(* Title: HOL/Tools/Sledgehammer/sledgehammer_isar_preplay.ML
Author: Steffen Juilf Smolka, TU Muenchen
Author: Jasmin Blanchette, TU Muenchen
Preplaying of Isar proofs.
*)
signature SLEDGEHAMMER_ISAR_PREPLAY =
sig
type play_outcome = Sledgehammer_Reconstructor.play_outcome
type isar_proof = Sledgehammer_Isar_Proof.isar_proof
type isar_step = Sledgehammer_Isar_Proof.isar_step
type label = Sledgehammer_Isar_Proof.label
val trace: bool Config.T
type preplay_interface =
{get_preplay_outcome: label -> play_outcome,
set_preplay_outcome: label -> play_outcome -> unit,
preplay_quietly: Time.time -> isar_step -> play_outcome,
overall_preplay_outcome: isar_proof -> play_outcome}
val proof_preplay_interface: bool -> Proof.context -> string -> string -> bool -> Time.time ->
isar_proof -> preplay_interface
end;
structure Sledgehammer_Isar_Preplay : SLEDGEHAMMER_ISAR_PREPLAY =
struct
open ATP_Util
open Sledgehammer_Util
open Sledgehammer_Reconstructor
open Sledgehammer_Isar_Proof
val trace = Attrib.setup_config_bool @{binding sledgehammer_preplay_trace} (K false)
fun preplay_trace ctxt assmsp concl result =
let
val ctxt = ctxt |> Config.put show_markup true
val assms = op @ assmsp
val time = "[" ^ string_of_play_outcome result ^ "]" |> Pretty.str
val nr_of_assms = length assms
val assms = assms
|> map (Display.pretty_thm ctxt)
|> (fn [] => Pretty.str ""
| [a] => a
| assms => Pretty.enum ";" "\<lbrakk>" "\<rbrakk>" assms) (* Syntax.pretty_term!? *)
val concl = concl |> Syntax.pretty_term ctxt
val trace_list = []
|> cons concl
|> nr_of_assms > 0 ? cons (Pretty.str "\<Longrightarrow>")
|> cons assms
|> cons time
val pretty_trace = Pretty.blk (2, Pretty.breaks trace_list)
in
tracing (Pretty.string_of pretty_trace)
end
fun take_time timeout tac arg =
let val timing = Timing.start () in
(TimeLimit.timeLimit timeout tac arg; Played (#cpu (Timing.result timing)))
handle TimeLimit.TimeOut => Play_Timed_Out timeout
end
fun resolve_fact_names ctxt names =
(names
|>> map string_of_label
|> pairself (maps (thms_of_name ctxt)))
handle ERROR msg => error ("preplay error: " ^ msg)
fun thm_of_proof ctxt (Proof (fixed_frees, assms, steps)) =
let
val thy = Proof_Context.theory_of ctxt
val concl =
(case try List.last steps of
SOME (Prove (_, [], _, t, _, _)) => t
| _ => raise Fail "preplay error: malformed subproof")
val var_idx = maxidx_of_term concl + 1
fun var_of_free (x, T) = Var ((x, var_idx), T)
val subst = map (`var_of_free #> swap #> apfst Free) fixed_frees
in
Logic.list_implies (assms |> map snd, concl)
|> subst_free subst
|> Skip_Proof.make_thm thy
end
fun tac_of_method meth type_enc lam_trans ctxt (local_facts, global_facts) =
Method.insert_tac local_facts THEN'
(case meth of
Meson_Method => Meson.meson_tac ctxt global_facts
| Metis_Method => Metis_Tactic.metis_tac [type_enc] lam_trans ctxt global_facts
| _ =>
Method.insert_tac global_facts THEN'
(case meth of
Simp_Method => Simplifier.asm_full_simp_tac ctxt
| Simp_Size_Method =>
Simplifier.asm_full_simp_tac (Simplifier.add_simp @{thm size_ne_size_imp_ne} ctxt)
| Auto_Method => K (Clasimp.auto_tac ctxt)
| Fastforce_Method => Clasimp.fast_force_tac ctxt
| Force_Method => Clasimp.force_tac ctxt
| Arith_Method => Arith_Data.arith_tac ctxt
| Blast_Method => blast_tac ctxt
| _ => raise Fail "Sledgehammer_Isar_Preplay: tac_of_method"))
(* main function for preplaying Isar steps; may throw exceptions *)
fun preplay_raw _ _ _ _ _ (Let _) = Played Time.zeroTime
| preplay_raw debug type_enc lam_trans ctxt timeout
(Prove (_, xs, _, t, subproofs, (fact_names, (meth :: _) :: _))) =
let
val goal =
(case xs of
[] => t
| _ =>
(* proof obligation: !!thesis. (!!x. A x ==> thesis) ==> thesis
(cf. "~~/src/Pure/Isar/obtain.ML") *)
let
(* FIXME: generate fresh name *)
val thesis = Free ("thesis", HOLogic.boolT)
val thesis_prop = thesis |> HOLogic.mk_Trueprop
val frees = map Free xs
(* !!x1..xn. t ==> thesis (xs = [x1, .., xn]) *)
val inner_prop = fold_rev Logic.all frees (Logic.mk_implies (t, thesis_prop))
in
(* !!thesis. (!!x1..xn. t ==> thesis) ==> thesis *)
Logic.all thesis (Logic.mk_implies (inner_prop, thesis_prop))
end)
val facts =
resolve_fact_names ctxt fact_names
|>> append (map (thm_of_proof ctxt) subproofs)
val ctxt' = ctxt |> silence_reconstructors debug
fun prove () =
Goal.prove ctxt' [] [] goal (fn {context = ctxt, ...} =>
HEADGOAL (tac_of_method meth type_enc lam_trans ctxt facts))
handle ERROR msg => error ("Preplay error: " ^ msg)
val play_outcome = take_time timeout prove ()
in
(if Config.get ctxt trace then preplay_trace ctxt facts goal play_outcome else ();
play_outcome)
end
(*** proof preplay interface ***)
type preplay_interface =
{get_preplay_outcome: label -> play_outcome,
set_preplay_outcome: label -> play_outcome -> unit,
preplay_quietly: Time.time -> isar_step -> play_outcome,
overall_preplay_outcome: isar_proof -> play_outcome}
fun enrich_context_with_local_facts proof ctxt =
let
val thy = Proof_Context.theory_of ctxt
fun enrich_with_fact l t =
Proof_Context.put_thms false (string_of_label l, SOME [Skip_Proof.make_thm thy t])
val enrich_with_assms = fold (uncurry enrich_with_fact)
fun enrich_with_proof (Proof (_, assms, isar_steps)) =
enrich_with_assms assms #> fold enrich_with_step isar_steps
and enrich_with_step (Let _) = I
| enrich_with_step (Prove (_, _, l, t, subproofs, _)) =
enrich_with_fact l t #> fold enrich_with_proof subproofs
in
enrich_with_proof proof ctxt
end
fun merge_preplay_outcomes _ Play_Failed = Play_Failed
| merge_preplay_outcomes Play_Failed _ = Play_Failed
| merge_preplay_outcomes (Play_Timed_Out t1) (Play_Timed_Out t2) =
Play_Timed_Out (Time.+ (t1, t2))
| merge_preplay_outcomes (Played t1) (Play_Timed_Out t2) = Play_Timed_Out (Time.+ (t1, t2))
| merge_preplay_outcomes (Play_Timed_Out t1) (Played t2) = Play_Timed_Out (Time.+ (t1, t2))
| merge_preplay_outcomes (Played t1) (Played t2) = Played (Time.+ (t1, t2))
(* Given a proof, produces an imperative preplay interface with a shared table mapping from labels
to preplay results. The preplay results are caluclated lazyly and cached to avoid repeated
calculation.
Precondition: The proof must be labeled canonically; cf.
"Slegehammer_Proof.relabel_proof_canonically". *)
fun proof_preplay_interface debug ctxt type_enc lam_trans do_preplay preplay_timeout proof =
if not do_preplay then
(* the "dont_preplay" option pretends that everything works just fine *)
{get_preplay_outcome = K (Played Time.zeroTime),
set_preplay_outcome = K (K ()),
preplay_quietly = K (K (Played Time.zeroTime)),
overall_preplay_outcome = K (Played Time.zeroTime)} : preplay_interface
else
let
val ctxt = enrich_context_with_local_facts proof ctxt
fun preplay quietly timeout step =
preplay_raw debug type_enc lam_trans ctxt timeout step
handle exn =>
if Exn.is_interrupt exn then
reraise exn
else
(if not quietly andalso debug then
warning ("Preplay failure:\n " ^ @{make_string} step ^ "\n " ^
@{make_string} exn)
else
();
Play_Failed)
(* preplay steps treating exceptions like timeouts *)
fun preplay_quietly timeout = preplay true timeout
val preplay_tab =
let
fun add_step_to_tab step tab =
(case label_of_step step of
NONE => tab
| SOME l =>
Canonical_Lbl_Tab.update_new
(l, (fn () => preplay false preplay_timeout step) |> Lazy.lazy) tab)
handle Canonical_Lbl_Tab.DUP _ =>
raise Fail "Sledgehammer_Isar_Preplay: preplay time table"
in
Canonical_Lbl_Tab.empty
|> fold_isar_steps add_step_to_tab (steps_of_proof proof)
|> Unsynchronized.ref
end
fun get_preplay_outcome l =
Canonical_Lbl_Tab.lookup (!preplay_tab) l |> the |> Lazy.force
handle Option.Option => raise Fail "Sledgehammer_Isar_Preplay: preplay time table"
fun set_preplay_outcome l result =
preplay_tab := Canonical_Lbl_Tab.update (l, Lazy.value result) (!preplay_tab)
val result_of_step =
try (label_of_step #> the #> get_preplay_outcome)
#> the_default (Played Time.zeroTime)
fun overall_preplay_outcome (Proof (_, _, steps)) =
fold_isar_steps (merge_preplay_outcomes o result_of_step) steps (Played Time.zeroTime)
in
{get_preplay_outcome = get_preplay_outcome,
set_preplay_outcome = set_preplay_outcome,
preplay_quietly = preplay_quietly,
overall_preplay_outcome = overall_preplay_outcome}
end
end;