src/HOL/Library/SMT/smt_normalize.ML
changeset 58055 625bdd5c70b2
parent 57996 ca917ea6969c
equal deleted inserted replaced
58054:1d9edd486479 58055:625bdd5c70b2
       
     1 (*  Title:      HOL/Library/SMT/smt_normalize.ML
       
     2     Author:     Sascha Boehme, TU Muenchen
       
     3 
       
     4 Normalization steps on theorems required by SMT solvers.
       
     5 *)
       
     6 
       
     7 signature SMT_NORMALIZE =
       
     8 sig
       
     9   val drop_fact_warning: Proof.context -> thm -> unit
       
    10   val atomize_conv: Proof.context -> conv
       
    11   type extra_norm = Proof.context -> thm list * thm list -> thm list * thm list
       
    12   val add_extra_norm: SMT_Utils.class * extra_norm -> Context.generic ->
       
    13     Context.generic
       
    14   val normalize: (int * (int option * thm)) list -> Proof.context ->
       
    15     (int * thm) list * Proof.context
       
    16   val setup: theory -> theory
       
    17 end
       
    18 
       
    19 structure SMT_Normalize: SMT_NORMALIZE =
       
    20 struct
       
    21 
       
    22 fun drop_fact_warning ctxt =
       
    23   SMT_Config.verbose_msg ctxt (prefix "Warning: dropping assumption: " o
       
    24     Display.string_of_thm ctxt)
       
    25 
       
    26 
       
    27 (* general theorem normalizations *)
       
    28 
       
    29 (** instantiate elimination rules **)
       
    30  
       
    31 local
       
    32   val (cpfalse, cfalse) =
       
    33     `SMT_Utils.mk_cprop (Thm.cterm_of @{theory} @{const False})
       
    34 
       
    35   fun inst f ct thm =
       
    36     let val cv = f (Drule.strip_imp_concl (Thm.cprop_of thm))
       
    37     in Thm.instantiate ([], [(cv, ct)]) thm end
       
    38 in
       
    39 
       
    40 fun instantiate_elim thm =
       
    41   (case Thm.concl_of thm of
       
    42     @{const Trueprop} $ Var (_, @{typ bool}) => inst Thm.dest_arg cfalse thm
       
    43   | Var _ => inst I cpfalse thm
       
    44   | _ => thm)
       
    45 
       
    46 end
       
    47 
       
    48 
       
    49 (** normalize definitions **)
       
    50 
       
    51 fun norm_def thm =
       
    52   (case Thm.prop_of thm of
       
    53     @{const Trueprop} $ (Const (@{const_name HOL.eq}, _) $ _ $ Abs _) =>
       
    54       norm_def (thm RS @{thm fun_cong})
       
    55   | Const (@{const_name Pure.eq}, _) $ _ $ Abs _ =>
       
    56       norm_def (thm RS @{thm meta_eq_to_obj_eq})
       
    57   | _ => thm)
       
    58 
       
    59 
       
    60 (** atomization **)
       
    61 
       
    62 fun atomize_conv ctxt ct =
       
    63   (case Thm.term_of ct of
       
    64     @{const Pure.imp} $ _ $ _ =>
       
    65       Conv.binop_conv (atomize_conv ctxt) then_conv
       
    66       Conv.rewr_conv @{thm atomize_imp}
       
    67   | Const (@{const_name Pure.eq}, _) $ _ $ _ =>
       
    68       Conv.binop_conv (atomize_conv ctxt) then_conv
       
    69       Conv.rewr_conv @{thm atomize_eq}
       
    70   | Const (@{const_name Pure.all}, _) $ Abs _ =>
       
    71       Conv.binder_conv (atomize_conv o snd) ctxt then_conv
       
    72       Conv.rewr_conv @{thm atomize_all}
       
    73   | _ => Conv.all_conv) ct
       
    74 
       
    75 val setup_atomize =
       
    76   fold SMT_Builtin.add_builtin_fun_ext'' [@{const_name Pure.imp},
       
    77     @{const_name Pure.eq}, @{const_name Pure.all}, @{const_name Trueprop}]
       
    78 
       
    79 
       
    80 (** unfold special quantifiers **)
       
    81 
       
    82 local
       
    83   val ex1_def = mk_meta_eq @{lemma
       
    84     "Ex1 = (%P. EX x. P x & (ALL y. P y --> y = x))"
       
    85     by (rule ext) (simp only: Ex1_def)}
       
    86 
       
    87   val ball_def = mk_meta_eq @{lemma "Ball = (%A P. ALL x. x : A --> P x)"
       
    88     by (rule ext)+ (rule Ball_def)}
       
    89 
       
    90   val bex_def = mk_meta_eq @{lemma "Bex = (%A P. EX x. x : A & P x)"
       
    91     by (rule ext)+ (rule Bex_def)}
       
    92 
       
    93   val special_quants = [(@{const_name Ex1}, ex1_def),
       
    94     (@{const_name Ball}, ball_def), (@{const_name Bex}, bex_def)]
       
    95   
       
    96   fun special_quant (Const (n, _)) = AList.lookup (op =) special_quants n
       
    97     | special_quant _ = NONE
       
    98 
       
    99   fun special_quant_conv _ ct =
       
   100     (case special_quant (Thm.term_of ct) of
       
   101       SOME thm => Conv.rewr_conv thm
       
   102     | NONE => Conv.all_conv) ct
       
   103 in
       
   104 
       
   105 fun unfold_special_quants_conv ctxt =
       
   106   SMT_Utils.if_exists_conv (is_some o special_quant)
       
   107     (Conv.top_conv special_quant_conv ctxt)
       
   108 
       
   109 val setup_unfolded_quants =
       
   110   fold (SMT_Builtin.add_builtin_fun_ext'' o fst) special_quants
       
   111 
       
   112 end
       
   113 
       
   114 
       
   115 (** trigger inference **)
       
   116 
       
   117 local
       
   118   (*** check trigger syntax ***)
       
   119 
       
   120   fun dest_trigger (Const (@{const_name pat}, _) $ _) = SOME true
       
   121     | dest_trigger (Const (@{const_name nopat}, _) $ _) = SOME false
       
   122     | dest_trigger _ = NONE
       
   123 
       
   124   fun eq_list [] = false
       
   125     | eq_list (b :: bs) = forall (equal b) bs
       
   126 
       
   127   fun proper_trigger t =
       
   128     t
       
   129     |> these o try HOLogic.dest_list
       
   130     |> map (map_filter dest_trigger o these o try HOLogic.dest_list)
       
   131     |> (fn [] => false | bss => forall eq_list bss)
       
   132 
       
   133   fun proper_quant inside f t =
       
   134     (case t of
       
   135       Const (@{const_name All}, _) $ Abs (_, _, u) => proper_quant true f u
       
   136     | Const (@{const_name Ex}, _) $ Abs (_, _, u) => proper_quant true f u
       
   137     | @{const trigger} $ p $ u =>
       
   138         (if inside then f p else false) andalso proper_quant false f u
       
   139     | Abs (_, _, u) => proper_quant false f u
       
   140     | u1 $ u2 => proper_quant false f u1 andalso proper_quant false f u2
       
   141     | _ => true)
       
   142 
       
   143   fun check_trigger_error ctxt t =
       
   144     error ("SMT triggers must only occur under quantifier and multipatterns " ^
       
   145       "must have the same kind: " ^ Syntax.string_of_term ctxt t)
       
   146 
       
   147   fun check_trigger_conv ctxt ct =
       
   148     if proper_quant false proper_trigger (SMT_Utils.term_of ct) then
       
   149       Conv.all_conv ct
       
   150     else check_trigger_error ctxt (Thm.term_of ct)
       
   151 
       
   152 
       
   153   (*** infer simple triggers ***)
       
   154 
       
   155   fun dest_cond_eq ct =
       
   156     (case Thm.term_of ct of
       
   157       Const (@{const_name HOL.eq}, _) $ _ $ _ => Thm.dest_binop ct
       
   158     | @{const HOL.implies} $ _ $ _ => dest_cond_eq (Thm.dest_arg ct)
       
   159     | _ => raise CTERM ("no equation", [ct]))
       
   160 
       
   161   fun get_constrs thy (Type (n, _)) = these (Datatype_Data.get_constrs thy n)
       
   162     | get_constrs _ _ = []
       
   163 
       
   164   fun is_constr thy (n, T) =
       
   165     let fun match (m, U) = m = n andalso Sign.typ_instance thy (T, U)
       
   166     in can (the o find_first match o get_constrs thy o Term.body_type) T end
       
   167 
       
   168   fun is_constr_pat thy t =
       
   169     (case Term.strip_comb t of
       
   170       (Free _, []) => true
       
   171     | (Const c, ts) => is_constr thy c andalso forall (is_constr_pat thy) ts
       
   172     | _ => false)
       
   173 
       
   174   fun is_simp_lhs ctxt t =
       
   175     (case Term.strip_comb t of
       
   176       (Const c, ts as _ :: _) =>
       
   177         not (SMT_Builtin.is_builtin_fun_ext ctxt c ts) andalso
       
   178         forall (is_constr_pat (Proof_Context.theory_of ctxt)) ts
       
   179     | _ => false)
       
   180 
       
   181   fun has_all_vars vs t =
       
   182     subset (op aconv) (vs, map Free (Term.add_frees t []))
       
   183 
       
   184   fun minimal_pats vs ct =
       
   185     if has_all_vars vs (Thm.term_of ct) then
       
   186       (case Thm.term_of ct of
       
   187         _ $ _ =>
       
   188           (case pairself (minimal_pats vs) (Thm.dest_comb ct) of
       
   189             ([], []) => [[ct]]
       
   190           | (ctss, ctss') => union (eq_set (op aconvc)) ctss ctss')
       
   191       | _ => [])
       
   192     else []
       
   193 
       
   194   fun proper_mpat _ _ _ [] = false
       
   195     | proper_mpat thy gen u cts =
       
   196         let
       
   197           val tps = (op ~~) (`gen (map Thm.term_of cts))
       
   198           fun some_match u = tps |> exists (fn (t', t) =>
       
   199             Pattern.matches thy (t', u) andalso not (t aconv u))
       
   200         in not (Term.exists_subterm some_match u) end
       
   201 
       
   202   val pat =
       
   203     SMT_Utils.mk_const_pat @{theory} @{const_name SMT.pat} SMT_Utils.destT1
       
   204   fun mk_pat ct = Thm.apply (SMT_Utils.instT' ct pat) ct
       
   205 
       
   206   fun mk_clist T = pairself (Thm.cterm_of @{theory})
       
   207     (HOLogic.cons_const T, HOLogic.nil_const T)
       
   208   fun mk_list (ccons, cnil) f cts = fold_rev (Thm.mk_binop ccons o f) cts cnil
       
   209   val mk_pat_list = mk_list (mk_clist @{typ SMT.pattern})
       
   210   val mk_mpat_list = mk_list (mk_clist @{typ "SMT.pattern list"})  
       
   211   fun mk_trigger ctss = mk_mpat_list (mk_pat_list mk_pat) ctss
       
   212 
       
   213   val trigger_eq =
       
   214     mk_meta_eq @{lemma "p = SMT.trigger t p" by (simp add: trigger_def)}
       
   215 
       
   216   fun insert_trigger_conv [] ct = Conv.all_conv ct
       
   217     | insert_trigger_conv ctss ct =
       
   218         let val (ctr, cp) = Thm.dest_binop (Thm.rhs_of trigger_eq) ||> rpair ct
       
   219         in Thm.instantiate ([], [cp, (ctr, mk_trigger ctss)]) trigger_eq end
       
   220 
       
   221   fun infer_trigger_eq_conv outer_ctxt (ctxt, cvs) ct =
       
   222     let
       
   223       val (lhs, rhs) = dest_cond_eq ct
       
   224 
       
   225       val vs = map Thm.term_of cvs
       
   226       val thy = Proof_Context.theory_of ctxt
       
   227 
       
   228       fun get_mpats ct =
       
   229         if is_simp_lhs ctxt (Thm.term_of ct) then minimal_pats vs ct
       
   230         else []
       
   231       val gen = Variable.export_terms ctxt outer_ctxt
       
   232       val filter_mpats = filter (proper_mpat thy gen (Thm.term_of rhs))
       
   233 
       
   234     in insert_trigger_conv (filter_mpats (get_mpats lhs)) ct end
       
   235 
       
   236   fun has_trigger (@{const SMT.trigger} $ _ $ _) = true
       
   237     | has_trigger _ = false
       
   238 
       
   239   fun try_trigger_conv cv ct =
       
   240     if SMT_Utils.under_quant has_trigger (SMT_Utils.term_of ct) then
       
   241       Conv.all_conv ct
       
   242     else Conv.try_conv cv ct
       
   243 
       
   244   fun infer_trigger_conv ctxt =
       
   245     if Config.get ctxt SMT_Config.infer_triggers then
       
   246       try_trigger_conv
       
   247         (SMT_Utils.under_quant_conv (infer_trigger_eq_conv ctxt) ctxt)
       
   248     else Conv.all_conv
       
   249 in
       
   250 
       
   251 fun trigger_conv ctxt =
       
   252   SMT_Utils.prop_conv
       
   253     (check_trigger_conv ctxt then_conv infer_trigger_conv ctxt)
       
   254 
       
   255 val setup_trigger =
       
   256   fold SMT_Builtin.add_builtin_fun_ext''
       
   257     [@{const_name SMT.pat}, @{const_name SMT.nopat}, @{const_name SMT.trigger}]
       
   258 
       
   259 end
       
   260 
       
   261 
       
   262 (** adding quantifier weights **)
       
   263 
       
   264 local
       
   265   (*** check weight syntax ***)
       
   266 
       
   267   val has_no_weight =
       
   268     not o Term.exists_subterm (fn @{const SMT.weight} => true | _ => false)
       
   269 
       
   270   fun is_weight (@{const SMT.weight} $ w $ t) =
       
   271         (case try HOLogic.dest_number w of
       
   272           SOME (_, i) => i >= 0 andalso has_no_weight t
       
   273         | _ => false)
       
   274     | is_weight t = has_no_weight t
       
   275 
       
   276   fun proper_trigger (@{const SMT.trigger} $ _ $ t) = is_weight t
       
   277     | proper_trigger t = is_weight t 
       
   278 
       
   279   fun check_weight_error ctxt t =
       
   280     error ("SMT weight must be a non-negative number and must only occur " ^
       
   281       "under the top-most quantifier and an optional trigger: " ^
       
   282       Syntax.string_of_term ctxt t)
       
   283 
       
   284   fun check_weight_conv ctxt ct =
       
   285     if SMT_Utils.under_quant proper_trigger (SMT_Utils.term_of ct) then
       
   286       Conv.all_conv ct
       
   287     else check_weight_error ctxt (Thm.term_of ct)
       
   288 
       
   289 
       
   290   (*** insertion of weights ***)
       
   291 
       
   292   fun under_trigger_conv cv ct =
       
   293     (case Thm.term_of ct of
       
   294       @{const SMT.trigger} $ _ $ _ => Conv.arg_conv cv
       
   295     | _ => cv) ct
       
   296 
       
   297   val weight_eq =
       
   298     mk_meta_eq @{lemma "p = SMT.weight i p" by (simp add: weight_def)}
       
   299   fun mk_weight_eq w =
       
   300     let val cv = Thm.dest_arg1 (Thm.rhs_of weight_eq)
       
   301     in
       
   302       Thm.instantiate ([], [(cv, Numeral.mk_cnumber @{ctyp int} w)]) weight_eq
       
   303     end
       
   304 
       
   305   fun add_weight_conv NONE _ = Conv.all_conv
       
   306     | add_weight_conv (SOME weight) ctxt =
       
   307         let val cv = Conv.rewr_conv (mk_weight_eq weight)
       
   308         in SMT_Utils.under_quant_conv (K (under_trigger_conv cv)) ctxt end
       
   309 in
       
   310 
       
   311 fun weight_conv weight ctxt = 
       
   312   SMT_Utils.prop_conv
       
   313     (check_weight_conv ctxt then_conv add_weight_conv weight ctxt)
       
   314 
       
   315 val setup_weight = SMT_Builtin.add_builtin_fun_ext'' @{const_name SMT.weight}
       
   316 
       
   317 end
       
   318 
       
   319 
       
   320 (** combined general normalizations **)
       
   321 
       
   322 fun gen_normalize1_conv ctxt weight =
       
   323   atomize_conv ctxt then_conv
       
   324   unfold_special_quants_conv ctxt then_conv
       
   325   Thm.beta_conversion true then_conv
       
   326   trigger_conv ctxt then_conv
       
   327   weight_conv weight ctxt
       
   328 
       
   329 fun gen_normalize1 ctxt weight thm =
       
   330   thm
       
   331   |> instantiate_elim
       
   332   |> norm_def
       
   333   |> Conv.fconv_rule (Thm.beta_conversion true then_conv Thm.eta_conversion)
       
   334   |> Drule.forall_intr_vars
       
   335   |> Conv.fconv_rule (gen_normalize1_conv ctxt weight)
       
   336 
       
   337 fun gen_norm1_safe ctxt (i, (weight, thm)) =
       
   338   (case try (gen_normalize1 ctxt weight) thm of
       
   339     SOME thm' => SOME (i, thm')
       
   340   | NONE => (drop_fact_warning ctxt thm; NONE))
       
   341 
       
   342 fun gen_normalize ctxt iwthms = map_filter (gen_norm1_safe ctxt) iwthms
       
   343 
       
   344 
       
   345 
       
   346 (* unfolding of definitions and theory-specific rewritings *)
       
   347 
       
   348 fun expand_head_conv cv ct =
       
   349   (case Thm.term_of ct of
       
   350     _ $ _ =>
       
   351       Conv.fun_conv (expand_head_conv cv) then_conv
       
   352       Conv.try_conv (Thm.beta_conversion false)
       
   353   | _ => cv) ct
       
   354 
       
   355 
       
   356 (** rewrite bool case expressions as if expressions **)
       
   357 
       
   358 local
       
   359   fun is_case_bool (Const (@{const_name "bool.case_bool"}, _)) = true
       
   360     | is_case_bool _ = false
       
   361 
       
   362   val thm = mk_meta_eq @{lemma
       
   363     "case_bool = (%x y P. if P then x else y)" by (rule ext)+ simp}
       
   364 
       
   365   fun unfold_conv _ =
       
   366     SMT_Utils.if_true_conv (is_case_bool o Term.head_of)
       
   367       (expand_head_conv (Conv.rewr_conv thm))
       
   368 in
       
   369 
       
   370 fun rewrite_case_bool_conv ctxt =
       
   371   SMT_Utils.if_exists_conv is_case_bool (Conv.top_conv unfold_conv ctxt)
       
   372 
       
   373 val setup_case_bool =
       
   374   SMT_Builtin.add_builtin_fun_ext'' @{const_name "bool.case_bool"}
       
   375 
       
   376 end
       
   377 
       
   378 
       
   379 (** unfold abs, min and max **)
       
   380 
       
   381 local
       
   382   val abs_def = mk_meta_eq @{lemma
       
   383     "abs = (%a::'a::abs_if. if a < 0 then - a else a)"
       
   384     by (rule ext) (rule abs_if)}
       
   385 
       
   386   val min_def = mk_meta_eq @{lemma "min = (%a b. if a <= b then a else b)"
       
   387     by (rule ext)+ (rule min_def)}
       
   388 
       
   389   val max_def = mk_meta_eq  @{lemma "max = (%a b. if a <= b then b else a)"
       
   390     by (rule ext)+ (rule max_def)}
       
   391 
       
   392   val defs = [(@{const_name min}, min_def), (@{const_name max}, max_def),
       
   393     (@{const_name abs}, abs_def)]
       
   394 
       
   395   fun is_builtinT ctxt T =
       
   396     SMT_Builtin.is_builtin_typ_ext ctxt (Term.domain_type T)
       
   397 
       
   398   fun abs_min_max ctxt (Const (n, T)) =
       
   399         (case AList.lookup (op =) defs n of
       
   400           NONE => NONE
       
   401         | SOME thm => if is_builtinT ctxt T then SOME thm else NONE)
       
   402     | abs_min_max _ _ = NONE
       
   403 
       
   404   fun unfold_amm_conv ctxt ct =
       
   405     (case abs_min_max ctxt (Term.head_of (Thm.term_of ct)) of
       
   406       SOME thm => expand_head_conv (Conv.rewr_conv thm)
       
   407     | NONE => Conv.all_conv) ct
       
   408 in
       
   409 
       
   410 fun unfold_abs_min_max_conv ctxt =
       
   411   SMT_Utils.if_exists_conv (is_some o abs_min_max ctxt)
       
   412     (Conv.top_conv unfold_amm_conv ctxt)
       
   413   
       
   414 val setup_abs_min_max = fold (SMT_Builtin.add_builtin_fun_ext'' o fst) defs
       
   415 
       
   416 end
       
   417 
       
   418 
       
   419 (** embedding of standard natural number operations into integer operations **)
       
   420 
       
   421 local
       
   422   val nat_embedding = @{lemma
       
   423     "ALL n. nat (int n) = n"
       
   424     "ALL i. i >= 0 --> int (nat i) = i"
       
   425     "ALL i. i < 0 --> int (nat i) = 0"
       
   426     by simp_all}
       
   427 
       
   428   val simple_nat_ops = [
       
   429     @{const less (nat)}, @{const less_eq (nat)},
       
   430     @{const Suc}, @{const plus (nat)}, @{const minus (nat)}]
       
   431 
       
   432   val mult_nat_ops =
       
   433     [@{const times (nat)}, @{const div (nat)}, @{const mod (nat)}]
       
   434 
       
   435   val nat_ops = simple_nat_ops @ mult_nat_ops
       
   436 
       
   437   val nat_consts = nat_ops @ [@{const numeral (nat)},
       
   438     @{const zero_class.zero (nat)}, @{const one_class.one (nat)}]
       
   439 
       
   440   val nat_int_coercions = [@{const of_nat (int)}, @{const nat}]
       
   441 
       
   442   val builtin_nat_ops = nat_int_coercions @ simple_nat_ops
       
   443 
       
   444   val is_nat_const = member (op aconv) nat_consts
       
   445 
       
   446   fun is_nat_const' @{const of_nat (int)} = true
       
   447     | is_nat_const' t = is_nat_const t
       
   448 
       
   449   val expands = map mk_meta_eq @{lemma
       
   450     "0 = nat 0"
       
   451     "1 = nat 1"
       
   452     "(numeral :: num => nat) = (%i. nat (numeral i))"
       
   453     "op < = (%a b. int a < int b)"
       
   454     "op <= = (%a b. int a <= int b)"
       
   455     "Suc = (%a. nat (int a + 1))"
       
   456     "op + = (%a b. nat (int a + int b))"
       
   457     "op - = (%a b. nat (int a - int b))"
       
   458     "op * = (%a b. nat (int a * int b))"
       
   459     "op div = (%a b. nat (int a div int b))"
       
   460     "op mod = (%a b. nat (int a mod int b))"
       
   461     by (fastforce simp add: nat_mult_distrib nat_div_distrib nat_mod_distrib)+}
       
   462 
       
   463   val ints = map mk_meta_eq @{lemma
       
   464     "int 0 = 0"
       
   465     "int 1 = 1"
       
   466     "int (Suc n) = int n + 1"
       
   467     "int (n + m) = int n + int m"
       
   468     "int (n - m) = int (nat (int n - int m))"
       
   469     "int (n * m) = int n * int m"
       
   470     "int (n div m) = int n div int m"
       
   471     "int (n mod m) = int n mod int m"
       
   472     by (auto simp add: int_mult zdiv_int zmod_int)}
       
   473 
       
   474   val int_if = mk_meta_eq @{lemma
       
   475     "int (if P then n else m) = (if P then int n else int m)"
       
   476     by simp}
       
   477 
       
   478   fun mk_number_eq ctxt i lhs =
       
   479     let
       
   480       val eq = SMT_Utils.mk_cequals lhs (Numeral.mk_cnumber @{ctyp int} i)
       
   481       val tac =
       
   482         Simplifier.simp_tac (put_simpset HOL_ss ctxt addsimps [@{thm Int.int_numeral}]) 1
       
   483     in Goal.norm_result ctxt (Goal.prove_internal ctxt [] eq (K tac)) end
       
   484 
       
   485   fun ite_conv cv1 cv2 =
       
   486     Conv.combination_conv (Conv.combination_conv (Conv.arg_conv cv1) cv2) cv2
       
   487 
       
   488   fun int_conv ctxt ct =
       
   489     (case Thm.term_of ct of
       
   490       @{const of_nat (int)} $ (n as (@{const numeral (nat)} $ _)) =>
       
   491         Conv.rewr_conv (mk_number_eq ctxt (snd (HOLogic.dest_number n)) ct)
       
   492     | @{const of_nat (int)} $ _ =>
       
   493         (Conv.rewrs_conv ints then_conv Conv.sub_conv ints_conv ctxt) else_conv
       
   494         (Conv.rewr_conv int_if then_conv
       
   495           ite_conv (nat_conv ctxt) (int_conv ctxt)) else_conv
       
   496         Conv.sub_conv (Conv.top_sweep_conv nat_conv) ctxt
       
   497     | _ => Conv.no_conv) ct
       
   498 
       
   499   and ints_conv ctxt = Conv.top_sweep_conv int_conv ctxt
       
   500 
       
   501   and expand_conv ctxt =
       
   502     SMT_Utils.if_conv (is_nat_const o Term.head_of)
       
   503       (expand_head_conv (Conv.rewrs_conv expands) then_conv ints_conv ctxt)
       
   504       (int_conv ctxt)
       
   505 
       
   506   and nat_conv ctxt = SMT_Utils.if_exists_conv is_nat_const'
       
   507     (Conv.top_sweep_conv expand_conv ctxt)
       
   508 
       
   509   val uses_nat_int = Term.exists_subterm (member (op aconv) nat_int_coercions)
       
   510 in
       
   511 
       
   512 val nat_as_int_conv = nat_conv
       
   513 
       
   514 fun add_nat_embedding thms =
       
   515   if exists (uses_nat_int o Thm.prop_of) thms then (thms, nat_embedding)
       
   516   else (thms, [])
       
   517 
       
   518 val setup_nat_as_int =
       
   519   SMT_Builtin.add_builtin_typ_ext (@{typ nat}, K true) #>
       
   520   fold (SMT_Builtin.add_builtin_fun_ext' o Term.dest_Const) builtin_nat_ops
       
   521 
       
   522 end
       
   523 
       
   524 
       
   525 (** normalize numerals **)
       
   526 
       
   527 local
       
   528   (*
       
   529     rewrite Numeral1 into 1
       
   530     rewrite - 0 into 0
       
   531   *)
       
   532 
       
   533   fun is_irregular_number (Const (@{const_name numeral}, _) $ Const (@{const_name num.One}, _)) =
       
   534         true
       
   535     | is_irregular_number (Const (@{const_name uminus}, _) $ Const (@{const_name Groups.zero}, _)) =
       
   536         true
       
   537     | is_irregular_number _ =
       
   538         false;
       
   539 
       
   540   fun is_strange_number ctxt t = is_irregular_number t andalso SMT_Builtin.is_builtin_num ctxt t;
       
   541 
       
   542   val proper_num_ss =
       
   543     simpset_of (put_simpset HOL_ss @{context}
       
   544       addsimps @{thms Num.numeral_One minus_zero})
       
   545 
       
   546   fun norm_num_conv ctxt =
       
   547     SMT_Utils.if_conv (is_strange_number ctxt)
       
   548       (Simplifier.rewrite (put_simpset proper_num_ss ctxt)) Conv.no_conv
       
   549 in
       
   550 
       
   551 fun normalize_numerals_conv ctxt =
       
   552   SMT_Utils.if_exists_conv (is_strange_number ctxt)
       
   553     (Conv.top_sweep_conv norm_num_conv ctxt)
       
   554 
       
   555 end
       
   556 
       
   557 
       
   558 (** combined unfoldings and rewritings **)
       
   559 
       
   560 fun unfold_conv ctxt =
       
   561   rewrite_case_bool_conv ctxt then_conv
       
   562   unfold_abs_min_max_conv ctxt then_conv
       
   563   nat_as_int_conv ctxt then_conv
       
   564   Thm.beta_conversion true
       
   565 
       
   566 fun unfold1 ctxt = map (apsnd (Conv.fconv_rule (unfold_conv ctxt)))
       
   567 
       
   568 fun burrow_ids f ithms =
       
   569   let
       
   570     val (is, thms) = split_list ithms
       
   571     val (thms', extra_thms) = f thms
       
   572   in (is ~~ thms') @ map (pair ~1) extra_thms end
       
   573 
       
   574 fun unfold2 ctxt ithms =
       
   575   ithms
       
   576   |> map (apsnd (Conv.fconv_rule (normalize_numerals_conv ctxt)))
       
   577   |> burrow_ids add_nat_embedding
       
   578 
       
   579 
       
   580 
       
   581 (* overall normalization *)
       
   582 
       
   583 type extra_norm = Proof.context -> thm list * thm list -> thm list * thm list
       
   584 
       
   585 structure Extra_Norms = Generic_Data
       
   586 (
       
   587   type T = extra_norm SMT_Utils.dict
       
   588   val empty = []
       
   589   val extend = I
       
   590   fun merge data = SMT_Utils.dict_merge fst data
       
   591 )
       
   592 
       
   593 fun add_extra_norm (cs, norm) =
       
   594   Extra_Norms.map (SMT_Utils.dict_update (cs, norm))
       
   595 
       
   596 fun apply_extra_norms ctxt ithms =
       
   597   let
       
   598     val cs = SMT_Config.solver_class_of ctxt
       
   599     val es = SMT_Utils.dict_lookup (Extra_Norms.get (Context.Proof ctxt)) cs
       
   600   in burrow_ids (fold (fn e => e ctxt) es o rpair []) ithms end
       
   601 
       
   602 local
       
   603   val ignored = member (op =) [@{const_name All}, @{const_name Ex},
       
   604     @{const_name Let}, @{const_name If}, @{const_name HOL.eq}]
       
   605 
       
   606   val schematic_consts_of =
       
   607     let
       
   608       fun collect (@{const SMT.trigger} $ p $ t) =
       
   609             collect_trigger p #> collect t
       
   610         | collect (t $ u) = collect t #> collect u
       
   611         | collect (Abs (_, _, t)) = collect t
       
   612         | collect (t as Const (n, _)) = 
       
   613             if not (ignored n) then Monomorph.add_schematic_consts_of t else I
       
   614         | collect _ = I
       
   615       and collect_trigger t =
       
   616         let val dest = these o try HOLogic.dest_list 
       
   617         in fold (fold collect_pat o dest) (dest t) end
       
   618       and collect_pat (Const (@{const_name SMT.pat}, _) $ t) = collect t
       
   619         | collect_pat (Const (@{const_name SMT.nopat}, _) $ t) = collect t
       
   620         | collect_pat _ = I
       
   621     in (fn t => collect t Symtab.empty) end
       
   622 in
       
   623 
       
   624 fun monomorph ctxt xthms =
       
   625   let val (xs, thms) = split_list xthms
       
   626   in
       
   627     map (pair 1) thms
       
   628     |> Monomorph.monomorph schematic_consts_of ctxt
       
   629     |> maps (uncurry (map o pair)) o map2 pair xs o map (map snd)
       
   630   end
       
   631 
       
   632 end
       
   633 
       
   634 fun normalize iwthms ctxt =
       
   635   iwthms
       
   636   |> gen_normalize ctxt
       
   637   |> unfold1 ctxt
       
   638   |> monomorph ctxt
       
   639   |> unfold2 ctxt
       
   640   |> apply_extra_norms ctxt
       
   641   |> rpair ctxt
       
   642 
       
   643 val setup = Context.theory_map (
       
   644   setup_atomize #>
       
   645   setup_unfolded_quants #>
       
   646   setup_trigger #>
       
   647   setup_weight #>
       
   648   setup_case_bool #>
       
   649   setup_abs_min_max #>
       
   650   setup_nat_as_int)
       
   651 
       
   652 end