wneuper/isa: src/Pure/simplifier.ML@36d0e00af606

     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 simpset_of: theory -> simpset

    13   val simpset: unit -> simpset

    14   val SIMPSET: (simpset -> tactic) -> tactic

    15   val SIMPSET': (simpset -> 'a -> tactic) -> 'a -> tactic

    16   val Addsimps: thm list -> unit

    17   val Delsimps: thm list -> unit

    18   val Addsimprocs: simproc list -> unit

    19   val Delsimprocs: simproc list -> unit

    20   val Addcongs: thm list -> unit

    21   val Delcongs: thm list -> unit

    22   val local_simpset_of: Proof.context -> simpset

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

    24   val safe_asm_full_simp_tac: simpset -> int -> tactic

    25   val               simp_tac: simpset -> int -> tactic

    26   val           asm_simp_tac: simpset -> int -> tactic

    27   val          full_simp_tac: simpset -> int -> tactic

    28   val        asm_lr_simp_tac: simpset -> int -> tactic

    29   val      asm_full_simp_tac: simpset -> int -> tactic

    30   val               Simp_tac:            int -> tactic

    31   val           Asm_simp_tac:            int -> tactic

    32   val          Full_simp_tac:            int -> tactic

    33   val        Asm_lr_simp_tac:            int -> tactic

    34   val      Asm_full_simp_tac:            int -> tactic

    35   val          simplify: simpset -> thm -> thm

    36   val      asm_simplify: simpset -> thm -> thm

    37   val     full_simplify: simpset -> thm -> thm

    38   val   asm_lr_simplify: simpset -> thm -> thm

    39   val asm_full_simplify: simpset -> thm -> thm

    40 end;

    42 signature SIMPLIFIER =

    43 sig

    44   include BASIC_SIMPLIFIER

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

    46   val clear_ss: simpset -> simpset

    47   val debug_bounds: bool ref

    48   val inherit_context: simpset -> simpset -> simpset

    49   val the_context: simpset -> Proof.context

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

    51   val theory_context: theory  -> simpset -> simpset

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

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

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

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

    56   val          rewrite: simpset -> conv

    57   val      asm_rewrite: simpset -> conv

    58   val     full_rewrite: simpset -> conv

    59   val   asm_lr_rewrite: simpset -> conv

    60   val asm_full_rewrite: simpset -> conv

    61   val get_ss: Context.generic -> simpset

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

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

    64   val simp_add: attribute

    65   val simp_del: attribute

    66   val cong_add: attribute

    67   val cong_del: attribute

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

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

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

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

    72     local_theory -> local_theory

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

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

    75     local_theory -> local_theory

    76   val cong_modifiers: (Args.T list -> (Method.modifier * Args.T list)) list

    77   val simp_modifiers': (Args.T list -> (Method.modifier * Args.T list)) list

    78   val simp_modifiers: (Args.T list -> (Method.modifier * Args.T list)) list

    79   val method_setup: (Args.T list -> (Method.modifier * Args.T list)) list

    80     -> theory -> theory

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

    82 end;

    84 structure Simplifier: SIMPLIFIER =

    85 struct

    87 open MetaSimplifier;

    90 (** pretty printing **)

    92 fun pretty_ss ctxt ss =

    93   let

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

    95     val pretty_thm = ProofContext.pretty_thm ctxt;

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

    97     fun pretty_cong (name, thm) =

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

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

   101   in

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

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

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

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

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

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

   108     |> Pretty.chunks

   109   end;

   113 (** simpset data **)

   115 structure SimpsetData = GenericDataFun

   116 (

   117   type T = simpset;

   118   val empty = empty_ss;

   119   fun extend ss = MetaSimplifier.inherit_context empty_ss ss;

   120   fun merge _ = merge_ss;

   121 );

   123 val get_ss = SimpsetData.get;

   124 val map_ss = SimpsetData.map;

   127 (* attributes *)

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

   131 val simp_add = attrib (op addsimps);

   132 val simp_del = attrib (op delsimps);

   133 val cong_add = attrib (op addcongs);

   134 val cong_del = attrib (op delcongs);

   137 (* global simpset *)

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

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

   141 fun simpset_of thy = MetaSimplifier.context (ProofContext.init thy) (get_ss (Context.Theory thy));

   142 val simpset = simpset_of o ML_Context.the_global_context;

   144 fun SIMPSET tacf st = tacf (simpset_of (Thm.theory_of_thm st)) st;

   145 fun SIMPSET' tacf i st = tacf (simpset_of (Thm.theory_of_thm st)) i st;

   147 fun Addsimps args = change_simpset (fn ss => ss addsimps args);

   148 fun Delsimps args = change_simpset (fn ss => ss delsimps args);

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

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

   151 fun Addcongs args = change_simpset (fn ss => ss addcongs args);

   152 fun Delcongs args = change_simpset (fn ss => ss delcongs args);

   155 (* local simpset *)

   157 fun local_simpset_of ctxt = MetaSimplifier.context ctxt (get_ss (Context.Proof ctxt));

   159 val _ = ML_Antiquote.value "simpset"

   160   (Scan.succeed "Simplifier.local_simpset_of (ML_Context.the_local_context ())");

   164 (** named simprocs **)

   166 fun err_dup_simproc name = error ("Duplicate simproc: " ^ quote name);

   169 (* data *)

   171 structure Simprocs = GenericDataFun

   172 (

   173   type T = simproc NameSpace.table;

   174   val empty = NameSpace.empty_table;

   175   val extend = I;

   176   fun merge _ simprocs = NameSpace.merge_tables eq_simproc simprocs

   177     handle Symtab.DUP dup => err_dup_simproc dup;

   178 );

   181 (* get simprocs *)

   183 fun get_simproc context xname =

   184   let

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

   186     val name = NameSpace.intern space xname;

   187   in

   188     (case Symtab.lookup tab name of

   189       SOME proc => proc

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

   191   end;

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

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

   197 (* define simprocs *)

   199 local

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

   202   let

   203     val b = Binding.name name;

   204     val naming = LocalTheory.full_naming lthy;

   205     val simproc = make_simproc

   206       {name = LocalTheory.full_name lthy b,

   207        lhss =

   208         let

   209           val lhss' = prep lthy lhss;

   210           val ctxt' = lthy

   211             |> fold Variable.declare_term lhss'

   212             |> fold Variable.auto_fixes lhss';

   213         in Variable.export_terms ctxt' lthy lhss' end

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

   215        proc = proc,

   216        identifier = identifier}

   217       |> morph_simproc (LocalTheory.target_morphism lthy);

   218   in

   219     lthy |> LocalTheory.declaration (fn phi =>

   220       let

   221         val b' = Morphism.binding phi b;

   222         val simproc' = morph_simproc phi simproc;

   223       in

   224         Simprocs.map (fn simprocs =>

   225           NameSpace.bind naming (b', simproc') simprocs |> snd

   226             handle Symtab.DUP dup => err_dup_simproc dup)

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

   228       end)

   229   end;

   231 in

   233 val def_simproc = gen_simproc Syntax.read_terms;

   234 val def_simproc_i = gen_simproc Syntax.check_terms;

   236 end;

   240 (** simplification tactics and rules **)

   242 fun solve_all_tac solvers ss =

   243   let

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

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

   246   in DEPTH_SOLVE (solve_tac 1) end;

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

   249 fun generic_simp_tac safe mode ss =

   250   let

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

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

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

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

   256     fun simp_loop_tac i =

   257       asm_rewrite_goal_tac mode (solve_all_tac unsafe_solvers) ss i THEN

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

   259   in simp_loop_tac end;

   261 local

   263 fun simp rew mode ss thm =

   264   let

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

   266     val tacf = solve_all_tac (rev unsafe_solvers);

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

   268   in rew mode prover ss thm end;

   270 in

   272 val simp_thm = simp MetaSimplifier.rewrite_thm;

   273 val simp_cterm = simp MetaSimplifier.rewrite_cterm;

   275 end;

   278 (* tactics *)

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

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

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

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

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

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

   287 (*the abstraction over the proof state delays the dereferencing*)

   288 fun          Simp_tac i st =          simp_tac (simpset ()) i st;

   289 fun      Asm_simp_tac i st =      asm_simp_tac (simpset ()) i st;

   290 fun     Full_simp_tac i st =     full_simp_tac (simpset ()) i st;

   291 fun   Asm_lr_simp_tac i st =   asm_lr_simp_tac (simpset ()) i st;

   292 fun Asm_full_simp_tac i st = asm_full_simp_tac (simpset ()) i st;

   295 (* conversions *)

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

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

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

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

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

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

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

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

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

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

   311 (** concrete syntax of attributes **)

   313 (* add / del *)

   315 val simpN = "simp";

   316 val congN = "cong";

   317 val addN = "add";

   318 val delN = "del";

   319 val onlyN = "only";

   320 val no_asmN = "no_asm";

   321 val no_asm_useN = "no_asm_use";

   322 val no_asm_simpN = "no_asm_simp";

   323 val asm_lrN = "asm_lr";

   326 (* simprocs *)

   328 local

   330 val add_del =

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

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

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

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

   336 in

   338 val simproc_att = Attrib.syntax

   339   (Scan.peek (fn context =>

   340     add_del :|-- (fn decl =>

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

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

   344 end;

   347 (* conversions *)

   349 local

   351 fun conv_mode x =

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

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

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

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

   357 in

   359 val simplified =

   360   Attrib.syntax (conv_mode -- Attrib.thms >> (fn (f, ths) => Thm.rule_attribute (fn context =>

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

   362         (local_simpset_of (Context.proof_of context)) addsimps ths))));

   364 end;

   367 (* setup attributes *)

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

   370  (Attrib.add_attributes

   371    [(simpN, Attrib.add_del_args simp_add simp_del, "declaration of Simplifier rewrite rule"),

   372     (congN, Attrib.add_del_args cong_add cong_del, "declaration of Simplifier congruence rule"),

   373     ("simproc", simproc_att, "declaration of simplification procedures"),

   374     ("simplified", simplified, "simplified rule")]));

   378 (** proof methods **)

   380 (* simplification *)

   382 val simp_options =

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

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

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

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

   387   Scan.succeed asm_full_simp_tac);

   389 val cong_modifiers =

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

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

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

   394 val simp_modifiers =

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

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

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

   398   Args.$$$ simpN -- Args.$$$ onlyN -- Args.colon

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

   400    @ cong_modifiers;

   402 val simp_modifiers' =

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

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

   405   Args.$$$ onlyN -- Args.colon

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

   407    @ cong_modifiers;

   409 fun simp_args more_mods =

   410   Method.sectioned_args (Args.bang_facts -- Scan.lift simp_options)

   411     (more_mods @ simp_modifiers');

   413 fun simp_method (prems, tac) ctxt = Method.METHOD (fn facts =>

   414   ALLGOALS (Method.insert_tac (prems @ facts)) THEN

   415     (CHANGED_PROP o ALLGOALS o tac) (local_simpset_of ctxt));

   417 fun simp_method' (prems, tac) ctxt = Method.METHOD (fn facts =>

   418   HEADGOAL (Method.insert_tac (prems @ facts) THEN'

   419       ((CHANGED_PROP) oo tac) (local_simpset_of ctxt)));

   423 (** setup **)

   425 fun method_setup more_mods = Method.add_methods

   426  [(simpN, simp_args more_mods simp_method', "simplification"),

   427   ("simp_all", simp_args more_mods simp_method, "simplification (all goals)")];

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

   430   let

   431     val trivialities = Drule.reflexive_thm :: trivs;

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

   434     val unsafe_solver = mk_solver "easy unsafe" unsafe_solver_tac;

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

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

   438     val safe_solver = mk_solver "easy safe" safe_solver_tac;

   440     fun mk_eq thm =

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

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

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

   445   in

   446     empty_ss setsubgoaler asm_simp_tac

   447     setSSolver safe_solver

   448     setSolver unsafe_solver

   449     setmksimps mksimps

   450   end));

   452 end;

   454 structure BasicSimplifier: BASIC_SIMPLIFIER = Simplifier;

   455 open BasicSimplifier;

author	wenzelm
	Sun, 08 Mar 2009 12:15:58 +0100
changeset 30356	36d0e00af606
parent 30342	efd1bec4630a
child 30466	5f31e24937c5
permissions	-rw-r--r--