src/HOL/Tools/Nitpick/nitpick_preproc.ML
changeset 35070 96136eb6218f
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     1 (*  Title:      HOL/Tools/Nitpick/nitpick_preproc.ML
       
     2     Author:     Jasmin Blanchette, TU Muenchen
       
     3     Copyright   2008, 2009, 2010
       
     4 
       
     5 Nitpick's HOL preprocessor.
       
     6 *)
       
     7 
       
     8 signature NITPICK_PREPROC =
       
     9 sig
       
    10   type hol_context = Nitpick_HOL.hol_context
       
    11   val preprocess_term :
       
    12     hol_context -> term -> ((term list * term list) * (bool * bool)) * term
       
    13 end
       
    14 
       
    15 structure Nitpick_Preproc : NITPICK_PREPROC =
       
    16 struct
       
    17 
       
    18 open Nitpick_Util
       
    19 open Nitpick_HOL
       
    20 
       
    21 (* polarity -> string -> bool *)
       
    22 fun is_positive_existential polar quant_s =
       
    23   (polar = Pos andalso quant_s = @{const_name Ex}) orelse
       
    24   (polar = Neg andalso quant_s <> @{const_name Ex})
       
    25 
       
    26 (** Binary coding of integers **)
       
    27 
       
    28 (* If a formula contains a numeral whose absolute value is more than this
       
    29    threshold, the unary coding is likely not to work well and we prefer the
       
    30    binary coding. *)
       
    31 val binary_int_threshold = 3
       
    32 
       
    33 (* term -> bool *)
       
    34 fun may_use_binary_ints (t1 $ t2) =
       
    35     may_use_binary_ints t1 andalso may_use_binary_ints t2
       
    36   | may_use_binary_ints (t as Const (s, _)) =
       
    37     t <> @{const Suc} andalso
       
    38     not (member (op =) [@{const_name Abs_Frac}, @{const_name Rep_Frac},
       
    39                         @{const_name nat_gcd}, @{const_name nat_lcm},
       
    40                         @{const_name Frac}, @{const_name norm_frac}] s)
       
    41   | may_use_binary_ints (Abs (_, _, t')) = may_use_binary_ints t'
       
    42   | may_use_binary_ints _ = true
       
    43 fun should_use_binary_ints (t1 $ t2) =
       
    44     should_use_binary_ints t1 orelse should_use_binary_ints t2
       
    45   | should_use_binary_ints (Const (s, _)) =
       
    46     member (op =) [@{const_name times_nat_inst.times_nat},
       
    47                    @{const_name div_nat_inst.div_nat},
       
    48                    @{const_name times_int_inst.times_int},
       
    49                    @{const_name div_int_inst.div_int}] s orelse
       
    50     (String.isPrefix numeral_prefix s andalso
       
    51      let val n = the (Int.fromString (unprefix numeral_prefix s)) in
       
    52        n < ~ binary_int_threshold orelse n > binary_int_threshold
       
    53      end)
       
    54   | should_use_binary_ints (Abs (_, _, t')) = should_use_binary_ints t'
       
    55   | should_use_binary_ints _ = false
       
    56 
       
    57 (* typ -> typ *)
       
    58 fun binarize_nat_and_int_in_type @{typ nat} = @{typ "unsigned_bit word"}
       
    59   | binarize_nat_and_int_in_type @{typ int} = @{typ "signed_bit word"}
       
    60   | binarize_nat_and_int_in_type (Type (s, Ts)) =
       
    61     Type (s, map binarize_nat_and_int_in_type Ts)
       
    62   | binarize_nat_and_int_in_type T = T
       
    63 (* term -> term *)
       
    64 val binarize_nat_and_int_in_term = map_types binarize_nat_and_int_in_type
       
    65 
       
    66 (** Uncurrying **)
       
    67 
       
    68 (* theory -> term -> int Termtab.tab -> int Termtab.tab *)
       
    69 fun add_to_uncurry_table thy t =
       
    70   let
       
    71     (* term -> term list -> int Termtab.tab -> int Termtab.tab *)
       
    72     fun aux (t1 $ t2) args table =
       
    73         let val table = aux t2 [] table in aux t1 (t2 :: args) table end
       
    74       | aux (Abs (_, _, t')) _ table = aux t' [] table
       
    75       | aux (t as Const (x as (s, _))) args table =
       
    76         if is_built_in_const true x orelse is_constr_like thy x orelse
       
    77            is_sel s orelse s = @{const_name Sigma} then
       
    78           table
       
    79         else
       
    80           Termtab.map_default (t, 65536) (curry Int.min (length args)) table
       
    81       | aux _ _ table = table
       
    82   in aux t [] end
       
    83 
       
    84 (* int -> int -> string *)
       
    85 fun uncurry_prefix_for k j =
       
    86   uncurry_prefix ^ string_of_int k ^ "@" ^ string_of_int j ^ name_sep
       
    87 
       
    88 (* int Termtab.tab term -> term *)
       
    89 fun uncurry_term table t =
       
    90   let
       
    91     (* term -> term list -> term *)
       
    92     fun aux (t1 $ t2) args = aux t1 (aux t2 [] :: args)
       
    93       | aux (Abs (s, T, t')) args = betapplys (Abs (s, T, aux t' []), args)
       
    94       | aux (t as Const (s, T)) args =
       
    95         (case Termtab.lookup table t of
       
    96            SOME n =>
       
    97            if n >= 2 then
       
    98              let
       
    99                val (arg_Ts, rest_T) = strip_n_binders n T
       
   100                val j =
       
   101                  if hd arg_Ts = @{typ bisim_iterator} orelse
       
   102                     is_fp_iterator_type (hd arg_Ts) then
       
   103                    1
       
   104                  else case find_index (not_equal bool_T) arg_Ts of
       
   105                    ~1 => n
       
   106                  | j => j
       
   107                val ((before_args, tuple_args), after_args) =
       
   108                  args |> chop n |>> chop j
       
   109                val ((before_arg_Ts, tuple_arg_Ts), rest_T) =
       
   110                  T |> strip_n_binders n |>> chop j
       
   111                val tuple_T = HOLogic.mk_tupleT tuple_arg_Ts
       
   112              in
       
   113                if n - j < 2 then
       
   114                  betapplys (t, args)
       
   115                else
       
   116                  betapplys (Const (uncurry_prefix_for (n - j) j ^ s,
       
   117                                    before_arg_Ts ---> tuple_T --> rest_T),
       
   118                             before_args @ [mk_flat_tuple tuple_T tuple_args] @
       
   119                             after_args)
       
   120              end
       
   121            else
       
   122              betapplys (t, args)
       
   123          | NONE => betapplys (t, args))
       
   124       | aux t args = betapplys (t, args)
       
   125   in aux t [] end
       
   126 
       
   127 (** Boxing **)
       
   128 
       
   129 (* hol_context -> typ -> term -> term *)
       
   130 fun constr_expand (hol_ctxt as {thy, ...}) T t =
       
   131   (case head_of t of
       
   132      Const x => if is_constr_like thy x then t else raise SAME ()
       
   133    | _ => raise SAME ())
       
   134   handle SAME () =>
       
   135          let
       
   136            val x' as (_, T') =
       
   137              if is_pair_type T then
       
   138                let val (T1, T2) = HOLogic.dest_prodT T in
       
   139                  (@{const_name Pair}, T1 --> T2 --> T)
       
   140                end
       
   141              else
       
   142                datatype_constrs hol_ctxt T |> hd
       
   143            val arg_Ts = binder_types T'
       
   144          in
       
   145            list_comb (Const x', map2 (select_nth_constr_arg thy x' t)
       
   146                                      (index_seq 0 (length arg_Ts)) arg_Ts)
       
   147          end
       
   148 
       
   149 (* hol_context -> bool -> term -> term *)
       
   150 fun box_fun_and_pair_in_term (hol_ctxt as {thy, fast_descrs, ...}) def orig_t =
       
   151   let
       
   152     (* typ -> typ *)
       
   153     fun box_relational_operator_type (Type ("fun", Ts)) =
       
   154         Type ("fun", map box_relational_operator_type Ts)
       
   155       | box_relational_operator_type (Type ("*", Ts)) =
       
   156         Type ("*", map (box_type hol_ctxt InPair) Ts)
       
   157       | box_relational_operator_type T = T
       
   158     (* (term -> term) -> int -> term -> term *)
       
   159     fun coerce_bound_no f j t =
       
   160       case t of
       
   161         t1 $ t2 => coerce_bound_no f j t1 $ coerce_bound_no f j t2
       
   162       | Abs (s, T, t') => Abs (s, T, coerce_bound_no f (j + 1) t')
       
   163       | Bound j' => if j' = j then f t else t
       
   164       | _ => t
       
   165     (* typ -> typ -> term -> term *)
       
   166     fun coerce_bound_0_in_term new_T old_T =
       
   167       old_T <> new_T ? coerce_bound_no (coerce_term [new_T] old_T new_T) 0
       
   168     (* typ list -> typ -> term -> term *)
       
   169     and coerce_term Ts new_T old_T t =
       
   170       if old_T = new_T then
       
   171         t
       
   172       else
       
   173         case (new_T, old_T) of
       
   174           (Type (new_s, new_Ts as [new_T1, new_T2]),
       
   175            Type ("fun", [old_T1, old_T2])) =>
       
   176           (case eta_expand Ts t 1 of
       
   177              Abs (s, _, t') =>
       
   178              Abs (s, new_T1,
       
   179                   t' |> coerce_bound_0_in_term new_T1 old_T1
       
   180                      |> coerce_term (new_T1 :: Ts) new_T2 old_T2)
       
   181              |> Envir.eta_contract
       
   182              |> new_s <> "fun"
       
   183                 ? construct_value thy (@{const_name FunBox},
       
   184                                        Type ("fun", new_Ts) --> new_T) o single
       
   185            | t' => raise TERM ("Nitpick_Preproc.box_fun_and_pair_in_term.\
       
   186                                \coerce_term", [t']))
       
   187         | (Type (new_s, new_Ts as [new_T1, new_T2]),
       
   188            Type (old_s, old_Ts as [old_T1, old_T2])) =>
       
   189           if old_s = @{type_name fun_box} orelse
       
   190              old_s = @{type_name pair_box} orelse old_s = "*" then
       
   191             case constr_expand hol_ctxt old_T t of
       
   192               Const (@{const_name FunBox}, _) $ t1 =>
       
   193               if new_s = "fun" then
       
   194                 coerce_term Ts new_T (Type ("fun", old_Ts)) t1
       
   195               else
       
   196                 construct_value thy
       
   197                     (@{const_name FunBox}, Type ("fun", new_Ts) --> new_T)
       
   198                      [coerce_term Ts (Type ("fun", new_Ts))
       
   199                                   (Type ("fun", old_Ts)) t1]
       
   200             | Const _ $ t1 $ t2 =>
       
   201               construct_value thy
       
   202                   (if new_s = "*" then @{const_name Pair}
       
   203                    else @{const_name PairBox}, new_Ts ---> new_T)
       
   204                   [coerce_term Ts new_T1 old_T1 t1,
       
   205                    coerce_term Ts new_T2 old_T2 t2]
       
   206             | t' => raise TERM ("Nitpick_Preproc.box_fun_and_pair_in_term.\
       
   207                                 \coerce_term", [t'])
       
   208           else
       
   209             raise TYPE ("coerce_term", [new_T, old_T], [t])
       
   210         | _ => raise TYPE ("coerce_term", [new_T, old_T], [t])
       
   211     (* indexname * typ -> typ * term -> typ option list -> typ option list *)
       
   212     fun add_boxed_types_for_var (z as (_, T)) (T', t') =
       
   213       case t' of
       
   214         Var z' => z' = z ? insert (op =) T'
       
   215       | Const (@{const_name Pair}, _) $ t1 $ t2 =>
       
   216         (case T' of
       
   217            Type (_, [T1, T2]) =>
       
   218            fold (add_boxed_types_for_var z) [(T1, t1), (T2, t2)]
       
   219          | _ => raise TYPE ("Nitpick_Preproc.box_fun_and_pair_in_term.\
       
   220                             \add_boxed_types_for_var", [T'], []))
       
   221       | _ => exists_subterm (curry (op =) (Var z)) t' ? insert (op =) T
       
   222     (* typ list -> typ list -> term -> indexname * typ -> typ *)
       
   223     fun box_var_in_def new_Ts old_Ts t (z as (_, T)) =
       
   224       case t of
       
   225         @{const Trueprop} $ t1 => box_var_in_def new_Ts old_Ts t1 z
       
   226       | Const (s0, _) $ t1 $ _ =>
       
   227         if s0 = @{const_name "=="} orelse s0 = @{const_name "op ="} then
       
   228           let
       
   229             val (t', args) = strip_comb t1
       
   230             val T' = fastype_of1 (new_Ts, do_term new_Ts old_Ts Neut t')
       
   231           in
       
   232             case fold (add_boxed_types_for_var z)
       
   233                       (fst (strip_n_binders (length args) T') ~~ args) [] of
       
   234               [T''] => T''
       
   235             | _ => T
       
   236           end
       
   237         else
       
   238           T
       
   239       | _ => T
       
   240     (* typ list -> typ list -> polarity -> string -> typ -> string -> typ
       
   241        -> term -> term *)
       
   242     and do_quantifier new_Ts old_Ts polar quant_s quant_T abs_s abs_T t =
       
   243       let
       
   244         val abs_T' =
       
   245           if polar = Neut orelse is_positive_existential polar quant_s then
       
   246             box_type hol_ctxt InFunLHS abs_T
       
   247           else
       
   248             abs_T
       
   249         val body_T = body_type quant_T
       
   250       in
       
   251         Const (quant_s, (abs_T' --> body_T) --> body_T)
       
   252         $ Abs (abs_s, abs_T',
       
   253                t |> do_term (abs_T' :: new_Ts) (abs_T :: old_Ts) polar)
       
   254       end
       
   255     (* typ list -> typ list -> string -> typ -> term -> term -> term *)
       
   256     and do_equals new_Ts old_Ts s0 T0 t1 t2 =
       
   257       let
       
   258         val (t1, t2) = pairself (do_term new_Ts old_Ts Neut) (t1, t2)
       
   259         val (T1, T2) = pairself (curry fastype_of1 new_Ts) (t1, t2)
       
   260         val T = [T1, T2] |> sort TermOrd.typ_ord |> List.last
       
   261       in
       
   262         list_comb (Const (s0, T --> T --> body_type T0),
       
   263                    map2 (coerce_term new_Ts T) [T1, T2] [t1, t2])
       
   264       end
       
   265     (* string -> typ -> term *)
       
   266     and do_description_operator s T =
       
   267       let val T1 = box_type hol_ctxt InFunLHS (range_type T) in
       
   268         Const (s, (T1 --> bool_T) --> T1)
       
   269       end
       
   270     (* typ list -> typ list -> polarity -> term -> term *)
       
   271     and do_term new_Ts old_Ts polar t =
       
   272       case t of
       
   273         Const (s0 as @{const_name all}, T0) $ Abs (s1, T1, t1) =>
       
   274         do_quantifier new_Ts old_Ts polar s0 T0 s1 T1 t1
       
   275       | Const (s0 as @{const_name "=="}, T0) $ t1 $ t2 =>
       
   276         do_equals new_Ts old_Ts s0 T0 t1 t2
       
   277       | @{const "==>"} $ t1 $ t2 =>
       
   278         @{const "==>"} $ do_term new_Ts old_Ts (flip_polarity polar) t1
       
   279         $ do_term new_Ts old_Ts polar t2
       
   280       | @{const Pure.conjunction} $ t1 $ t2 =>
       
   281         @{const Pure.conjunction} $ do_term new_Ts old_Ts polar t1
       
   282         $ do_term new_Ts old_Ts polar t2
       
   283       | @{const Trueprop} $ t1 =>
       
   284         @{const Trueprop} $ do_term new_Ts old_Ts polar t1
       
   285       | @{const Not} $ t1 =>
       
   286         @{const Not} $ do_term new_Ts old_Ts (flip_polarity polar) t1
       
   287       | Const (s0 as @{const_name All}, T0) $ Abs (s1, T1, t1) =>
       
   288         do_quantifier new_Ts old_Ts polar s0 T0 s1 T1 t1
       
   289       | Const (s0 as @{const_name Ex}, T0) $ Abs (s1, T1, t1) =>
       
   290         do_quantifier new_Ts old_Ts polar s0 T0 s1 T1 t1
       
   291       | Const (s0 as @{const_name "op ="}, T0) $ t1 $ t2 =>
       
   292         do_equals new_Ts old_Ts s0 T0 t1 t2
       
   293       | @{const "op &"} $ t1 $ t2 =>
       
   294         @{const "op &"} $ do_term new_Ts old_Ts polar t1
       
   295         $ do_term new_Ts old_Ts polar t2
       
   296       | @{const "op |"} $ t1 $ t2 =>
       
   297         @{const "op |"} $ do_term new_Ts old_Ts polar t1
       
   298         $ do_term new_Ts old_Ts polar t2
       
   299       | @{const "op -->"} $ t1 $ t2 =>
       
   300         @{const "op -->"} $ do_term new_Ts old_Ts (flip_polarity polar) t1
       
   301         $ do_term new_Ts old_Ts polar t2
       
   302       | Const (s as @{const_name The}, T) => do_description_operator s T
       
   303       | Const (s as @{const_name Eps}, T) => do_description_operator s T
       
   304       | Const (@{const_name quot_normal}, Type ("fun", [_, T2])) =>
       
   305         let val T' = box_type hol_ctxt InSel T2 in
       
   306           Const (@{const_name quot_normal}, T' --> T')
       
   307         end
       
   308       | Const (s as @{const_name Tha}, T) => do_description_operator s T
       
   309       | Const (x as (s, T)) =>
       
   310         Const (s, if s = @{const_name converse} orelse
       
   311                      s = @{const_name trancl} then
       
   312                     box_relational_operator_type T
       
   313                   else if is_built_in_const fast_descrs x orelse
       
   314                           s = @{const_name Sigma} then
       
   315                     T
       
   316                   else if is_constr_like thy x then
       
   317                     box_type hol_ctxt InConstr T
       
   318                   else if is_sel s
       
   319                        orelse is_rep_fun thy x then
       
   320                     box_type hol_ctxt InSel T
       
   321                   else
       
   322                     box_type hol_ctxt InExpr T)
       
   323       | t1 $ Abs (s, T, t2') =>
       
   324         let
       
   325           val t1 = do_term new_Ts old_Ts Neut t1
       
   326           val T1 = fastype_of1 (new_Ts, t1)
       
   327           val (s1, Ts1) = dest_Type T1
       
   328           val T' = hd (snd (dest_Type (hd Ts1)))
       
   329           val t2 = Abs (s, T', do_term (T' :: new_Ts) (T :: old_Ts) Neut t2')
       
   330           val T2 = fastype_of1 (new_Ts, t2)
       
   331           val t2 = coerce_term new_Ts (hd Ts1) T2 t2
       
   332         in
       
   333           betapply (if s1 = "fun" then
       
   334                       t1
       
   335                     else
       
   336                       select_nth_constr_arg thy
       
   337                           (@{const_name FunBox}, Type ("fun", Ts1) --> T1) t1 0
       
   338                           (Type ("fun", Ts1)), t2)
       
   339         end
       
   340       | t1 $ t2 =>
       
   341         let
       
   342           val t1 = do_term new_Ts old_Ts Neut t1
       
   343           val T1 = fastype_of1 (new_Ts, t1)
       
   344           val (s1, Ts1) = dest_Type T1
       
   345           val t2 = do_term new_Ts old_Ts Neut t2
       
   346           val T2 = fastype_of1 (new_Ts, t2)
       
   347           val t2 = coerce_term new_Ts (hd Ts1) T2 t2
       
   348         in
       
   349           betapply (if s1 = "fun" then
       
   350                       t1
       
   351                     else
       
   352                       select_nth_constr_arg thy
       
   353                           (@{const_name FunBox}, Type ("fun", Ts1) --> T1) t1 0
       
   354                           (Type ("fun", Ts1)), t2)
       
   355         end
       
   356       | Free (s, T) => Free (s, box_type hol_ctxt InExpr T)
       
   357       | Var (z as (x, T)) =>
       
   358         Var (x, if def then box_var_in_def new_Ts old_Ts orig_t z
       
   359                 else box_type hol_ctxt InExpr T)
       
   360       | Bound _ => t
       
   361       | Abs (s, T, t') =>
       
   362         Abs (s, T, do_term (T :: new_Ts) (T :: old_Ts) Neut t')
       
   363   in do_term [] [] Pos orig_t end
       
   364 
       
   365 (** Destruction of constructors **)
       
   366 
       
   367 val val_var_prefix = nitpick_prefix ^ "v"
       
   368 
       
   369 (* typ list -> int -> int -> int -> term -> term *)
       
   370 fun fresh_value_var Ts k n j t =
       
   371   Var ((val_var_prefix ^ nat_subscript (n - j), k), fastype_of1 (Ts, t))
       
   372 
       
   373 (* typ list -> int -> term -> bool *)
       
   374 fun has_heavy_bounds_or_vars Ts level t =
       
   375   let
       
   376     (* typ list -> bool *)
       
   377     fun aux [] = false
       
   378       | aux [T] = is_fun_type T orelse is_pair_type T
       
   379       | aux _ = true
       
   380   in aux (map snd (Term.add_vars t []) @ map (nth Ts) (loose_bnos t)) end
       
   381 
       
   382 (* theory -> typ list -> bool -> int -> int -> term -> term list -> term list
       
   383    -> term * term list *)
       
   384 fun pull_out_constr_comb thy Ts relax k level t args seen =
       
   385   let val t_comb = list_comb (t, args) in
       
   386     case t of
       
   387       Const x =>
       
   388       if not relax andalso is_constr thy x andalso
       
   389          not (is_fun_type (fastype_of1 (Ts, t_comb))) andalso
       
   390          has_heavy_bounds_or_vars Ts level t_comb andalso
       
   391          not (loose_bvar (t_comb, level)) then
       
   392         let
       
   393           val (j, seen) = case find_index (curry (op =) t_comb) seen of
       
   394                             ~1 => (0, t_comb :: seen)
       
   395                           | j => (j, seen)
       
   396         in (fresh_value_var Ts k (length seen) j t_comb, seen) end
       
   397       else
       
   398         (t_comb, seen)
       
   399     | _ => (t_comb, seen)
       
   400   end
       
   401 
       
   402 (* (term -> term) -> typ list -> int -> term list -> term list *)
       
   403 fun equations_for_pulled_out_constrs mk_eq Ts k seen =
       
   404   let val n = length seen in
       
   405     map2 (fn j => fn t => mk_eq (fresh_value_var Ts k n j t, t))
       
   406          (index_seq 0 n) seen
       
   407   end
       
   408 
       
   409 (* theory -> bool -> term -> term *)
       
   410 fun pull_out_universal_constrs thy def t =
       
   411   let
       
   412     val k = maxidx_of_term t + 1
       
   413     (* typ list -> bool -> term -> term list -> term list -> term * term list *)
       
   414     fun do_term Ts def t args seen =
       
   415       case t of
       
   416         (t0 as Const (@{const_name "=="}, _)) $ t1 $ t2 =>
       
   417         do_eq_or_imp Ts true def t0 t1 t2 seen
       
   418       | (t0 as @{const "==>"}) $ t1 $ t2 =>
       
   419         if def then (t, []) else do_eq_or_imp Ts false def t0 t1 t2 seen
       
   420       | (t0 as Const (@{const_name "op ="}, _)) $ t1 $ t2 =>
       
   421         do_eq_or_imp Ts true def t0 t1 t2 seen
       
   422       | (t0 as @{const "op -->"}) $ t1 $ t2 =>
       
   423         do_eq_or_imp Ts false def t0 t1 t2 seen
       
   424       | Abs (s, T, t') =>
       
   425         let val (t', seen) = do_term (T :: Ts) def t' [] seen in
       
   426           (list_comb (Abs (s, T, t'), args), seen)
       
   427         end
       
   428       | t1 $ t2 =>
       
   429         let val (t2, seen) = do_term Ts def t2 [] seen in
       
   430           do_term Ts def t1 (t2 :: args) seen
       
   431         end
       
   432       | _ => pull_out_constr_comb thy Ts def k 0 t args seen
       
   433     (* typ list -> bool -> bool -> term -> term -> term -> term list
       
   434        -> term * term list *)
       
   435     and do_eq_or_imp Ts eq def t0 t1 t2 seen =
       
   436       let
       
   437         val (t2, seen) = if eq andalso def then (t2, seen)
       
   438                          else do_term Ts false t2 [] seen
       
   439         val (t1, seen) = do_term Ts false t1 [] seen
       
   440       in (t0 $ t1 $ t2, seen) end
       
   441     val (concl, seen) = do_term [] def t [] []
       
   442   in
       
   443     Logic.list_implies (equations_for_pulled_out_constrs Logic.mk_equals [] k
       
   444                                                          seen, concl)
       
   445   end
       
   446 
       
   447 (* term -> term -> term *)
       
   448 fun mk_exists v t =
       
   449   HOLogic.exists_const (fastype_of v) $ lambda v (incr_boundvars 1 t)
       
   450 
       
   451 (* theory -> term -> term *)
       
   452 fun pull_out_existential_constrs thy t =
       
   453   let
       
   454     val k = maxidx_of_term t + 1
       
   455     (* typ list -> int -> term -> term list -> term list -> term * term list *)
       
   456     fun aux Ts num_exists t args seen =
       
   457       case t of
       
   458         (t0 as Const (@{const_name Ex}, _)) $ Abs (s1, T1, t1) =>
       
   459         let
       
   460           val (t1, seen') = aux (T1 :: Ts) (num_exists + 1) t1 [] []
       
   461           val n = length seen'
       
   462           (* unit -> term list *)
       
   463           fun vars () = map2 (fresh_value_var Ts k n) (index_seq 0 n) seen'
       
   464         in
       
   465           (equations_for_pulled_out_constrs HOLogic.mk_eq Ts k seen'
       
   466            |> List.foldl s_conj t1 |> fold mk_exists (vars ())
       
   467            |> curry3 Abs s1 T1 |> curry (op $) t0, seen)
       
   468         end
       
   469       | t1 $ t2 =>
       
   470         let val (t2, seen) = aux Ts num_exists t2 [] seen in
       
   471           aux Ts num_exists t1 (t2 :: args) seen
       
   472         end
       
   473       | Abs (s, T, t') =>
       
   474         let
       
   475           val (t', seen) = aux (T :: Ts) 0 t' [] (map (incr_boundvars 1) seen)
       
   476         in (list_comb (Abs (s, T, t'), args), map (incr_boundvars ~1) seen) end
       
   477       | _ =>
       
   478         if num_exists > 0 then
       
   479           pull_out_constr_comb thy Ts false k num_exists t args seen
       
   480         else
       
   481           (list_comb (t, args), seen)
       
   482   in aux [] 0 t [] [] |> fst end
       
   483 
       
   484 (* hol_context -> bool -> term -> term *)
       
   485 fun destroy_pulled_out_constrs (hol_ctxt as {thy, ...}) axiom t =
       
   486   let
       
   487     (* styp -> int *)
       
   488     val num_occs_of_var =
       
   489       fold_aterms (fn Var z => (fn f => fn z' => f z' |> z = z' ? Integer.add 1)
       
   490                     | _ => I) t (K 0)
       
   491     (* bool -> term -> term *)
       
   492     fun aux careful ((t0 as Const (@{const_name "=="}, _)) $ t1 $ t2) =
       
   493         aux_eq careful true t0 t1 t2
       
   494       | aux careful ((t0 as @{const "==>"}) $ t1 $ t2) =
       
   495         t0 $ aux false t1 $ aux careful t2
       
   496       | aux careful ((t0 as Const (@{const_name "op ="}, _)) $ t1 $ t2) =
       
   497         aux_eq careful true t0 t1 t2
       
   498       | aux careful ((t0 as @{const "op -->"}) $ t1 $ t2) =
       
   499         t0 $ aux false t1 $ aux careful t2
       
   500       | aux careful (Abs (s, T, t')) = Abs (s, T, aux careful t')
       
   501       | aux careful (t1 $ t2) = aux careful t1 $ aux careful t2
       
   502       | aux _ t = t
       
   503     (* bool -> bool -> term -> term -> term -> term *)
       
   504     and aux_eq careful pass1 t0 t1 t2 =
       
   505       ((if careful then
       
   506           raise SAME ()
       
   507         else if axiom andalso is_Var t2 andalso
       
   508                 num_occs_of_var (dest_Var t2) = 1 then
       
   509           @{const True}
       
   510         else case strip_comb t2 of
       
   511           (* The first case is not as general as it could be. *)
       
   512           (Const (@{const_name PairBox}, _),
       
   513                   [Const (@{const_name fst}, _) $ Var z1,
       
   514                    Const (@{const_name snd}, _) $ Var z2]) =>
       
   515           if z1 = z2 andalso num_occs_of_var z1 = 2 then @{const True}
       
   516           else raise SAME ()
       
   517         | (Const (x as (s, T)), args) =>
       
   518           let val arg_Ts = binder_types T in
       
   519             if length arg_Ts = length args andalso
       
   520                (is_constr thy x orelse s = @{const_name Pair} orelse
       
   521                 x = (@{const_name Suc}, nat_T --> nat_T)) andalso
       
   522                (not careful orelse not (is_Var t1) orelse
       
   523                 String.isPrefix val_var_prefix (fst (fst (dest_Var t1)))) then
       
   524               discriminate_value hol_ctxt x t1 ::
       
   525               map3 (sel_eq x t1) (index_seq 0 (length args)) arg_Ts args
       
   526               |> foldr1 s_conj
       
   527             else
       
   528               raise SAME ()
       
   529           end
       
   530         | _ => raise SAME ())
       
   531        |> body_type (type_of t0) = prop_T ? HOLogic.mk_Trueprop)
       
   532       handle SAME () => if pass1 then aux_eq careful false t0 t2 t1
       
   533                         else t0 $ aux false t2 $ aux false t1
       
   534     (* styp -> term -> int -> typ -> term -> term *)
       
   535     and sel_eq x t n nth_T nth_t =
       
   536       HOLogic.eq_const nth_T $ nth_t $ select_nth_constr_arg thy x t n nth_T
       
   537       |> aux false
       
   538   in aux axiom t end
       
   539 
       
   540 (** Destruction of universal and existential equalities **)
       
   541 
       
   542 (* term -> term *)
       
   543 fun curry_assms (@{const "==>"} $ (@{const Trueprop}
       
   544                                    $ (@{const "op &"} $ t1 $ t2)) $ t3) =
       
   545     curry_assms (Logic.list_implies ([t1, t2] |> map HOLogic.mk_Trueprop, t3))
       
   546   | curry_assms (@{const "==>"} $ t1 $ t2) =
       
   547     @{const "==>"} $ curry_assms t1 $ curry_assms t2
       
   548   | curry_assms t = t
       
   549 
       
   550 (* term -> term *)
       
   551 val destroy_universal_equalities =
       
   552   let
       
   553     (* term list -> (indexname * typ) list -> term -> term *)
       
   554     fun aux prems zs t =
       
   555       case t of
       
   556         @{const "==>"} $ t1 $ t2 => aux_implies prems zs t1 t2
       
   557       | _ => Logic.list_implies (rev prems, t)
       
   558     (* term list -> (indexname * typ) list -> term -> term -> term *)
       
   559     and aux_implies prems zs t1 t2 =
       
   560       case t1 of
       
   561         Const (@{const_name "=="}, _) $ Var z $ t' => aux_eq prems zs z t' t1 t2
       
   562       | @{const Trueprop} $ (Const (@{const_name "op ="}, _) $ Var z $ t') =>
       
   563         aux_eq prems zs z t' t1 t2
       
   564       | @{const Trueprop} $ (Const (@{const_name "op ="}, _) $ t' $ Var z) =>
       
   565         aux_eq prems zs z t' t1 t2
       
   566       | _ => aux (t1 :: prems) (Term.add_vars t1 zs) t2
       
   567     (* term list -> (indexname * typ) list -> indexname * typ -> term -> term
       
   568        -> term -> term *)
       
   569     and aux_eq prems zs z t' t1 t2 =
       
   570       if not (member (op =) zs z) andalso
       
   571          not (exists_subterm (curry (op =) (Var z)) t') then
       
   572         aux prems zs (subst_free [(Var z, t')] t2)
       
   573       else
       
   574         aux (t1 :: prems) (Term.add_vars t1 zs) t2
       
   575   in aux [] [] end
       
   576 
       
   577 (* theory -> int -> term list -> term list -> (term * term list) option *)
       
   578 fun find_bound_assign _ _ _ [] = NONE
       
   579   | find_bound_assign thy j seen (t :: ts) =
       
   580     let
       
   581       (* bool -> term -> term -> (term * term list) option *)
       
   582       fun aux pass1 t1 t2 =
       
   583         (if loose_bvar1 (t2, j) then
       
   584            if pass1 then aux false t2 t1 else raise SAME ()
       
   585          else case t1 of
       
   586            Bound j' => if j' = j then SOME (t2, ts @ seen) else raise SAME ()
       
   587          | Const (s, Type ("fun", [T1, T2])) $ Bound j' =>
       
   588            if j' = j andalso
       
   589               s = nth_sel_name_for_constr_name @{const_name FunBox} 0 then
       
   590              SOME (construct_value thy (@{const_name FunBox}, T2 --> T1) [t2],
       
   591                    ts @ seen)
       
   592            else
       
   593              raise SAME ()
       
   594          | _ => raise SAME ())
       
   595         handle SAME () => find_bound_assign thy j (t :: seen) ts
       
   596     in
       
   597       case t of
       
   598         Const (@{const_name "op ="}, _) $ t1 $ t2 => aux true t1 t2
       
   599       | _ => find_bound_assign thy j (t :: seen) ts
       
   600     end
       
   601 
       
   602 (* int -> term -> term -> term *)
       
   603 fun subst_one_bound j arg t =
       
   604   let
       
   605     fun aux (Bound i, lev) =
       
   606         if i < lev then raise SAME ()
       
   607         else if i = lev then incr_boundvars (lev - j) arg
       
   608         else Bound (i - 1)
       
   609       | aux (Abs (a, T, body), lev) = Abs (a, T, aux (body, lev + 1))
       
   610       | aux (f $ t, lev) =
       
   611         (aux (f, lev) $ (aux (t, lev) handle SAME () => t)
       
   612          handle SAME () => f $ aux (t, lev))
       
   613       | aux _ = raise SAME ()
       
   614   in aux (t, j) handle SAME () => t end
       
   615 
       
   616 (* theory -> term -> term *)
       
   617 fun destroy_existential_equalities thy =
       
   618   let
       
   619     (* string list -> typ list -> term list -> term *)
       
   620     fun kill [] [] ts = foldr1 s_conj ts
       
   621       | kill (s :: ss) (T :: Ts) ts =
       
   622         (case find_bound_assign thy (length ss) [] ts of
       
   623            SOME (_, []) => @{const True}
       
   624          | SOME (arg_t, ts) =>
       
   625            kill ss Ts (map (subst_one_bound (length ss)
       
   626                                 (incr_bv (~1, length ss + 1, arg_t))) ts)
       
   627          | NONE =>
       
   628            Const (@{const_name Ex}, (T --> bool_T) --> bool_T)
       
   629            $ Abs (s, T, kill ss Ts ts))
       
   630       | kill _ _ _ = raise UnequalLengths
       
   631     (* string list -> typ list -> term -> term *)
       
   632     fun gather ss Ts ((t0 as Const (@{const_name Ex}, _)) $ Abs (s1, T1, t1)) =
       
   633         gather (ss @ [s1]) (Ts @ [T1]) t1
       
   634       | gather [] [] (Abs (s, T, t1)) = Abs (s, T, gather [] [] t1)
       
   635       | gather [] [] (t1 $ t2) = gather [] [] t1 $ gather [] [] t2
       
   636       | gather [] [] t = t
       
   637       | gather ss Ts t = kill ss Ts (conjuncts_of (gather [] [] t))
       
   638   in gather [] [] end
       
   639 
       
   640 (** Skolemization **)
       
   641 
       
   642 (* int -> int -> string *)
       
   643 fun skolem_prefix_for k j =
       
   644   skolem_prefix ^ string_of_int k ^ "@" ^ string_of_int j ^ name_sep
       
   645 
       
   646 (* hol_context -> int -> term -> term *)
       
   647 fun skolemize_term_and_more (hol_ctxt as {thy, def_table, skolems, ...})
       
   648                             skolem_depth =
       
   649   let
       
   650     (* int list -> int list *)
       
   651     val incrs = map (Integer.add 1)
       
   652     (* string list -> typ list -> int list -> int -> polarity -> term -> term *)
       
   653     fun aux ss Ts js depth polar t =
       
   654       let
       
   655         (* string -> typ -> string -> typ -> term -> term *)
       
   656         fun do_quantifier quant_s quant_T abs_s abs_T t =
       
   657           if not (loose_bvar1 (t, 0)) then
       
   658             aux ss Ts js depth polar (incr_boundvars ~1 t)
       
   659           else if depth <= skolem_depth andalso
       
   660                   is_positive_existential polar quant_s then
       
   661             let
       
   662               val j = length (!skolems) + 1
       
   663               val sko_s = skolem_prefix_for (length js) j ^ abs_s
       
   664               val _ = Unsynchronized.change skolems (cons (sko_s, ss))
       
   665               val sko_t = list_comb (Const (sko_s, rev Ts ---> abs_T),
       
   666                                      map Bound (rev js))
       
   667               val abs_t = Abs (abs_s, abs_T, aux ss Ts (incrs js) depth polar t)
       
   668             in
       
   669               if null js then betapply (abs_t, sko_t)
       
   670               else Const (@{const_name Let}, abs_T --> quant_T) $ sko_t $ abs_t
       
   671             end
       
   672           else
       
   673             Const (quant_s, quant_T)
       
   674             $ Abs (abs_s, abs_T,
       
   675                    if is_higher_order_type abs_T then
       
   676                      t
       
   677                    else
       
   678                      aux (abs_s :: ss) (abs_T :: Ts) (0 :: incrs js)
       
   679                          (depth + 1) polar t)
       
   680       in
       
   681         case t of
       
   682           Const (s0 as @{const_name all}, T0) $ Abs (s1, T1, t1) =>
       
   683           do_quantifier s0 T0 s1 T1 t1
       
   684         | @{const "==>"} $ t1 $ t2 =>
       
   685           @{const "==>"} $ aux ss Ts js depth (flip_polarity polar) t1
       
   686           $ aux ss Ts js depth polar t2
       
   687         | @{const Pure.conjunction} $ t1 $ t2 =>
       
   688           @{const Pure.conjunction} $ aux ss Ts js depth polar t1
       
   689           $ aux ss Ts js depth polar t2
       
   690         | @{const Trueprop} $ t1 =>
       
   691           @{const Trueprop} $ aux ss Ts js depth polar t1
       
   692         | @{const Not} $ t1 =>
       
   693           @{const Not} $ aux ss Ts js depth (flip_polarity polar) t1
       
   694         | Const (s0 as @{const_name All}, T0) $ Abs (s1, T1, t1) =>
       
   695           do_quantifier s0 T0 s1 T1 t1
       
   696         | Const (s0 as @{const_name Ex}, T0) $ Abs (s1, T1, t1) =>
       
   697           do_quantifier s0 T0 s1 T1 t1
       
   698         | @{const "op &"} $ t1 $ t2 =>
       
   699           @{const "op &"} $ aux ss Ts js depth polar t1
       
   700           $ aux ss Ts js depth polar t2
       
   701         | @{const "op |"} $ t1 $ t2 =>
       
   702           @{const "op |"} $ aux ss Ts js depth polar t1
       
   703           $ aux ss Ts js depth polar t2
       
   704         | @{const "op -->"} $ t1 $ t2 =>
       
   705           @{const "op -->"} $ aux ss Ts js depth (flip_polarity polar) t1
       
   706           $ aux ss Ts js depth polar t2
       
   707         | (t0 as Const (@{const_name Let}, T0)) $ t1 $ t2 =>
       
   708           t0 $ t1 $ aux ss Ts js depth polar t2
       
   709         | Const (x as (s, T)) =>
       
   710           if is_inductive_pred hol_ctxt x andalso
       
   711              not (is_well_founded_inductive_pred hol_ctxt x) then
       
   712             let
       
   713               val gfp = (fixpoint_kind_of_const thy def_table x = Gfp)
       
   714               val (pref, connective, set_oper) =
       
   715                 if gfp then
       
   716                   (lbfp_prefix,
       
   717                    @{const "op |"},
       
   718                    @{const_name upper_semilattice_fun_inst.sup_fun})
       
   719                 else
       
   720                   (ubfp_prefix,
       
   721                    @{const "op &"},
       
   722                    @{const_name lower_semilattice_fun_inst.inf_fun})
       
   723               (* unit -> term *)
       
   724               fun pos () = unrolled_inductive_pred_const hol_ctxt gfp x
       
   725                            |> aux ss Ts js depth polar
       
   726               fun neg () = Const (pref ^ s, T)
       
   727             in
       
   728               (case polar |> gfp ? flip_polarity of
       
   729                  Pos => pos ()
       
   730                | Neg => neg ()
       
   731                | Neut =>
       
   732                  if is_fun_type T then
       
   733                    let
       
   734                      val ((trunk_arg_Ts, rump_arg_T), body_T) =
       
   735                        T |> strip_type |>> split_last
       
   736                      val set_T = rump_arg_T --> body_T
       
   737                      (* (unit -> term) -> term *)
       
   738                      fun app f =
       
   739                        list_comb (f (),
       
   740                                   map Bound (length trunk_arg_Ts - 1 downto 0))
       
   741                    in
       
   742                      List.foldr absdummy
       
   743                                 (Const (set_oper, set_T --> set_T --> set_T)
       
   744                                         $ app pos $ app neg) trunk_arg_Ts
       
   745                    end
       
   746                  else
       
   747                    connective $ pos () $ neg ())
       
   748             end
       
   749           else
       
   750             Const x
       
   751         | t1 $ t2 =>
       
   752           betapply (aux ss Ts [] (skolem_depth + 1) polar t1,
       
   753                     aux ss Ts [] depth Neut t2)
       
   754         | Abs (s, T, t1) => Abs (s, T, aux ss Ts (incrs js) depth polar t1)
       
   755         | _ => t
       
   756       end
       
   757   in aux [] [] [] 0 Pos end
       
   758 
       
   759 (** Function specialization **)
       
   760 
       
   761 (* term -> term list *)
       
   762 fun params_in_equation (@{const "==>"} $ _ $ t2) = params_in_equation t2
       
   763   | params_in_equation (@{const Trueprop} $ t1) = params_in_equation t1
       
   764   | params_in_equation (Const (@{const_name "op ="}, _) $ t1 $ _) =
       
   765     snd (strip_comb t1)
       
   766   | params_in_equation _ = []
       
   767 
       
   768 (* styp -> styp -> int list -> term list -> term list -> term -> term *)
       
   769 fun specialize_fun_axiom x x' fixed_js fixed_args extra_args t =
       
   770   let
       
   771     val k = fold Integer.max (map maxidx_of_term (fixed_args @ extra_args)) 0
       
   772             + 1
       
   773     val t = map_aterms (fn Var ((s, i), T) => Var ((s, k + i), T) | t' => t') t
       
   774     val fixed_params = filter_indices fixed_js (params_in_equation t)
       
   775     (* term list -> term -> term *)
       
   776     fun aux args (Abs (s, T, t)) = list_comb (Abs (s, T, aux [] t), args)
       
   777       | aux args (t1 $ t2) = aux (aux [] t2 :: args) t1
       
   778       | aux args t =
       
   779         if t = Const x then
       
   780           list_comb (Const x', extra_args @ filter_out_indices fixed_js args)
       
   781         else
       
   782           let val j = find_index (curry (op =) t) fixed_params in
       
   783             list_comb (if j >= 0 then nth fixed_args j else t, args)
       
   784           end
       
   785   in aux [] t end
       
   786 
       
   787 (* hol_context -> styp -> (int * term option) list *)
       
   788 fun static_args_in_term ({ersatz_table, ...} : hol_context) x t =
       
   789   let
       
   790     (* term -> term list -> term list -> term list list *)
       
   791     fun fun_calls (Abs (_, _, t)) _ = fun_calls t []
       
   792       | fun_calls (t1 $ t2) args = fun_calls t2 [] #> fun_calls t1 (t2 :: args)
       
   793       | fun_calls t args =
       
   794         (case t of
       
   795            Const (x' as (s', T')) =>
       
   796            x = x' orelse (case AList.lookup (op =) ersatz_table s' of
       
   797                             SOME s'' => x = (s'', T')
       
   798                           | NONE => false)
       
   799          | _ => false) ? cons args
       
   800     (* term list list -> term list list -> term list -> term list list *)
       
   801     fun call_sets [] [] vs = [vs]
       
   802       | call_sets [] uss vs = vs :: call_sets uss [] []
       
   803       | call_sets ([] :: _) _ _ = []
       
   804       | call_sets ((t :: ts) :: tss) uss vs =
       
   805         OrdList.insert TermOrd.term_ord t vs |> call_sets tss (ts :: uss)
       
   806     val sets = call_sets (fun_calls t [] []) [] []
       
   807     val indexed_sets = sets ~~ (index_seq 0 (length sets))
       
   808   in
       
   809     fold_rev (fn (set, j) =>
       
   810                  case set of
       
   811                    [Var _] => AList.lookup (op =) indexed_sets set = SOME j
       
   812                               ? cons (j, NONE)
       
   813                  | [t as Const _] => cons (j, SOME t)
       
   814                  | [t as Free _] => cons (j, SOME t)
       
   815                  | _ => I) indexed_sets []
       
   816   end
       
   817 (* hol_context -> styp -> term list -> (int * term option) list *)
       
   818 fun static_args_in_terms hol_ctxt x =
       
   819   map (static_args_in_term hol_ctxt x)
       
   820   #> fold1 (OrdList.inter (prod_ord int_ord (option_ord TermOrd.term_ord)))
       
   821 
       
   822 (* (int * term option) list -> (int * term) list -> int list *)
       
   823 fun overlapping_indices [] _ = []
       
   824   | overlapping_indices _ [] = []
       
   825   | overlapping_indices (ps1 as (j1, t1) :: ps1') (ps2 as (j2, t2) :: ps2') =
       
   826     if j1 < j2 then overlapping_indices ps1' ps2
       
   827     else if j1 > j2 then overlapping_indices ps1 ps2'
       
   828     else overlapping_indices ps1' ps2' |> the_default t2 t1 = t2 ? cons j1
       
   829 
       
   830 (* typ list -> term -> bool *)
       
   831 fun is_eligible_arg Ts t =
       
   832   let val bad_Ts = map snd (Term.add_vars t []) @ map (nth Ts) (loose_bnos t) in
       
   833     null bad_Ts orelse
       
   834     (is_higher_order_type (fastype_of1 (Ts, t)) andalso
       
   835      forall (not o is_higher_order_type) bad_Ts)
       
   836   end
       
   837 
       
   838 (* int -> string *)
       
   839 fun special_prefix_for j = special_prefix ^ string_of_int j ^ name_sep
       
   840 
       
   841 (* If a constant's definition is picked up deeper than this threshold, we
       
   842    prevent excessive specialization by not specializing it. *)
       
   843 val special_max_depth = 20
       
   844 
       
   845 val bound_var_prefix = "b"
       
   846 
       
   847 (* hol_context -> int -> term -> term *)
       
   848 fun specialize_consts_in_term (hol_ctxt as {thy, specialize, simp_table,
       
   849                                             special_funs, ...}) depth t =
       
   850   if not specialize orelse depth > special_max_depth then
       
   851     t
       
   852   else
       
   853     let
       
   854       val blacklist = if depth = 0 then []
       
   855                       else case term_under_def t of Const x => [x] | _ => []
       
   856       (* term list -> typ list -> term -> term *)
       
   857       fun aux args Ts (Const (x as (s, T))) =
       
   858           ((if not (member (op =) blacklist x) andalso not (null args) andalso
       
   859                not (String.isPrefix special_prefix s) andalso
       
   860                is_equational_fun hol_ctxt x then
       
   861               let
       
   862                 val eligible_args = filter (is_eligible_arg Ts o snd)
       
   863                                            (index_seq 0 (length args) ~~ args)
       
   864                 val _ = not (null eligible_args) orelse raise SAME ()
       
   865                 val old_axs = equational_fun_axioms hol_ctxt x
       
   866                               |> map (destroy_existential_equalities thy)
       
   867                 val static_params = static_args_in_terms hol_ctxt x old_axs
       
   868                 val fixed_js = overlapping_indices static_params eligible_args
       
   869                 val _ = not (null fixed_js) orelse raise SAME ()
       
   870                 val fixed_args = filter_indices fixed_js args
       
   871                 val vars = fold Term.add_vars fixed_args []
       
   872                            |> sort (TermOrd.fast_indexname_ord o pairself fst)
       
   873                 val bound_js = fold (fn t => fn js => add_loose_bnos (t, 0, js))
       
   874                                     fixed_args []
       
   875                                |> sort int_ord
       
   876                 val live_args = filter_out_indices fixed_js args
       
   877                 val extra_args = map Var vars @ map Bound bound_js @ live_args
       
   878                 val extra_Ts = map snd vars @ filter_indices bound_js Ts
       
   879                 val k = maxidx_of_term t + 1
       
   880                 (* int -> term *)
       
   881                 fun var_for_bound_no j =
       
   882                   Var ((bound_var_prefix ^
       
   883                         nat_subscript (find_index (curry (op =) j) bound_js
       
   884                                        + 1), k),
       
   885                        nth Ts j)
       
   886                 val fixed_args_in_axiom =
       
   887                   map (curry subst_bounds
       
   888                              (map var_for_bound_no (index_seq 0 (length Ts))))
       
   889                       fixed_args
       
   890               in
       
   891                 case AList.lookup (op =) (!special_funs)
       
   892                                   (x, fixed_js, fixed_args_in_axiom) of
       
   893                   SOME x' => list_comb (Const x', extra_args)
       
   894                 | NONE =>
       
   895                   let
       
   896                     val extra_args_in_axiom =
       
   897                       map Var vars @ map var_for_bound_no bound_js
       
   898                     val x' as (s', _) =
       
   899                       (special_prefix_for (length (!special_funs) + 1) ^ s,
       
   900                        extra_Ts @ filter_out_indices fixed_js (binder_types T)
       
   901                        ---> body_type T)
       
   902                     val new_axs =
       
   903                       map (specialize_fun_axiom x x' fixed_js
       
   904                                fixed_args_in_axiom extra_args_in_axiom) old_axs
       
   905                     val _ =
       
   906                       Unsynchronized.change special_funs
       
   907                           (cons ((x, fixed_js, fixed_args_in_axiom), x'))
       
   908                     val _ = add_simps simp_table s' new_axs
       
   909                   in list_comb (Const x', extra_args) end
       
   910               end
       
   911             else
       
   912               raise SAME ())
       
   913            handle SAME () => list_comb (Const x, args))
       
   914         | aux args Ts (Abs (s, T, t)) =
       
   915           list_comb (Abs (s, T, aux [] (T :: Ts) t), args)
       
   916         | aux args Ts (t1 $ t2) = aux (aux [] Ts t2 :: args) Ts t1
       
   917         | aux args _ t = list_comb (t, args)
       
   918     in aux [] [] t end
       
   919 
       
   920 type special_triple = int list * term list * styp
       
   921 
       
   922 val cong_var_prefix = "c"
       
   923 
       
   924 (* styp -> special_triple -> special_triple -> term *)
       
   925 fun special_congruence_axiom (s, T) (js1, ts1, x1) (js2, ts2, x2) =
       
   926   let
       
   927     val (bounds1, bounds2) = pairself (map Var o special_bounds) (ts1, ts2)
       
   928     val Ts = binder_types T
       
   929     val max_j = fold (fold Integer.max) [js1, js2] ~1
       
   930     val (eqs, (args1, args2)) =
       
   931       fold (fn j => case pairself (fn ps => AList.lookup (op =) ps j)
       
   932                                   (js1 ~~ ts1, js2 ~~ ts2) of
       
   933                       (SOME t1, SOME t2) => apfst (cons (t1, t2))
       
   934                     | (SOME t1, NONE) => apsnd (apsnd (cons t1))
       
   935                     | (NONE, SOME t2) => apsnd (apfst (cons t2))
       
   936                     | (NONE, NONE) =>
       
   937                       let val v = Var ((cong_var_prefix ^ nat_subscript j, 0),
       
   938                                        nth Ts j) in
       
   939                         apsnd (pairself (cons v))
       
   940                       end) (max_j downto 0) ([], ([], []))
       
   941   in
       
   942     Logic.list_implies (eqs |> filter_out (op =) |> distinct (op =)
       
   943                             |> map Logic.mk_equals,
       
   944                         Logic.mk_equals (list_comb (Const x1, bounds1 @ args1),
       
   945                                          list_comb (Const x2, bounds2 @ args2)))
       
   946     |> Refute.close_form (* TODO: needed? *)
       
   947   end
       
   948 
       
   949 (* hol_context -> styp list -> term list *)
       
   950 fun special_congruence_axioms (hol_ctxt as {special_funs, ...}) xs =
       
   951   let
       
   952     val groups =
       
   953       !special_funs
       
   954       |> map (fn ((x, js, ts), x') => (x, (js, ts, x')))
       
   955       |> AList.group (op =)
       
   956       |> filter_out (is_equational_fun_surely_complete hol_ctxt o fst)
       
   957       |> map (fn (x, zs) => (x, zs |> member (op =) xs x ? cons ([], [], x)))
       
   958     (* special_triple -> int *)
       
   959     fun generality (js, _, _) = ~(length js)
       
   960     (* special_triple -> special_triple -> bool *)
       
   961     fun is_more_specific (j1, t1, x1) (j2, t2, x2) =
       
   962       x1 <> x2 andalso OrdList.subset (prod_ord int_ord TermOrd.term_ord)
       
   963                                       (j2 ~~ t2, j1 ~~ t1)
       
   964     (* styp -> special_triple list -> special_triple list -> special_triple list
       
   965        -> term list -> term list *)
       
   966     fun do_pass_1 _ [] [_] [_] = I
       
   967       | do_pass_1 x skipped _ [] = do_pass_2 x skipped
       
   968       | do_pass_1 x skipped all (z :: zs) =
       
   969         case filter (is_more_specific z) all
       
   970              |> sort (int_ord o pairself generality) of
       
   971           [] => do_pass_1 x (z :: skipped) all zs
       
   972         | (z' :: _) => cons (special_congruence_axiom x z z')
       
   973                        #> do_pass_1 x skipped all zs
       
   974     (* styp -> special_triple list -> term list -> term list *)
       
   975     and do_pass_2 _ [] = I
       
   976       | do_pass_2 x (z :: zs) =
       
   977         fold (cons o special_congruence_axiom x z) zs #> do_pass_2 x zs
       
   978   in fold (fn (x, zs) => do_pass_1 x [] zs zs) groups [] end
       
   979 
       
   980 (** Axiom selection **)
       
   981 
       
   982 (* Similar to "Refute.specialize_type" but returns all matches rather than only
       
   983    the first (preorder) match. *)
       
   984 (* theory -> styp -> term -> term list *)
       
   985 fun multi_specialize_type thy slack (x as (s, T)) t =
       
   986   let
       
   987     (* term -> (typ * term) list -> (typ * term) list *)
       
   988     fun aux (Const (s', T')) ys =
       
   989         if s = s' then
       
   990           ys |> (if AList.defined (op =) ys T' then
       
   991                    I
       
   992                  else
       
   993                   cons (T', Refute.monomorphic_term
       
   994                                 (Sign.typ_match thy (T', T) Vartab.empty) t)
       
   995                   handle Type.TYPE_MATCH => I
       
   996                        | Refute.REFUTE _ =>
       
   997                          if slack then
       
   998                            I
       
   999                          else
       
  1000                            raise NOT_SUPPORTED ("too much polymorphism in \
       
  1001                                                 \axiom involving " ^ quote s))
       
  1002         else
       
  1003           ys
       
  1004       | aux _ ys = ys
       
  1005   in map snd (fold_aterms aux t []) end
       
  1006 
       
  1007 (* theory -> bool -> const_table -> styp -> term list *)
       
  1008 fun nondef_props_for_const thy slack table (x as (s, _)) =
       
  1009   these (Symtab.lookup table s) |> maps (multi_specialize_type thy slack x)
       
  1010 
       
  1011 (* 'a Symtab.table -> 'a list *)
       
  1012 fun all_table_entries table = Symtab.fold (append o snd) table []
       
  1013 (* const_table -> string -> const_table *)
       
  1014 fun extra_table table s = Symtab.make [(s, all_table_entries table)]
       
  1015 
       
  1016 (* int -> term -> term *)
       
  1017 fun eval_axiom_for_term j t =
       
  1018   Logic.mk_equals (Const (eval_prefix ^ string_of_int j, fastype_of t), t)
       
  1019 
       
  1020 (* term -> bool *)
       
  1021 val is_trivial_equation = the_default false o try (op aconv o Logic.dest_equals)
       
  1022 
       
  1023 (* Prevents divergence in case of cyclic or infinite axiom dependencies. *)
       
  1024 val axioms_max_depth = 255
       
  1025 
       
  1026 (* hol_context -> term -> (term list * term list) * (bool * bool) *)
       
  1027 fun axioms_for_term
       
  1028         (hol_ctxt as {thy, max_bisim_depth, user_axioms, fast_descrs, evals,
       
  1029                       def_table, nondef_table, user_nondefs, ...}) t =
       
  1030   let
       
  1031     type accumulator = styp list * (term list * term list)
       
  1032     (* (term list * term list -> term list)
       
  1033        -> ((term list -> term list) -> term list * term list
       
  1034            -> term list * term list)
       
  1035        -> int -> term -> accumulator -> accumulator *)
       
  1036     fun add_axiom get app depth t (accum as (xs, axs)) =
       
  1037       let
       
  1038         val t = t |> unfold_defs_in_term hol_ctxt
       
  1039                   |> skolemize_term_and_more hol_ctxt ~1
       
  1040       in
       
  1041         if is_trivial_equation t then
       
  1042           accum
       
  1043         else
       
  1044           let val t' = t |> specialize_consts_in_term hol_ctxt depth in
       
  1045             if exists (member (op aconv) (get axs)) [t, t'] then accum
       
  1046             else add_axioms_for_term (depth + 1) t' (xs, app (cons t') axs)
       
  1047           end
       
  1048       end
       
  1049     (* int -> term -> accumulator -> accumulator *)
       
  1050     and add_def_axiom depth = add_axiom fst apfst depth
       
  1051     and add_nondef_axiom depth = add_axiom snd apsnd depth
       
  1052     and add_maybe_def_axiom depth t =
       
  1053       (if head_of t <> @{const "==>"} then add_def_axiom
       
  1054        else add_nondef_axiom) depth t
       
  1055     and add_eq_axiom depth t =
       
  1056       (if is_constr_pattern_formula thy t then add_def_axiom
       
  1057        else add_nondef_axiom) depth t
       
  1058     (* int -> term -> accumulator -> accumulator *)
       
  1059     and add_axioms_for_term depth t (accum as (xs, axs)) =
       
  1060       case t of
       
  1061         t1 $ t2 => accum |> fold (add_axioms_for_term depth) [t1, t2]
       
  1062       | Const (x as (s, T)) =>
       
  1063         (if member (op =) xs x orelse is_built_in_const fast_descrs x then
       
  1064            accum
       
  1065          else
       
  1066            let val accum as (xs, _) = (x :: xs, axs) in
       
  1067              if depth > axioms_max_depth then
       
  1068                raise TOO_LARGE ("Nitpick_Preproc.axioms_for_term.\
       
  1069                                 \add_axioms_for_term",
       
  1070                                 "too many nested axioms (" ^
       
  1071                                 string_of_int depth ^ ")")
       
  1072              else if Refute.is_const_of_class thy x then
       
  1073                let
       
  1074                  val class = Logic.class_of_const s
       
  1075                  val of_class = Logic.mk_of_class (TVar (("'a", 0), [class]),
       
  1076                                                    class)
       
  1077                  val ax1 = try (Refute.specialize_type thy x) of_class
       
  1078                  val ax2 = Option.map (Refute.specialize_type thy x o snd)
       
  1079                                       (Refute.get_classdef thy class)
       
  1080                in
       
  1081                  fold (add_maybe_def_axiom depth) (map_filter I [ax1, ax2])
       
  1082                       accum
       
  1083                end
       
  1084              else if is_constr thy x then
       
  1085                accum
       
  1086              else if is_equational_fun hol_ctxt x then
       
  1087                fold (add_eq_axiom depth) (equational_fun_axioms hol_ctxt x)
       
  1088                     accum
       
  1089              else if is_abs_fun thy x then
       
  1090                if is_quot_type thy (range_type T) then
       
  1091                  raise NOT_SUPPORTED "\"Abs_\" function of quotient type"
       
  1092                else
       
  1093                  accum |> fold (add_nondef_axiom depth)
       
  1094                                (nondef_props_for_const thy false nondef_table x)
       
  1095                        |> is_funky_typedef thy (range_type T)
       
  1096                           ? fold (add_maybe_def_axiom depth)
       
  1097                                  (nondef_props_for_const thy true
       
  1098                                                     (extra_table def_table s) x)
       
  1099              else if is_rep_fun thy x then
       
  1100                if is_quot_type thy (domain_type T) then
       
  1101                  raise NOT_SUPPORTED "\"Rep_\" function of quotient type"
       
  1102                else
       
  1103                  accum |> fold (add_nondef_axiom depth)
       
  1104                                (nondef_props_for_const thy false nondef_table x)
       
  1105                        |> is_funky_typedef thy (range_type T)
       
  1106                           ? fold (add_maybe_def_axiom depth)
       
  1107                                  (nondef_props_for_const thy true
       
  1108                                                     (extra_table def_table s) x)
       
  1109                        |> add_axioms_for_term depth
       
  1110                                               (Const (mate_of_rep_fun thy x))
       
  1111                        |> fold (add_def_axiom depth)
       
  1112                                (inverse_axioms_for_rep_fun thy x)
       
  1113              else
       
  1114                accum |> user_axioms <> SOME false
       
  1115                         ? fold (add_nondef_axiom depth)
       
  1116                                (nondef_props_for_const thy false nondef_table x)
       
  1117            end)
       
  1118         |> add_axioms_for_type depth T
       
  1119       | Free (_, T) => add_axioms_for_type depth T accum
       
  1120       | Var (_, T) => add_axioms_for_type depth T accum
       
  1121       | Bound _ => accum
       
  1122       | Abs (_, T, t) => accum |> add_axioms_for_term depth t
       
  1123                                |> add_axioms_for_type depth T
       
  1124     (* int -> typ -> accumulator -> accumulator *)
       
  1125     and add_axioms_for_type depth T =
       
  1126       case T of
       
  1127         Type ("fun", Ts) => fold (add_axioms_for_type depth) Ts
       
  1128       | Type ("*", Ts) => fold (add_axioms_for_type depth) Ts
       
  1129       | @{typ prop} => I
       
  1130       | @{typ bool} => I
       
  1131       | @{typ unit} => I
       
  1132       | TFree (_, S) => add_axioms_for_sort depth T S
       
  1133       | TVar (_, S) => add_axioms_for_sort depth T S
       
  1134       | Type (z as (s, Ts)) =>
       
  1135         fold (add_axioms_for_type depth) Ts
       
  1136         #> (if is_pure_typedef thy T then
       
  1137               fold (add_maybe_def_axiom depth) (optimized_typedef_axioms thy z)
       
  1138             else if is_quot_type thy T then
       
  1139               fold (add_def_axiom depth) (optimized_quot_type_axioms thy z)
       
  1140             else if max_bisim_depth >= 0 andalso is_codatatype thy T then
       
  1141               fold (add_maybe_def_axiom depth)
       
  1142                    (codatatype_bisim_axioms hol_ctxt T)
       
  1143             else
       
  1144               I)
       
  1145     (* int -> typ -> sort -> accumulator -> accumulator *)
       
  1146     and add_axioms_for_sort depth T S =
       
  1147       let
       
  1148         val supers = Sign.complete_sort thy S
       
  1149         val class_axioms =
       
  1150           maps (fn class => map prop_of (AxClass.get_info thy class |> #axioms
       
  1151                                          handle ERROR _ => [])) supers
       
  1152         val monomorphic_class_axioms =
       
  1153           map (fn t => case Term.add_tvars t [] of
       
  1154                          [] => t
       
  1155                        | [(x, S)] =>
       
  1156                          Refute.monomorphic_term (Vartab.make [(x, (S, T))]) t
       
  1157                        | _ => raise TERM ("Nitpick_Preproc.axioms_for_term.\
       
  1158                                           \add_axioms_for_sort", [t]))
       
  1159               class_axioms
       
  1160       in fold (add_nondef_axiom depth) monomorphic_class_axioms end
       
  1161     val (mono_user_nondefs, poly_user_nondefs) =
       
  1162       List.partition (null o Term.hidden_polymorphism) user_nondefs
       
  1163     val eval_axioms = map2 eval_axiom_for_term (index_seq 0 (length evals))
       
  1164                            evals
       
  1165     val (xs, (defs, nondefs)) =
       
  1166       ([], ([], [])) |> add_axioms_for_term 1 t 
       
  1167                      |> fold_rev (add_def_axiom 1) eval_axioms
       
  1168                      |> user_axioms = SOME true
       
  1169                         ? fold (add_nondef_axiom 1) mono_user_nondefs
       
  1170     val defs = defs @ special_congruence_axioms hol_ctxt xs
       
  1171   in
       
  1172     ((defs, nondefs), (user_axioms = SOME true orelse null mono_user_nondefs,
       
  1173                        null poly_user_nondefs))
       
  1174   end
       
  1175 
       
  1176 (** Simplification of constructor/selector terms **)
       
  1177 
       
  1178 (* theory -> term -> term *)
       
  1179 fun simplify_constrs_and_sels thy t =
       
  1180   let
       
  1181     (* term -> int -> term *)
       
  1182     fun is_nth_sel_on t' n (Const (s, _) $ t) =
       
  1183         (t = t' andalso is_sel_like_and_no_discr s andalso
       
  1184          sel_no_from_name s = n)
       
  1185       | is_nth_sel_on _ _ _ = false
       
  1186     (* term -> term list -> term *)
       
  1187     fun do_term (Const (@{const_name Rep_Frac}, _)
       
  1188                  $ (Const (@{const_name Abs_Frac}, _) $ t1)) [] = do_term t1 []
       
  1189       | do_term (Const (@{const_name Abs_Frac}, _)
       
  1190                  $ (Const (@{const_name Rep_Frac}, _) $ t1)) [] = do_term t1 []
       
  1191       | do_term (t1 $ t2) args = do_term t1 (do_term t2 [] :: args)
       
  1192       | do_term (t as Const (x as (s, T))) (args as _ :: _) =
       
  1193         ((if is_constr_like thy x then
       
  1194             if length args = num_binder_types T then
       
  1195               case hd args of
       
  1196                 Const (x' as (_, T')) $ t' =>
       
  1197                 if domain_type T' = body_type T andalso
       
  1198                    forall (uncurry (is_nth_sel_on t'))
       
  1199                           (index_seq 0 (length args) ~~ args) then
       
  1200                   t'
       
  1201                 else
       
  1202                   raise SAME ()
       
  1203               | _ => raise SAME ()
       
  1204             else
       
  1205               raise SAME ()
       
  1206           else if is_sel_like_and_no_discr s then
       
  1207             case strip_comb (hd args) of
       
  1208               (Const (x' as (s', T')), ts') =>
       
  1209               if is_constr_like thy x' andalso
       
  1210                  constr_name_for_sel_like s = s' andalso
       
  1211                  not (exists is_pair_type (binder_types T')) then
       
  1212                 list_comb (nth ts' (sel_no_from_name s), tl args)
       
  1213               else
       
  1214                 raise SAME ()
       
  1215             | _ => raise SAME ()
       
  1216           else
       
  1217             raise SAME ())
       
  1218          handle SAME () => betapplys (t, args))
       
  1219       | do_term (Abs (s, T, t')) args =
       
  1220         betapplys (Abs (s, T, do_term t' []), args)
       
  1221       | do_term t args = betapplys (t, args)
       
  1222   in do_term t [] end
       
  1223 
       
  1224 (** Quantifier massaging: Distributing quantifiers **)
       
  1225 
       
  1226 (* term -> term *)
       
  1227 fun distribute_quantifiers t =
       
  1228   case t of
       
  1229     (t0 as Const (@{const_name All}, T0)) $ Abs (s, T1, t1) =>
       
  1230     (case t1 of
       
  1231        (t10 as @{const "op &"}) $ t11 $ t12 =>
       
  1232        t10 $ distribute_quantifiers (t0 $ Abs (s, T1, t11))
       
  1233            $ distribute_quantifiers (t0 $ Abs (s, T1, t12))
       
  1234      | (t10 as @{const Not}) $ t11 =>
       
  1235        t10 $ distribute_quantifiers (Const (@{const_name Ex}, T0)
       
  1236                                      $ Abs (s, T1, t11))
       
  1237      | t1 =>
       
  1238        if not (loose_bvar1 (t1, 0)) then
       
  1239          distribute_quantifiers (incr_boundvars ~1 t1)
       
  1240        else
       
  1241          t0 $ Abs (s, T1, distribute_quantifiers t1))
       
  1242   | (t0 as Const (@{const_name Ex}, T0)) $ Abs (s, T1, t1) =>
       
  1243     (case distribute_quantifiers t1 of
       
  1244        (t10 as @{const "op |"}) $ t11 $ t12 =>
       
  1245        t10 $ distribute_quantifiers (t0 $ Abs (s, T1, t11))
       
  1246            $ distribute_quantifiers (t0 $ Abs (s, T1, t12))
       
  1247      | (t10 as @{const "op -->"}) $ t11 $ t12 =>
       
  1248        t10 $ distribute_quantifiers (Const (@{const_name All}, T0)
       
  1249                                      $ Abs (s, T1, t11))
       
  1250            $ distribute_quantifiers (t0 $ Abs (s, T1, t12))
       
  1251      | (t10 as @{const Not}) $ t11 =>
       
  1252        t10 $ distribute_quantifiers (Const (@{const_name All}, T0)
       
  1253                                      $ Abs (s, T1, t11))
       
  1254      | t1 =>
       
  1255        if not (loose_bvar1 (t1, 0)) then
       
  1256          distribute_quantifiers (incr_boundvars ~1 t1)
       
  1257        else
       
  1258          t0 $ Abs (s, T1, distribute_quantifiers t1))
       
  1259   | t1 $ t2 => distribute_quantifiers t1 $ distribute_quantifiers t2
       
  1260   | Abs (s, T, t') => Abs (s, T, distribute_quantifiers t')
       
  1261   | _ => t
       
  1262 
       
  1263 (** Quantifier massaging: Pushing quantifiers inward **)
       
  1264 
       
  1265 (* int -> int -> (int -> int) -> term -> term *)
       
  1266 fun renumber_bounds j n f t =
       
  1267   case t of
       
  1268     t1 $ t2 => renumber_bounds j n f t1 $ renumber_bounds j n f t2
       
  1269   | Abs (s, T, t') => Abs (s, T, renumber_bounds (j + 1) n f t')
       
  1270   | Bound j' =>
       
  1271     Bound (if j' >= j andalso j' < j + n then f (j' - j) + j else j')
       
  1272   | _ => t
       
  1273 
       
  1274 (* Maximum number of quantifiers in a cluster for which the exponential
       
  1275    algorithm is used. Larger clusters use a heuristic inspired by Claessen &
       
  1276    Sörensson's polynomial binary splitting procedure (p. 5 of their MODEL 2003
       
  1277    paper). *)
       
  1278 val quantifier_cluster_threshold = 7
       
  1279 
       
  1280 (* theory -> term -> term *)
       
  1281 fun push_quantifiers_inward thy =
       
  1282   let
       
  1283     (* string -> string list -> typ list -> term -> term *)
       
  1284     fun aux quant_s ss Ts t =
       
  1285       (case t of
       
  1286          (t0 as Const (s0, _)) $ Abs (s1, T1, t1 as _ $ _) =>
       
  1287          if s0 = quant_s then
       
  1288            aux s0 (s1 :: ss) (T1 :: Ts) t1
       
  1289          else if quant_s = "" andalso
       
  1290                  (s0 = @{const_name All} orelse s0 = @{const_name Ex}) then
       
  1291            aux s0 [s1] [T1] t1
       
  1292          else
       
  1293            raise SAME ()
       
  1294        | _ => raise SAME ())
       
  1295       handle SAME () =>
       
  1296              case t of
       
  1297                t1 $ t2 =>
       
  1298                if quant_s = "" then
       
  1299                  aux "" [] [] t1 $ aux "" [] [] t2
       
  1300                else
       
  1301                  let
       
  1302                    val typical_card = 4
       
  1303                    (* ('a -> ''b list) -> 'a list -> ''b list *)
       
  1304                    fun big_union proj ps =
       
  1305                      fold (fold (insert (op =)) o proj) ps []
       
  1306                    val (ts, connective) = strip_any_connective t
       
  1307                    val T_costs =
       
  1308                      map (bounded_card_of_type 65536 typical_card []) Ts
       
  1309                    val t_costs = map size_of_term ts
       
  1310                    val num_Ts = length Ts
       
  1311                    (* int -> int *)
       
  1312                    val flip = curry (op -) (num_Ts - 1)
       
  1313                    val t_boundss = map (map flip o loose_bnos) ts
       
  1314                    (* (int list * int) list -> int list
       
  1315                       -> (int list * int) list *)
       
  1316                    fun merge costly_boundss [] = costly_boundss
       
  1317                      | merge costly_boundss (j :: js) =
       
  1318                        let
       
  1319                          val (yeas, nays) =
       
  1320                            List.partition (fn (bounds, _) =>
       
  1321                                               member (op =) bounds j)
       
  1322                                           costly_boundss
       
  1323                          val yeas_bounds = big_union fst yeas
       
  1324                          val yeas_cost = Integer.sum (map snd yeas)
       
  1325                                          * nth T_costs j
       
  1326                        in merge ((yeas_bounds, yeas_cost) :: nays) js end
       
  1327                    (* (int list * int) list -> int list -> int *)
       
  1328                    val cost = Integer.sum o map snd oo merge
       
  1329                    (* (int list * int) list -> int list -> int list *)
       
  1330                    fun heuristically_best_permutation _ [] = []
       
  1331                      | heuristically_best_permutation costly_boundss js =
       
  1332                        let
       
  1333                          val (costly_boundss, (j, js)) =
       
  1334                            js |> map (`(merge costly_boundss o single))
       
  1335                               |> sort (int_ord
       
  1336                                        o pairself (Integer.sum o map snd o fst))
       
  1337                               |> split_list |>> hd ||> pairf hd tl
       
  1338                        in
       
  1339                          j :: heuristically_best_permutation costly_boundss js
       
  1340                        end
       
  1341                    val js =
       
  1342                      if length Ts <= quantifier_cluster_threshold then
       
  1343                        all_permutations (index_seq 0 num_Ts)
       
  1344                        |> map (`(cost (t_boundss ~~ t_costs)))
       
  1345                        |> sort (int_ord o pairself fst) |> hd |> snd
       
  1346                      else
       
  1347                        heuristically_best_permutation (t_boundss ~~ t_costs)
       
  1348                                                       (index_seq 0 num_Ts)
       
  1349                    val back_js = map (fn j => find_index (curry (op =) j) js)
       
  1350                                      (index_seq 0 num_Ts)
       
  1351                    val ts = map (renumber_bounds 0 num_Ts (nth back_js o flip))
       
  1352                                 ts
       
  1353                    (* (term * int list) list -> term *)
       
  1354                    fun mk_connection [] =
       
  1355                        raise ARG ("Nitpick_Preproc.push_quantifiers_inward.aux.\
       
  1356                                   \mk_connection", "")
       
  1357                      | mk_connection ts_cum_bounds =
       
  1358                        ts_cum_bounds |> map fst
       
  1359                        |> foldr1 (fn (t1, t2) => connective $ t1 $ t2)
       
  1360                    (* (term * int list) list -> int list -> term *)
       
  1361                    fun build ts_cum_bounds [] = ts_cum_bounds |> mk_connection
       
  1362                      | build ts_cum_bounds (j :: js) =
       
  1363                        let
       
  1364                          val (yeas, nays) =
       
  1365                            List.partition (fn (_, bounds) =>
       
  1366                                               member (op =) bounds j)
       
  1367                                           ts_cum_bounds
       
  1368                            ||> map (apfst (incr_boundvars ~1))
       
  1369                        in
       
  1370                          if null yeas then
       
  1371                            build nays js
       
  1372                          else
       
  1373                            let val T = nth Ts (flip j) in
       
  1374                              build ((Const (quant_s, (T --> bool_T) --> bool_T)
       
  1375                                      $ Abs (nth ss (flip j), T,
       
  1376                                             mk_connection yeas),
       
  1377                                       big_union snd yeas) :: nays) js
       
  1378                            end
       
  1379                        end
       
  1380                  in build (ts ~~ t_boundss) js end
       
  1381              | Abs (s, T, t') => Abs (s, T, aux "" [] [] t')
       
  1382              | _ => t
       
  1383   in aux "" [] [] end
       
  1384 
       
  1385 (** Preprocessor entry point **)
       
  1386 
       
  1387 (* hol_context -> term -> ((term list * term list) * (bool * bool)) * term *)
       
  1388 fun preprocess_term (hol_ctxt as {thy, binary_ints, destroy_constrs, boxes,
       
  1389                                   skolemize, uncurry, ...}) t =
       
  1390   let
       
  1391     val skolem_depth = if skolemize then 4 else ~1
       
  1392     val (((def_ts, nondef_ts), (got_all_mono_user_axioms, no_poly_user_axioms)),
       
  1393          core_t) = t |> unfold_defs_in_term hol_ctxt
       
  1394                      |> Refute.close_form
       
  1395                      |> skolemize_term_and_more hol_ctxt skolem_depth
       
  1396                      |> specialize_consts_in_term hol_ctxt 0
       
  1397                      |> `(axioms_for_term hol_ctxt)
       
  1398     val binarize =
       
  1399       case binary_ints of
       
  1400         SOME false => false
       
  1401       | _ =>
       
  1402         forall may_use_binary_ints (core_t :: def_ts @ nondef_ts) andalso
       
  1403         (binary_ints = SOME true orelse
       
  1404          exists should_use_binary_ints (core_t :: def_ts @ nondef_ts))
       
  1405     val box = exists (not_equal (SOME false) o snd) boxes
       
  1406     val table =
       
  1407       Termtab.empty |> uncurry
       
  1408         ? fold (add_to_uncurry_table thy) (core_t :: def_ts @ nondef_ts)
       
  1409     (* bool -> bool -> term -> term *)
       
  1410     fun do_rest def core =
       
  1411       binarize ? binarize_nat_and_int_in_term
       
  1412       #> uncurry ? uncurry_term table
       
  1413       #> box ? box_fun_and_pair_in_term hol_ctxt def
       
  1414       #> destroy_constrs ? (pull_out_universal_constrs thy def
       
  1415                             #> pull_out_existential_constrs thy
       
  1416                             #> destroy_pulled_out_constrs hol_ctxt def)
       
  1417       #> curry_assms
       
  1418       #> destroy_universal_equalities
       
  1419       #> destroy_existential_equalities thy
       
  1420       #> simplify_constrs_and_sels thy
       
  1421       #> distribute_quantifiers
       
  1422       #> push_quantifiers_inward thy
       
  1423       #> not core ? Refute.close_form
       
  1424       #> Term.map_abs_vars shortest_name
       
  1425   in
       
  1426     (((map (do_rest true false) def_ts, map (do_rest false false) nondef_ts),
       
  1427       (got_all_mono_user_axioms, no_poly_user_axioms)),
       
  1428      do_rest false true core_t)
       
  1429   end
       
  1430 
       
  1431 end;