src/HOL/Tools/ATP/atp_reconstruct.ML
changeset 46320 0b8b73b49848
parent 46319 c248e4f1be74
child 46321 484dc68c8c89
equal deleted inserted replaced
46319:c248e4f1be74 46320:0b8b73b49848
     1 (*  Title:      HOL/Tools/ATP/atp_reconstruct.ML
       
     2     Author:     Lawrence C. Paulson, Cambridge University Computer Laboratory
       
     3     Author:     Claire Quigley, Cambridge University Computer Laboratory
       
     4     Author:     Jasmin Blanchette, TU Muenchen
       
     5 
       
     6 Proof reconstruction from ATP proofs.
       
     7 *)
       
     8 
       
     9 signature ATP_RECONSTRUCT =
       
    10 sig
       
    11   type ('a, 'b) ho_term = ('a, 'b) ATP_Problem.ho_term
       
    12   type ('a, 'b, 'c) formula = ('a, 'b, 'c) ATP_Problem.formula
       
    13   type 'a proof = 'a ATP_Proof.proof
       
    14   type locality = ATP_Translate.locality
       
    15 
       
    16   datatype reconstructor =
       
    17     Metis of string * string |
       
    18     SMT
       
    19 
       
    20   datatype play =
       
    21     Played of reconstructor * Time.time |
       
    22     Trust_Playable of reconstructor * Time.time option |
       
    23     Failed_to_Play of reconstructor
       
    24 
       
    25   type minimize_command = string list -> string
       
    26   type one_line_params =
       
    27     play * string * (string * locality) list * minimize_command * int * int
       
    28   type isar_params =
       
    29     bool * int * string Symtab.table * (string * locality) list vector
       
    30     * int Symtab.table * string proof * thm
       
    31 
       
    32   val metisN : string
       
    33   val smtN : string
       
    34   val full_typesN : string
       
    35   val partial_typesN : string
       
    36   val no_typesN : string
       
    37   val really_full_type_enc : string
       
    38   val full_type_enc : string
       
    39   val partial_type_enc : string
       
    40   val no_type_enc : string
       
    41   val full_type_encs : string list
       
    42   val partial_type_encs : string list
       
    43   val metis_default_lam_trans : string
       
    44   val metis_call : string -> string -> string
       
    45   val string_for_reconstructor : reconstructor -> string
       
    46   val used_facts_in_atp_proof :
       
    47     Proof.context -> (string * locality) list vector -> string proof
       
    48     -> (string * locality) list
       
    49   val lam_trans_from_atp_proof : string proof -> string -> string
       
    50   val is_typed_helper_used_in_atp_proof : string proof -> bool
       
    51   val used_facts_in_unsound_atp_proof :
       
    52     Proof.context -> (string * locality) list vector -> 'a proof
       
    53     -> string list option
       
    54   val unalias_type_enc : string -> string list
       
    55   val one_line_proof_text : one_line_params -> string
       
    56   val make_tvar : string -> typ
       
    57   val make_tfree : Proof.context -> string -> typ
       
    58   val term_from_atp :
       
    59     Proof.context -> bool -> int Symtab.table -> typ option
       
    60     -> (string, string) ho_term -> term
       
    61   val prop_from_atp :
       
    62     Proof.context -> bool -> int Symtab.table
       
    63     -> (string, string, (string, string) ho_term) formula -> term
       
    64   val isar_proof_text :
       
    65     Proof.context -> bool -> isar_params -> one_line_params -> string
       
    66   val proof_text :
       
    67     Proof.context -> bool -> isar_params -> one_line_params -> string
       
    68 end;
       
    69 
       
    70 structure ATP_Reconstruct : ATP_RECONSTRUCT =
       
    71 struct
       
    72 
       
    73 open ATP_Util
       
    74 open ATP_Problem
       
    75 open ATP_Proof
       
    76 open ATP_Translate
       
    77 
       
    78 structure String_Redirect = ATP_Redirect(
       
    79     type key = step_name
       
    80     val ord = fn ((s, _ : string list), (s', _)) => fast_string_ord (s, s')
       
    81     val string_of = fst)
       
    82 
       
    83 open String_Redirect
       
    84 
       
    85 datatype reconstructor =
       
    86   Metis of string * string |
       
    87   SMT
       
    88 
       
    89 datatype play =
       
    90   Played of reconstructor * Time.time |
       
    91   Trust_Playable of reconstructor * Time.time option |
       
    92   Failed_to_Play of reconstructor
       
    93 
       
    94 type minimize_command = string list -> string
       
    95 type one_line_params =
       
    96   play * string * (string * locality) list * minimize_command * int * int
       
    97 type isar_params =
       
    98   bool * int * string Symtab.table * (string * locality) list vector
       
    99   * int Symtab.table * string proof * thm
       
   100 
       
   101 val metisN = "metis"
       
   102 val smtN = "smt"
       
   103 
       
   104 val full_typesN = "full_types"
       
   105 val partial_typesN = "partial_types"
       
   106 val no_typesN = "no_types"
       
   107 
       
   108 val really_full_type_enc = "mono_tags"
       
   109 val full_type_enc = "poly_guards_query"
       
   110 val partial_type_enc = "poly_args"
       
   111 val no_type_enc = "erased"
       
   112 
       
   113 val full_type_encs = [full_type_enc, really_full_type_enc]
       
   114 val partial_type_encs = partial_type_enc :: full_type_encs
       
   115 
       
   116 val type_enc_aliases =
       
   117   [(full_typesN, full_type_encs),
       
   118    (partial_typesN, partial_type_encs),
       
   119    (no_typesN, [no_type_enc])]
       
   120 
       
   121 fun unalias_type_enc s =
       
   122   AList.lookup (op =) type_enc_aliases s |> the_default [s]
       
   123 
       
   124 val metis_default_lam_trans = combinatorsN
       
   125 
       
   126 fun metis_call type_enc lam_trans =
       
   127   let
       
   128     val type_enc =
       
   129       case AList.find (fn (enc, encs) => enc = hd encs) type_enc_aliases
       
   130                       type_enc of
       
   131         [alias] => alias
       
   132       | _ => type_enc
       
   133     val opts = [] |> type_enc <> partial_typesN ? cons type_enc
       
   134                   |> lam_trans <> metis_default_lam_trans ? cons lam_trans
       
   135   in metisN ^ (if null opts then "" else " (" ^ commas opts ^ ")") end
       
   136 
       
   137 fun string_for_reconstructor (Metis (type_enc, lam_trans)) =
       
   138     metis_call type_enc lam_trans
       
   139   | string_for_reconstructor SMT = smtN
       
   140 
       
   141 fun find_first_in_list_vector vec key =
       
   142   Vector.foldl (fn (ps, NONE) => AList.lookup (op =) ps key
       
   143                  | (_, value) => value) NONE vec
       
   144 
       
   145 val unprefix_fact_number = space_implode "_" o tl o space_explode "_"
       
   146 
       
   147 fun resolve_one_named_fact fact_names s =
       
   148   case try (unprefix fact_prefix) s of
       
   149     SOME s' =>
       
   150     let val s' = s' |> unprefix_fact_number |> unascii_of in
       
   151       s' |> find_first_in_list_vector fact_names |> Option.map (pair s')
       
   152     end
       
   153   | NONE => NONE
       
   154 fun resolve_fact fact_names = map_filter (resolve_one_named_fact fact_names)
       
   155 fun is_fact fact_names = not o null o resolve_fact fact_names
       
   156 
       
   157 fun resolve_one_named_conjecture s =
       
   158   case try (unprefix conjecture_prefix) s of
       
   159     SOME s' => Int.fromString s'
       
   160   | NONE => NONE
       
   161 
       
   162 val resolve_conjecture = map_filter resolve_one_named_conjecture
       
   163 val is_conjecture = not o null o resolve_conjecture
       
   164 
       
   165 fun is_axiom_used_in_proof pred =
       
   166   exists (fn Inference ((_, ss), _, _, []) => exists pred ss | _ => false)
       
   167 
       
   168 val is_combinator_def = String.isPrefix (helper_prefix ^ combinator_prefix)
       
   169 
       
   170 val ascii_of_lam_fact_prefix = ascii_of lam_fact_prefix
       
   171 
       
   172 (* overapproximation (good enough) *)
       
   173 fun is_lam_lifted s =
       
   174   String.isPrefix fact_prefix s andalso
       
   175   String.isSubstring ascii_of_lam_fact_prefix s
       
   176 
       
   177 fun lam_trans_from_atp_proof atp_proof default =
       
   178   if is_axiom_used_in_proof is_combinator_def atp_proof then combinatorsN
       
   179   else if is_axiom_used_in_proof is_lam_lifted atp_proof then lam_liftingN
       
   180   else default
       
   181 
       
   182 val is_typed_helper_name =
       
   183   String.isPrefix helper_prefix andf String.isSuffix typed_helper_suffix
       
   184 fun is_typed_helper_used_in_atp_proof atp_proof =
       
   185   is_axiom_used_in_proof is_typed_helper_name atp_proof
       
   186 
       
   187 val leo2_ext = "extcnf_equal_neg"
       
   188 val isa_ext = Thm.get_name_hint @{thm ext}
       
   189 val isa_short_ext = Long_Name.base_name isa_ext
       
   190 
       
   191 fun ext_name ctxt =
       
   192   if Thm.eq_thm_prop (@{thm ext},
       
   193          singleton (Attrib.eval_thms ctxt) (Facts.named isa_short_ext, [])) then
       
   194     isa_short_ext
       
   195   else
       
   196     isa_ext
       
   197 
       
   198 fun add_fact _ fact_names (Inference ((_, ss), _, _, [])) =
       
   199     union (op =) (resolve_fact fact_names ss)
       
   200   | add_fact ctxt _ (Inference (_, _, rule, _)) =
       
   201     if rule = leo2_ext then insert (op =) (ext_name ctxt, General) else I
       
   202   | add_fact _ _ _ = I
       
   203 
       
   204 fun used_facts_in_atp_proof ctxt fact_names atp_proof =
       
   205   if null atp_proof then Vector.foldl (uncurry (union (op =))) [] fact_names
       
   206   else fold (add_fact ctxt fact_names) atp_proof []
       
   207 
       
   208 (* (quasi-)underapproximation of the truth *)
       
   209 fun is_locality_global Local = false
       
   210   | is_locality_global Assum = false
       
   211   | is_locality_global Chained = false
       
   212   | is_locality_global _ = true
       
   213 
       
   214 fun used_facts_in_unsound_atp_proof _ _ [] = NONE
       
   215   | used_facts_in_unsound_atp_proof ctxt fact_names atp_proof =
       
   216     let
       
   217       val used_facts = used_facts_in_atp_proof ctxt fact_names atp_proof
       
   218     in
       
   219       if forall (is_locality_global o snd) used_facts andalso
       
   220          not (is_axiom_used_in_proof (is_conjecture o single) atp_proof) then
       
   221         SOME (map fst used_facts)
       
   222       else
       
   223         NONE
       
   224     end
       
   225 
       
   226 
       
   227 (** Soft-core proof reconstruction: one-liners **)
       
   228 
       
   229 fun string_for_label (s, num) = s ^ string_of_int num
       
   230 
       
   231 fun show_time NONE = ""
       
   232   | show_time (SOME ext_time) = " (" ^ string_from_ext_time ext_time ^ ")"
       
   233 
       
   234 fun apply_on_subgoal _ 1 = "by "
       
   235   | apply_on_subgoal 1 _ = "apply "
       
   236   | apply_on_subgoal i n =
       
   237     "prefer " ^ string_of_int i ^ " " ^ apply_on_subgoal 1 n
       
   238 fun command_call name [] =
       
   239     name |> not (Lexicon.is_identifier name) ? enclose "(" ")"
       
   240   | command_call name args = "(" ^ name ^ " " ^ space_implode " " args ^ ")"
       
   241 fun try_command_line banner time command =
       
   242   banner ^ ": " ^ Markup.markup Isabelle_Markup.sendback command ^ show_time time ^ "."
       
   243 fun using_labels [] = ""
       
   244   | using_labels ls =
       
   245     "using " ^ space_implode " " (map string_for_label ls) ^ " "
       
   246 fun reconstructor_command reconstr i n (ls, ss) =
       
   247   using_labels ls ^ apply_on_subgoal i n ^
       
   248   command_call (string_for_reconstructor reconstr) ss
       
   249 fun minimize_line _ [] = ""
       
   250   | minimize_line minimize_command ss =
       
   251     case minimize_command ss of
       
   252       "" => ""
       
   253     | command => "\nTo minimize: " ^ Markup.markup Isabelle_Markup.sendback command ^ "."
       
   254 
       
   255 val split_used_facts =
       
   256   List.partition (curry (op =) Chained o snd)
       
   257   #> pairself (sort_distinct (string_ord o pairself fst))
       
   258 
       
   259 fun one_line_proof_text (preplay, banner, used_facts, minimize_command,
       
   260                          subgoal, subgoal_count) =
       
   261   let
       
   262     val (chained, extra) = split_used_facts used_facts
       
   263     val (failed, reconstr, ext_time) =
       
   264       case preplay of
       
   265         Played (reconstr, time) => (false, reconstr, (SOME (false, time)))
       
   266       | Trust_Playable (reconstr, time) =>
       
   267         (false, reconstr,
       
   268          case time of
       
   269            NONE => NONE
       
   270          | SOME time =>
       
   271            if time = Time.zeroTime then NONE else SOME (true, time))
       
   272       | Failed_to_Play reconstr => (true, reconstr, NONE)
       
   273     val try_line =
       
   274       ([], map fst extra)
       
   275       |> reconstructor_command reconstr subgoal subgoal_count
       
   276       |> (if failed then enclose "One-line proof reconstruction failed: " "."
       
   277           else try_command_line banner ext_time)
       
   278   in try_line ^ minimize_line minimize_command (map fst (extra @ chained)) end
       
   279 
       
   280 (** Hard-core proof reconstruction: structured Isar proofs **)
       
   281 
       
   282 fun forall_of v t = HOLogic.all_const (fastype_of v) $ lambda v t
       
   283 fun exists_of v t = HOLogic.exists_const (fastype_of v) $ lambda v t
       
   284 
       
   285 fun make_tvar s = TVar (("'" ^ s, 0), HOLogic.typeS)
       
   286 fun make_tfree ctxt w =
       
   287   let val ww = "'" ^ w in
       
   288     TFree (ww, the_default HOLogic.typeS (Variable.def_sort ctxt (ww, ~1)))
       
   289   end
       
   290 
       
   291 val indent_size = 2
       
   292 val no_label = ("", ~1)
       
   293 
       
   294 val raw_prefix = "x"
       
   295 val assum_prefix = "a"
       
   296 val have_prefix = "f"
       
   297 
       
   298 fun raw_label_for_name (num, ss) =
       
   299   case resolve_conjecture ss of
       
   300     [j] => (conjecture_prefix, j)
       
   301   | _ => case Int.fromString num of
       
   302            SOME j => (raw_prefix, j)
       
   303          | NONE => (raw_prefix ^ num, 0)
       
   304 
       
   305 (**** INTERPRETATION OF TSTP SYNTAX TREES ****)
       
   306 
       
   307 exception HO_TERM of (string, string) ho_term list
       
   308 exception FORMULA of (string, string, (string, string) ho_term) formula list
       
   309 exception SAME of unit
       
   310 
       
   311 (* Type variables are given the basic sort "HOL.type". Some will later be
       
   312    constrained by information from type literals, or by type inference. *)
       
   313 fun typ_from_atp ctxt (u as ATerm (a, us)) =
       
   314   let val Ts = map (typ_from_atp ctxt) us in
       
   315     case unprefix_and_unascii type_const_prefix a of
       
   316       SOME b => Type (invert_const b, Ts)
       
   317     | NONE =>
       
   318       if not (null us) then
       
   319         raise HO_TERM [u]  (* only "tconst"s have type arguments *)
       
   320       else case unprefix_and_unascii tfree_prefix a of
       
   321         SOME b => make_tfree ctxt b
       
   322       | NONE =>
       
   323         (* Could be an Isabelle variable or a variable from the ATP, say "X1"
       
   324            or "_5018". Sometimes variables from the ATP are indistinguishable
       
   325            from Isabelle variables, which forces us to use a type parameter in
       
   326            all cases. *)
       
   327         (a |> perhaps (unprefix_and_unascii tvar_prefix), HOLogic.typeS)
       
   328         |> Type_Infer.param 0
       
   329   end
       
   330 
       
   331 (* Type class literal applied to a type. Returns triple of polarity, class,
       
   332    type. *)
       
   333 fun type_constraint_from_term ctxt (u as ATerm (a, us)) =
       
   334   case (unprefix_and_unascii class_prefix a, map (typ_from_atp ctxt) us) of
       
   335     (SOME b, [T]) => (b, T)
       
   336   | _ => raise HO_TERM [u]
       
   337 
       
   338 (* Accumulate type constraints in a formula: negative type literals. *)
       
   339 fun add_var (key, z)  = Vartab.map_default (key, []) (cons z)
       
   340 fun add_type_constraint false (cl, TFree (a ,_)) = add_var ((a, ~1), cl)
       
   341   | add_type_constraint false (cl, TVar (ix, _)) = add_var (ix, cl)
       
   342   | add_type_constraint _ _ = I
       
   343 
       
   344 fun repair_variable_name f s =
       
   345   let
       
   346     fun subscript_name s n = s ^ nat_subscript n
       
   347     val s = String.map f s
       
   348   in
       
   349     case space_explode "_" s of
       
   350       [_] => (case take_suffix Char.isDigit (String.explode s) of
       
   351                 (cs1 as _ :: _, cs2 as _ :: _) =>
       
   352                 subscript_name (String.implode cs1)
       
   353                                (the (Int.fromString (String.implode cs2)))
       
   354               | (_, _) => s)
       
   355     | [s1, s2] => (case Int.fromString s2 of
       
   356                      SOME n => subscript_name s1 n
       
   357                    | NONE => s)
       
   358     | _ => s
       
   359   end
       
   360 
       
   361 (* The number of type arguments of a constant, zero if it's monomorphic. For
       
   362    (instances of) Skolem pseudoconstants, this information is encoded in the
       
   363    constant name. *)
       
   364 fun num_type_args thy s =
       
   365   if String.isPrefix skolem_const_prefix s then
       
   366     s |> space_explode Long_Name.separator |> List.last |> Int.fromString |> the
       
   367   else if String.isPrefix lam_lifted_prefix s then
       
   368     if String.isPrefix lam_lifted_poly_prefix s then 2 else 0
       
   369   else
       
   370     (s, Sign.the_const_type thy s) |> Sign.const_typargs thy |> length
       
   371 
       
   372 fun slack_fastype_of t = fastype_of t handle TERM _ => HOLogic.typeT
       
   373 
       
   374 (* First-order translation. No types are known for variables. "HOLogic.typeT"
       
   375    should allow them to be inferred. *)
       
   376 fun term_from_atp ctxt textual sym_tab =
       
   377   let
       
   378     val thy = Proof_Context.theory_of ctxt
       
   379     (* For Metis, we use 1 rather than 0 because variable references in clauses
       
   380        may otherwise conflict with variable constraints in the goal. At least,
       
   381        type inference often fails otherwise. See also "axiom_inference" in
       
   382        "Metis_Reconstruct". *)
       
   383     val var_index = if textual then 0 else 1
       
   384     fun do_term extra_ts opt_T u =
       
   385       case u of
       
   386         ATerm (s, us) =>
       
   387         if String.isPrefix simple_type_prefix s then
       
   388           @{const True} (* ignore TPTP type information *)
       
   389         else if s = tptp_equal then
       
   390           let val ts = map (do_term [] NONE) us in
       
   391             if textual andalso length ts = 2 andalso
       
   392               hd ts aconv List.last ts then
       
   393               (* Vampire is keen on producing these. *)
       
   394               @{const True}
       
   395             else
       
   396               list_comb (Const (@{const_name HOL.eq}, HOLogic.typeT), ts)
       
   397           end
       
   398         else case unprefix_and_unascii const_prefix s of
       
   399           SOME s' =>
       
   400           let
       
   401             val ((s', s''), mangled_us) =
       
   402               s' |> unmangled_const |>> `invert_const
       
   403           in
       
   404             if s' = type_tag_name then
       
   405               case mangled_us @ us of
       
   406                 [typ_u, term_u] =>
       
   407                 do_term extra_ts (SOME (typ_from_atp ctxt typ_u)) term_u
       
   408               | _ => raise HO_TERM us
       
   409             else if s' = predicator_name then
       
   410               do_term [] (SOME @{typ bool}) (hd us)
       
   411             else if s' = app_op_name then
       
   412               let val extra_t = do_term [] NONE (List.last us) in
       
   413                 do_term (extra_t :: extra_ts)
       
   414                         (case opt_T of
       
   415                            SOME T => SOME (slack_fastype_of extra_t --> T)
       
   416                          | NONE => NONE)
       
   417                         (nth us (length us - 2))
       
   418               end
       
   419             else if s' = type_guard_name then
       
   420               @{const True} (* ignore type predicates *)
       
   421             else
       
   422               let
       
   423                 val new_skolem = String.isPrefix new_skolem_const_prefix s''
       
   424                 val num_ty_args =
       
   425                   length us - the_default 0 (Symtab.lookup sym_tab s)
       
   426                 val (type_us, term_us) =
       
   427                   chop num_ty_args us |>> append mangled_us
       
   428                 val term_ts = map (do_term [] NONE) term_us
       
   429                 val T =
       
   430                   (if not (null type_us) andalso
       
   431                       num_type_args thy s' = length type_us then
       
   432                      let val Ts = type_us |> map (typ_from_atp ctxt) in
       
   433                        if new_skolem then
       
   434                          SOME (Type_Infer.paramify_vars (tl Ts ---> hd Ts))
       
   435                        else if textual then
       
   436                          try (Sign.const_instance thy) (s', Ts)
       
   437                        else
       
   438                          NONE
       
   439                      end
       
   440                    else
       
   441                      NONE)
       
   442                   |> (fn SOME T => T
       
   443                        | NONE => map slack_fastype_of term_ts --->
       
   444                                  (case opt_T of
       
   445                                     SOME T => T
       
   446                                   | NONE => HOLogic.typeT))
       
   447                 val t =
       
   448                   if new_skolem then
       
   449                     Var ((new_skolem_var_name_from_const s'', var_index), T)
       
   450                   else
       
   451                     Const (unproxify_const s', T)
       
   452               in list_comb (t, term_ts @ extra_ts) end
       
   453           end
       
   454         | NONE => (* a free or schematic variable *)
       
   455           let
       
   456             val term_ts = map (do_term [] NONE) us
       
   457             val ts = term_ts @ extra_ts
       
   458             val T =
       
   459               case opt_T of
       
   460                 SOME T => map slack_fastype_of term_ts ---> T
       
   461               | NONE => map slack_fastype_of ts ---> HOLogic.typeT
       
   462             val t =
       
   463               case unprefix_and_unascii fixed_var_prefix s of
       
   464                 SOME s => Free (s, T)
       
   465               | NONE =>
       
   466                 case unprefix_and_unascii schematic_var_prefix s of
       
   467                   SOME s => Var ((s, var_index), T)
       
   468                 | NONE =>
       
   469                   Var ((s |> textual ? repair_variable_name Char.toLower,
       
   470                         var_index), T)
       
   471           in list_comb (t, ts) end
       
   472   in do_term [] end
       
   473 
       
   474 fun term_from_atom ctxt textual sym_tab pos (u as ATerm (s, _)) =
       
   475   if String.isPrefix class_prefix s then
       
   476     add_type_constraint pos (type_constraint_from_term ctxt u)
       
   477     #> pair @{const True}
       
   478   else
       
   479     pair (term_from_atp ctxt textual sym_tab (SOME @{typ bool}) u)
       
   480 
       
   481 val combinator_table =
       
   482   [(@{const_name Meson.COMBI}, @{thm Meson.COMBI_def_raw}),
       
   483    (@{const_name Meson.COMBK}, @{thm Meson.COMBK_def_raw}),
       
   484    (@{const_name Meson.COMBB}, @{thm Meson.COMBB_def_raw}),
       
   485    (@{const_name Meson.COMBC}, @{thm Meson.COMBC_def_raw}),
       
   486    (@{const_name Meson.COMBS}, @{thm Meson.COMBS_def_raw})]
       
   487 
       
   488 fun uncombine_term thy =
       
   489   let
       
   490     fun aux (t1 $ t2) = betapply (pairself aux (t1, t2))
       
   491       | aux (Abs (s, T, t')) = Abs (s, T, aux t')
       
   492       | aux (t as Const (x as (s, _))) =
       
   493         (case AList.lookup (op =) combinator_table s of
       
   494            SOME thm => thm |> prop_of |> specialize_type thy x
       
   495                            |> Logic.dest_equals |> snd
       
   496          | NONE => t)
       
   497       | aux t = t
       
   498   in aux end
       
   499 
       
   500 (* Update schematic type variables with detected sort constraints. It's not
       
   501    totally clear whether this code is necessary. *)
       
   502 fun repair_tvar_sorts (t, tvar_tab) =
       
   503   let
       
   504     fun do_type (Type (a, Ts)) = Type (a, map do_type Ts)
       
   505       | do_type (TVar (xi, s)) =
       
   506         TVar (xi, the_default s (Vartab.lookup tvar_tab xi))
       
   507       | do_type (TFree z) = TFree z
       
   508     fun do_term (Const (a, T)) = Const (a, do_type T)
       
   509       | do_term (Free (a, T)) = Free (a, do_type T)
       
   510       | do_term (Var (xi, T)) = Var (xi, do_type T)
       
   511       | do_term (t as Bound _) = t
       
   512       | do_term (Abs (a, T, t)) = Abs (a, do_type T, do_term t)
       
   513       | do_term (t1 $ t2) = do_term t1 $ do_term t2
       
   514   in t |> not (Vartab.is_empty tvar_tab) ? do_term end
       
   515 
       
   516 fun quantify_over_var quant_of var_s t =
       
   517   let
       
   518     val vars = [] |> Term.add_vars t |> filter (fn ((s, _), _) => s = var_s)
       
   519                   |> map Var
       
   520   in fold_rev quant_of vars t end
       
   521 
       
   522 (* Interpret an ATP formula as a HOL term, extracting sort constraints as they
       
   523    appear in the formula. *)
       
   524 fun prop_from_atp ctxt textual sym_tab phi =
       
   525   let
       
   526     fun do_formula pos phi =
       
   527       case phi of
       
   528         AQuant (_, [], phi) => do_formula pos phi
       
   529       | AQuant (q, (s, _) :: xs, phi') =>
       
   530         do_formula pos (AQuant (q, xs, phi'))
       
   531         (* FIXME: TFF *)
       
   532         #>> quantify_over_var (case q of
       
   533                                  AForall => forall_of
       
   534                                | AExists => exists_of)
       
   535                               (s |> textual ? repair_variable_name Char.toLower)
       
   536       | AConn (ANot, [phi']) => do_formula (not pos) phi' #>> s_not
       
   537       | AConn (c, [phi1, phi2]) =>
       
   538         do_formula (pos |> c = AImplies ? not) phi1
       
   539         ##>> do_formula pos phi2
       
   540         #>> (case c of
       
   541                AAnd => s_conj
       
   542              | AOr => s_disj
       
   543              | AImplies => s_imp
       
   544              | AIff => s_iff
       
   545              | ANot => raise Fail "impossible connective")
       
   546       | AAtom tm => term_from_atom ctxt textual sym_tab pos tm
       
   547       | _ => raise FORMULA [phi]
       
   548   in repair_tvar_sorts (do_formula true phi Vartab.empty) end
       
   549 
       
   550 fun infer_formula_types ctxt =
       
   551   Type.constraint HOLogic.boolT
       
   552   #> Syntax.check_term
       
   553          (Proof_Context.set_mode Proof_Context.mode_schematic ctxt)
       
   554 
       
   555 fun uncombined_etc_prop_from_atp ctxt textual sym_tab =
       
   556   let val thy = Proof_Context.theory_of ctxt in
       
   557     prop_from_atp ctxt textual sym_tab
       
   558     #> textual ? uncombine_term thy #> infer_formula_types ctxt
       
   559   end
       
   560 
       
   561 (**** Translation of TSTP files to Isar proofs ****)
       
   562 
       
   563 fun unvarify_term (Var ((s, 0), T)) = Free (s, T)
       
   564   | unvarify_term t = raise TERM ("unvarify_term: non-Var", [t])
       
   565 
       
   566 fun decode_line sym_tab (Definition (name, phi1, phi2)) ctxt =
       
   567     let
       
   568       val thy = Proof_Context.theory_of ctxt
       
   569       val t1 = prop_from_atp ctxt true sym_tab phi1
       
   570       val vars = snd (strip_comb t1)
       
   571       val frees = map unvarify_term vars
       
   572       val unvarify_args = subst_atomic (vars ~~ frees)
       
   573       val t2 = prop_from_atp ctxt true sym_tab phi2
       
   574       val (t1, t2) =
       
   575         HOLogic.eq_const HOLogic.typeT $ t1 $ t2
       
   576         |> unvarify_args |> uncombine_term thy |> infer_formula_types ctxt
       
   577         |> HOLogic.dest_eq
       
   578     in
       
   579       (Definition (name, t1, t2),
       
   580        fold Variable.declare_term (maps Misc_Legacy.term_frees [t1, t2]) ctxt)
       
   581     end
       
   582   | decode_line sym_tab (Inference (name, u, rule, deps)) ctxt =
       
   583     let val t = u |> uncombined_etc_prop_from_atp ctxt true sym_tab in
       
   584       (Inference (name, t, rule, deps),
       
   585        fold Variable.declare_term (Misc_Legacy.term_frees t) ctxt)
       
   586     end
       
   587 fun decode_lines ctxt sym_tab lines =
       
   588   fst (fold_map (decode_line sym_tab) lines ctxt)
       
   589 
       
   590 fun is_same_inference _ (Definition _) = false
       
   591   | is_same_inference t (Inference (_, t', _, _)) = t aconv t'
       
   592 
       
   593 (* No "real" literals means only type information (tfree_tcs, clsrel, or
       
   594    clsarity). *)
       
   595 val is_only_type_information = curry (op aconv) @{term True}
       
   596 
       
   597 fun replace_one_dependency (old, new) dep =
       
   598   if is_same_atp_step dep old then new else [dep]
       
   599 fun replace_dependencies_in_line _ (line as Definition _) = line
       
   600   | replace_dependencies_in_line p (Inference (name, t, rule, deps)) =
       
   601     Inference (name, t, rule,
       
   602                fold (union (op =) o replace_one_dependency p) deps [])
       
   603 
       
   604 (* Discard facts; consolidate adjacent lines that prove the same formula, since
       
   605    they differ only in type information.*)
       
   606 fun add_line _ (line as Definition _) lines = line :: lines
       
   607   | add_line fact_names (Inference (name as (_, ss), t, rule, [])) lines =
       
   608     (* No dependencies: fact, conjecture, or (for Vampire) internal facts or
       
   609        definitions. *)
       
   610     if is_fact fact_names ss then
       
   611       (* Facts are not proof lines. *)
       
   612       if is_only_type_information t then
       
   613         map (replace_dependencies_in_line (name, [])) lines
       
   614       (* Is there a repetition? If so, replace later line by earlier one. *)
       
   615       else case take_prefix (not o is_same_inference t) lines of
       
   616         (_, []) => lines (* no repetition of proof line *)
       
   617       | (pre, Inference (name', _, _, _) :: post) =>
       
   618         pre @ map (replace_dependencies_in_line (name', [name])) post
       
   619       | _ => raise Fail "unexpected inference"
       
   620     else if is_conjecture ss then
       
   621       Inference (name, s_not t, rule, []) :: lines
       
   622     else
       
   623       map (replace_dependencies_in_line (name, [])) lines
       
   624   | add_line _ (Inference (name, t, rule, deps)) lines =
       
   625     (* Type information will be deleted later; skip repetition test. *)
       
   626     if is_only_type_information t then
       
   627       Inference (name, t, rule, deps) :: lines
       
   628     (* Is there a repetition? If so, replace later line by earlier one. *)
       
   629     else case take_prefix (not o is_same_inference t) lines of
       
   630       (* FIXME: Doesn't this code risk conflating proofs involving different
       
   631          types? *)
       
   632        (_, []) => Inference (name, t, rule, deps) :: lines
       
   633      | (pre, Inference (name', t', rule, _) :: post) =>
       
   634        Inference (name, t', rule, deps) ::
       
   635        pre @ map (replace_dependencies_in_line (name', [name])) post
       
   636      | _ => raise Fail "unexpected inference"
       
   637 
       
   638 (* Recursively delete empty lines (type information) from the proof. *)
       
   639 fun add_nontrivial_line (line as Inference (name, t, _, [])) lines =
       
   640     if is_only_type_information t then delete_dependency name lines
       
   641     else line :: lines
       
   642   | add_nontrivial_line line lines = line :: lines
       
   643 and delete_dependency name lines =
       
   644   fold_rev add_nontrivial_line
       
   645            (map (replace_dependencies_in_line (name, [])) lines) []
       
   646 
       
   647 (* ATPs sometimes reuse free variable names in the strangest ways. Removing
       
   648    offending lines often does the trick. *)
       
   649 fun is_bad_free frees (Free x) = not (member (op =) frees x)
       
   650   | is_bad_free _ _ = false
       
   651 
       
   652 fun add_desired_line _ _ _ (line as Definition (name, _, _)) (j, lines) =
       
   653     (j, line :: map (replace_dependencies_in_line (name, [])) lines)
       
   654   | add_desired_line isar_shrink_factor fact_names frees
       
   655                      (Inference (name as (_, ss), t, rule, deps)) (j, lines) =
       
   656     (j + 1,
       
   657      if is_fact fact_names ss orelse
       
   658         is_conjecture ss orelse
       
   659         (* the last line must be kept *)
       
   660         j = 0 orelse
       
   661         (not (is_only_type_information t) andalso
       
   662          null (Term.add_tvars t []) andalso
       
   663          not (exists_subterm (is_bad_free frees) t) andalso
       
   664          length deps >= 2 andalso j mod isar_shrink_factor = 0 andalso
       
   665          (* kill next to last line, which usually results in a trivial step *)
       
   666          j <> 1) then
       
   667        Inference (name, t, rule, deps) :: lines  (* keep line *)
       
   668      else
       
   669        map (replace_dependencies_in_line (name, deps)) lines)  (* drop line *)
       
   670 
       
   671 (** Isar proof construction and manipulation **)
       
   672 
       
   673 type label = string * int
       
   674 type facts = label list * string list
       
   675 
       
   676 datatype isar_qualifier = Show | Then | Moreover | Ultimately
       
   677 
       
   678 datatype isar_step =
       
   679   Fix of (string * typ) list |
       
   680   Let of term * term |
       
   681   Assume of label * term |
       
   682   Prove of isar_qualifier list * label * term * byline
       
   683 and byline =
       
   684   By_Metis of facts |
       
   685   Case_Split of isar_step list list * facts
       
   686 
       
   687 fun add_fact_from_dependency fact_names (name as (_, ss)) =
       
   688   if is_fact fact_names ss then
       
   689     apsnd (union (op =) (map fst (resolve_fact fact_names ss)))
       
   690   else
       
   691     apfst (insert (op =) (raw_label_for_name name))
       
   692 
       
   693 fun repair_name "$true" = "c_True"
       
   694   | repair_name "$false" = "c_False"
       
   695   | repair_name "$$e" = tptp_equal (* seen in Vampire proofs *)
       
   696   | repair_name s =
       
   697     if is_tptp_equal s orelse
       
   698        (* seen in Vampire proofs *)
       
   699        (String.isPrefix "sQ" s andalso String.isSuffix "_eqProxy" s) then
       
   700       tptp_equal
       
   701     else
       
   702       s
       
   703 
       
   704 (* FIXME: Still needed? Try with SPASS proofs perhaps. *)
       
   705 val kill_duplicate_assumptions_in_proof =
       
   706   let
       
   707     fun relabel_facts subst =
       
   708       apfst (map (fn l => AList.lookup (op =) subst l |> the_default l))
       
   709     fun do_step (step as Assume (l, t)) (proof, subst, assums) =
       
   710         (case AList.lookup (op aconv) assums t of
       
   711            SOME l' => (proof, (l, l') :: subst, assums)
       
   712          | NONE => (step :: proof, subst, (t, l) :: assums))
       
   713       | do_step (Prove (qs, l, t, by)) (proof, subst, assums) =
       
   714         (Prove (qs, l, t,
       
   715                 case by of
       
   716                   By_Metis facts => By_Metis (relabel_facts subst facts)
       
   717                 | Case_Split (proofs, facts) =>
       
   718                   Case_Split (map do_proof proofs,
       
   719                               relabel_facts subst facts)) ::
       
   720          proof, subst, assums)
       
   721       | do_step step (proof, subst, assums) = (step :: proof, subst, assums)
       
   722     and do_proof proof = fold do_step proof ([], [], []) |> #1 |> rev
       
   723   in do_proof end
       
   724 
       
   725 fun used_labels_of_step (Prove (_, _, _, by)) =
       
   726     (case by of
       
   727        By_Metis (ls, _) => ls
       
   728      | Case_Split (proofs, (ls, _)) =>
       
   729        fold (union (op =) o used_labels_of) proofs ls)
       
   730   | used_labels_of_step _ = []
       
   731 and used_labels_of proof = fold (union (op =) o used_labels_of_step) proof []
       
   732 
       
   733 fun kill_useless_labels_in_proof proof =
       
   734   let
       
   735     val used_ls = used_labels_of proof
       
   736     fun do_label l = if member (op =) used_ls l then l else no_label
       
   737     fun do_step (Assume (l, t)) = Assume (do_label l, t)
       
   738       | do_step (Prove (qs, l, t, by)) =
       
   739         Prove (qs, do_label l, t,
       
   740                case by of
       
   741                  Case_Split (proofs, facts) =>
       
   742                  Case_Split (map (map do_step) proofs, facts)
       
   743                | _ => by)
       
   744       | do_step step = step
       
   745   in map do_step proof end
       
   746 
       
   747 fun prefix_for_depth n = replicate_string (n + 1)
       
   748 
       
   749 val relabel_proof =
       
   750   let
       
   751     fun aux _ _ _ [] = []
       
   752       | aux subst depth (next_assum, next_fact) (Assume (l, t) :: proof) =
       
   753         if l = no_label then
       
   754           Assume (l, t) :: aux subst depth (next_assum, next_fact) proof
       
   755         else
       
   756           let val l' = (prefix_for_depth depth assum_prefix, next_assum) in
       
   757             Assume (l', t) ::
       
   758             aux ((l, l') :: subst) depth (next_assum + 1, next_fact) proof
       
   759           end
       
   760       | aux subst depth (next_assum, next_fact)
       
   761             (Prove (qs, l, t, by) :: proof) =
       
   762         let
       
   763           val (l', subst, next_fact) =
       
   764             if l = no_label then
       
   765               (l, subst, next_fact)
       
   766             else
       
   767               let
       
   768                 val l' = (prefix_for_depth depth have_prefix, next_fact)
       
   769               in (l', (l, l') :: subst, next_fact + 1) end
       
   770           val relabel_facts =
       
   771             apfst (maps (the_list o AList.lookup (op =) subst))
       
   772           val by =
       
   773             case by of
       
   774               By_Metis facts => By_Metis (relabel_facts facts)
       
   775             | Case_Split (proofs, facts) =>
       
   776               Case_Split (map (aux subst (depth + 1) (1, 1)) proofs,
       
   777                           relabel_facts facts)
       
   778         in
       
   779           Prove (qs, l', t, by) :: aux subst depth (next_assum, next_fact) proof
       
   780         end
       
   781       | aux subst depth nextp (step :: proof) =
       
   782         step :: aux subst depth nextp proof
       
   783   in aux [] 0 (1, 1) end
       
   784 
       
   785 fun string_for_proof ctxt0 type_enc lam_trans i n =
       
   786   let
       
   787     val ctxt =
       
   788       ctxt0 |> Config.put show_free_types false
       
   789             |> Config.put show_types true
       
   790             |> Config.put show_sorts true
       
   791     fun fix_print_mode f x =
       
   792       Print_Mode.setmp (filter (curry (op =) Symbol.xsymbolsN)
       
   793                                (print_mode_value ())) f x
       
   794     fun do_indent ind = replicate_string (ind * indent_size) " "
       
   795     fun do_free (s, T) =
       
   796       maybe_quote s ^ " :: " ^
       
   797       maybe_quote (fix_print_mode (Syntax.string_of_typ ctxt) T)
       
   798     fun do_label l = if l = no_label then "" else string_for_label l ^ ": "
       
   799     fun do_have qs =
       
   800       (if member (op =) qs Moreover then "moreover " else "") ^
       
   801       (if member (op =) qs Ultimately then "ultimately " else "") ^
       
   802       (if member (op =) qs Then then
       
   803          if member (op =) qs Show then "thus" else "hence"
       
   804        else
       
   805          if member (op =) qs Show then "show" else "have")
       
   806     val do_term = maybe_quote o fix_print_mode (Syntax.string_of_term ctxt)
       
   807     val reconstr = Metis (type_enc, lam_trans)
       
   808     fun do_facts (ls, ss) =
       
   809       reconstructor_command reconstr 1 1
       
   810           (ls |> sort_distinct (prod_ord string_ord int_ord),
       
   811            ss |> sort_distinct string_ord)
       
   812     and do_step ind (Fix xs) =
       
   813         do_indent ind ^ "fix " ^ space_implode " and " (map do_free xs) ^ "\n"
       
   814       | do_step ind (Let (t1, t2)) =
       
   815         do_indent ind ^ "let " ^ do_term t1 ^ " = " ^ do_term t2 ^ "\n"
       
   816       | do_step ind (Assume (l, t)) =
       
   817         do_indent ind ^ "assume " ^ do_label l ^ do_term t ^ "\n"
       
   818       | do_step ind (Prove (qs, l, t, By_Metis facts)) =
       
   819         do_indent ind ^ do_have qs ^ " " ^
       
   820         do_label l ^ do_term t ^ " " ^ do_facts facts ^ "\n"
       
   821       | do_step ind (Prove (qs, l, t, Case_Split (proofs, facts))) =
       
   822         implode (map (prefix (do_indent ind ^ "moreover\n") o do_block ind)
       
   823                      proofs) ^
       
   824         do_indent ind ^ do_have qs ^ " " ^ do_label l ^ do_term t ^ " " ^
       
   825         do_facts facts ^ "\n"
       
   826     and do_steps prefix suffix ind steps =
       
   827       let val s = implode (map (do_step ind) steps) in
       
   828         replicate_string (ind * indent_size - size prefix) " " ^ prefix ^
       
   829         String.extract (s, ind * indent_size,
       
   830                         SOME (size s - ind * indent_size - 1)) ^
       
   831         suffix ^ "\n"
       
   832       end
       
   833     and do_block ind proof = do_steps "{ " " }" (ind + 1) proof
       
   834     (* One-step proofs are pointless; better use the Metis one-liner
       
   835        directly. *)
       
   836     and do_proof [Prove (_, _, _, By_Metis _)] = ""
       
   837       | do_proof proof =
       
   838         (if i <> 1 then "prefer " ^ string_of_int i ^ "\n" else "") ^
       
   839         do_indent 0 ^ "proof -\n" ^ do_steps "" "" 1 proof ^ do_indent 0 ^
       
   840         (if n <> 1 then "next" else "qed")
       
   841   in do_proof end
       
   842 
       
   843 fun isar_proof_text ctxt isar_proof_requested
       
   844         (debug, isar_shrink_factor, pool, fact_names, sym_tab, atp_proof, goal)
       
   845         (one_line_params as (_, _, _, _, subgoal, subgoal_count)) =
       
   846   let
       
   847     val isar_shrink_factor =
       
   848       (if isar_proof_requested then 1 else 2) * isar_shrink_factor
       
   849     val (params, hyp_ts, concl_t) = strip_subgoal ctxt goal subgoal
       
   850     val frees = fold Term.add_frees (concl_t :: hyp_ts) []
       
   851     val one_line_proof = one_line_proof_text one_line_params
       
   852     val type_enc =
       
   853       if is_typed_helper_used_in_atp_proof atp_proof then full_typesN
       
   854       else partial_typesN
       
   855     val lam_trans = lam_trans_from_atp_proof atp_proof metis_default_lam_trans
       
   856 
       
   857     fun isar_proof_of () =
       
   858       let
       
   859         val atp_proof =
       
   860           atp_proof
       
   861           |> clean_up_atp_proof_dependencies
       
   862           |> nasty_atp_proof pool
       
   863           |> map_term_names_in_atp_proof repair_name
       
   864           |> decode_lines ctxt sym_tab
       
   865           |> rpair [] |-> fold_rev (add_line fact_names)
       
   866           |> rpair [] |-> fold_rev add_nontrivial_line
       
   867           |> rpair (0, [])
       
   868           |-> fold_rev (add_desired_line isar_shrink_factor fact_names frees)
       
   869           |> snd
       
   870         val conj_name = conjecture_prefix ^ string_of_int (length hyp_ts)
       
   871         val conjs =
       
   872           atp_proof
       
   873           |> map_filter (fn Inference (name as (_, ss), _, _, []) =>
       
   874                             if member (op =) ss conj_name then SOME name else NONE
       
   875                           | _ => NONE)
       
   876         fun dep_of_step (Definition _) = NONE
       
   877           | dep_of_step (Inference (name, _, _, from)) = SOME (from, name)
       
   878         val ref_graph = atp_proof |> map_filter dep_of_step |> make_ref_graph
       
   879         val axioms = axioms_of_ref_graph ref_graph conjs
       
   880         val tainted = tainted_atoms_of_ref_graph ref_graph conjs
       
   881         val props =
       
   882           Symtab.empty
       
   883           |> fold (fn Definition _ => I (* FIXME *)
       
   884                     | Inference ((s, _), t, _, _) =>
       
   885                       Symtab.update_new (s,
       
   886                           t |> member (op = o apsnd fst) tainted s ? s_not))
       
   887                   atp_proof
       
   888         (* FIXME: add "fold_rev forall_of (map Var (Term.add_vars t []))"? *)
       
   889         fun prop_of_clause c =
       
   890           fold (curry s_disj) (map_filter (Symtab.lookup props o fst) c)
       
   891                @{term False}
       
   892         fun label_of_clause c = (space_implode "___" (map fst c), 0)
       
   893         fun maybe_show outer c =
       
   894           (outer andalso length c = 1 andalso subset (op =) (c, conjs))
       
   895           ? cons Show
       
   896         fun do_have outer qs (gamma, c) =
       
   897           Prove (maybe_show outer c qs, label_of_clause c, prop_of_clause c,
       
   898                  By_Metis (fold (add_fact_from_dependency fact_names
       
   899                                  o the_single) gamma ([], [])))
       
   900         fun do_inf outer (Have z) = do_have outer [] z
       
   901           | do_inf outer (Hence z) = do_have outer [Then] z
       
   902           | do_inf outer (Cases cases) =
       
   903             let val c = succedent_of_cases cases in
       
   904               Prove (maybe_show outer c [Ultimately], label_of_clause c,
       
   905                      prop_of_clause c,
       
   906                      Case_Split (map (do_case false) cases, ([], [])))
       
   907             end
       
   908         and do_case outer (c, infs) =
       
   909           Assume (label_of_clause c, prop_of_clause c) ::
       
   910           map (do_inf outer) infs
       
   911         val isar_proof =
       
   912           (if null params then [] else [Fix params]) @
       
   913           (ref_graph
       
   914            |> redirect_graph axioms tainted
       
   915            |> chain_direct_proof
       
   916            |> map (do_inf true)
       
   917            |> kill_duplicate_assumptions_in_proof
       
   918            |> kill_useless_labels_in_proof
       
   919            |> relabel_proof)
       
   920           |> string_for_proof ctxt type_enc lam_trans subgoal subgoal_count
       
   921       in
       
   922         case isar_proof of
       
   923           "" =>
       
   924           if isar_proof_requested then
       
   925             "\nNo structured proof available (proof too short)."
       
   926           else
       
   927             ""
       
   928         | _ =>
       
   929           "\n\n" ^ (if isar_proof_requested then "Structured proof"
       
   930                     else "Perhaps this will work") ^
       
   931           ":\n" ^ Markup.markup Isabelle_Markup.sendback isar_proof
       
   932       end
       
   933     val isar_proof =
       
   934       if debug then
       
   935         isar_proof_of ()
       
   936       else case try isar_proof_of () of
       
   937         SOME s => s
       
   938       | NONE => if isar_proof_requested then
       
   939                   "\nWarning: The Isar proof construction failed."
       
   940                 else
       
   941                   ""
       
   942   in one_line_proof ^ isar_proof end
       
   943 
       
   944 fun proof_text ctxt isar_proof isar_params
       
   945                (one_line_params as (preplay, _, _, _, _, _)) =
       
   946   (if case preplay of Failed_to_Play _ => true | _ => isar_proof then
       
   947      isar_proof_text ctxt isar_proof isar_params
       
   948    else
       
   949      one_line_proof_text) one_line_params
       
   950 
       
   951 end;