wneuper/isa: src/Pure/simplifier.ML@421760a1efe7

     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_eqcong: thm -> simpset -> simpset

    41   val del_eqcong: thm -> simpset -> simpset

    42   val add_cong: thm -> simpset -> simpset

    43   val del_cong: thm -> simpset -> simpset

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

    45   val mksimps: simpset -> thm -> thm list

    46   val set_mksimps: (simpset -> thm -> thm list) -> simpset -> simpset

    47   val set_mkcong: (simpset -> thm -> thm) -> simpset -> simpset

    48   val set_mksym: (simpset -> thm -> thm option) -> simpset -> simpset

    49   val set_mkeqTrue: (simpset -> thm -> thm option) -> simpset -> simpset

    50   val set_termless: (term * term -> bool) -> simpset -> simpset

    51   val set_subgoaler: (simpset -> int -> tactic) -> simpset -> simpset

    52   val inherit_context: simpset -> simpset -> simpset

    53   val the_context: simpset -> Proof.context

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

    55   val global_context: theory -> simpset -> simpset

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

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

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

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

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

    61   val rewrite: simpset -> conv

    62   val asm_rewrite: simpset -> conv

    63   val full_rewrite: simpset -> conv

    64   val asm_lr_rewrite: simpset -> conv

    65   val asm_full_rewrite: simpset -> conv

    66   val get_ss: Context.generic -> simpset

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

    68   val attrib: (thm -> simpset -> simpset) -> attribute

    69   val simp_add: attribute

    70   val simp_del: attribute

    71   val cong_add: attribute

    72   val cong_del: attribute

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

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

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

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

    77     local_theory -> local_theory

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

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

    80     local_theory -> local_theory

    81   val cong_modifiers: Method.modifier parser list

    82   val simp_modifiers': Method.modifier parser list

    83   val simp_modifiers: Method.modifier parser list

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

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

    86 end;

    88 structure Simplifier: SIMPLIFIER =

    89 struct

    91 open Raw_Simplifier;

    94 (** data **)

    96 structure Data = Generic_Data

    97 (

    98   type T = simpset * simproc Name_Space.table;

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

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

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

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

   103 );

   105 val get_ss = fst o Data.get;

   107 fun map_ss f context =

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

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

   114 (** pretty printing **)

   116 fun pretty_ss ctxt ss =

   117   let

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

   119     val pretty_thm = Display.pretty_thm ctxt;

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

   121     fun pretty_cong (name, thm) =

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

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

   125   in

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

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

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

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

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

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

   132     |> Pretty.chunks

   133   end;

   137 (** simpset data **)

   139 (* attributes *)

   141 fun attrib f = Thm.declaration_attribute (map_ss o f);

   143 val simp_add = attrib add_simp;

   144 val simp_del = attrib del_simp;

   145 val cong_add = attrib add_cong;

   146 val cong_del = attrib del_cong;

   149 (* local simpset *)

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

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

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

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

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

   159 (* global simpset *)

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

   162 fun global_simpset_of thy =

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

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

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

   170 (** named simprocs **)

   172 (* get simprocs *)

   174 fun check_simproc ctxt = Name_Space.check (Context.Proof ctxt) (get_simprocs ctxt) #> #1;

   175 val the_simproc = Name_Space.get o get_simprocs;

   177 val _ =

   178   Context.>> (Context.map_theory

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

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

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

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

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

   186 (* define simprocs *)

   188 local

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

   191   let

   192     val simproc = make_simproc

   193       {name = Local_Theory.full_name lthy b,

   194        lhss =

   195         let

   196           val lhss' = prep lthy lhss;

   197           val ctxt' = fold Variable.auto_fixes lhss' lthy;

   198         in Variable.export_terms ctxt' lthy lhss' end

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

   200        proc = proc,

   201        identifier = identifier};

   202   in

   203     lthy |> Local_Theory.declaration {syntax = false, pervasive = true} (fn phi => fn context =>

   204       let

   205         val b' = Morphism.binding phi b;

   206         val simproc' = transform_simproc phi simproc;

   207       in

   208         context

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

   210           (ss addsimprocs [simproc'], #2 (Name_Space.define context true (b', simproc') tab)))

   211       end)

   212   end;

   214 in

   216 val def_simproc = gen_simproc Syntax.check_terms;

   217 val def_simproc_cmd = gen_simproc Syntax.read_terms;

   219 end;

   223 (** simplification tactics and rules **)

   225 fun solve_all_tac solvers ss =

   226   let

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

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

   229   in DEPTH_SOLVE (solve_tac 1) end;

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

   232 fun generic_simp_tac safe mode ss =

   233   let

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

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

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

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

   239     fun simp_loop_tac i =

   240       Raw_Simplifier.generic_rewrite_goal_tac mode (solve_all_tac unsafe_solvers) ss i THEN

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

   242   in simp_loop_tac end;

   244 local

   246 fun simp rew mode ss thm =

   247   let

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

   249     val tacf = solve_all_tac (rev unsafe_solvers);

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

   251   in rew mode prover ss thm end;

   253 in

   255 val simp_thm = simp Raw_Simplifier.rewrite_thm;

   256 val simp_cterm = simp Raw_Simplifier.rewrite_cterm;

   258 end;

   261 (* tactics *)

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

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

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

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

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

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

   271 (* conversions *)

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

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

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

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

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

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

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

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

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

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

   287 (** concrete syntax of attributes **)

   289 (* add / del *)

   291 val simpN = "simp";

   292 val congN = "cong";

   293 val onlyN = "only";

   294 val no_asmN = "no_asm";

   295 val no_asm_useN = "no_asm_use";

   296 val no_asm_simpN = "no_asm_simp";

   297 val asm_lrN = "asm_lr";

   300 (* simprocs *)

   302 local

   304 val add_del =

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

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

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

   308       (K (map_ss (fn ss => f (ss, [transform_simproc phi simproc])))));

   310 in

   312 val simproc_att =

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

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

   315   >> (fn atts => Thm.declaration_attribute (fn th =>

   316         fold (fn att => Thm.attribute_declaration (Morphism.form att) th) atts));

   318 end;

   321 (* conversions *)

   323 local

   325 fun conv_mode x =

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

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

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

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

   331 in

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

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

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

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

   338 end;

   341 (* setup attributes *)

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

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

   345     "declaration of Simplifier rewrite rule" #>

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

   347     "declaration of Simplifier congruence rule" #>

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

   349     "declaration of simplification procedures" #>

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

   354 (** method syntax **)

   356 val cong_modifiers =

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

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

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

   361 val simp_modifiers =

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

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

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

   365   Args.$$$ simpN -- Args.$$$ onlyN -- Args.colon

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

   367    @ cong_modifiers;

   369 val simp_modifiers' =

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

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

   372   Args.$$$ onlyN -- Args.colon

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

   374    @ cong_modifiers;

   376 val simp_options =

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

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

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

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

   381   Scan.succeed asm_full_simp_tac);

   383 fun simp_method more_mods meth =

   384   Scan.lift simp_options --|

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

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

   390 (** setup **)

   392 fun method_setup more_mods =

   393   Method.setup (Binding.name simpN)

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

   395       HEADGOAL (Method.insert_tac facts THEN'

   396         (CHANGED_PROP oo tac) (simpset_of ctxt))))

   397     "simplification" #>

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

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

   400       ALLGOALS (Method.insert_tac facts) THEN

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

   402     "simplification (all goals)";

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

   405   let

   406     val trivialities = Drule.reflexive_thm :: trivs;

   408     fun unsafe_solver_tac ss =

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

   410     val unsafe_solver = mk_solver "easy unsafe" unsafe_solver_tac;

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

   413     fun safe_solver_tac ss =

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

   415     val safe_solver = mk_solver "easy safe" safe_solver_tac;

   417     fun mk_eq thm =

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

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

   421     fun mksimps thm = mk_eq (Thm.forall_elim_vars (Thm.maxidx_of thm + 1) thm);

   422   in

   423     empty_ss

   424     setSSolver safe_solver

   425     setSolver unsafe_solver

   426     |> set_subgoaler asm_simp_tac

   427     |> set_mksimps (K mksimps)

   428   end));

   430 end;

   432 structure Basic_Simplifier: BASIC_SIMPLIFIER = Simplifier;

   433 open Basic_Simplifier;

author	wenzelm
	Sun, 18 Mar 2012 13:04:22 +0100
changeset 47876	421760a1efe7
parent 47872	a0e370d3d149
child 48110	0b1829860149
permissions	-rw-r--r--