
  1049
              val tprems = map term_of prems;
skalberg@15570
  1050
              val i = 1 + Library.foldl Int.max (~1, map (fn p =>
berghofe@13607
  1051
                find_index_eq p tprems) (#hyps (rep_thm eqn)));
wenzelm@15023
  1052
              val (rrs', asm') = rules_of_prem ss prem'
berghofe@13607
  1053
            in mut_impc prems concl rrss asms (prem' :: prems')
skalberg@15574
  1054
              (rrs' :: rrss') (asm' :: asms') (SOME (foldr (disch true)
skalberg@15574
  1055
                (Drule.imp_cong' eqn (reflexive (Drule.list_implies
skalberg@15574
  1056
                  (Library.drop (i, prems), concl)))) (Library.take (i, prems))) :: eqns) ss (length prems') ~1
berghofe@13607
  1057
            end
berghofe@13607
  1058
wenzelm@15023
  1059
     (*legacy code - only for backwards compatibility*)
wenzelm@15023
  1060
     and nonmut_impc ct ss =
berghofe@13607
  1061
       let val (prem, conc) = dest_implies ct;
skalberg@15531
  1062
           val thm1 = if simprem then botc skel0 ss prem else NONE;
skalberg@15570
  1063
           val prem1 = getOpt (Option.map rhs_of thm1, prem);
wenzelm@15023
  1064
           val ss1 = if not useprem then ss else add_rrules
wenzelm@15023
  1065
             (apsnd single (apfst single (rules_of_prem ss prem1))) ss
wenzelm@15023
  1066
       in (case botc skel0 ss1 conc of
skalberg@15531
  1067
           NONE => (case thm1 of
skalberg@15531
  1068
               NONE => NONE
skalberg@15531
  1069
             | SOME thm1' => SOME (Drule.imp_cong' thm1' (reflexive conc)))
skalberg@15531
  1070
         | SOME thm2 =>
berghofe@13607
  1071
           let val thm2' = disch false (prem1, thm2)
berghofe@10413
  1072
           in (case thm1 of
skalberg@15531
  1073
               NONE => SOME thm2'
skalberg@15531
  1074
             | SOME thm1' =>
skalberg@15531
  1075
                 SOME (transitive (Drule.imp_cong' thm1' (reflexive conc)) thm2'))
berghofe@10413
  1076
           end)
berghofe@10413
  1077
       end
berghofe@10413
  1078
wenzelm@15023
  1079
 in try_botc end;
berghofe@10413
  1080
berghofe@10413
  1081
wenzelm@15023
  1082
(* Meta-rewriting: rewrites t to u and returns the theorem t==u *)
berghofe@10413
  1083
berghofe@10413
  1084
(*
berghofe@10413
  1085
  Parameters:
berghofe@10413
  1086
    mode = (simplify A,
berghofe@10413
  1087
            use A in simplifying B,
berghofe@10413
  1088
            use prems of B (if B is again a meta-impl.) to simplify A)
berghofe@10413
  1089
           when simplifying A ==> B
berghofe@10413
  1090
    prover: how to solve premises in conditional rewrites and congruences
berghofe@10413
  1091
*)
berghofe@10413
  1092
wenzelm@15023
  1093
fun rewrite_cterm mode prover ss ct =
nipkow@16042
  1094
  (simp_depth := !simp_depth + 1;
nipkow@16042
  1095
   if !simp_depth mod 10 = 0
nipkow@16042
  1096
   then warning ("Simplification depth " ^ string_of_int (!simp_depth))
nipkow@16042
  1097
   else ();
nipkow@16042
  1098
   trace_cterm false "SIMPLIFIER INVOKED ON THE FOLLOWING TERM:" ct;
nipkow@16042
  1099
   let val {sign, t, maxidx, ...} = Thm.rep_cterm ct
nipkow@16042
  1100
       val res = bottomc (mode, prover, sign, maxidx) ss ct
nipkow@16042
  1101
         handle THM (s, _, thms) =>
nipkow@16042
  1102
         error ("Exception THM was raised in simplifier:\n" ^ s ^ "\n" ^
nipkow@16042
  1103
           Pretty.string_of (Display.pretty_thms thms))
nipkow@16042
  1104
   in simp_depth := !simp_depth - 1; res end
nipkow@16378
  1105
  ) handle exn => (simp_depth := !simp_depth - 1; raise exn);
berghofe@10413
  1106
wenzelm@11760
  1107
(*Rewrite a cterm*)
wenzelm@11767
  1108
fun rewrite_aux _ _ [] = (fn ct => Thm.reflexive ct)
wenzelm@15023
  1109
  | rewrite_aux prover full thms =
wenzelm@15023
  1110
      rewrite_cterm (full, false, false) prover (empty_ss addsimps thms);
wenzelm@11672
  1111
berghofe@10413
  1112
(*Rewrite a theorem*)
wenzelm@11767
  1113
fun simplify_aux _ _ [] = (fn th => th)
wenzelm@11767
  1114
  | simplify_aux prover full thms =
wenzelm@15023
  1115
      Drule.fconv_rule (rewrite_cterm (full, false, false) prover (empty_ss addsimps thms));
berghofe@10413
  1116
wenzelm@15023
  1117
(*simple term rewriting -- no proof*)
wenzelm@15023
  1118
fun rewrite_term sg rules procs =
wenzelm@15023
  1119
  Pattern.rewrite_term (Sign.tsig_of sg) (map decomp_simp' rules) procs;
wenzelm@15023
  1120
wenzelm@15023
  1121
fun rewrite_thm mode prover ss = Drule.fconv_rule (rewrite_cterm mode prover ss);
berghofe@10413
  1122
berghofe@10413
  1123
(*Rewrite the subgoals of a proof state (represented by a theorem) *)
berghofe@10413
  1124
fun rewrite_goals_rule_aux _ []   th = th
berghofe@10413
  1125
  | rewrite_goals_rule_aux prover thms th =
skalberg@15001
  1126
      Drule.fconv_rule (Drule.goals_conv (K true) (rewrite_cterm (true, true, false) prover
wenzelm@15023
  1127
        (empty_ss addsimps thms))) th;
berghofe@10413
  1128
wenzelm@15023
  1129
(*Rewrite the subgoal of a proof state (represented by a theorem)*)
skalberg@15011
  1130
fun rewrite_goal_rule mode prover ss i thm =
berghofe@10413
  1131
  if 0 < i  andalso  i <= nprems_of thm
skalberg@15011
  1132
  then Drule.fconv_rule (Drule.goals_conv (fn j => j=i) (rewrite_cterm mode prover ss)) thm
berghofe@10413
  1133
  else raise THM("rewrite_goal_rule",i,[thm]);
berghofe@10413
  1134
wenzelm@15023
  1135
(*Rewrite subgoal i only.  SELECT_GOAL avoids inefficiencies in goals_conv.*)
wenzelm@15023
  1136
fun asm_rewrite_goal_tac mode prover_tac ss =
wenzelm@15023
  1137
  SELECT_GOAL
wenzelm@15023
  1138
    (PRIMITIVE (rewrite_goal_rule mode (SINGLE o prover_tac) ss 1));
wenzelm@12783
  1139
wenzelm@15023
  1140
skalberg@15006
  1141
wenzelm@15023
  1142
(** simplification tactics and rules **)
skalberg@15006
  1143
wenzelm@15023
  1144
fun solve_all_tac solvers ss =
skalberg@15006
  1145
  let
wenzelm@15023
  1146
    val Simpset (_, {subgoal_tac, ...}) = ss;
wenzelm@15023
  1147
    val solve_tac = subgoal_tac (set_solvers solvers ss) THEN_ALL_NEW (K no_tac);
wenzelm@15023
  1148
  in DEPTH_SOLVE (solve_tac 1) end;
skalberg@15006
  1149
wenzelm@15023
  1150
(*NOTE: may instantiate unknowns that appear also in other subgoals*)
wenzelm@15023
  1151
fun generic_simp_tac safe mode ss =
wenzelm@15023
  1152
  let
wenzelm@15023
  1153
    val Simpset ({prems, ...}, {loop_tacs, solvers = (unsafe_solvers, solvers), ...}) = ss;
wenzelm@15023
  1154
    val loop_tac = FIRST' (map #2 loop_tacs);
wenzelm@15023
  1155
    val solve_tac = FIRST' (map (solver prems) (if safe then solvers else unsafe_solvers));
skalberg@15006
  1156
wenzelm@15023
  1157
    fun simp_loop_tac i =
wenzelm@15023
  1158
      asm_rewrite_goal_tac mode (solve_all_tac unsafe_solvers) ss i THEN
wenzelm@15023
  1159
      (solve_tac i ORELSE TRY ((loop_tac THEN_ALL_NEW simp_loop_tac) i));
wenzelm@15023
  1160
  in simp_loop_tac end;
skalberg@15006
  1161
wenzelm@15023
  1162
fun simp rew mode ss thm =
skalberg@15006
  1163
  let
wenzelm@15023
  1164
    val Simpset (_, {solvers = (unsafe_solvers, _), ...}) = ss;
wenzelm@15023
  1165
    val tacf = solve_all_tac unsafe_solvers;
skalberg@15570
  1166
    fun prover s th = Option.map #1 (Seq.pull (tacf s th));
skalberg@15011
  1167
  in rew mode prover ss thm end;
skalberg@15006
  1168
skalberg@15006
  1169
val simp_thm = simp rewrite_thm;
skalberg@15006
  1170
val simp_cterm = simp rewrite_cterm;
skalberg@15006
  1171
berghofe@10413
  1172
end;
berghofe@10413
  1173
wenzelm@11672
  1174
structure BasicMetaSimplifier: BASIC_META_SIMPLIFIER = MetaSimplifier;
wenzelm@11672
  1175
open BasicMetaSimplifier;