1 (* Title: HOL/Tools/Sledgehammer/sledgehammer_mash.ML
2 Author: Jasmin Blanchette, TU Muenchen
4 Sledgehammer's machine-learning-based relevance filter (MaSh).
7 signature SLEDGEHAMMER_MASH =
9 type status = ATP_Problem_Generate.status
10 type stature = ATP_Problem_Generate.stature
11 type fact = Sledgehammer_Fact.fact
12 type fact_override = Sledgehammer_Fact.fact_override
13 type params = Sledgehammer_Provers.params
14 type relevance_fudge = Sledgehammer_Provers.relevance_fudge
15 type prover_result = Sledgehammer_Provers.prover_result
17 val trace : bool Config.T
22 val fact_filters : string list
23 val escape_meta : string -> string
24 val escape_metas : string list -> string
25 val unescape_meta : string -> string
26 val unescape_metas : string -> string list
27 val extract_query : string -> string * string list
28 val nickname_of : thm -> string
29 val suggested_facts : string list -> ('a * thm) list -> ('a * thm) list
31 int -> (('a * thm) list * ('a * thm) list) list -> ('a * thm) list
32 val is_likely_tautology_or_too_meta : thm -> bool
33 val theory_ord : theory * theory -> order
34 val thm_ord : thm * thm -> order
36 Proof.context -> string -> theory -> status -> term list -> string list
37 val isabelle_dependencies_of : unit Symtab.table -> thm -> string list
38 val goal_of_thm : theory -> thm -> thm
39 val run_prover_for_mash :
40 Proof.context -> params -> string -> fact list -> thm -> prover_result
41 val mash_CLEAR : Proof.context -> unit
44 -> (string * string list * string list * string list) list -> unit
47 -> (string * string list * string list * string list) list -> unit
49 Proof.context -> bool -> int -> string list * string list -> string list
50 val mash_unlearn : Proof.context -> unit
51 val mash_could_suggest_facts : unit -> bool
52 val mash_can_suggest_facts : Proof.context -> bool
53 val mash_suggest_facts :
54 Proof.context -> params -> string -> int -> term list -> term
55 -> ('a * thm) list -> ('a * thm) list * ('a * thm) list
57 Proof.context -> params -> theory -> Time.time -> fact list -> string
58 val mash_learn_proof :
59 Proof.context -> params -> term -> ('a * thm) list -> thm list -> unit
61 Proof.context -> params -> string -> int -> fact_override -> term list
62 -> term -> fact list -> fact list
63 val kill_learners : unit -> unit
64 val running_learners : unit -> unit
67 structure Sledgehammer_MaSh : SLEDGEHAMMER_MASH =
71 open ATP_Problem_Generate
72 open Sledgehammer_Util
73 open Sledgehammer_Fact
74 open Sledgehammer_Provers
75 open Sledgehammer_Minimize
76 open Sledgehammer_MePo
79 Attrib.setup_config_bool @{binding sledgehammer_mash_trace} (K false)
80 fun trace_msg ctxt msg = if Config.get ctxt trace then tracing (msg ()) else ()
88 val fact_filters = [meshN, mepoN, mashN]
90 fun mash_home () = getenv "MASH_HOME"
91 fun mash_state_dir () =
92 getenv "ISABELLE_HOME_USER" ^ "/mash"
93 |> tap (Isabelle_System.mkdir o Path.explode)
94 fun mash_state_path () = mash_state_dir () ^ "/state" |> Path.explode
97 (*** Isabelle helpers ***)
100 if Char.isAlphaNum c orelse c = #"_" orelse c = #"." orelse c = #"(" orelse
101 c = #")" orelse c = #"," then
104 (* fixed width, in case more digits follow *)
105 "\\" ^ stringN_of_int 3 (Char.ord c)
107 fun unmeta_chars accum [] = String.implode (rev accum)
108 | unmeta_chars accum (#"\\" :: d1 :: d2 :: d3 :: cs) =
109 (case Int.fromString (String.implode [d1, d2, d3]) of
110 SOME n => unmeta_chars (Char.chr n :: accum) cs
111 | NONE => "" (* error *))
112 | unmeta_chars _ (#"\\" :: _) = "" (* error *)
113 | unmeta_chars accum (c :: cs) = unmeta_chars (c :: accum) cs
115 val escape_meta = String.translate meta_char
116 val escape_metas = map escape_meta #> space_implode " "
117 val unescape_meta = String.explode #> unmeta_chars []
119 space_explode " " #> filter_out (curry (op =) "") #> map unescape_meta
121 fun extract_query line =
122 case space_explode ":" line of
123 [goal_name, suggs] => (unescape_meta goal_name, unescape_metas suggs)
126 fun parent_of_local_thm th =
128 val thy = th |> Thm.theory_of_thm
129 val facts = thy |> Global_Theory.facts_of
130 val space = facts |> Facts.space_of
131 fun id_of s = #id (Name_Space.the_entry space s)
132 fun max_id (s', _) (s, id) =
133 let val id' = id_of s' in if id > id' then (s, id) else (s', id') end
134 in ("", ~1) |> Facts.fold_static max_id facts |> fst end
136 val local_prefix = "local" ^ Long_Name.separator
139 let val hint = Thm.get_name_hint th in
140 (* FIXME: There must be a better way to detect local facts. *)
141 case try (unprefix local_prefix) hint of
143 parent_of_local_thm th ^ Long_Name.separator ^ Long_Name.separator ^ suff
147 fun suggested_facts suggs facts =
149 fun add_fact (fact as (_, th)) = Symtab.default (nickname_of th, fact)
150 val tab = Symtab.empty |> fold add_fact facts
151 in map_filter (Symtab.lookup tab) suggs end
153 (* Ad hoc score function roughly based on Blanchette's Ringberg 2011 data. *)
154 fun score x = Math.pow (1.5, 15.5 - 0.05 * Real.fromInt x) + 15.0
156 fun sum_sq_avg [] = 0
158 Real.ceil (100000.0 * fold (curry (op +) o score) xs 0.0) div length xs
160 fun mesh_facts max_facts [(selected, unknown)] =
161 take max_facts selected @ take (max_facts - length selected) unknown
162 | mesh_facts max_facts mess =
164 val mess = mess |> map (apfst (`length))
165 val fact_eq = Thm.eq_thm o pairself snd
166 fun score_in fact ((sel_len, sels), unks) =
167 case find_index (curry fact_eq fact) sels of
168 ~1 => (case find_index (curry fact_eq fact) unks of
172 fun score_of fact = mess |> map_filter (score_in fact) |> sum_sq_avg
173 val facts = fold (union fact_eq o take max_facts o snd o fst) mess []
175 facts |> map (`score_of) |> sort (int_ord o swap o pairself fst)
176 |> map snd |> take max_facts
179 val thy_feature_prefix = "y_"
181 val thy_feature_name_of = prefix thy_feature_prefix
182 val const_name_of = prefix const_prefix
183 val type_name_of = prefix type_const_prefix
184 val class_name_of = prefix class_prefix
186 fun is_likely_tautology_or_too_meta th =
188 val is_boring_const = member (op =) atp_widely_irrelevant_consts
189 fun is_boring_bool t =
190 not (exists_Const (not o is_boring_const o fst) t) orelse
191 exists_type (exists_subtype (curry (op =) @{typ prop})) t
192 fun is_boring_prop (@{const Trueprop} $ t) = is_boring_bool t
193 | is_boring_prop (@{const "==>"} $ t $ u) =
194 is_boring_prop t andalso is_boring_prop u
195 | is_boring_prop (Const (@{const_name all}, _) $ (Abs (_, _, t)) $ u) =
196 is_boring_prop t andalso is_boring_prop u
197 | is_boring_prop (Const (@{const_name "=="}, _) $ t $ u) =
198 is_boring_bool t andalso is_boring_bool u
199 | is_boring_prop _ = true
201 is_boring_prop (prop_of th) andalso not (Thm.eq_thm_prop (@{thm ext}, th))
205 if Theory.eq_thy p then
207 else if Theory.subthy p then
209 else if Theory.subthy (swap p) then
211 else case int_ord (pairself (length o Theory.ancestors_of) p) of
212 EQUAL => string_ord (pairself Context.theory_name p)
215 val thm_ord = theory_ord o pairself theory_of_thm
217 val bad_types = [@{type_name prop}, @{type_name bool}, @{type_name fun}]
219 fun interesting_terms_types_and_classes ctxt prover term_max_depth
222 fun is_bad_const (x as (s, _)) args =
223 member (op =) atp_logical_consts s orelse
224 fst (is_built_in_const_for_prover ctxt prover x args)
225 fun add_classes @{sort type} = I
226 | add_classes S = union (op =) (map class_name_of S)
227 fun do_add_type (Type (s, Ts)) =
228 (not (member (op =) bad_types s) ? insert (op =) (type_name_of s))
229 #> fold do_add_type Ts
230 | do_add_type (TFree (_, S)) = add_classes S
231 | do_add_type (TVar (_, S)) = add_classes S
232 fun add_type T = type_max_depth >= 0 ? do_add_type T
234 if member (op <>) args "" then s ^ "(" ^ space_implode "," args ^ ")"
236 fun patternify ~1 _ = ""
237 | patternify depth t =
239 (Const (s, _), args) =>
240 mk_app (const_name_of s) (map (patternify (depth - 1)) args)
242 fun add_term_patterns ~1 _ = I
243 | add_term_patterns depth t =
244 insert (op =) (patternify depth t)
245 #> add_term_patterns (depth - 1) t
246 val add_term = add_term_patterns term_max_depth
248 let val (head, args) = strip_comb t in
250 Const (x as (_, T)) =>
251 not (is_bad_const x args) ? (add_term t #> add_type T)
252 | Free (_, T) => add_type T
253 | Var (_, T) => add_type T
254 | Abs (_, T, body) => add_type T #> add_patterns body
256 #> fold add_patterns args
258 in [] |> fold add_patterns ts end
260 fun is_exists (s, _) = (s = @{const_name Ex} orelse s = @{const_name Ex1})
262 val term_max_depth = 1
263 val type_max_depth = 1
265 (* TODO: Generate type classes for types? *)
266 fun features_of ctxt prover thy status ts =
267 thy_feature_name_of (Context.theory_name thy) ::
268 interesting_terms_types_and_classes ctxt prover term_max_depth type_max_depth
270 |> forall is_lambda_free ts ? cons "no_lams"
271 |> forall (not o exists_Const is_exists) ts ? cons "no_skos"
274 | Induction => cons "induction"
275 | Intro => cons "intro"
276 | Inductive => cons "inductive"
277 | Elim => cons "elim"
278 | Simp => cons "simp"
281 fun isabelle_dependencies_of all_facts = thms_in_proof (SOME all_facts)
283 val freezeT = Type.legacy_freeze_type
285 fun freeze (t $ u) = freeze t $ freeze u
286 | freeze (Abs (s, T, t)) = Abs (s, freezeT T, freeze t)
287 | freeze (Var ((s, _), T)) = Free (s, freezeT T)
288 | freeze (Const (s, T)) = Const (s, freezeT T)
289 | freeze (Free (s, T)) = Free (s, freezeT T)
292 fun goal_of_thm thy = prop_of #> freeze #> cterm_of thy #> Goal.init
294 fun run_prover_for_mash ctxt params prover facts goal =
297 {state = Proof.init ctxt, goal = goal, subgoal = 1, subgoal_count = 1,
298 facts = facts |> map (apfst (apfst (fn name => name ())))
299 |> map Untranslated_Fact}
300 val prover = get_minimizing_prover ctxt Normal (K ()) prover
301 in prover params (K (K (K ""))) problem end
304 (*** Low-level communication with MaSh ***)
306 fun write_file (xs, f) file =
307 let val path = Path.explode file in
310 |> List.app (File.append path o space_implode "" o map f)
313 fun mash_info overlord =
314 if overlord then (getenv "ISABELLE_HOME_USER", "")
315 else (getenv "ISABELLE_TMP", serial_string ())
317 fun and_rm_files overlord flags files =
321 " && rm -f" ^ flags ^ " -- " ^
322 space_implode " " (map File.shell_quote files)
324 fun run_mash ctxt overlord (temp_dir, serial) async core =
326 val log_file = temp_dir ^ "/mash_log" ^ serial
327 val err_file = temp_dir ^ "/mash_err" ^ serial
329 "(" ^ mash_home () ^ "/mash --quiet --outputDir " ^ mash_state_dir () ^
330 " --log " ^ log_file ^ " " ^ core ^ ") 2>&1 > " ^ err_file ^
331 and_rm_files overlord "" [log_file, err_file] ^
332 (if async then " &" else "")
334 trace_msg ctxt (fn () =>
335 (if async then "Launching " else "Running ") ^ command);
336 write_file ([], K "") log_file;
337 write_file ([], K "") err_file;
338 Isabelle_System.bash command;
339 if not async then trace_msg ctxt (K "Done") else ()
342 (* TODO: Eliminate code once "mash.py" handles sequences of ADD commands as fast
344 fun run_mash_init ctxt overlord write_access write_feats write_deps =
346 val info as (temp_dir, serial) = mash_info overlord
347 val in_dir = temp_dir ^ "/mash_init" ^ serial
348 |> tap (Path.explode #> Isabelle_System.mkdir)
350 write_file write_access (in_dir ^ "/mash_accessibility");
351 write_file write_feats (in_dir ^ "/mash_features");
352 write_file write_deps (in_dir ^ "/mash_dependencies");
353 run_mash ctxt overlord info true
354 ("--init --inputDir " ^ in_dir ^
355 and_rm_files overlord " -r" [in_dir])
358 fun run_mash_commands ctxt overlord async save max_suggs write_cmds read_suggs =
360 val info as (temp_dir, serial) = mash_info overlord
361 val sugg_file = temp_dir ^ "/mash_suggs" ^ serial
362 val cmd_file = temp_dir ^ "/mash_commands" ^ serial
364 write_file ([], K "") sugg_file;
365 write_file write_cmds cmd_file;
366 run_mash ctxt overlord info async
367 ("--inputFile " ^ cmd_file ^ " --predictions " ^ sugg_file ^
368 " --numberOfPredictions " ^ string_of_int max_suggs ^
369 (if save then " --saveModel" else "") ^
370 (and_rm_files overlord "" [sugg_file, cmd_file]));
371 read_suggs (fn () => File.read_lines (Path.explode sugg_file))
374 fun str_of_update (name, parents, feats, deps) =
375 "! " ^ escape_meta name ^ ": " ^ escape_metas parents ^ "; " ^
376 escape_metas feats ^ "; " ^ escape_metas deps ^ "\n"
378 fun str_of_query (parents, feats) =
379 "? " ^ escape_metas parents ^ "; " ^ escape_metas feats
381 fun init_str_of_update get (upd as (name, _, _, _)) =
382 escape_meta name ^ ": " ^ escape_metas (get upd) ^ "\n"
384 fun mash_CLEAR ctxt =
385 let val path = mash_state_dir () |> Path.explode in
386 trace_msg ctxt (K "MaSh CLEAR");
387 File.fold_dir (fn file => fn () =>
388 File.rm (Path.append path (Path.basic file)))
392 fun mash_INIT ctxt _ [] = mash_CLEAR ctxt
393 | mash_INIT ctxt overlord upds =
394 (trace_msg ctxt (fn () => "MaSh INIT " ^
395 elide_string 1000 (space_implode " " (map #1 upds)));
396 run_mash_init ctxt overlord (upds, init_str_of_update #2)
397 (upds, init_str_of_update #3) (upds, init_str_of_update #4))
399 fun mash_ADD _ _ [] = ()
400 | mash_ADD ctxt overlord upds =
401 (trace_msg ctxt (fn () => "MaSh ADD " ^
402 elide_string 1000 (space_implode " " (map #1 upds)));
403 run_mash_commands ctxt overlord true true 0 (upds, str_of_update) (K ()))
405 fun mash_QUERY ctxt overlord max_suggs (query as (_, feats)) =
406 (trace_msg ctxt (fn () => "MaSh QUERY " ^ space_implode " " feats);
407 run_mash_commands ctxt overlord false false max_suggs
408 ([query], str_of_query)
409 (fn suggs => snd (extract_query (List.last (suggs ()))))
410 handle List.Empty => [])
413 (*** High-level communication with MaSh ***)
415 fun try_graph ctxt when def f =
417 handle Graph.CYCLES (cycle :: _) =>
418 (trace_msg ctxt (fn () =>
419 "Cycle involving " ^ commas cycle ^ " when " ^ when); def)
420 | Graph.UNDEF name =>
421 (trace_msg ctxt (fn () =>
422 "Unknown fact " ^ quote name ^ " when " ^ when); def)
425 {thys : bool Symtab.table,
426 fact_graph : unit Graph.T}
428 val empty_state = {thys = Symtab.empty, fact_graph = Graph.empty}
432 fun mash_load _ (state as (true, _)) = state
434 let val path = mash_state_path () in
436 case try File.read_lines path of
437 SOME (comp_thys :: incomp_thys :: fact_lines) =>
439 fun add_thy comp thy = Symtab.update (thy, comp)
440 fun add_edge_to name parent =
441 Graph.default_node (parent, ())
442 #> Graph.add_edge (parent, name)
443 fun add_fact_line line =
444 case extract_query line of
445 ("", _) => I (* shouldn't happen *)
447 Graph.default_node (name, ())
448 #> fold (add_edge_to name) parents
450 Symtab.empty |> fold (add_thy true) (unescape_metas comp_thys)
451 |> fold (add_thy false) (unescape_metas incomp_thys)
453 try_graph ctxt "loading state" Graph.empty (fn () =>
454 Graph.empty |> fold add_fact_line fact_lines)
455 in {thys = thys, fact_graph = fact_graph} end
459 fun mash_save ({thys, fact_graph, ...} : mash_state) =
461 val path = mash_state_path ()
462 val thys = Symtab.dest thys
463 val line_for_thys = escape_metas o AList.find (op =) thys
464 fun fact_line_for name parents =
465 escape_meta name ^ ": " ^ escape_metas parents
466 val append_fact = File.append path o suffix "\n" oo fact_line_for
468 File.write path (line_for_thys true ^ "\n" ^ line_for_thys false ^ "\n");
469 Graph.fold (fn (name, ((), (parents, _))) => fn () =>
470 append_fact name (Graph.Keys.dest parents))
475 Synchronized.var "Sledgehammer_MaSh.global_state" (false, empty_state)
479 fun mash_map ctxt f =
480 Synchronized.change global_state (mash_load ctxt ##> (f #> tap mash_save))
483 Synchronized.change_result global_state (mash_load ctxt #> `snd)
485 fun mash_unlearn ctxt =
486 Synchronized.change global_state (fn _ =>
487 (mash_CLEAR ctxt; File.write (mash_state_path ()) "";
488 (true, empty_state)))
492 fun mash_could_suggest_facts () = mash_home () <> ""
493 fun mash_can_suggest_facts ctxt =
494 not (Graph.is_empty (#fact_graph (mash_get ctxt)))
496 fun parents_wrt_facts facts fact_graph =
498 val facts = [] |> fold (cons o nickname_of o snd) facts
499 val tab = Symtab.empty |> fold (fn name => Symtab.update (name, ())) facts
500 fun insert_not_seen seen name =
501 not (member (op =) seen name) ? insert (op =) name
502 fun parents_of _ parents [] = parents
503 | parents_of seen parents (name :: names) =
504 if Symtab.defined tab name then
505 parents_of (name :: seen) (name :: parents) names
507 parents_of (name :: seen) parents
508 (Graph.Keys.fold (insert_not_seen seen)
509 (Graph.imm_preds fact_graph name) names)
510 in parents_of [] [] (Graph.maximals fact_graph) end
512 (* Generate more suggestions than requested, because some might be thrown out
513 later for various reasons and "meshing" gives better results with some
515 fun max_suggs_of max_facts = max_facts + Int.min (200, max_facts)
517 fun is_fact_in_graph fact_graph (_, th) =
518 can (Graph.get_node fact_graph) (nickname_of th)
520 fun mash_suggest_facts ctxt ({overlord, ...} : params) prover max_facts hyp_ts
523 val thy = Proof_Context.theory_of ctxt
524 val fact_graph = #fact_graph (mash_get ctxt)
525 val parents = parents_wrt_facts facts fact_graph
526 val feats = features_of ctxt prover thy General (concl_t :: hyp_ts)
528 if Graph.is_empty fact_graph then []
529 else mash_QUERY ctxt overlord (max_suggs_of max_facts) (parents, feats)
530 val selected = facts |> suggested_facts suggs
531 val unknown = facts |> filter_out (is_fact_in_graph fact_graph)
532 in (selected, unknown) end
534 fun add_thys_for thy =
535 let fun add comp thy = Symtab.update (Context.theory_name thy, comp) in
536 add false thy #> fold (add true) (Theory.ancestors_of thy)
539 fun update_fact_graph ctxt (name, parents, feats, deps) (upds, graph) =
541 fun maybe_add_from from (accum as (parents, graph)) =
542 try_graph ctxt "updating graph" accum (fn () =>
543 (from :: parents, Graph.add_edge_acyclic (from, name) graph))
544 val graph = graph |> Graph.default_node (name, ())
545 val (parents, graph) = ([], graph) |> fold maybe_add_from parents
546 val (deps, graph) = ([], graph) |> fold maybe_add_from deps
547 in ((name, parents, feats, deps) :: upds, graph) end
549 val pass1_learn_timeout_factor = 0.5
551 (* Too many dependencies is a sign that a decision procedure is at work. There
552 isn't much too learn from such proofs. *)
553 val max_dependencies = 10
555 (* The timeout is understood in a very slack fashion. *)
556 fun mash_learn_thy ctxt ({provers, verbose, overlord, ...} : params) thy timeout
559 val timer = Timer.startRealTimer ()
560 val prover = hd provers
562 Time.> (Timer.checkRealTimer timer, time_mult frac timeout)
563 val {fact_graph, ...} = mash_get ctxt
565 facts |> filter_out (is_fact_in_graph fact_graph)
566 |> sort (thm_ord o pairself snd)
568 if null new_facts then
572 val ths = facts |> map snd
574 ths |> filter_out is_likely_tautology_or_too_meta
575 |> map (rpair () o nickname_of)
577 fun trim_deps deps = if length deps > max_dependencies then [] else deps
578 fun do_fact _ (accum as (_, true)) = accum
579 | do_fact ((_, (_, status)), th) ((parents, upds), false) =
581 val name = nickname_of th
583 features_of ctxt prover (theory_of_thm th) status [prop_of th]
584 val deps = isabelle_dependencies_of all_names th |> trim_deps
585 val upd = (name, parents, feats, deps)
586 in (([name], upd :: upds), timed_out pass1_learn_timeout_factor) end
587 val parents = parents_wrt_facts facts fact_graph
589 ((parents, []), false) |> fold do_fact new_facts |>> apsnd rev
591 fun trans {thys, fact_graph} =
593 val mash_INIT_or_ADD =
594 if Graph.is_empty fact_graph then mash_INIT else mash_ADD
595 val (upds, fact_graph) =
596 ([], fact_graph) |> fold (update_fact_graph ctxt) upds
598 (mash_INIT_or_ADD ctxt overlord (rev upds);
599 {thys = thys |> add_thys_for thy,
600 fact_graph = fact_graph})
605 "Processed " ^ string_of_int n ^ " proof" ^ plural_s n ^
607 " in " ^ string_from_time (Timer.checkRealTimer timer)
615 fun mash_learn_proof ctxt ({provers, overlord, ...} : params) t facts used_ths =
617 val thy = Proof_Context.theory_of ctxt
618 val prover = hd provers
619 val name = ATP_Util.timestamp () ^ " " ^ serial_string () (* fresh enough *)
620 val feats = features_of ctxt prover thy General [t]
621 val deps = used_ths |> map nickname_of
623 mash_map ctxt (fn {thys, fact_graph} =>
625 val parents = parents_wrt_facts facts fact_graph
626 val upds = [(name, parents, feats, deps)]
627 val (upds, fact_graph) =
628 ([], fact_graph) |> fold (update_fact_graph ctxt) upds
630 mash_ADD ctxt overlord upds;
631 {thys = thys, fact_graph = fact_graph}
635 (* The threshold should be large enough so that MaSh doesn't kick in for Auto
636 Sledgehammer and Try. *)
637 val min_secs_for_learning = 15
638 val learn_timeout_factor = 2.0
640 fun relevant_facts ctxt (params as {learn, fact_filter, timeout, ...}) prover
641 max_facts ({add, only, ...} : fact_override) hyp_ts concl_t facts =
642 if not (subset (op =) (the_list fact_filter, fact_filters)) then
643 error ("Unknown fact filter: " ^ quote (the fact_filter) ^ ".")
646 else if max_facts <= 0 orelse null facts then
650 val thy = Proof_Context.theory_of ctxt
652 if not learn orelse Async_Manager.has_running_threads MaShN then
654 else if Time.toSeconds timeout >= min_secs_for_learning then
656 val soft_timeout = time_mult learn_timeout_factor timeout
657 val hard_timeout = time_mult 4.0 soft_timeout
658 val birth_time = Time.now ()
659 val death_time = Time.+ (birth_time, hard_timeout)
660 val desc = ("machine learner for Sledgehammer", "")
662 Async_Manager.launch MaShN birth_time death_time desc
664 (true, mash_learn_thy ctxt params thy soft_timeout facts))
670 SOME ff => (() |> ff <> mepoN ? maybe_learn; ff)
672 if mash_can_suggest_facts ctxt then (maybe_learn (); meshN)
673 else if mash_could_suggest_facts () then (maybe_learn (); mepoN)
675 val add_ths = Attrib.eval_thms ctxt add
676 fun prepend_facts ths accepts =
677 ((facts |> filter (member Thm.eq_thm_prop ths o snd)) @
678 (accepts |> filter_out (member Thm.eq_thm_prop ths o snd)))
681 iterative_relevant_facts ctxt params prover max_facts NONE hyp_ts
684 mash_suggest_facts ctxt params prover max_facts hyp_ts concl_t facts
686 [] |> (if fact_filter <> mashN then cons (iter (), []) else I)
687 |> (if fact_filter <> mepoN then cons (mash ()) else I)
689 mesh_facts max_facts mess
690 |> not (null add_ths) ? prepend_facts add_ths
693 fun kill_learners () = Async_Manager.kill_threads MaShN "learner"
694 fun running_learners () = Async_Manager.running_threads MaShN "learner"