1(*  Title:      HOL/Tools/Sledgehammer/sledgehammer_prover_atp.ML
2    Author:     Fabian Immler, TU Muenchen
3    Author:     Makarius
4    Author:     Jasmin Blanchette, TU Muenchen
5
6ATPs as Sledgehammer provers.
7*)
8
9signature SLEDGEHAMMER_PROVER_ATP =
10sig
11  type mode = Sledgehammer_Prover.mode
12  type prover = Sledgehammer_Prover.prover
13
14  val atp_dest_dir : string Config.T
15  val atp_problem_prefix : string Config.T
16  val atp_completish : int Config.T
17  val atp_full_names : bool Config.T
18
19  val is_ho_atp : Proof.context -> string -> bool
20
21  val run_atp : mode -> string -> prover
22end;
23
24structure Sledgehammer_Prover_ATP : SLEDGEHAMMER_PROVER_ATP =
25struct
26
27open ATP_Util
28open ATP_Problem
29open ATP_Proof
30open ATP_Problem_Generate
31open ATP_Proof_Reconstruct
32open ATP_Satallax
33open ATP_Systems
34open Sledgehammer_Util
35open Sledgehammer_Proof_Methods
36open Sledgehammer_Isar
37open Sledgehammer_Prover
38
39(* Empty string means create files in Isabelle's temporary files directory. *)
40val atp_dest_dir = Attrib.setup_config_string \<^binding>\<open>sledgehammer_atp_dest_dir\<close> (K "")
41val atp_problem_prefix =
42  Attrib.setup_config_string \<^binding>\<open>sledgehammer_atp_problem_prefix\<close> (K "prob")
43val atp_completish = Attrib.setup_config_int \<^binding>\<open>sledgehammer_atp_completish\<close> (K 0)
44(* In addition to being easier to read, readable names are often much shorter, especially if types
45   are mangled in names. This makes a difference for some provers (e.g., E). For these reason, short
46   names are enabled by default. *)
47val atp_full_names = Attrib.setup_config_bool \<^binding>\<open>sledgehammer_atp_full_names\<close> (K false)
48
49fun is_atp_of_format is_format ctxt name =
50  let val thy = Proof_Context.theory_of ctxt in
51    (case try (get_atp thy) name of
52      SOME config =>
53      exists (fn (_, ((_, format, _, _, _), _)) => is_format format) (#best_slices (config ()) ctxt)
54    | NONE => false)
55  end
56
57val is_ho_atp = is_atp_of_format is_format_higher_order
58
59fun choose_type_enc strictness best_type_enc format =
60  the_default best_type_enc
61  #> type_enc_of_string strictness
62  #> adjust_type_enc format
63
64fun has_bound_or_var_of_type pred =
65  exists_subterm (fn Var (_, T as Type _) => pred T
66                   | Abs (_, T as Type _, _) => pred T
67                   | _ => false)
68
69(* Unwanted equalities are those between a (bound or schematic) variable that does not properly
70   occur in the second operand. *)
71val is_exhaustive_finite =
72  let
73    fun is_bad_equal (Var z) t =
74        not (exists_subterm (fn Var z' => z = z' | _ => false) t)
75      | is_bad_equal (Bound j) t = not (loose_bvar1 (t, j))
76      | is_bad_equal _ _ = false
77    fun do_equals t1 t2 = is_bad_equal t1 t2 orelse is_bad_equal t2 t1
78    fun do_formula pos t =
79      (case (pos, t) of
80        (_, \<^const>\<open>Trueprop\<close> $ t1) => do_formula pos t1
81      | (true, Const (\<^const_name>\<open>Pure.all\<close>, _) $ Abs (_, _, t')) => do_formula pos t'
82      | (true, Const (\<^const_name>\<open>All\<close>, _) $ Abs (_, _, t')) => do_formula pos t'
83      | (false, Const (\<^const_name>\<open>Ex\<close>, _) $ Abs (_, _, t')) => do_formula pos t'
84      | (_, \<^const>\<open>Pure.imp\<close> $ t1 $ t2) =>
85        do_formula (not pos) t1 andalso (t2 = \<^prop>\<open>False\<close> orelse do_formula pos t2)
86      | (_, \<^const>\<open>HOL.implies\<close> $ t1 $ t2) =>
87        do_formula (not pos) t1 andalso (t2 = \<^const>\<open>False\<close> orelse do_formula pos t2)
88      | (_, \<^const>\<open>Not\<close> $ t1) => do_formula (not pos) t1
89      | (true, \<^const>\<open>HOL.disj\<close> $ t1 $ t2) => forall (do_formula pos) [t1, t2]
90      | (false, \<^const>\<open>HOL.conj\<close> $ t1 $ t2) => forall (do_formula pos) [t1, t2]
91      | (true, Const (\<^const_name>\<open>HOL.eq\<close>, _) $ t1 $ t2) => do_equals t1 t2
92      | (true, Const (\<^const_name>\<open>Pure.eq\<close>, _) $ t1 $ t2) => do_equals t1 t2
93      | _ => false)
94  in do_formula true end
95
96(* Facts containing variables of finite types such as "unit" or "bool" or of the form
97   "ALL x. x = A | x = B | x = C" are likely to lead to untypable proofs for unsound type
98   encodings. *)
99fun is_dangerous_prop ctxt =
100  transform_elim_prop
101  #> (has_bound_or_var_of_type (is_type_surely_finite ctxt) orf is_exhaustive_finite)
102
103fun get_slices slice slices =
104  (0 upto length slices - 1) ~~ slices |> not slice ? (List.last #> single)
105
106fun get_facts_of_filter _ [(_, facts)] = facts
107  | get_facts_of_filter fact_filter factss =
108    (case AList.lookup (op =) factss fact_filter of
109      SOME facts => facts
110    | NONE => snd (hd factss))
111
112(* For low values of "max_facts", this fudge value ensures that most slices are invoked with a
113   nontrivial amount of facts. *)
114val max_fact_factor_fudge = 5
115
116val mono_max_privileged_facts = 10
117
118fun suffix_of_mode Auto_Try = "_try"
119  | suffix_of_mode Try = "_try"
120  | suffix_of_mode Normal = ""
121  | suffix_of_mode MaSh = ""
122  | suffix_of_mode Minimize = "_min"
123
124(* Give the ATPs some slack before interrupting them the hard way. "z3_tptp" on Linux appears to be
125   the only ATP that does not honor its time limit. *)
126val atp_timeout_slack = seconds 1.0
127
128(* Important messages are important but not so important that users want to see them each time. *)
129val atp_important_message_keep_quotient = 25
130
131fun run_atp mode name
132    ({debug, verbose, overlord, type_enc, strict, lam_trans, uncurried_aliases, fact_filter,
133     max_facts, max_mono_iters, max_new_mono_instances, isar_proofs, compress, try0, smt_proofs,
134     slice, minimize, timeout, preplay_timeout, ...} : params)
135    ({comment, state, goal, subgoal, subgoal_count, factss, found_proof, ...} : prover_problem) =
136  let
137    val thy = Proof.theory_of state
138    val ctxt = Proof.context_of state
139
140    val {exec, arguments, proof_delims, known_failures, prem_role, best_slices, best_max_mono_iters,
141      best_max_new_mono_instances, ...} = get_atp thy name ()
142
143    val full_proofs = isar_proofs |> the_default (mode = Minimize)
144    val local_name = perhaps (try (unprefix remote_prefix)) name
145    val spassy = (local_name = pirateN orelse local_name = spassN)
146
147    val completish = Config.get ctxt atp_completish
148    val atp_mode = if completish > 0 then Sledgehammer_Completish completish else Sledgehammer
149    val (_, hyp_ts, concl_t) = strip_subgoal goal subgoal ctxt
150    val (dest_dir, problem_prefix) =
151      if overlord then overlord_file_location_of_prover name
152      else (Config.get ctxt atp_dest_dir, Config.get ctxt atp_problem_prefix)
153    val problem_file_name =
154      Path.basic (problem_prefix ^ (if overlord then "" else serial_string ()) ^
155        suffix_of_mode mode ^ "_" ^ string_of_int subgoal)
156    val prob_path =
157      if dest_dir = "" then
158        File.tmp_path problem_file_name
159      else if File.exists (Path.explode dest_dir) then
160        Path.append (Path.explode dest_dir) problem_file_name
161      else
162        error ("No such directory: " ^ quote dest_dir)
163    val exec = exec full_proofs
164    val command0 =
165      (case find_first (fn var => getenv var <> "") (fst exec) of
166        SOME var =>
167        let
168          val pref = getenv var ^ "/"
169          val paths =
170            map (Path.explode o prefix pref)
171              (if ML_System.platform_is_windows then
172                map (suffix ".exe") (snd exec) @ snd exec
173               else snd exec);
174        in
175          (case find_first File.exists paths of
176            SOME path => path
177          | NONE => error ("Bad executable: " ^ Path.print (hd paths)))
178        end
179      | NONE => error ("The environment variable " ^ quote (List.last (fst exec)) ^ " is not set"))
180
181    fun split_time s =
182      let
183        val split = String.tokens (fn c => str c = "\n")
184        val (output, t) = s |> split |> (try split_last #> the_default ([], "0")) |>> cat_lines
185        val num = Scan.many1 Symbol.is_ascii_digit >> (fst o read_int)
186        val digit = Scan.one Symbol.is_ascii_digit
187        val num3 = digit ::: digit ::: (digit >> single) >> (fst o read_int)
188        val time = num --| Scan.$$ "." -- num3 >> (fn (a, b) => a * 1000 + b)
189        val as_time = raw_explode #> Scan.read Symbol.stopper time #> the_default 0
190      in (output, as_time t |> Time.fromMilliseconds) end
191
192    fun run () =
193      let
194        (* If slicing is disabled, we expand the last slice to fill the entire time available. *)
195        val all_slices = best_slices ctxt
196        val actual_slices = get_slices slice all_slices
197
198        fun max_facts_of_slices (slices : (real * (slice_spec * string)) list) =
199          fold (Integer.max o fst o #1 o fst o snd) slices 0
200
201        val num_actual_slices = length actual_slices
202        val max_fact_factor =
203          Real.fromInt (case max_facts of NONE => max_facts_of_slices all_slices | SOME max => max)
204          / Real.fromInt (max_facts_of_slices (map snd actual_slices))
205
206        fun monomorphize_facts facts =
207          let
208            val ctxt =
209              ctxt
210              |> repair_monomorph_context max_mono_iters best_max_mono_iters max_new_mono_instances
211                   best_max_new_mono_instances
212            (* pseudo-theorem involving the same constants as the subgoal *)
213            val subgoal_th =
214              Logic.list_implies (hyp_ts, concl_t) |> Skip_Proof.make_thm thy
215            val rths =
216              facts |> chop mono_max_privileged_facts
217                    |>> map (pair 1 o snd)
218                    ||> map (pair 2 o snd)
219                    |> op @
220                    |> cons (0, subgoal_th)
221          in
222            Monomorph.monomorph atp_schematic_consts_of ctxt rths
223            |> tl |> curry ListPair.zip (map fst facts)
224            |> maps (fn (name, rths) => map (pair name o zero_var_indexes o snd) rths)
225          end
226
227        fun run_slice time_left (cache_key, cache_value) (slice, (time_frac,
228            (key as ((best_max_facts, best_fact_filter), format, best_type_enc, best_lam_trans,
229               best_uncurried_aliases),
230             extra))) =
231          let
232            val effective_fact_filter = fact_filter |> the_default best_fact_filter
233            val facts = get_facts_of_filter effective_fact_filter factss
234            val num_facts =
235              Real.ceil (max_fact_factor * Real.fromInt best_max_facts) + max_fact_factor_fudge
236              |> Integer.min (length facts)
237            val generate_info = (case format of DFG _ => true | _ => false)
238            val strictness = if strict then Strict else Non_Strict
239            val type_enc = type_enc |> choose_type_enc strictness best_type_enc format
240            val sound = is_type_enc_sound type_enc
241            val real_ms = Real.fromInt o Time.toMilliseconds
242            val slice_timeout =
243              (real_ms time_left
244               |> (if slice < num_actual_slices - 1 then
245                     curry Real.min (time_frac * real_ms timeout)
246                   else
247                     I))
248              * 0.001
249              |> seconds
250            val generous_slice_timeout =
251              if mode = MaSh then one_day else slice_timeout + atp_timeout_slack
252            val _ =
253              if debug then
254                quote name ^ " slice #" ^ string_of_int (slice + 1) ^
255                " with " ^ string_of_int num_facts ^ " fact" ^
256                plural_s num_facts ^ " for " ^ string_of_time slice_timeout ^ "..."
257                |> writeln
258              else
259                ()
260            val readable_names = not (Config.get ctxt atp_full_names)
261            val lam_trans = lam_trans |> the_default best_lam_trans
262            val uncurried_aliases = uncurried_aliases |> the_default best_uncurried_aliases
263            val value as (atp_problem, _, _, _) =
264              if cache_key = SOME key then
265                cache_value
266              else
267                facts
268                |> not sound ? filter_out (is_dangerous_prop ctxt o Thm.prop_of o snd)
269                |> take num_facts
270                |> not (is_type_enc_polymorphic type_enc) ? monomorphize_facts
271                |> map (apsnd Thm.prop_of)
272                |> generate_atp_problem ctxt generate_info format prem_role type_enc atp_mode
273                  lam_trans uncurried_aliases readable_names true hyp_ts concl_t
274
275            fun sel_weights () = atp_problem_selection_weights atp_problem
276            fun ord_info () = atp_problem_term_order_info atp_problem
277
278            val ord = effective_term_order ctxt name
279            val args =
280              arguments ctxt full_proofs extra slice_timeout (File.bash_path prob_path)
281                (ord, ord_info, sel_weights)
282            val command =
283              "(exec 2>&1; " ^ File.bash_path command0 ^ " " ^ args ^ " " ^ ")"
284              |> enclose "TIMEFORMAT='%3R'; { time " " ; }"
285
286            val _ =
287              atp_problem
288              |> lines_of_atp_problem format ord ord_info
289              |> cons ("% " ^ command ^ "\n" ^ (if comment = "" then "" else "% " ^ comment ^ "\n"))
290              |> File.write_list prob_path
291
292            val ((output, run_time), (atp_proof, outcome)) =
293              Timeout.apply generous_slice_timeout Isabelle_System.bash_output command
294              |>> (if overlord then prefix ("% " ^ command ^ "\n% " ^ timestamp () ^ "\n") else I)
295              |> fst |> split_time
296              |> (fn accum as (output, _) =>
297                (accum,
298                 extract_tstplike_proof_and_outcome verbose proof_delims known_failures output
299                 |>> atp_proof_of_tstplike_proof (perhaps (try (unprefix remote_prefix)) name)
300                   atp_problem
301                 handle UNRECOGNIZED_ATP_PROOF () => ([], SOME ProofUnparsable)))
302              handle Timeout.TIMEOUT _ => (("", slice_timeout), ([], SOME TimedOut))
303
304            val outcome =
305              (case outcome of
306                NONE =>
307                (case used_facts_in_unsound_atp_proof ctxt (map fst facts) atp_proof of
308                  SOME facts =>
309                  let
310                    val failure = UnsoundProof (is_type_enc_sound type_enc, sort string_ord facts)
311                  in
312                    if debug then (warning (string_of_atp_failure failure); NONE) else SOME failure
313                  end
314                | NONE => (found_proof (); NONE))
315              | _ => outcome)
316          in
317            ((SOME key, value), (output, run_time, facts, atp_proof, outcome),
318              SOME (format, type_enc))
319          end
320
321        val timer = Timer.startRealTimer ()
322
323        fun maybe_run_slice slice (result as (cache, (_, run_time0, _, _, SOME _), _)) =
324            let val time_left = timeout - Timer.checkRealTimer timer in
325              if time_left <= Time.zeroTime then
326                result
327              else
328                run_slice time_left cache slice
329                |> (fn (cache, (output, run_time, used_from, atp_proof, outcome),
330                        format_type_enc) =>
331                  (cache, (output, run_time0 + run_time, used_from, atp_proof, outcome),
332                   format_type_enc))
333            end
334          | maybe_run_slice _ result = result
335      in
336        ((NONE, ([], Symtab.empty, [], Symtab.empty)),
337         ("", Time.zeroTime, [], [], SOME InternalError), NONE)
338        |> fold maybe_run_slice actual_slices
339      end
340
341    (* If the problem file has not been exported, remove it; otherwise, export
342       the proof file too. *)
343    fun clean_up () = if dest_dir = "" then (try File.rm prob_path; ()) else ()
344    fun export (_, (output, _, _, _, _), _) =
345      if dest_dir = "" then ()
346      else File.write (Path.explode (Path.implode prob_path ^ "_proof")) output
347
348    val ((_, (_, pool, lifted, sym_tab)), (output, run_time, used_from, atp_proof, outcome),
349         SOME (format, type_enc)) =
350      with_cleanup clean_up run () |> tap export
351
352    val important_message =
353      if mode = Normal andalso Random.random_range 0 (atp_important_message_keep_quotient - 1) = 0
354      then extract_important_message output
355      else ""
356
357    val (used_facts, preferred_methss, message) =
358      (case outcome of
359        NONE =>
360        let
361          val used_facts = sort_by fst (used_facts_in_atp_proof ctxt (map fst used_from) atp_proof)
362          val needs_full_types = is_typed_helper_used_in_atp_proof atp_proof
363          val preferred_methss =
364            (Metis_Method (NONE, NONE),
365             bunches_of_proof_methods try0 (smt_proofs <> SOME false) needs_full_types
366               (if atp_proof_prefers_lifting atp_proof then liftingN else hide_lamsN))
367        in
368          (used_facts, preferred_methss,
369           fn preplay =>
370              let
371                val _ = if verbose then writeln "Generating proof text..." else ()
372
373                fun isar_params () =
374                  let
375                    val metis_type_enc =
376                      if is_typed_helper_used_in_atp_proof atp_proof then SOME full_typesN else NONE
377                    val metis_lam_trans =
378                      if atp_proof_prefers_lifting atp_proof then SOME liftingN else NONE
379                    val atp_proof =
380                      atp_proof
381                      |> termify_atp_proof ctxt name format type_enc pool lifted sym_tab
382                      |> spassy ? introduce_spassy_skolems
383                      |> factify_atp_proof (map fst used_from) hyp_ts concl_t
384                  in
385                    (verbose, (metis_type_enc, metis_lam_trans), preplay_timeout, compress, try0,
386                     minimize, atp_proof, goal)
387                  end
388
389                val one_line_params = (preplay (), proof_banner mode name, subgoal, subgoal_count)
390                val num_chained = length (#facts (Proof.goal state))
391              in
392                proof_text ctxt debug isar_proofs smt_proofs isar_params num_chained
393                  one_line_params ^
394                (if important_message <> "" then
395                   "\n\nImportant message from Dr. Geoff Sutcliffe:\n" ^ important_message
396                 else
397                   "")
398              end)
399        end
400      | SOME failure =>
401        ([], (Auto_Method (* dummy *), []), fn _ => string_of_atp_failure failure))
402  in
403    {outcome = outcome, used_facts = used_facts, used_from = used_from,
404     preferred_methss = preferred_methss, run_time = run_time, message = message}
405  end
406
407end;
408