src/HOL/Tools/SMT/smt_translate.ML
changeset 41127 2ea84c8535c6
parent 41123 3bb9be510a9d
child 41165 ceb81a08534e
equal deleted inserted replaced
41126:e0bd443c0fdd 41127:2ea84c8535c6
    13     SVar of int |
    13     SVar of int |
    14     SApp of string * sterm list |
    14     SApp of string * sterm list |
    15     SLet of string * sterm * sterm |
    15     SLet of string * sterm * sterm |
    16     SQua of squant * string list * sterm spattern list * int option * sterm
    16     SQua of squant * string list * sterm spattern list * int option * sterm
    17 
    17 
    18   (*configuration options*)
    18   (*translation configuration*)
    19   type prefixes = {sort_prefix: string, func_prefix: string}
    19   type prefixes = {sort_prefix: string, func_prefix: string}
    20   type sign = {
    20   type sign = {
    21     header: string list,
    21     header: string list,
    22     sorts: string list,
    22     sorts: string list,
    23     dtyps: (string * (string * (string * string) list) list) list list,
    23     dtyps: (string * (string * (string * string) list) list) list list,
    24     funcs: (string * (string list * string)) list }
    24     funcs: (string * (string list * string)) list }
    25   type config = {
    25   type config = {
    26     prefixes: prefixes,
    26     prefixes: prefixes,
    27     header: Proof.context -> term list -> string list,
    27     header: term list -> string list,
    28     is_fol: bool,
    28     is_fol: bool,
    29     has_datatypes: bool,
    29     has_datatypes: bool,
    30     serialize: string list -> sign -> sterm list -> string }
    30     serialize: string list -> sign -> sterm list -> string }
    31   type recon = {
    31   type recon = {
       
    32     context: Proof.context,
    32     typs: typ Symtab.table,
    33     typs: typ Symtab.table,
    33     terms: term Symtab.table,
    34     terms: term Symtab.table,
    34     unfolds: thm list,
    35     rewrite_rules: thm list,
    35     assms: (int * thm) list }
    36     assms: (int * thm) list }
    36 
    37 
    37   val translate: config -> Proof.context -> string list -> (int * thm) list ->
    38   (*translation*)
       
    39   val add_config: SMT_Utils.class * (Proof.context -> config) ->
       
    40     Context.generic -> Context.generic 
       
    41   val translate: Proof.context -> string list -> (int * thm) list ->
    38     string * recon
    42     string * recon
    39 end
    43 end
    40 
    44 
    41 structure SMT_Translate: SMT_TRANSLATE =
    45 structure SMT_Translate: SMT_TRANSLATE =
    42 struct
    46 struct
    57   SLet of string * sterm * sterm |
    61   SLet of string * sterm * sterm |
    58   SQua of squant * string list * sterm spattern list * int option * sterm
    62   SQua of squant * string list * sterm spattern list * int option * sterm
    59 
    63 
    60 
    64 
    61 
    65 
    62 (* configuration options *)
    66 (* translation configuration *)
    63 
    67 
    64 type prefixes = {sort_prefix: string, func_prefix: string}
    68 type prefixes = {sort_prefix: string, func_prefix: string}
    65 
    69 
    66 type sign = {
    70 type sign = {
    67   header: string list,
    71   header: string list,
    69   dtyps: (string * (string * (string * string) list) list) list list,
    73   dtyps: (string * (string * (string * string) list) list) list list,
    70   funcs: (string * (string list * string)) list }
    74   funcs: (string * (string list * string)) list }
    71 
    75 
    72 type config = {
    76 type config = {
    73   prefixes: prefixes,
    77   prefixes: prefixes,
    74   header: Proof.context -> term list -> string list,
    78   header: term list -> string list,
    75   is_fol: bool,
    79   is_fol: bool,
    76   has_datatypes: bool,
    80   has_datatypes: bool,
    77   serialize: string list -> sign -> sterm list -> string }
    81   serialize: string list -> sign -> sterm list -> string }
    78 
    82 
    79 type recon = {
    83 type recon = {
       
    84   context: Proof.context,
    80   typs: typ Symtab.table,
    85   typs: typ Symtab.table,
    81   terms: term Symtab.table,
    86   terms: term Symtab.table,
    82   unfolds: thm list,
    87   rewrite_rules: thm list,
    83   assms: (int * thm) list }
    88   assms: (int * thm) list }
    84 
    89 
    85 
    90 
    86 
    91 
    87 (* utility functions *)
    92 (* translation context *)
       
    93 
       
    94 fun make_tr_context {sort_prefix, func_prefix} =
       
    95   (sort_prefix, 1, Typtab.empty, func_prefix, 1, Termtab.empty)
       
    96 
       
    97 fun string_of_index pre i = pre ^ string_of_int i
       
    98 
       
    99 fun add_typ T proper (cx as (sp, Tidx, typs, fp, idx, terms)) =
       
   100   (case Typtab.lookup typs T of
       
   101     SOME (n, _) => (n, cx)
       
   102   | NONE =>
       
   103       let
       
   104         val n = string_of_index sp Tidx
       
   105         val typs' = Typtab.update (T, (n, proper)) typs
       
   106       in (n, (sp, Tidx+1, typs', fp, idx, terms)) end)
       
   107 
       
   108 fun add_fun t sort (cx as (sp, Tidx, typs, fp, idx, terms)) =
       
   109   (case Termtab.lookup terms t of
       
   110     SOME (n, _) => (n, cx)
       
   111   | NONE => 
       
   112       let
       
   113         val n = string_of_index fp idx
       
   114         val terms' = Termtab.update (t, (n, sort)) terms
       
   115       in (n, (sp, Tidx, typs, fp, idx+1, terms')) end)
       
   116 
       
   117 fun sign_of header dtyps (_, _, typs, _, _, terms) = {
       
   118   header = header,
       
   119   sorts = Typtab.fold (fn (_, (n, true)) => cons n | _ => I) typs [],
       
   120   dtyps = dtyps,
       
   121   funcs = Termtab.fold (fn (_, (n, SOME ss)) => cons (n,ss) | _ => I) terms []}
       
   122 
       
   123 fun recon_of ctxt rules thms ithms revertT revert (_, _, typs, _, _, terms) =
       
   124   let
       
   125     fun add_typ (T, (n, _)) = Symtab.update (n, revertT T)
       
   126     val typs' = Typtab.fold add_typ typs Symtab.empty
       
   127 
       
   128     fun add_fun (t, (n, _)) = Symtab.update (n, revert t)
       
   129     val terms' = Termtab.fold add_fun terms Symtab.empty
       
   130 
       
   131     val assms = map (pair ~1) thms @ ithms
       
   132   in
       
   133     {context=ctxt, typs=typs', terms=terms', rewrite_rules=rules, assms=assms}
       
   134   end
       
   135 
       
   136 
       
   137 
       
   138 (* preprocessing *)
       
   139 
       
   140 (** mark built-in constants as Var **)
       
   141 
       
   142 fun mark_builtins ctxt =
       
   143   let
       
   144     (*
       
   145       Note: schematic terms cannot occur anymore in terms at this stage.
       
   146     *)
       
   147     fun mark t =
       
   148       (case Term.strip_comb t of
       
   149         (u as Const (@{const_name If}, _), ts) => marks u ts
       
   150       | (u as Const c, ts) =>
       
   151           (case B.builtin_num ctxt t of
       
   152             SOME (n, T) =>
       
   153               let val v = ((n, 0), T)
       
   154               in Vartab.update v #> pair (Var v) end
       
   155           | NONE =>
       
   156               (case B.builtin_fun ctxt c ts of
       
   157                 SOME ((ni, T), us, U) =>
       
   158                   Vartab.update (ni, U) #> marks (Var (ni, T)) us
       
   159               | NONE => marks u ts))
       
   160       | (Abs (n, T, u), ts) => mark u #-> (fn u' => marks (Abs (n, T, u')) ts)
       
   161       | (u, ts) => marks u ts)
       
   162  
       
   163     and marks t ts = fold_map mark ts #>> Term.list_comb o pair t
       
   164 
       
   165   in (fn ts => swap (fold_map mark ts Vartab.empty)) end
       
   166 
       
   167 fun mark_builtins' ctxt t = hd (snd (mark_builtins ctxt [t]))
       
   168 
       
   169 
       
   170 (** FIXME **)
       
   171 
       
   172 local
       
   173   (*
       
   174     mark constructors and selectors as Vars (forcing eta-expansion),
       
   175     add missing datatype selectors via hypothetical definitions,
       
   176     also return necessary datatype and record theorems
       
   177   *)
       
   178 in
       
   179 
       
   180 fun collect_datatypes_and_records (tr_context, ctxt) ts =
       
   181   (([], tr_context, ctxt), ts)
       
   182 
       
   183 end
       
   184 
       
   185 
       
   186 (** eta-expand quantifiers, let expressions and built-ins *)
       
   187 
       
   188 local
       
   189   fun eta T t = Abs (Name.uu, T, Term.incr_boundvars 1 t $ Bound 0)
       
   190 
       
   191   fun exp T = eta (Term.domain_type (Term.domain_type T))
       
   192 
       
   193   fun exp2 T q =
       
   194     let val U = Term.domain_type T
       
   195     in Abs (Name.uu, U, q $ eta (Term.domain_type U) (Bound 0)) end
       
   196 
       
   197   fun exp2' T l =
       
   198     let val (U1, U2) = Term.dest_funT T ||> Term.domain_type
       
   199     in Abs (Name.uu, U1, eta U2 (l $ Bound 0)) end
       
   200 
       
   201   fun expf t i T ts =
       
   202     let val Ts = U.dest_funT i T |> fst |> drop (length ts)
       
   203     in Term.list_comb (t, ts) |> fold_rev eta Ts end
       
   204 
       
   205   fun expand ((q as Const (@{const_name All}, _)) $ Abs a) = q $ abs_expand a
       
   206     | expand ((q as Const (@{const_name All}, T)) $ t) = q $ exp T t
       
   207     | expand (q as Const (@{const_name All}, T)) = exp2 T q
       
   208     | expand ((q as Const (@{const_name Ex}, _)) $ Abs a) = q $ abs_expand a
       
   209     | expand ((q as Const (@{const_name Ex}, T)) $ t) = q $ exp T t
       
   210     | expand (q as Const (@{const_name Ex}, T)) = exp2 T q
       
   211     | expand ((l as Const (@{const_name Let}, _)) $ t $ Abs a) =
       
   212         l $ expand t $ abs_expand a
       
   213     | expand ((l as Const (@{const_name Let}, T)) $ t $ u) =
       
   214         l $ expand t $ exp (Term.range_type T) u
       
   215     | expand ((l as Const (@{const_name Let}, T)) $ t) = exp2 T (l $ expand t)
       
   216     | expand (l as Const (@{const_name Let}, T)) = exp2' T l
       
   217     | expand (Abs a) = abs_expand a
       
   218     | expand t =
       
   219         (case Term.strip_comb t of
       
   220           (u as Const (@{const_name If}, T), ts) => expf u 3 T (map expand ts)
       
   221         | (u as Var ((_, i), T), ts) => expf u i T (map expand ts)
       
   222         | (u, ts) => Term.list_comb (u, map expand ts))
       
   223 
       
   224   and abs_expand (n, T, t) = Abs (n, T, expand t)
       
   225 in
       
   226 
       
   227 val eta_expand = map expand
       
   228 
       
   229 end
       
   230 
       
   231 
       
   232 (** lambda-lifting **)
       
   233 
       
   234 local
       
   235   fun mk_def Ts T lhs rhs =
       
   236     let
       
   237       val eq = HOLogic.eq_const T $ lhs $ rhs
       
   238       val trigger =
       
   239         [[Const (@{const_name SMT.pat}, T --> @{typ SMT.pattern}) $ lhs]]
       
   240         |> map (HOLogic.mk_list @{typ SMT.pattern})
       
   241         |> HOLogic.mk_list @{typ "SMT.pattern list"}
       
   242       fun mk_all T t = HOLogic.all_const T $ Abs (Name.uu, T, t)
       
   243     in fold mk_all Ts (@{const SMT.trigger} $ trigger $ eq) end
       
   244 
       
   245   fun replace_lambda Us Ts t (cx as (defs, ctxt)) =
       
   246     let
       
   247       val T = Term.fastype_of1 (Us @ Ts, t)
       
   248       val lev = length Us
       
   249       val bs = sort int_ord (Term.add_loose_bnos (t, lev, []))
       
   250       val bss = map_index (fn (i, j) => (j, Integer.add lev i)) bs
       
   251       val norm = perhaps (AList.lookup (op =) bss)
       
   252       val t' = Term.map_aterms (fn Bound i => Bound (norm i) | t => t) t
       
   253       val Ts' = map (nth Ts) bs
       
   254 
       
   255       fun mk_abs U u = Abs (Name.uu, U, u)
       
   256       val abs_rhs = fold mk_abs Ts' (fold mk_abs Us t')
       
   257     in
       
   258       (case Termtab.lookup defs abs_rhs of
       
   259         SOME (f, _) => (Term.list_comb (f, map Bound bs), cx)
       
   260       | NONE =>
       
   261           let
       
   262             val (n, ctxt') =
       
   263               yield_singleton Variable.variant_fixes Name.uu ctxt
       
   264             val f = Free (n, rev Ts' ---> (rev Us ---> T))
       
   265             fun mk_bapp i t = t $ Bound i
       
   266             val lhs =
       
   267               f
       
   268               |> fold_rev (mk_bapp o snd) bss
       
   269               |> fold_rev mk_bapp (0 upto (length Us - 1))
       
   270             val def = mk_def (Us @ Ts') T lhs t'
       
   271           in (f, (Termtab.update (abs_rhs, (f, def)) defs, ctxt')) end)
       
   272     end
       
   273 
       
   274   fun dest_abs Ts (Abs (_, T, t)) = dest_abs (T :: Ts) t
       
   275     | dest_abs Ts t = (Ts, t)
       
   276 
       
   277   fun traverse Ts t =
       
   278     (case t of
       
   279       (q as Const (@{const_name All}, _)) $ Abs a =>
       
   280         abs_traverse Ts a #>> (fn a' => q $ Abs a')
       
   281     | (q as Const (@{const_name Ex}, _)) $ Abs a =>
       
   282         abs_traverse Ts a #>> (fn a' => q $ Abs a')
       
   283     | (l as Const (@{const_name Let}, _)) $ u $ Abs a =>
       
   284         traverse Ts u ##>> abs_traverse Ts a #>>
       
   285         (fn (u', a') => l $ u' $ Abs a')
       
   286     | Abs _ =>
       
   287         let val (Us, u) = dest_abs [] t
       
   288         in traverse (Us @ Ts) u #-> replace_lambda Us Ts end
       
   289     | u1 $ u2 => traverse Ts u1 ##>> traverse Ts u2 #>> (op $)
       
   290     | _ => pair t)
       
   291 
       
   292   and abs_traverse Ts (n, T, t) = traverse (T::Ts) t #>> (fn t' => (n, T, t'))
       
   293 in
       
   294 
       
   295 fun lift_lambdas ctxt ts =
       
   296   (Termtab.empty, ctxt)
       
   297   |> fold_map (traverse []) ts
       
   298   |> (fn (us, (defs, ctxt')) =>
       
   299        (ctxt', Termtab.fold (cons o snd o snd) defs us))
       
   300 
       
   301 end
       
   302 
       
   303 
       
   304 (** introduce explicit applications **)
       
   305 
       
   306 local
       
   307   (*
       
   308     Make application explicit for functions with varying number of arguments.
       
   309   *)
       
   310 
       
   311   fun add t ts =
       
   312     Termtab.map_default (t, []) (Ord_List.insert int_ord (length ts))
       
   313 
       
   314   fun collect t =
       
   315     (case Term.strip_comb t of
       
   316       (u as Const _, ts) => add u ts #> fold collect ts
       
   317     | (u as Free _, ts) => add u ts #> fold collect ts
       
   318     | (Abs (_, _, u), ts) => collect u #> fold collect ts
       
   319     | (_, ts) => fold collect ts)
       
   320 
       
   321   fun app ts (t, T) =
       
   322     let val f = Const (@{const_name SMT.fun_app}, T --> T)
       
   323     in (Term.list_comb (f $ t, ts), snd (U.dest_funT (length ts) T)) end 
       
   324 
       
   325   fun appl _ _ [] = fst
       
   326     | appl _ [] ts = fst o app ts
       
   327     | appl i (k :: ks) ts =
       
   328         let val (ts1, ts2) = chop (k - i) ts
       
   329         in appl k ks ts2 o app ts1 end
       
   330 
       
   331   fun appl0 [_] ts (t, _) = Term.list_comb (t, ts)
       
   332     | appl0 (0 :: ks) ts tT = appl 0 ks ts tT
       
   333     | appl0 ks ts tT = appl 0 ks ts tT
       
   334 
       
   335   fun apply terms T t ts = appl0 (Termtab.lookup_list terms t) ts (t, T)
       
   336 
       
   337   fun get_arities i t =
       
   338     (case Term.strip_comb t of
       
   339       (Bound j, ts) =>
       
   340         (if i = j then Ord_List.insert int_ord (length ts) else I) #>
       
   341         fold (get_arities i) ts
       
   342     | (Abs (_, _, u), ts) => get_arities (i+1) u #> fold (get_arities i) ts
       
   343     | (_, ts) => fold (get_arities i) ts)
       
   344 in
       
   345 
       
   346 fun intro_explicit_application ts =
       
   347   let
       
   348     val terms = fold collect ts Termtab.empty
       
   349 
       
   350     fun traverse (env as (arities, Ts)) t =
       
   351       (case Term.strip_comb t of
       
   352         (u as Const (_, T), ts) => apply terms T u (map (traverse env) ts)
       
   353       | (u as Free (_, T), ts) => apply terms T u (map (traverse env) ts)
       
   354       | (u as Bound i, ts) =>
       
   355           appl0 (nth arities i) (map (traverse env) ts) (u, nth Ts i)
       
   356       | (Abs (n, T, u), ts) =>
       
   357           let val env' = (get_arities 0 u [] :: arities, T :: Ts)
       
   358           in traverses env (Abs (n, T, traverse env' u)) ts end
       
   359       | (u, ts) => traverses env u ts)
       
   360     and traverses env t ts = Term.list_comb (t, map (traverse env) ts)
       
   361   in map (traverse ([], [])) ts end
       
   362 
       
   363 val fun_app_eq = mk_meta_eq @{thm SMT.fun_app_def}
       
   364 
       
   365 end
       
   366 
       
   367 
       
   368 (** map HOL formulas to FOL formulas (i.e., separate formulas froms terms) **)
       
   369 
       
   370 val tboolT = @{typ SMT.term_bool}
       
   371 val term_true = Const (@{const_name True}, tboolT)
       
   372 val term_false = Const (@{const_name False}, tboolT)
       
   373 
       
   374 val term_bool = @{lemma "True ~= False" by simp}
       
   375 val term_bool_prop =
       
   376   let
       
   377     fun replace @{const HOL.eq (bool)} = @{const HOL.eq (SMT.term_bool)}
       
   378       | replace @{const True} = term_true
       
   379       | replace @{const False} = term_false
       
   380       | replace t = t
       
   381   in
       
   382     Term.map_aterms replace (HOLogic.dest_Trueprop (Thm.prop_of term_bool))
       
   383   end
       
   384 
       
   385 val fol_rules = [
       
   386   Let_def,
       
   387   @{lemma "P = True == P" by (rule eq_reflection) simp},
       
   388   @{lemma "if P then True else False == P" by (rule eq_reflection) simp}]
       
   389 
       
   390 fun reduce_let (Const (@{const_name Let}, _) $ t $ u) =
       
   391       reduce_let (Term.betapply (u, t))
       
   392   | reduce_let (t $ u) = reduce_let t $ reduce_let u
       
   393   | reduce_let (Abs (n, T, t)) = Abs (n, T, reduce_let t)
       
   394   | reduce_let t = t
       
   395 
       
   396 fun is_pred_type NONE = false
       
   397   | is_pred_type (SOME T) = (Term.body_type T = @{typ bool})
       
   398 
       
   399 fun is_conn_type NONE = false
       
   400   | is_conn_type (SOME T) =
       
   401       forall (equal @{typ bool}) (Term.body_type T :: Term.binder_types T)
       
   402 
       
   403 fun revert_typ @{typ SMT.term_bool} = @{typ bool}
       
   404   | revert_typ (Type (n, Ts)) = Type (n, map revert_typ Ts)
       
   405   | revert_typ T = T
       
   406 
       
   407 val revert_types = Term.map_types revert_typ
       
   408 
       
   409 fun folify ctxt builtins =
       
   410   let
       
   411     fun as_term t = @{const HOL.eq (SMT.term_bool)} $ t $ term_true
       
   412 
       
   413     fun as_tbool @{typ bool} = tboolT
       
   414       | as_tbool (Type (n, Ts)) = Type (n, map as_tbool Ts)
       
   415       | as_tbool T = T
       
   416     fun mapTs f g i = U.dest_funT i #> (fn (Ts, T) => map f Ts ---> g T)
       
   417     fun predT i = mapTs as_tbool I i
       
   418     fun funcT i = mapTs as_tbool as_tbool i
       
   419     fun func i (n, T) = (n, funcT i T)
       
   420 
       
   421     fun map_ifT T = T |> Term.dest_funT ||> funcT 2 |> (op -->)
       
   422     val if_term = @{const If (bool)} |> Term.dest_Const ||> map_ifT |> Const
       
   423     fun wrap_in_if t = if_term $ t $ term_true $ term_false
       
   424 
       
   425     fun in_list T f t = HOLogic.mk_list T (map f (HOLogic.dest_list t))
       
   426 
       
   427     fun in_term t =
       
   428       (case Term.strip_comb t of
       
   429         (Const (n as @{const_name If}, T), [t1, t2, t3]) =>
       
   430           Const (n, map_ifT T) $ in_form t1 $ in_term t2 $ in_term t3
       
   431       | (Const (@{const_name HOL.eq}, _), _) => wrap_in_if (in_form t)
       
   432       | (Var (ni as (_, i), T), ts) =>
       
   433           let val U = Vartab.lookup builtins ni
       
   434           in
       
   435             if is_conn_type U orelse is_pred_type U then wrap_in_if (in_form t)
       
   436             else Term.list_comb (Var (ni, funcT i T), map in_term ts)
       
   437           end
       
   438       | (Const c, ts) =>
       
   439           Term.list_comb (Const (func (length ts) c), map in_term ts)
       
   440       | (Free c, ts) =>
       
   441           Term.list_comb (Free (func (length ts) c), map in_term ts)
       
   442       | _ => t)
       
   443 
       
   444     and in_weight ((c as @{const SMT.weight}) $ w $ t) = c $ w $ in_form t
       
   445       | in_weight t = in_form t 
       
   446 
       
   447     and in_pat (Const (c as (@{const_name pat}, _)) $ t) =
       
   448           Const (func 1 c) $ in_term t
       
   449       | in_pat (Const (c as (@{const_name nopat}, _)) $ t) =
       
   450           Const (func 1 c) $ in_term t
       
   451       | in_pat t = raise TERM ("bad pattern", [t])
       
   452 
       
   453     and in_pats ps =
       
   454       in_list @{typ "pattern list"} (in_list @{typ pattern} in_pat) ps
       
   455 
       
   456     and in_trig ((c as @{const trigger}) $ p $ t) = c $ in_pats p $ in_weight t
       
   457       | in_trig t = in_weight t
       
   458 
       
   459     and in_form t =
       
   460       (case Term.strip_comb t of
       
   461         (q as Const (qn, _), [Abs (n, T, u)]) =>
       
   462           if member (op =) [@{const_name All}, @{const_name Ex}] qn then
       
   463             q $ Abs (n, as_tbool T, in_trig u)
       
   464           else as_term (in_term t)
       
   465       | (u as Const (@{const_name If}, _), ts) =>
       
   466           Term.list_comb (u, map in_form ts)
       
   467       | (b as @{const HOL.eq (bool)}, ts) => Term.list_comb (b, map in_form ts)
       
   468       | (Const (n as @{const_name HOL.eq}, T), ts) =>
       
   469           Term.list_comb (Const (n, predT 2 T), map in_term ts)
       
   470       | (b as Var (ni as (_, i), T), ts) =>
       
   471           if is_conn_type (Vartab.lookup builtins ni) then
       
   472             Term.list_comb (b, map in_form ts)
       
   473           else if is_pred_type (Vartab.lookup builtins ni) then
       
   474             Term.list_comb (Var (ni, predT i T), map in_term ts)
       
   475           else as_term (in_term t)
       
   476       | _ => as_term (in_term t))
       
   477   in
       
   478     map (reduce_let #> in_form) #>
       
   479     cons (mark_builtins' ctxt term_bool_prop) #>
       
   480     pair (fol_rules, [term_bool])
       
   481   end
       
   482 
       
   483 
       
   484 
       
   485 (* translation into intermediate format *)
       
   486 
       
   487 (** utility functions **)
    88 
   488 
    89 val quantifier = (fn
   489 val quantifier = (fn
    90     @{const_name All} => SOME SForall
   490     @{const_name All} => SOME SForall
    91   | @{const_name Ex} => SOME SExists
   491   | @{const_name Ex} => SOME SExists
    92   | _ => NONE)
   492   | _ => NONE)
    99       (SOME (snd (HOLogic.dest_number w)), t)
   499       (SOME (snd (HOLogic.dest_number w)), t)
   100   | dest_weight t = (NONE, t)
   500   | dest_weight t = (NONE, t)
   101 
   501 
   102 fun dest_pat (Const (@{const_name pat}, _) $ t) = (t, true)
   502 fun dest_pat (Const (@{const_name pat}, _) $ t) = (t, true)
   103   | dest_pat (Const (@{const_name nopat}, _) $ t) = (t, false)
   503   | dest_pat (Const (@{const_name nopat}, _) $ t) = (t, false)
   104   | dest_pat t = raise TERM ("dest_pat", [t])
   504   | dest_pat t = raise TERM ("bad pattern", [t])
   105 
   505 
   106 fun dest_pats [] = I
   506 fun dest_pats [] = I
   107   | dest_pats ts =
   507   | dest_pats ts =
   108       (case map dest_pat ts |> split_list ||> distinct (op =) of
   508       (case map dest_pat ts |> split_list ||> distinct (op =) of
   109         (ps, [true]) => cons (SPat ps)
   509         (ps, [true]) => cons (SPat ps)
   110       | (ps, [false]) => cons (SNoPat ps)
   510       | (ps, [false]) => cons (SNoPat ps)
   111       | _ => raise TERM ("dest_pats", ts))
   511       | _ => raise TERM ("bad multi-pattern", ts))
   112 
   512 
   113 fun dest_trigger (@{const trigger} $ tl $ t) =
   513 fun dest_trigger (@{const trigger} $ tl $ t) =
   114       (rev (fold (dest_pats o HOLogic.dest_list) (HOLogic.dest_list tl) []), t)
   514       (rev (fold (dest_pats o HOLogic.dest_list) (HOLogic.dest_list tl) []), t)
   115   | dest_trigger t = ([], t)
   515   | dest_trigger t = ([], t)
   116 
   516 
   122   in (q, rev Ts, ps, w, b) end)
   522   in (q, rev Ts, ps, w, b) end)
   123 
   523 
   124 fun fold_map_pat f (SPat ts) = fold_map f ts #>> SPat
   524 fun fold_map_pat f (SPat ts) = fold_map f ts #>> SPat
   125   | fold_map_pat f (SNoPat ts) = fold_map f ts #>> SNoPat
   525   | fold_map_pat f (SNoPat ts) = fold_map f ts #>> SNoPat
   126 
   526 
   127 fun prop_of thm = HOLogic.dest_Trueprop (Thm.prop_of thm)
   527 
   128 
   528 (** translation from Isabelle terms into SMT intermediate terms **)
   129 
   529 
   130 
   530 fun intermediate header dtyps ctxt ts trx =
   131 (* map HOL formulas to FOL formulas (i.e., separate formulas froms terms) *)
   531   let
   132 
   532     fun transT (T as TFree _) = add_typ T true
   133 val tboolT = @{typ SMT.term_bool}
   533       | transT (T as TVar _) = (fn _ => raise TYPE ("bad SMT type", [T], []))
   134 val term_true = Const (@{const_name True}, tboolT)
   534       | transT (T as Type _) =
   135 val term_false = Const (@{const_name False}, tboolT)
       
   136 
       
   137 val term_bool = @{lemma "True ~= False" by simp}
       
   138 val term_bool_prop =
       
   139   let
       
   140     fun replace @{const HOL.eq (bool)} = @{const HOL.eq (SMT.term_bool)}
       
   141       | replace @{const True} = term_true
       
   142       | replace @{const False} = term_false
       
   143       | replace t = t
       
   144   in Term.map_aterms replace (prop_of term_bool) end
       
   145 
       
   146 val needs_rewrite = Thm.prop_of #> Term.exists_subterm (fn
       
   147     Const (@{const_name Let}, _) => true
       
   148   | @{const HOL.eq (bool)} $ _ $ @{const True} => true
       
   149   | Const (@{const_name If}, _) $ _ $ @{const True} $ @{const False} => true
       
   150   | _ => false)
       
   151 
       
   152 val rewrite_rules = [
       
   153   Let_def,
       
   154   @{lemma "P = True == P" by (rule eq_reflection) simp},
       
   155   @{lemma "if P then True else False == P" by (rule eq_reflection) simp}]
       
   156 
       
   157 fun rewrite ctxt ct =
       
   158   Conv.top_sweep_conv (fn ctxt' =>
       
   159     Conv.rewrs_conv rewrite_rules then_conv rewrite ctxt') ctxt ct
       
   160 
       
   161 fun normalize ctxt thm =
       
   162   if needs_rewrite thm then Conv.fconv_rule (rewrite ctxt) thm else thm
       
   163 
       
   164 fun revert_typ @{typ SMT.term_bool} = @{typ bool}
       
   165   | revert_typ (Type (n, Ts)) = Type (n, map revert_typ Ts)
       
   166   | revert_typ T = T
       
   167 
       
   168 val revert_types = Term.map_types revert_typ
       
   169 
       
   170 fun folify ctxt =
       
   171   let
       
   172     fun is_builtin_conn (@{const_name True}, _) _ = false
       
   173       | is_builtin_conn (@{const_name False}, _) _ = false
       
   174       | is_builtin_conn c ts = B.is_builtin_conn ctxt c ts
       
   175 
       
   176     fun as_term t = @{const HOL.eq (SMT.term_bool)} $ t $ term_true
       
   177 
       
   178     fun as_tbool @{typ bool} = tboolT
       
   179       | as_tbool (Type (n, Ts)) = Type (n, map as_tbool Ts)
       
   180       | as_tbool T = T
       
   181     fun mapTs f g = Term.strip_type #> (fn (Ts, T) => map f Ts ---> g T)
       
   182     fun predT T = mapTs as_tbool I T
       
   183     fun funcT T = mapTs as_tbool as_tbool T
       
   184     fun func (n, T) = Const (n, funcT T)
       
   185 
       
   186     fun map_ifT T = T |> Term.dest_funT ||> funcT |> (op -->)
       
   187     val if_term = @{const If (bool)} |> Term.dest_Const ||> map_ifT |> Const
       
   188     fun wrap_in_if t = if_term $ t $ term_true $ term_false
       
   189 
       
   190     fun in_list T f t = HOLogic.mk_list T (map f (HOLogic.dest_list t))
       
   191 
       
   192     fun in_term t =
       
   193       (case Term.strip_comb t of
       
   194         (Const (c as @{const_name If}, T), [t1, t2, t3]) =>
       
   195           Const (c, map_ifT T) $ in_form t1 $ in_term t2 $ in_term t3
       
   196       | (Const c, ts) =>
       
   197           if is_builtin_conn c ts orelse B.is_builtin_pred ctxt c ts
       
   198           then wrap_in_if (in_form t)
       
   199           else Term.list_comb (func c, map in_term ts)
       
   200       | (Free (n, T), ts) => Term.list_comb (Free (n, funcT T), map in_term ts)
       
   201       | _ => t)
       
   202 
       
   203     and in_weight ((c as @{const SMT.weight}) $ w $ t) = c $ w $ in_form t
       
   204       | in_weight t = in_form t 
       
   205 
       
   206     and in_pat (Const (c as (@{const_name pat}, _)) $ t) = func c $ in_term t
       
   207       | in_pat (Const (c as (@{const_name nopat}, _)) $ t) = func c $ in_term t
       
   208       | in_pat t = raise TERM ("in_pat", [t])
       
   209 
       
   210     and in_pats ps =
       
   211       in_list @{typ "pattern list"} (in_list @{typ pattern} in_pat) ps
       
   212 
       
   213     and in_trig ((c as @{const trigger}) $ p $ t) = c $ in_pats p $ in_weight t
       
   214       | in_trig t = in_weight t
       
   215 
       
   216     and in_form t =
       
   217       (case Term.strip_comb t of
       
   218         (q as Const (qn, _), [Abs (n, T, t')]) =>
       
   219           if is_some (quantifier qn) then q $ Abs (n, as_tbool T, in_trig t')
       
   220           else as_term (in_term t)
       
   221       | (Const (c as (n as @{const_name distinct}, T)), [t']) =>
       
   222           if B.is_builtin_fun ctxt c [t'] then
       
   223             Const (n, predT T) $ in_list T in_term t'
       
   224           else as_term (in_term t)
       
   225       | (Const (c as (n, T)), ts) =>
       
   226           if B.is_builtin_conn ctxt c ts
       
   227           then Term.list_comb (Const c, map in_form ts)
       
   228           else if B.is_builtin_pred ctxt c ts
       
   229           then Term.list_comb (Const (n, predT T), map in_term ts)
       
   230           else as_term (in_term t)
       
   231       | _ => as_term (in_term t))
       
   232   in
       
   233     map (apsnd (normalize ctxt)) #> (fn irules =>
       
   234     ((rewrite_rules, (~1, term_bool) :: irules),
       
   235      term_bool_prop :: map (in_form o prop_of o snd) irules))
       
   236   end
       
   237 
       
   238 
       
   239 
       
   240 (* translation from Isabelle terms into SMT intermediate terms *)
       
   241 
       
   242 val empty_context = (1, Typtab.empty, [], 1, Termtab.empty)
       
   243 
       
   244 fun make_sign header (_, typs, dtyps, _, terms) = {
       
   245   header = header,
       
   246   sorts = Typtab.fold (fn (_, (n, true)) => cons n | _ => I) typs [],
       
   247   funcs = Termtab.fold (fn (_, (n, SOME ss)) => cons (n,ss) | _ => I) terms [],
       
   248   dtyps = rev dtyps }
       
   249 
       
   250 fun make_recon (unfolds, assms) (_, typs, _, _, terms) = {
       
   251   typs = Symtab.make (map (apfst fst o swap) (Typtab.dest typs)),
       
   252     (*FIXME: don't drop the datatype information! *)
       
   253   terms = Symtab.make (map (fn (t, (n, _)) => (n, t)) (Termtab.dest terms)),
       
   254   unfolds = unfolds,
       
   255   assms = assms }
       
   256 
       
   257 fun string_of_index pre i = pre ^ string_of_int i
       
   258 
       
   259 fun new_typ sort_prefix proper T (Tidx, typs, dtyps, idx, terms) =
       
   260   let
       
   261     val s = string_of_index sort_prefix Tidx
       
   262     val U = revert_typ T
       
   263   in (s, (Tidx+1, Typtab.update (U, (s, proper)) typs, dtyps, idx, terms)) end
       
   264 
       
   265 fun lookup_typ (_, typs, _, _, _) = Typtab.lookup typs o revert_typ
       
   266 
       
   267 fun fresh_typ T f cx =
       
   268   (case lookup_typ cx T of
       
   269     SOME (s, _) => (s, cx)
       
   270   | NONE => f T cx)
       
   271 
       
   272 fun new_fun func_prefix t ss (Tidx, typs, dtyps, idx, terms) =
       
   273   let
       
   274     val f = string_of_index func_prefix idx
       
   275     val terms' = Termtab.update (revert_types t, (f, ss)) terms
       
   276   in (f, (Tidx, typs, dtyps, idx+1, terms')) end
       
   277 
       
   278 fun fresh_fun func_prefix t ss (cx as (_, _, _, _, terms)) =
       
   279   (case Termtab.lookup terms (revert_types t) of
       
   280     SOME (f, _) => (f, cx)
       
   281   | NONE => new_fun func_prefix t ss cx)
       
   282 
       
   283 fun mk_type (_, Tfs) (d as Datatype.DtTFree _) = the (AList.lookup (op =) Tfs d)
       
   284   | mk_type Ts (Datatype.DtType (n, ds)) = Type (n, map (mk_type Ts) ds)
       
   285   | mk_type (Tds, _) (Datatype.DtRec i) = nth Tds i
       
   286 
       
   287 fun mk_selector ctxt Ts T n (i, d) =
       
   288   (case Datatype_Selectors.lookup_selector ctxt (n, i+1) of
       
   289     NONE => raise Fail ("missing selector for datatype constructor " ^ quote n)
       
   290   | SOME m => mk_type Ts d |> (fn U => (Const (m, T --> U), U)))
       
   291 
       
   292 fun mk_constructor ctxt Ts T (n, args) =
       
   293   let val (sels, Us) = split_list (map_index (mk_selector ctxt Ts T n) args)
       
   294   in (Const (n, Us ---> T), sels) end
       
   295 
       
   296 fun lookup_datatype ctxt n Ts =
       
   297   if member (op =) [@{type_name bool}, @{type_name nat}] n then NONE
       
   298   else
       
   299     Datatype.get_info (ProofContext.theory_of ctxt) n
       
   300     |> Option.map (fn {descr, ...} =>
       
   301          let
       
   302            val Tds = map (fn (_, (tn, _, _)) => Type (tn, Ts))
       
   303              (sort (int_ord o pairself fst) descr)
       
   304            val Tfs = (case hd descr of (_, (_, tfs, _)) => tfs ~~ Ts)
       
   305          in
       
   306            descr |> map (fn (i, (_, _, cs)) =>
       
   307              (nth Tds i, map (mk_constructor ctxt (Tds, Tfs) (nth Tds i)) cs))
       
   308          end)
       
   309 
       
   310 fun relaxed irules = (([], irules), map (prop_of o snd) irules)
       
   311 
       
   312 fun with_context header f (ths, ts) =
       
   313   let val (us, context) = fold_map f ts empty_context
       
   314   in ((make_sign (header ts) context, us), make_recon ths context) end
       
   315 
       
   316 
       
   317 fun translate config ctxt comments =
       
   318   let
       
   319     val {prefixes, is_fol, header, has_datatypes, serialize} = config
       
   320     val {sort_prefix, func_prefix} = prefixes
       
   321 
       
   322     fun transT (T as TFree _) = fresh_typ T (new_typ sort_prefix true)
       
   323       | transT (T as TVar _) = (fn _ => raise TYPE ("smt_translate", [T], []))
       
   324       | transT (T as Type (n, Ts)) =
       
   325           (case B.builtin_typ ctxt T of
   535           (case B.builtin_typ ctxt T of
   326             SOME n => pair n
   536             SOME n => pair n
   327           | NONE => fresh_typ T (fn _ => fn cx =>
   537           | NONE => add_typ T true)
   328               if not has_datatypes then new_typ sort_prefix true T cx
   538 
   329               else
   539     val unmarked_builtins = [@{const_name If}, @{const_name HOL.eq}]
   330                 (case lookup_datatype ctxt n Ts of
       
   331                   NONE => new_typ sort_prefix true T cx
       
   332                 | SOME dts =>
       
   333                     let val cx' = new_dtyps dts cx 
       
   334                     in (fst (the (lookup_typ cx' T)), cx') end)))
       
   335 
       
   336     and new_dtyps dts cx =
       
   337       let
       
   338         fun new_decl i t =
       
   339           let val (Ts, T) = U.dest_funT i (Term.fastype_of t)
       
   340           in
       
   341             fold_map transT Ts ##>> transT T ##>>
       
   342             new_fun func_prefix t NONE #>> swap
       
   343           end
       
   344         fun new_dtyp_decl (con, sels) =
       
   345           new_decl (length sels) con ##>> fold_map (new_decl 1) sels #>>
       
   346           (fn ((con', _), sels') => (con', map (apsnd snd) sels'))
       
   347       in
       
   348         cx
       
   349         |> fold_map (new_typ sort_prefix false o fst) dts
       
   350         ||>> fold_map (fold_map new_dtyp_decl o snd) dts
       
   351         |-> (fn (ss, decls) => fn (Tidx, typs, dtyps, idx, terms) =>
       
   352               (Tidx, typs, (ss ~~ decls) :: dtyps, idx, terms))
       
   353       end
       
   354 
   540 
   355     fun app n ts = SApp (n, ts)
   541     fun app n ts = SApp (n, ts)
   356 
   542 
   357     fun trans t =
   543     fun trans t =
   358       (case Term.strip_comb t of
   544       (case Term.strip_comb t of
   359         (Const (qn, _), [Abs (_, T, t1)]) =>
   545         (Const (qn, _), [Abs (_, T, t1)]) =>
   360           (case dest_quant qn T t1 of
   546           (case dest_quant qn T t1 of
   361             SOME (q, Ts, ps, w, b) =>
   547             SOME (q, Ts, ps, w, b) =>
   362               fold_map transT Ts ##>> fold_map (fold_map_pat trans) ps ##>>
   548               fold_map transT Ts ##>> fold_map (fold_map_pat trans) ps ##>>
   363               trans b #>> (fn ((Ts', ps'), b') => SQua (q, Ts', ps', w, b'))
   549               trans b #>> (fn ((Ts', ps'), b') => SQua (q, Ts', ps', w, b'))
   364           | NONE => raise TERM ("intermediate", [t]))
   550           | NONE => raise TERM ("unsupported quantifier", [t]))
   365       | (Const (@{const_name Let}, _), [t1, Abs (_, T, t2)]) =>
   551       | (Const (@{const_name Let}, _), [t1, Abs (_, T, t2)]) =>
   366           transT T ##>> trans t1 ##>> trans t2 #>>
   552           transT T ##>> trans t1 ##>> trans t2 #>>
   367           (fn ((U, u1), u2) => SLet (U, u1, u2))
   553           (fn ((U, u1), u2) => SLet (U, u1, u2))
   368       | (h as Const (c as (@{const_name distinct}, T)), ts) =>
   554       | (Var ((n, _), _), ts) => fold_map trans ts #>> app n
   369           (case B.builtin_fun ctxt c ts of
   555       | (u as Const (c as (n, T)), ts) =>
   370             SOME (n, ts) => fold_map trans ts #>> app n
   556           if member (op =) unmarked_builtins n then
   371           | NONE => transs h T ts)
   557             (case B.builtin_fun ctxt c ts of
   372       | (h as Const (c as (_, T)), ts) =>
   558               SOME (((m, _), _), us, _) => fold_map trans us #>> app m
   373           (case B.builtin_num ctxt t of
   559             | NONE => raise TERM ("not a built-in symbol", [t]))
   374             SOME n => pair (SApp (n, []))
   560           else transs u T ts
   375           | NONE =>
   561       | (u as Free (_, T), ts) => transs u T ts
   376               (case B.builtin_fun ctxt c ts of
       
   377                 SOME (n, ts') => fold_map trans ts' #>> app n
       
   378               | NONE => transs h T ts))
       
   379       | (h as Free (_, T), ts) => transs h T ts
       
   380       | (Bound i, []) => pair (SVar i)
   562       | (Bound i, []) => pair (SVar i)
   381       | (Abs (_, _, t1 $ Bound 0), []) =>
   563       | _ => raise TERM ("bad SMT term", [t]))
   382         if not (loose_bvar1 (t1, 0)) then trans t1 (* eta-reduce on the fly *)
   564  
   383         else raise TERM ("smt_translate", [t])
       
   384       | _ => raise TERM ("smt_translate", [t]))
       
   385 
       
   386     and transs t T ts =
   565     and transs t T ts =
   387       let val (Us, U) = U.dest_funT (length ts) T
   566       let val (Us, U) = U.dest_funT (length ts) T
   388       in
   567       in
   389         fold_map transT Us ##>> transT U #-> (fn Up =>
   568         fold_map transT Us ##>> transT U #-> (fn Up =>
   390         fresh_fun func_prefix t (SOME Up) ##>> fold_map trans ts #>> SApp)
   569         add_fun t (SOME Up) ##>> fold_map trans ts #>> SApp)
   391       end
   570       end
       
   571 
       
   572     val (us, trx') = fold_map trans ts trx
       
   573   in ((sign_of (header ts) dtyps trx', us), trx') end
       
   574 
       
   575 
       
   576 
       
   577 (* translation *)
       
   578 
       
   579 structure Configs = Generic_Data
       
   580 (
       
   581   type T = (Proof.context -> config) U.dict
       
   582   val empty = []
       
   583   val extend = I
       
   584   val merge = U.dict_merge fst
       
   585 )
       
   586 
       
   587 fun add_config (cs, cfg) = Configs.map (U.dict_update (cs, cfg))
       
   588 
       
   589 fun translate ctxt comments ithms =
       
   590   let
       
   591     val cs = SMT_Config.solver_class_of ctxt
       
   592     val {prefixes, is_fol, header, has_datatypes, serialize} =
       
   593       (case U.dict_get (Configs.get (Context.Proof ctxt)) cs of
       
   594         SOME cfg => cfg ctxt
       
   595       | NONE => error ("SMT: no translation configuration found " ^
       
   596           "for solver class " ^ quote (U.string_of_class cs)))
       
   597       
       
   598     val with_datatypes =
       
   599       has_datatypes andalso Config.get ctxt SMT_Config.datatypes
       
   600 
       
   601     fun no_dtyps (tr_context, ctxt) ts = (([], tr_context, ctxt), ts)
       
   602 
       
   603     val (builtins, ts1) =
       
   604       ithms
       
   605       |> map (HOLogic.dest_Trueprop o Thm.prop_of o snd)
       
   606       |> map (Envir.eta_contract o Envir.beta_norm)
       
   607       |> mark_builtins ctxt
       
   608 
       
   609     val ((dtyps, tr_context, ctxt1), ts2) =
       
   610       ((make_tr_context prefixes, ctxt), ts1)
       
   611       |-> (if with_datatypes then collect_datatypes_and_records else no_dtyps)
       
   612 
       
   613     val (ctxt2, ts3) =
       
   614       ts2
       
   615       |> eta_expand
       
   616       |> lift_lambdas ctxt1
       
   617       ||> intro_explicit_application
       
   618 
       
   619     val ((rewrite_rules, extra_thms), ts4) =
       
   620       (if is_fol then folify ctxt2 builtins else pair ([], [])) ts3
       
   621 
       
   622     val rewrite_rules' = fun_app_eq :: rewrite_rules
   392   in
   623   in
   393     (if is_fol then folify ctxt else relaxed) #>
   624     (ts4, tr_context)
   394     with_context (header ctxt) trans #>> uncurry (serialize comments)
   625     |-> intermediate header dtyps ctxt2
       
   626     |>> uncurry (serialize comments)
       
   627     ||> recon_of ctxt2 rewrite_rules' extra_thms ithms revert_typ revert_types
   395   end
   628   end
   396 
   629 
   397 end
   630 end