wneuper/isa: src/Pure/simplifier.ML@a87ad4be59a4

     1 (*  Title:      Pure/simplifier.ML

     2     Author:     Tobias Nipkow and Markus Wenzel, TU Muenchen

     4 Generic simplifier, suitable for most logics (see also

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

     6 *)

     8 signature BASIC_SIMPLIFIER =

     9 sig

    10   include BASIC_META_SIMPLIFIER

    11   val change_simpset: (simpset -> simpset) -> unit

    12   val global_simpset_of: theory -> simpset

    13   val Addsimprocs: simproc list -> unit

    14   val Delsimprocs: simproc list -> unit

    15   val simpset_of: Proof.context -> simpset

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

    34   val clear_ss: simpset -> simpset

    35   val debug_bounds: bool Unsynchronized.ref

    36   val inherit_context: simpset -> simpset -> simpset

    37   val the_context: simpset -> Proof.context

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

    39   val theory_context: theory  -> simpset -> simpset

    40   val simproc_i: theory -> string -> term list

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

    42   val simproc: theory -> string -> string list

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

    44   val          rewrite: simpset -> conv

    45   val      asm_rewrite: simpset -> conv

    46   val     full_rewrite: simpset -> conv

    47   val   asm_lr_rewrite: simpset -> conv

    48   val asm_full_rewrite: simpset -> conv

    49   val get_ss: Context.generic -> simpset

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

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

    52   val simp_add: attribute

    53   val simp_del: attribute

    54   val cong_add: attribute

    55   val cong_del: attribute

    56   val map_simpset: (simpset -> simpset) -> theory -> theory

    57   val get_simproc: Context.generic -> xstring -> simproc

    58   val def_simproc: {name: string, lhss: string list,

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

    60     local_theory -> local_theory

    61   val def_simproc_i: {name: string, lhss: term list,

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

    63     local_theory -> local_theory

    64   val cong_modifiers: Method.modifier parser list

    65   val simp_modifiers': Method.modifier parser list

    66   val simp_modifiers: Method.modifier parser list

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

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

    69 end;

    71 structure Simplifier: SIMPLIFIER =

    72 struct

    74 open MetaSimplifier;

    77 (** pretty printing **)

    79 fun pretty_ss ctxt ss =

    80   let

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

    82     val pretty_thm = Display.pretty_thm ctxt;

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

    84     fun pretty_cong (name, thm) =

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

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

    88   in

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

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

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

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

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

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

    95     |> Pretty.chunks

    96   end;

   100 (** simpset data **)

   102 structure SimpsetData = Generic_Data

   103 (

   104   type T = simpset;

   105   val empty = empty_ss;

   106   fun extend ss = MetaSimplifier.inherit_context empty_ss ss;

   107   val merge = merge_ss;

   108 );

   110 val get_ss = SimpsetData.get;

   111 val map_ss = SimpsetData.map;

   114 (* attributes *)

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

   118 val simp_add = attrib (op addsimps);

   119 val simp_del = attrib (op delsimps);

   120 val cong_add = attrib (op addcongs);

   121 val cong_del = attrib (op delcongs);

   124 (* global simpset *)

   126 fun map_simpset f = Context.theory_map (map_ss f);

   127 fun change_simpset f = Context.>> (Context.map_theory (map_simpset f));

   128 fun global_simpset_of thy =

   129   MetaSimplifier.context (ProofContext.init thy) (get_ss (Context.Theory thy));

   131 fun Addsimprocs args = change_simpset (fn ss => ss addsimprocs args);

   132 fun Delsimprocs args = change_simpset (fn ss => ss delsimprocs args);

   135 (* local simpset *)

   137 fun simpset_of ctxt = MetaSimplifier.context ctxt (get_ss (Context.Proof ctxt));

   139 val _ = ML_Antiquote.value "simpset"

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

   144 (** named simprocs **)

   146 (* data *)

   148 structure Simprocs = Generic_Data

   149 (

   150   type T = simproc Name_Space.table;

   151   val empty : T = Name_Space.empty_table "simproc";

   152   val extend = I;

   153   fun merge simprocs = Name_Space.merge_tables simprocs;

   154 );

   157 (* get simprocs *)

   159 fun get_simproc context xname =

   160   let

   161     val (space, tab) = Simprocs.get context;

   162     val name = Name_Space.intern space xname;

   163   in

   164     (case Symtab.lookup tab name of

   165       SOME proc => proc

   166     | NONE => error ("Undefined simplification procedure: " ^ quote name))

   167   end;

   169 val _ = ML_Antiquote.value "simproc" (Scan.lift Args.name >> (fn name =>

   170   "Simplifier.get_simproc (ML_Context.the_generic_context ()) " ^ ML_Syntax.print_string name));

   173 (* define simprocs *)

   175 local

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

   178   let

   179     val b = Binding.name name;

   180     val naming = Local_Theory.naming_of lthy;

   181     val simproc = make_simproc

   182       {name = Name_Space.full_name naming b,

   183        lhss =

   184         let

   185           val lhss' = prep lthy lhss;

   186           val ctxt' = lthy

   187             |> fold Variable.declare_term lhss'

   188             |> fold Variable.auto_fixes lhss';

   189         in Variable.export_terms ctxt' lthy lhss' end

   190         |> map (Thm.cterm_of (ProofContext.theory_of lthy)),

   191        proc = proc,

   192        identifier = identifier};

   193   in

   194     lthy |> Local_Theory.declaration false (fn phi =>

   195       let

   196         val b' = Morphism.binding phi b;

   197         val simproc' = morph_simproc phi simproc;

   198       in

   199         Simprocs.map (#2 o Name_Space.define true naming (b', simproc'))

   200         #> map_ss (fn ss => ss addsimprocs [simproc'])

   201       end)

   202   end;

   204 in

   206 val def_simproc = gen_simproc Syntax.read_terms;

   207 val def_simproc_i = gen_simproc Syntax.check_terms;

   209 end;

   213 (** simplification tactics and rules **)

   215 fun solve_all_tac solvers ss =

   216   let

   217     val (_, {subgoal_tac, ...}) = MetaSimplifier.internal_ss ss;

   218     val solve_tac = subgoal_tac (MetaSimplifier.set_solvers solvers ss) THEN_ALL_NEW (K no_tac);

   219   in DEPTH_SOLVE (solve_tac 1) end;

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

   222 fun generic_simp_tac safe mode ss =

   223   let

   224     val (_, {loop_tacs, solvers = (unsafe_solvers, solvers), ...}) = MetaSimplifier.internal_ss ss;

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

   226     val solve_tac = FIRST' (map (MetaSimplifier.solver ss)

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

   229     fun simp_loop_tac i =

   230       asm_rewrite_goal_tac mode (solve_all_tac unsafe_solvers) ss i THEN

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

   232   in simp_loop_tac end;

   234 local

   236 fun simp rew mode ss thm =

   237   let

   238     val (_, {solvers = (unsafe_solvers, _), ...}) = MetaSimplifier.internal_ss ss;

   239     val tacf = solve_all_tac (rev unsafe_solvers);

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

   241   in rew mode prover ss thm end;

   243 in

   245 val simp_thm = simp MetaSimplifier.rewrite_thm;

   246 val simp_cterm = simp MetaSimplifier.rewrite_cterm;

   248 end;

   251 (* tactics *)

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

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

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

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

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

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

   261 (* conversions *)

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

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

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

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

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

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

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

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

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

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

   277 (** concrete syntax of attributes **)

   279 (* add / del *)

   281 val simpN = "simp";

   282 val congN = "cong";

   283 val onlyN = "only";

   284 val no_asmN = "no_asm";

   285 val no_asm_useN = "no_asm_use";

   286 val no_asm_simpN = "no_asm_simp";

   287 val asm_lrN = "asm_lr";

   290 (* simprocs *)

   292 local

   294 val add_del =

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

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

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

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

   300 in

   302 val simproc_att =

   303   Scan.peek (fn context =>

   304     add_del :|-- (fn decl =>

   305       Scan.repeat1 (Args.named_attribute (decl o get_simproc context))

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

   308 end;

   311 (* conversions *)

   313 local

   315 fun conv_mode x =

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

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

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

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

   321 in

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

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

   325     f ((if null ths then I else MetaSimplifier.clear_ss)

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

   328 end;

   331 (* setup attributes *)

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

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

   335     "declaration of Simplifier rewrite rule" #>

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

   337     "declaration of Simplifier congruence rule" #>

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

   339     "declaration of simplification procedures" #>

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

   344 (** method syntax **)

   346 val cong_modifiers =

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

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

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

   351 val simp_modifiers =

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

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

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

   355   Args.$$$ simpN -- Args.$$$ onlyN -- Args.colon

   356     >> K (Context.proof_map (map_ss MetaSimplifier.clear_ss), simp_add)]

   357    @ cong_modifiers;

   359 val simp_modifiers' =

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

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

   362   Args.$$$ onlyN -- Args.colon

   363     >> K (Context.proof_map (map_ss MetaSimplifier.clear_ss), simp_add)]

   364    @ cong_modifiers;

   366 val simp_options =

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

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

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

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

   371   Scan.succeed asm_full_simp_tac);

   373 fun simp_method more_mods meth =

   374   Args.bang_facts -- Scan.lift simp_options --|

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

   376     (fn (prems, tac) => fn ctxt => METHOD (fn facts => meth ctxt tac (prems @ facts)));

   380 (** setup **)

   382 fun method_setup more_mods =

   383   Method.setup (Binding.name simpN)

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

   385       HEADGOAL (Method.insert_tac facts THEN'

   386         (CHANGED_PROP oo tac) (simpset_of ctxt))))

   387     "simplification" #>

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

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

   390       ALLGOALS (Method.insert_tac facts) THEN

   391         (CHANGED_PROP o ALLGOALS o tac) (simpset_of ctxt)))

   392     "simplification (all goals)";

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

   395   let

   396     val trivialities = Drule.reflexive_thm :: trivs;

   398     fun unsafe_solver_tac prems = FIRST' [resolve_tac (trivialities @ prems), assume_tac];

   399     val unsafe_solver = mk_solver "easy unsafe" unsafe_solver_tac;

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

   402     fun safe_solver_tac prems = FIRST' [match_tac (trivialities @ prems), eq_assume_tac];

   403     val safe_solver = mk_solver "easy safe" safe_solver_tac;

   405     fun mk_eq thm =

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

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

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

   410   in

   411     empty_ss setsubgoaler asm_simp_tac

   412     setSSolver safe_solver

   413     setSolver unsafe_solver

   414     setmksimps mksimps

   415   end));

   417 end;

   419 structure Basic_Simplifier: BASIC_SIMPLIFIER = Simplifier;

   420 open Basic_Simplifier;

author	wenzelm
	Tue, 24 Nov 2009 17:54:33 +0100
changeset 33890	a87ad4be59a4
parent 33673	4b0f2599ed48
child 35232	f588e1169c8b
permissions	-rw-r--r--