--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/Pure/simplifier.ML Sun May 22 16:51:03 2005 +0200
@@ -0,0 +1,550 @@
+(* Title: Pure/simplifier.ML
+ ID: $Id$
+ Author: Tobias Nipkow and Markus Wenzel, TU Muenchen
+
+Generic simplifier, suitable for most logics (see also
+meta_simplifier.ML for the actual meta-level rewriting engine).
+*)
+
+(* added: put_delta_simpset, get_delta_simpset
+ changed: simp_add_local
+ 07/01/05
+*)
+
+
+signature BASIC_SIMPLIFIER =
+sig
+ include BASIC_META_SIMPLIFIER
+ type context_solver
+ val mk_context_solver: string -> (Proof.context -> thm list -> int -> tactic)
+ -> context_solver
+ type context_simproc
+ val mk_context_simproc: string -> cterm list ->
+ (Proof.context -> simpset -> term -> thm option) -> context_simproc
+ val print_simpset: theory -> unit
+ val simpset_ref_of_sg: Sign.sg -> simpset ref
+ val simpset_ref_of: theory -> simpset ref
+ val simpset_of_sg: Sign.sg -> simpset
+ val simpset_of: theory -> simpset
+ val SIMPSET: (simpset -> tactic) -> tactic
+ val SIMPSET': (simpset -> 'a -> tactic) -> 'a -> tactic
+ val simpset: unit -> simpset
+ val simpset_ref: unit -> simpset ref
+ val Addsimps: thm list -> unit
+ val Delsimps: thm list -> unit
+ val Addsimprocs: simproc list -> unit
+ val Delsimprocs: simproc list -> unit
+ val Addcongs: thm list -> unit
+ val Delcongs: thm list -> unit
+ val local_simpset_of: Proof.context -> simpset
+ val safe_asm_full_simp_tac: simpset -> int -> tactic
+ val simp_tac: simpset -> int -> tactic
+ val asm_simp_tac: simpset -> int -> tactic
+ val full_simp_tac: simpset -> int -> tactic
+ val asm_lr_simp_tac: simpset -> int -> tactic
+ val asm_full_simp_tac: simpset -> int -> tactic
+ val Simp_tac: int -> tactic
+ val Asm_simp_tac: int -> tactic
+ val Full_simp_tac: int -> tactic
+ val Asm_lr_simp_tac: int -> tactic
+ val Asm_full_simp_tac: int -> tactic
+ val simplify: simpset -> thm -> thm
+ val asm_simplify: simpset -> thm -> thm
+ val full_simplify: simpset -> thm -> thm
+ val asm_lr_simplify: simpset -> thm -> thm
+ val asm_full_simplify: simpset -> thm -> thm
+end;
+
+signature SIMPLIFIER =
+sig
+ include BASIC_SIMPLIFIER
+ val simproc_i: Sign.sg -> string -> term list
+ -> (Sign.sg -> simpset -> term -> thm option) -> simproc
+ val simproc: Sign.sg -> string -> string list
+ -> (Sign.sg -> simpset -> term -> thm option) -> simproc
+ val context_simproc_i: Sign.sg -> string -> term list
+ -> (Proof.context -> simpset -> term -> thm option) -> context_simproc
+ val context_simproc: Sign.sg -> string -> string list
+ -> (Proof.context -> simpset -> term -> thm option) -> context_simproc
+ val rewrite: simpset -> cterm -> thm
+ val asm_rewrite: simpset -> cterm -> thm
+ val full_rewrite: simpset -> cterm -> thm
+ val asm_lr_rewrite: simpset -> cterm -> thm
+ val asm_full_rewrite: simpset -> cterm -> thm
+ val add_context_simprocs: context_simproc list -> theory -> theory
+ val del_context_simprocs: context_simproc list -> theory -> theory
+ val set_context_subgoaler: (Proof.context -> simpset -> int -> tactic) -> theory -> theory
+ val reset_context_subgoaler: theory -> theory
+ val add_context_looper: string * (Proof.context -> int -> Tactical.tactic) ->
+ theory -> theory
+ val del_context_looper: string -> theory -> theory
+ val add_context_unsafe_solver: context_solver -> theory -> theory
+ val add_context_safe_solver: context_solver -> theory -> theory
+ val print_local_simpset: Proof.context -> unit
+ val get_local_simpset: Proof.context -> simpset
+ val put_local_simpset: simpset -> Proof.context -> Proof.context
+ val change_global_ss: (simpset * thm list -> simpset) -> theory attribute
+ val change_local_ss: (simpset * thm list -> simpset) -> Proof.context attribute
+ val simp_add_global: theory attribute
+ val simp_del_global: theory attribute
+ val simp_add_local: Proof.context attribute
+ val simp_del_local: Proof.context attribute
+ val cong_add_global: theory attribute
+ val cong_del_global: theory attribute
+ val cong_add_local: Proof.context attribute
+ val cong_del_local: Proof.context attribute
+ val change_simpset_of: (simpset * 'a -> simpset) -> 'a -> theory -> theory
+ val simp_modifiers: (Args.T list -> (Method.modifier * Args.T list)) list
+ val method_setup: (Args.T list -> (Method.modifier * Args.T list)) list
+ -> (theory -> theory) list
+ val easy_setup: thm -> thm list -> (theory -> theory) list
+
+ val get_delta_simpset: ProofContext.context -> Thm.thm list
+ val put_delta_simpset: Thm.thm list -> ProofContext.context -> ProofContext.context
+end;
+
+structure Simplifier: SIMPLIFIER =
+struct
+
+open MetaSimplifier;
+
+
+(** context dependent simpset components **)
+
+(* datatype context_solver *)
+
+datatype context_solver =
+ ContextSolver of (string * (Proof.context -> thm list -> int -> tactic)) * stamp;
+
+fun mk_context_solver name f = ContextSolver ((name, f), stamp ());
+fun eq_context_solver (ContextSolver (_, id1), ContextSolver (_, id2)) = (id1 = id2);
+val merge_context_solvers = gen_merge_lists eq_context_solver;
+
+
+(* datatype context_simproc *)
+
+datatype context_simproc = ContextSimproc of
+ (string * cterm list * (Proof.context -> simpset -> term -> thm option)) * stamp;
+
+fun mk_context_simproc name lhss f = ContextSimproc ((name, lhss, f), stamp ());
+fun eq_context_simproc (ContextSimproc (_, id1), ContextSimproc (_, id2)) = (id1 = id2);
+val merge_context_simprocs = gen_merge_lists eq_context_simproc;
+
+fun context_simproc_i sg name =
+ mk_context_simproc name o map (Thm.cterm_of sg o Logic.varify);
+
+fun context_simproc sg name =
+ context_simproc_i sg name o map (Sign.simple_read_term sg TypeInfer.logicT);
+
+
+(* datatype context_ss *)
+
+datatype context_ss = ContextSS of
+ {simprocs: context_simproc list,
+ subgoal_tac: (Proof.context -> simpset -> int -> tactic) option,
+ loop_tacs: (string * (Proof.context -> int -> tactic)) list,
+ unsafe_solvers: context_solver list,
+ solvers: context_solver list};
+
+fun context_ss ctxt ss ctxt_ss =
+ let
+ val ContextSS {simprocs, subgoal_tac, loop_tacs, unsafe_solvers, solvers} = ctxt_ss;
+ fun prep_simproc (ContextSimproc ((name, lhss, f), _)) =
+ mk_simproc name lhss (K (f ctxt));
+ fun add_loop (name, f) simpset = simpset addloop (name, f ctxt);
+ fun add_solver add (ContextSolver ((name, f), _)) simpset =
+ add (simpset, mk_solver name (f ctxt));
+ in
+ ((case subgoal_tac of NONE => ss | SOME tac => ss setsubgoaler tac ctxt)
+ addsimprocs map prep_simproc simprocs)
+ |> fold_rev add_loop loop_tacs
+ |> fold_rev (add_solver (op addSolver)) unsafe_solvers
+ |> fold_rev (add_solver (op addSSolver)) solvers
+ end;
+
+fun make_context_ss (simprocs, subgoal_tac, loop_tacs, unsafe_solvers, solvers) =
+ ContextSS {simprocs = simprocs, subgoal_tac = subgoal_tac, loop_tacs = loop_tacs,
+ unsafe_solvers = unsafe_solvers, solvers = solvers};
+
+val empty_context_ss = make_context_ss ([], NONE, [], [], []);
+
+fun merge_context_ss (ctxt_ss1, ctxt_ss2) =
+ let
+ val ContextSS {simprocs = simprocs1, subgoal_tac = subgoal_tac1, loop_tacs = loop_tacs1,
+ unsafe_solvers = unsafe_solvers1, solvers = solvers1} = ctxt_ss1;
+ val ContextSS {simprocs = simprocs2, subgoal_tac = subgoal_tac2, loop_tacs = loop_tacs2,
+ unsafe_solvers = unsafe_solvers2, solvers = solvers2} = ctxt_ss2;
+
+ val simprocs' = merge_context_simprocs simprocs1 simprocs2;
+ val subgoal_tac' = (case subgoal_tac1 of NONE => subgoal_tac2 | some => some);
+ val loop_tacs' = merge_alists loop_tacs1 loop_tacs2;
+ val unsafe_solvers' = merge_context_solvers unsafe_solvers1 unsafe_solvers2;
+ val solvers' = merge_context_solvers solvers1 solvers2;
+ in make_context_ss (simprocs', subgoal_tac', loop_tacs', unsafe_solvers', solvers') end;
+
+
+
+(** global and local simpset data **)
+
+(* theory data kind 'Pure/simpset' *)
+
+structure GlobalSimpsetArgs =
+struct
+ val name = "Pure/simpset";
+ type T = simpset ref * context_ss;
+
+ val empty = (ref empty_ss, empty_context_ss);
+ fun copy (ref ss, ctxt_ss) = (ref ss, ctxt_ss): T; (*create new reference!*)
+ val prep_ext = copy;
+ fun merge ((ref ss1, ctxt_ss1), (ref ss2, ctxt_ss2)) =
+ (ref (merge_ss (ss1, ss2)), merge_context_ss (ctxt_ss1, ctxt_ss2));
+ fun print _ (ref ss, _) = print_ss ss;
+end;
+
+structure GlobalSimpset = TheoryDataFun(GlobalSimpsetArgs);
+val _ = Context.add_setup [GlobalSimpset.init];
+val print_simpset = GlobalSimpset.print;
+
+val simpset_ref_of_sg = #1 o GlobalSimpset.get_sg;
+val simpset_ref_of = #1 o GlobalSimpset.get;
+val get_context_ss = #2 o GlobalSimpset.get o ProofContext.theory_of;
+
+fun map_context_ss f = GlobalSimpset.map (apsnd
+ (fn ContextSS {simprocs, subgoal_tac, loop_tacs, unsafe_solvers, solvers} =>
+ make_context_ss (f (simprocs, subgoal_tac, loop_tacs, unsafe_solvers, solvers))));
+
+
+(* access global simpset *)
+
+val simpset_of_sg = ! o simpset_ref_of_sg;
+val simpset_of = simpset_of_sg o Theory.sign_of;
+
+fun SIMPSET tacf state = tacf (simpset_of_sg (Thm.sign_of_thm state)) state;
+fun SIMPSET' tacf i state = tacf (simpset_of_sg (Thm.sign_of_thm state)) i state;
+
+val simpset = simpset_of o Context.the_context;
+val simpset_ref = simpset_ref_of_sg o Theory.sign_of o Context.the_context;
+
+
+(* change global simpset *)
+
+fun change_simpset_of f x thy =
+ let val r = simpset_ref_of thy
+ in r := f (! r, x); thy end;
+
+fun change_simpset f x = (change_simpset_of f x (Context.the_context ()); ());
+
+val Addsimps = change_simpset (op addsimps);
+val Delsimps = change_simpset (op delsimps);
+val Addsimprocs = change_simpset (op addsimprocs);
+val Delsimprocs = change_simpset (op delsimprocs);
+val Addcongs = change_simpset (op addcongs);
+val Delcongs = change_simpset (op delcongs);
+
+
+(* change context dependent components *)
+
+fun add_context_simprocs procs =
+ map_context_ss (fn (simprocs, subgoal_tac, loop_tacs, unsafe_solvers, solvers) =>
+ (merge_context_simprocs procs simprocs, subgoal_tac, loop_tacs,
+ unsafe_solvers, solvers));
+
+fun del_context_simprocs procs =
+ map_context_ss (fn (simprocs, subgoal_tac, loop_tacs, unsafe_solvers, solvers) =>
+ (gen_rems eq_context_simproc (simprocs, procs), subgoal_tac, loop_tacs,
+ unsafe_solvers, solvers));
+
+fun set_context_subgoaler tac =
+ map_context_ss (fn (simprocs, _, loop_tacs, unsafe_solvers, solvers) =>
+ (simprocs, SOME tac, loop_tacs, unsafe_solvers, solvers));
+
+val reset_context_subgoaler =
+ map_context_ss (fn (simprocs, _, loop_tacs, unsafe_solvers, solvers) =>
+ (simprocs, NONE, loop_tacs, unsafe_solvers, solvers));
+
+fun add_context_looper (name, tac) =
+ map_context_ss (fn (simprocs, subgoal_tac, loop_tacs, unsafe_solvers, solvers) =>
+ (simprocs, subgoal_tac, merge_alists [(name, tac)] loop_tacs,
+ unsafe_solvers, solvers));
+
+fun del_context_looper name =
+ map_context_ss (fn (simprocs, subgoal_tac, loop_tacs, unsafe_solvers, solvers) =>
+ (simprocs, subgoal_tac, filter_out (equal name o #1) loop_tacs,
+ unsafe_solvers, solvers));
+
+fun add_context_unsafe_solver solver =
+ map_context_ss (fn (simprocs, subgoal_tac, loop_tacs, unsafe_solvers, solvers) =>
+ (simprocs, subgoal_tac, loop_tacs,
+ merge_context_solvers [solver] unsafe_solvers, solvers));
+
+fun add_context_safe_solver solver =
+ map_context_ss (fn (simprocs, subgoal_tac, loop_tacs, unsafe_solvers, solvers) =>
+ (simprocs, subgoal_tac, loop_tacs, unsafe_solvers,
+ merge_context_solvers [solver] solvers));
+
+
+(* proof data kind 'Pure/simpset' *)
+
+structure LocalSimpsetArgs =
+struct
+ val name = "Pure/simpset";
+ type T = simpset;
+ val init = simpset_of;
+ fun print ctxt ss = print_ss (context_ss ctxt ss (get_context_ss ctxt));
+end;
+
+structure LocalSimpset = ProofDataFun(LocalSimpsetArgs);
+val _ = Context.add_setup [LocalSimpset.init];
+val print_local_simpset = LocalSimpset.print;
+
+val get_local_simpset = LocalSimpset.get;
+val put_local_simpset = LocalSimpset.put;
+fun map_local_simpset f ctxt = put_local_simpset (f (get_local_simpset ctxt)) ctxt;
+
+fun local_simpset_of ctxt =
+ context_ss ctxt (get_local_simpset ctxt) (get_context_ss ctxt);
+
+
+(* Jia: added DeltaSimpsetArgs and DeltaSimpset for delta_simpset
+ also added methods to retrieve them. *)
+(* CB: changed "delta simpsets" to context data,
+ moved counter to here, it is no longer a ref *)
+
+structure DeltaSimpsetArgs =
+struct
+ val name = "Pure/delta_simpset";
+ type T = Thm.thm list * int; (*the type is thm list * int*)
+ fun init _ = ([], 0);
+ fun print ctxt thms = ();
+end;
+
+structure DeltaSimpsetData = ProofDataFun(DeltaSimpsetArgs);
+val _ = Context.add_setup [DeltaSimpsetData.init];
+
+val get_delta_simpset = #1 o DeltaSimpsetData.get;
+fun put_delta_simpset ss = DeltaSimpsetData.map (fn (_, i) => (ss, i));
+fun delta_increment ctxt =
+ let val ctxt' = DeltaSimpsetData.map (fn (ss, i) => (ss, i+1)) ctxt
+ in (ctxt', #2 (DeltaSimpsetData.get ctxt'))
+ end;
+
+(* Jia: added to rename a local thm if necessary *)
+local
+fun rename_thm' (ctxt,thm) =
+ let val (new_ctxt, new_id) = delta_increment ctxt
+ val new_name = "anon_simp_" ^ (string_of_int new_id)
+ in
+ (new_ctxt, Thm.name_thm(new_name,thm))
+end;
+
+in
+
+fun rename_thm (ctxt,thm) = if (!Proof.call_atp) then rename_thm' (ctxt,thm) else (ctxt, thm);
+
+end
+
+(* attributes *)
+
+fun change_global_ss f (thy, th) =
+ let val r = simpset_ref_of thy
+ in r := f (! r, [th]); (thy, th) end;
+
+fun change_local_ss f (ctxt, th) =
+ let val ss = f (get_local_simpset ctxt, [th])
+ in (put_local_simpset ss ctxt, th) end;
+
+val simp_add_global = change_global_ss (op addsimps);
+val simp_del_global = change_global_ss (op delsimps);
+
+
+
+
+
+(* Jia: note: when simplifier rules are added to local_simpset, they are also added to delta_simpset in ProofContext.context, but not removed if simp_del_local is called *)
+fun simp_add_local (ctxt,th) =
+ let val delta_ss = get_delta_simpset ctxt
+ val thm_name = Thm.name_of_thm th
+ val (ctxt', th') =
+ if (thm_name = "") then rename_thm (ctxt,th) else (ctxt, th)
+ val new_dss = th'::delta_ss
+ val ctxt'' = put_delta_simpset new_dss ctxt'
+ in
+ change_local_ss (op addsimps) (ctxt'',th)
+ end;
+
+val simp_del_local = change_local_ss (op delsimps);
+
+val cong_add_global = change_global_ss (op addcongs);
+val cong_del_global = change_global_ss (op delcongs);
+val cong_add_local = change_local_ss (op addcongs);
+val cong_del_local = change_local_ss (op delcongs);
+
+
+val simp_tac = generic_simp_tac false (false, false, false);
+val asm_simp_tac = generic_simp_tac false (false, true, false);
+val full_simp_tac = generic_simp_tac false (true, false, false);
+val asm_lr_simp_tac = generic_simp_tac false (true, true, false);
+val asm_full_simp_tac = generic_simp_tac false (true, true, true);
+val safe_asm_full_simp_tac = generic_simp_tac true (true, true, true);
+
+
+
+(*the abstraction over the proof state delays the dereferencing*)
+fun Simp_tac i st = simp_tac (simpset ()) i st;
+fun Asm_simp_tac i st = asm_simp_tac (simpset ()) i st;
+fun Full_simp_tac i st = full_simp_tac (simpset ()) i st;
+fun Asm_lr_simp_tac i st = asm_lr_simp_tac (simpset ()) i st;
+fun Asm_full_simp_tac i st = asm_full_simp_tac (simpset ()) i st;
+
+val simplify = simp_thm (false, false, false);
+val asm_simplify = simp_thm (false, true, false);
+val full_simplify = simp_thm (true, false, false);
+val asm_lr_simplify = simp_thm (true, true, false);
+val asm_full_simplify = simp_thm (true, true, true);
+
+val rewrite = simp_cterm (false, false, false);
+val asm_rewrite = simp_cterm (false, true, false);
+val full_rewrite = simp_cterm (true, false, false);
+val asm_lr_rewrite = simp_cterm (true, true, false);
+val asm_full_rewrite = simp_cterm (true, true, true);
+
+
+
+(** concrete syntax of attributes **)
+
+(* add / del *)
+
+val simpN = "simp";
+val congN = "cong";
+val addN = "add";
+val delN = "del";
+val onlyN = "only";
+val no_asmN = "no_asm";
+val no_asm_useN = "no_asm_use";
+val no_asm_simpN = "no_asm_simp";
+val asm_lrN = "asm_lr";
+
+val simp_attr =
+ (Attrib.add_del_args simp_add_global simp_del_global,
+ Attrib.add_del_args simp_add_local simp_del_local);
+
+val cong_attr =
+ (Attrib.add_del_args cong_add_global cong_del_global,
+ Attrib.add_del_args cong_add_local cong_del_local);
+
+
+(* conversions *)
+
+local
+
+fun conv_mode x =
+ ((Args.parens (Args.$$$ no_asmN) >> K simplify ||
+ Args.parens (Args.$$$ no_asm_simpN) >> K asm_simplify ||
+ Args.parens (Args.$$$ no_asm_useN) >> K full_simplify ||
+ Scan.succeed asm_full_simplify) |> Scan.lift) x;
+
+fun simplified_att get args =
+ Attrib.syntax (conv_mode -- args >> (fn (f, ths) =>
+ Drule.rule_attribute (fn x => f ((if null ths then I else clear_ss) (get x) addsimps ths))));
+
+in
+
+val simplified_attr =
+ (simplified_att simpset_of Attrib.global_thmss,
+ simplified_att local_simpset_of Attrib.local_thmss);
+
+end;
+
+
+(* setup attributes *)
+
+val _ = Context.add_setup
+ [Attrib.add_attributes
+ [(simpN, simp_attr, "declaration of simplification rule"),
+ (congN, cong_attr, "declaration of Simplifier congruence rule"),
+ ("simplified", simplified_attr, "simplified rule")]];
+
+
+
+(** proof methods **)
+
+(* simplification *)
+
+val simp_options =
+ (Args.parens (Args.$$$ no_asmN) >> K simp_tac ||
+ Args.parens (Args.$$$ no_asm_simpN) >> K asm_simp_tac ||
+ Args.parens (Args.$$$ no_asm_useN) >> K full_simp_tac ||
+ Args.parens (Args.$$$ asm_lrN) >> K asm_lr_simp_tac ||
+ Scan.succeed asm_full_simp_tac);
+
+val cong_modifiers =
+ [Args.$$$ congN -- Args.colon >> K ((I, cong_add_local):Method.modifier),
+ Args.$$$ congN -- Args.add -- Args.colon >> K (I, cong_add_local),
+ Args.$$$ congN -- Args.del -- Args.colon >> K (I, cong_del_local)];
+
+val simp_modifiers =
+ [Args.$$$ simpN -- Args.colon >> K (I, simp_add_local),
+ Args.$$$ simpN -- Args.add -- Args.colon >> K (I, simp_add_local),
+ Args.$$$ simpN -- Args.del -- Args.colon >> K (I, simp_del_local),
+ Args.$$$ simpN -- Args.$$$ onlyN -- Args.colon >> K (map_local_simpset clear_ss, simp_add_local)]
+ @ cong_modifiers;
+
+val simp_modifiers' =
+ [Args.add -- Args.colon >> K (I, simp_add_local),
+ Args.del -- Args.colon >> K (I, simp_del_local),
+ Args.$$$ onlyN -- Args.colon >> K (map_local_simpset clear_ss, simp_add_local)]
+ @ cong_modifiers;
+
+fun simp_args more_mods =
+ Method.sectioned_args (Args.bang_facts -- Scan.lift simp_options) (more_mods @ simp_modifiers');
+
+
+fun simp_method (prems, tac) ctxt = Method.METHOD (fn facts =>
+ ALLGOALS (Method.insert_tac (prems @ facts)) THEN
+ (CHANGED_PROP o ALLGOALS o tac) (local_simpset_of ctxt));
+
+fun simp_method' (prems, tac) ctxt = Method.METHOD (fn facts =>
+ HEADGOAL (Method.insert_tac (prems @ facts) THEN'
+ (CHANGED_PROP oo tac) (local_simpset_of ctxt)));
+
+
+(* setup methods *)
+
+fun setup_methods more_mods = Method.add_methods
+ [(simpN, simp_args more_mods simp_method', "simplification"),
+ ("simp_all", simp_args more_mods simp_method, "simplification (all goals)")];
+
+fun method_setup mods = [setup_methods mods];
+
+
+(** easy_setup **)
+
+fun easy_setup reflect trivs =
+ let
+ val trivialities = Drule.reflexive_thm :: trivs;
+
+ fun unsafe_solver_tac prems = FIRST' [resolve_tac (trivialities @ prems), assume_tac];
+ val unsafe_solver = mk_solver "easy unsafe" unsafe_solver_tac;
+
+ (*no premature instantiation of variables during simplification*)
+ fun safe_solver_tac prems = FIRST' [match_tac (trivialities @ prems), eq_assume_tac];
+ val safe_solver = mk_solver "easy safe" safe_solver_tac;
+
+ fun mk_eq thm =
+ if Logic.is_equals (Thm.concl_of thm) then [thm]
+ else [thm RS reflect] handle THM _ => [];
+
+ fun mksimps thm = mk_eq (Drule.forall_elim_vars (#maxidx (Thm.rep_thm thm) + 1) thm);
+
+ fun init_ss thy =
+ (simpset_ref_of thy :=
+ empty_ss setsubgoaler asm_simp_tac
+ setSSolver safe_solver
+ setSolver unsafe_solver
+ setmksimps mksimps; thy);
+ in method_setup [] @ [init_ss] end;
+
+end;
+
+structure BasicSimplifier: BASIC_SIMPLIFIER = Simplifier;
+open BasicSimplifier;