wneuper/isa: src/Pure/simplifier.ML@b4a093e755db

     1 (*  Title:      Pure/simplifier.ML

     2     Author:     Tobias Nipkow and Markus Wenzel, TU Muenchen

     4 Generic simplifier, suitable for most logics (see also

     5 raw_simplifier.ML for the actual meta-level rewriting engine).

     6 *)

     8 signature BASIC_SIMPLIFIER =

     9 sig

    10   include BASIC_RAW_SIMPLIFIER

    11   val map_simpset: (simpset -> simpset) -> Proof.context -> Proof.context

    12   val simpset_of: Proof.context -> simpset

    13   val global_simpset_of: theory -> simpset

    14   val Addsimprocs: simproc list -> unit

    15   val Delsimprocs: simproc list -> unit

    16   val generic_simp_tac: bool -> bool * bool * bool -> simpset -> int -> tactic

    17   val safe_asm_full_simp_tac: simpset -> int -> tactic

    18   val simp_tac: simpset -> int -> tactic

    19   val asm_simp_tac: simpset -> int -> tactic

    20   val full_simp_tac: simpset -> int -> tactic

    21   val asm_lr_simp_tac: simpset -> int -> tactic

    22   val asm_full_simp_tac: simpset -> int -> tactic

    23   val simplify: simpset -> thm -> thm

    24   val asm_simplify: simpset -> thm -> thm

    25   val full_simplify: simpset -> thm -> thm

    26   val asm_lr_simplify: simpset -> thm -> thm

    27   val asm_full_simplify: simpset -> thm -> thm

    28 end;

    30 signature SIMPLIFIER =

    31 sig

    32   include BASIC_SIMPLIFIER

    33   val map_simpset_global: (simpset -> simpset) -> theory -> theory

    34   val pretty_ss: Proof.context -> simpset -> Pretty.T

    35   val clear_ss: simpset -> simpset

    36   val debug_bounds: bool Unsynchronized.ref

    37   val prems_of: simpset -> thm list

    38   val add_simp: thm -> simpset -> simpset

    39   val del_simp: thm -> simpset -> simpset

    40   val add_prems: thm list -> simpset -> simpset

    41   val inherit_context: simpset -> simpset -> simpset

    42   val the_context: simpset -> Proof.context

    43   val context: Proof.context -> simpset -> simpset

    44   val global_context: theory -> simpset -> simpset

    45   val with_context: Proof.context -> (simpset -> simpset) -> simpset -> simpset

    46   val simproc_global_i: theory -> string -> term list ->

    47     (theory -> simpset -> term -> thm option) -> simproc

    48   val simproc_global: theory -> string -> string list ->

    49     (theory -> simpset -> term -> thm option) -> simproc

    50   val rewrite: simpset -> conv

    51   val asm_rewrite: simpset -> conv

    52   val full_rewrite: simpset -> conv

    53   val asm_lr_rewrite: simpset -> conv

    54   val asm_full_rewrite: simpset -> conv

    55   val get_ss: Context.generic -> simpset

    56   val map_ss: (simpset -> simpset) -> Context.generic -> Context.generic

    57   val attrib: (simpset * thm list -> simpset) -> attribute

    58   val simp_add: attribute

    59   val simp_del: attribute

    60   val cong_add: attribute

    61   val cong_del: attribute

    62   val check_simproc: Proof.context -> xstring * Position.T -> string

    63   val the_simproc: Proof.context -> string -> simproc

    64   val def_simproc: {name: binding, lhss: term list,

    65     proc: morphism -> simpset -> cterm -> thm option, identifier: thm list} ->

    66     local_theory -> local_theory

    67   val def_simproc_cmd: {name: binding, lhss: string list,

    68     proc: morphism -> simpset -> cterm -> thm option, identifier: thm list} ->

    69     local_theory -> local_theory

    70   val cong_modifiers: Method.modifier parser list

    71   val simp_modifiers': Method.modifier parser list

    72   val simp_modifiers: Method.modifier parser list

    73   val method_setup: Method.modifier parser list -> theory -> theory

    74   val easy_setup: thm -> thm list -> theory -> theory

    75 end;

    77 structure Simplifier: SIMPLIFIER =

    78 struct

    80 open Raw_Simplifier;

    83 (** data **)

    85 structure Data = Generic_Data

    86 (

    87   type T = simpset * simproc Name_Space.table;

    88   val empty : T = (empty_ss, Name_Space.empty_table "simproc");

    89   fun extend (ss, tab) = (Raw_Simplifier.inherit_context empty_ss ss, tab);

    90   fun merge ((ss1, tab1), (ss2, tab2)) =

    91     (merge_ss (ss1, ss2), Name_Space.merge_tables (tab1, tab2));

    92 );

    94 val get_ss = fst o Data.get;

    96 fun map_ss f context =

    97   Data.map (apfst ((Raw_Simplifier.with_context (Context.proof_of context) f))) context;

    99 val get_simprocs = snd o Data.get o Context.Proof;

   103 (** pretty printing **)

   105 fun pretty_ss ctxt ss =

   106   let

   107     val pretty_cterm = Syntax.pretty_term ctxt o Thm.term_of;

   108     val pretty_thm = Display.pretty_thm ctxt;

   109     fun pretty_proc (name, lhss) = Pretty.big_list (name ^ ":") (map pretty_cterm lhss);

   110     fun pretty_cong (name, thm) =

   111       Pretty.block [Pretty.str (name ^ ":"), Pretty.brk 1, pretty_thm thm];

   113     val {simps, procs, congs, loopers, unsafe_solvers, safe_solvers, ...} = dest_ss ss;

   114   in

   115     [Pretty.big_list "simplification rules:" (map (pretty_thm o #2) simps),

   116       Pretty.big_list "simplification procedures:" (map pretty_proc (sort_wrt #1 procs)),

   117       Pretty.big_list "congruences:" (map pretty_cong congs),

   118       Pretty.strs ("loopers:" :: map quote loopers),

   119       Pretty.strs ("unsafe solvers:" :: map quote unsafe_solvers),

   120       Pretty.strs ("safe solvers:" :: map quote safe_solvers)]

   121     |> Pretty.chunks

   122   end;

   126 (** simpset data **)

   128 (* attributes *)

   130 fun attrib f = Thm.declaration_attribute (fn th => map_ss (fn ss => f (ss, [th])));

   132 val simp_add = attrib (op addsimps);

   133 val simp_del = attrib (op delsimps);

   134 val cong_add = attrib (op addcongs);

   135 val cong_del = attrib (op delcongs);

   138 (* local simpset *)

   140 fun map_simpset f = Context.proof_map (map_ss f);

   141 fun simpset_of ctxt = Raw_Simplifier.context ctxt (get_ss (Context.Proof ctxt));

   143 val _ = Context.>> (Context.map_theory

   144   (ML_Antiquote.value (Binding.name "simpset")

   145     (Scan.succeed "Simplifier.simpset_of (ML_Context.the_local_context ())")));

   148 (* global simpset *)

   150 fun map_simpset_global f = Context.theory_map (map_ss f);

   151 fun global_simpset_of thy =

   152   Raw_Simplifier.context (Proof_Context.init_global thy) (get_ss (Context.Theory thy));

   154 fun Addsimprocs args = Context.>> (map_ss (fn ss => ss addsimprocs args));

   155 fun Delsimprocs args = Context.>> (map_ss (fn ss => ss delsimprocs args));

   159 (** named simprocs **)

   161 (* get simprocs *)

   163 fun check_simproc ctxt = Name_Space.check ctxt (get_simprocs ctxt) #> #1;

   164 val the_simproc = Name_Space.get o get_simprocs;

   166 val _ =

   167   Context.>> (Context.map_theory

   168    (ML_Antiquote.value (Binding.name "simproc")

   169       (Args.context -- Scan.lift (Parse.position Args.name)

   170         >> (fn (ctxt, name) =>

   171           "Simplifier.the_simproc (ML_Context.the_local_context ()) " ^

   172             ML_Syntax.print_string (check_simproc ctxt name)))));

   175 (* define simprocs *)

   177 local

   179 fun gen_simproc prep {name = b, lhss, proc, identifier} lthy =

   180   let

   181     val naming = Local_Theory.naming_of lthy;

   182     val simproc = make_simproc

   183       {name = Name_Space.full_name naming b,

   184        lhss =

   185         let

   186           val lhss' = prep lthy lhss;

   187           val ctxt' = lthy

   188             |> fold Variable.declare_term lhss'

   189             |> fold Variable.auto_fixes lhss';

   190         in Variable.export_terms ctxt' lthy lhss' end

   191         |> map (Thm.cterm_of (Proof_Context.theory_of lthy)),

   192        proc = proc,

   193        identifier = identifier};

   194   in

   195     lthy |> Local_Theory.declaration false (fn phi => fn context =>

   196       let

   197         val b' = Morphism.binding phi b;

   198         val simproc' = morph_simproc phi simproc;

   199       in

   200         context

   201         |> Data.map (fn (ss, tab) =>

   202           (ss addsimprocs [simproc'],

   203             #2 (Name_Space.define (Context.proof_of context) true naming (b', simproc') tab)))

   204       end)

   205   end;

   207 in

   209 val def_simproc = gen_simproc Syntax.check_terms;

   210 val def_simproc_cmd = gen_simproc Syntax.read_terms;

   212 end;

   216 (** simplification tactics and rules **)

   218 fun solve_all_tac solvers ss =

   219   let

   220     val (_, {subgoal_tac, ...}) = Raw_Simplifier.internal_ss ss;

   221     val solve_tac = subgoal_tac (Raw_Simplifier.set_solvers solvers ss) THEN_ALL_NEW (K no_tac);

   222   in DEPTH_SOLVE (solve_tac 1) end;

   224 (*NOTE: may instantiate unknowns that appear also in other subgoals*)

   225 fun generic_simp_tac safe mode ss =

   226   let

   227     val (_, {loop_tacs, solvers = (unsafe_solvers, solvers), ...}) = Raw_Simplifier.internal_ss ss;

   228     val loop_tac = FIRST' (map (fn (_, tac) => tac ss) (rev loop_tacs));

   229     val solve_tac = FIRST' (map (Raw_Simplifier.solver ss)

   230       (rev (if safe then solvers else unsafe_solvers)));

   232     fun simp_loop_tac i =

   233       Raw_Simplifier.asm_rewrite_goal_tac mode (solve_all_tac unsafe_solvers) ss i THEN

   234       (solve_tac i ORELSE TRY ((loop_tac THEN_ALL_NEW simp_loop_tac) i));

   235   in simp_loop_tac end;

   237 local

   239 fun simp rew mode ss thm =

   240   let

   241     val (_, {solvers = (unsafe_solvers, _), ...}) = Raw_Simplifier.internal_ss ss;

   242     val tacf = solve_all_tac (rev unsafe_solvers);

   243     fun prover s th = Option.map #1 (Seq.pull (tacf s th));

   244   in rew mode prover ss thm end;

   246 in

   248 val simp_thm = simp Raw_Simplifier.rewrite_thm;

   249 val simp_cterm = simp Raw_Simplifier.rewrite_cterm;

   251 end;

   254 (* tactics *)

   256 val simp_tac = generic_simp_tac false (false, false, false);

   257 val asm_simp_tac = generic_simp_tac false (false, true, false);

   258 val full_simp_tac = generic_simp_tac false (true, false, false);

   259 val asm_lr_simp_tac = generic_simp_tac false (true, true, false);

   260 val asm_full_simp_tac = generic_simp_tac false (true, true, true);

   261 val safe_asm_full_simp_tac = generic_simp_tac true (true, true, true);

   264 (* conversions *)

   266 val          simplify = simp_thm (false, false, false);

   267 val      asm_simplify = simp_thm (false, true, false);

   268 val     full_simplify = simp_thm (true, false, false);

   269 val   asm_lr_simplify = simp_thm (true, true, false);

   270 val asm_full_simplify = simp_thm (true, true, true);

   272 val          rewrite = simp_cterm (false, false, false);

   273 val      asm_rewrite = simp_cterm (false, true, false);

   274 val     full_rewrite = simp_cterm (true, false, false);

   275 val   asm_lr_rewrite = simp_cterm (true, true, false);

   276 val asm_full_rewrite = simp_cterm (true, true, true);

   280 (** concrete syntax of attributes **)

   282 (* add / del *)

   284 val simpN = "simp";

   285 val congN = "cong";

   286 val onlyN = "only";

   287 val no_asmN = "no_asm";

   288 val no_asm_useN = "no_asm_use";

   289 val no_asm_simpN = "no_asm_simp";

   290 val asm_lrN = "asm_lr";

   293 (* simprocs *)

   295 local

   297 val add_del =

   298   (Args.del -- Args.colon >> K (op delsimprocs) ||

   299     Scan.option (Args.add -- Args.colon) >> K (op addsimprocs))

   300   >> (fn f => fn simproc => fn phi => Thm.declaration_attribute

   301       (K (map_ss (fn ss => f (ss, [morph_simproc phi simproc])))));

   303 in

   305 val simproc_att =

   306   (Args.context -- Scan.lift add_del) :|-- (fn (ctxt, decl) =>

   307     Scan.repeat1 (Scan.lift (Args.named_attribute (decl o the_simproc ctxt o check_simproc ctxt))))

   308   >> (Library.apply o map Morphism.form);

   310 end;

   313 (* conversions *)

   315 local

   317 fun conv_mode x =

   318   ((Args.parens (Args.$$$ no_asmN) >> K simplify ||

   319     Args.parens (Args.$$$ no_asm_simpN) >> K asm_simplify ||

   320     Args.parens (Args.$$$ no_asm_useN) >> K full_simplify ||

   321     Scan.succeed asm_full_simplify) |> Scan.lift) x;

   323 in

   325 val simplified = conv_mode -- Attrib.thms >>

   326   (fn (f, ths) => Thm.rule_attribute (fn context =>

   327     f ((if null ths then I else Raw_Simplifier.clear_ss)

   328         (simpset_of (Context.proof_of context)) addsimps ths)));

   330 end;

   333 (* setup attributes *)

   335 val _ = Context.>> (Context.map_theory

   336  (Attrib.setup (Binding.name simpN) (Attrib.add_del simp_add simp_del)

   337     "declaration of Simplifier rewrite rule" #>

   338   Attrib.setup (Binding.name congN) (Attrib.add_del cong_add cong_del)

   339     "declaration of Simplifier congruence rule" #>

   340   Attrib.setup (Binding.name "simproc") simproc_att

   341     "declaration of simplification procedures" #>

   342   Attrib.setup (Binding.name "simplified") simplified "simplified rule"));

   346 (** method syntax **)

   348 val cong_modifiers =

   349  [Args.$$$ congN -- Args.colon >> K ((I, cong_add): Method.modifier),

   350   Args.$$$ congN -- Args.add -- Args.colon >> K (I, cong_add),

   351   Args.$$$ congN -- Args.del -- Args.colon >> K (I, cong_del)];

   353 val simp_modifiers =

   354  [Args.$$$ simpN -- Args.colon >> K (I, simp_add),

   355   Args.$$$ simpN -- Args.add -- Args.colon >> K (I, simp_add),

   356   Args.$$$ simpN -- Args.del -- Args.colon >> K (I, simp_del),

   357   Args.$$$ simpN -- Args.$$$ onlyN -- Args.colon

   358     >> K (Context.proof_map (map_ss Raw_Simplifier.clear_ss), simp_add)]

   359    @ cong_modifiers;

   361 val simp_modifiers' =

   362  [Args.add -- Args.colon >> K (I, simp_add),

   363   Args.del -- Args.colon >> K (I, simp_del),

   364   Args.$$$ onlyN -- Args.colon

   365     >> K (Context.proof_map (map_ss Raw_Simplifier.clear_ss), simp_add)]

   366    @ cong_modifiers;

   368 val simp_options =

   369  (Args.parens (Args.$$$ no_asmN) >> K simp_tac ||

   370   Args.parens (Args.$$$ no_asm_simpN) >> K asm_simp_tac ||

   371   Args.parens (Args.$$$ no_asm_useN) >> K full_simp_tac ||

   372   Args.parens (Args.$$$ asm_lrN) >> K asm_lr_simp_tac ||

   373   Scan.succeed asm_full_simp_tac);

   375 fun simp_method more_mods meth =

   376   Scan.lift simp_options --|

   377     Method.sections (more_mods @ simp_modifiers') >>

   378     (fn tac => fn ctxt => METHOD (fn facts => meth ctxt tac facts));

   382 (** setup **)

   384 fun method_setup more_mods =

   385   Method.setup (Binding.name simpN)

   386     (simp_method more_mods (fn ctxt => fn tac => fn facts =>

   387       HEADGOAL (Method.insert_tac facts THEN'

   388         (CHANGED_PROP oo tac) (simpset_of ctxt))))

   389     "simplification" #>

   390   Method.setup (Binding.name "simp_all")

   391     (simp_method more_mods (fn ctxt => fn tac => fn facts =>

   392       ALLGOALS (Method.insert_tac facts) THEN

   393         (CHANGED_PROP o PARALLEL_GOALS o ALLGOALS o tac) (simpset_of ctxt)))

   394     "simplification (all goals)";

   396 fun easy_setup reflect trivs = method_setup [] #> Context.theory_map (map_ss (fn _ =>

   397   let

   398     val trivialities = Drule.reflexive_thm :: trivs;

   400     fun unsafe_solver_tac ss =

   401       FIRST' [resolve_tac (trivialities @ Raw_Simplifier.prems_of ss), assume_tac];

   402     val unsafe_solver = mk_solver "easy unsafe" unsafe_solver_tac;

   404     (*no premature instantiation of variables during simplification*)

   405     fun safe_solver_tac ss =

   406       FIRST' [match_tac (trivialities @ Raw_Simplifier.prems_of ss), eq_assume_tac];

   407     val safe_solver = mk_solver "easy safe" safe_solver_tac;

   409     fun mk_eq thm =

   410       if can Logic.dest_equals (Thm.concl_of thm) then [thm]

   411       else [thm RS reflect] handle THM _ => [];

   413     fun mksimps thm = mk_eq (Thm.forall_elim_vars (#maxidx (Thm.rep_thm thm) + 1) thm);

   414   in

   415     empty_ss setsubgoaler asm_simp_tac

   416     setSSolver safe_solver

   417     setSolver unsafe_solver

   418     setmksimps (K mksimps)

   419   end));

   421 end;

   423 structure Basic_Simplifier: BASIC_SIMPLIFIER = Simplifier;

   424 open Basic_Simplifier;

author	wenzelm
	Wed, 29 Jun 2011 21:34:16 +0200
changeset 44470	b4a093e755db
parent 44469	78211f66cf8d
child 44937	ae85c5d64913
permissions	-rw-r--r--