(* Title: HOL/Tools/Sledgehammer/sledgehammer_minimize.ML
Author: Philipp Meyer, TU Muenchen
Author: Jasmin Blanchette, TU Muenchen
Minimization of fact list for Metis using external provers.
*)
signature SLEDGEHAMMER_MINIMIZE =
sig
type stature = ATP_Problem_Generate.stature
type play = Sledgehammer_Reconstructor.play
type mode = Sledgehammer_Provers.mode
type params = Sledgehammer_Provers.params
type prover = Sledgehammer_Provers.prover
val binary_min_facts : int Config.T
val auto_minimize_min_facts : int Config.T
val auto_minimize_max_time : real Config.T
val minimize_facts :
(thm list -> unit) -> string -> params -> bool -> int -> int
-> Proof.state -> thm -> play Lazy.lazy option
-> ((string * stature) * thm list) list
-> ((string * stature) * thm list) list option
* (play Lazy.lazy * (play -> string) * string)
val get_minimizing_prover : Proof.context -> mode -> (thm list -> unit) -> string -> prover
val run_minimize : params -> (thm list -> unit) -> int -> (Facts.ref * Attrib.src list) list ->
Proof.state -> unit
end;
structure Sledgehammer_Minimize : SLEDGEHAMMER_MINIMIZE =
struct
open ATP_Util
open ATP_Proof
open ATP_Problem_Generate
open ATP_Systems
open Sledgehammer_Util
open Sledgehammer_Fact
open Sledgehammer_Reconstructor
open Sledgehammer_Reconstruct
open Sledgehammer_Provers
(* wrapper for calling external prover *)
fun n_facts names =
let val n = length names in
string_of_int n ^ " fact" ^ plural_s n ^
(if n > 0 then
": " ^ (names |> map fst |> sort string_ord |> space_implode " ")
else
"")
end
fun print silent f = if silent then () else Output.urgent_message (f ())
fun test_facts ({debug, verbose, overlord, spy, provers, max_mono_iters,
max_new_mono_instances, type_enc, strict, lam_trans,
uncurried_aliases, isar_proofs, isar_compress, isar_try0,
preplay_timeout, ...} : params)
silent (prover : prover) timeout i n state goal facts =
let
val _ =
print silent (fn () =>
"Testing " ^ n_facts (map fst facts) ^
(if verbose then
case timeout of
SOME timeout => " (timeout: " ^ string_of_time timeout ^ ")"
| _ => ""
else
"") ^ "...")
val facts = facts |> maps (fn (n, ths) => map (pair n) ths)
val params =
{debug = debug, verbose = verbose, overlord = overlord, spy = spy, blocking = true,
provers = provers, type_enc = type_enc, strict = strict, lam_trans = lam_trans,
uncurried_aliases = uncurried_aliases, learn = false, fact_filter = NONE,
max_facts = SOME (length facts), fact_thresholds = (1.01, 1.01),
max_mono_iters = max_mono_iters, max_new_mono_instances = max_new_mono_instances,
isar_proofs = isar_proofs, isar_compress = isar_compress, isar_try0 = isar_try0,
slice = false, minimize = SOME false, timeout = timeout, preplay_timeout = preplay_timeout,
expect = ""}
val problem =
{comment = "", state = state, goal = goal, subgoal = i, subgoal_count = n,
factss = [("", facts)]}
val result as {outcome, used_facts, run_time, ...} =
prover params (K (K (K ""))) problem
in
print silent
(fn () =>
case outcome of
SOME failure => string_of_atp_failure failure
| NONE =>
"Found proof" ^
(if length used_facts = length facts then ""
else " with " ^ n_facts used_facts) ^
" (" ^ string_of_time run_time ^ ").");
result
end
(* minimalization of facts *)
(* Give the external prover some slack. The ATP gets further slack because the
Sledgehammer preprocessing time is included in the estimate below but isn't
part of the timeout. *)
val slack_msecs = 200
fun new_timeout NONE _ = NONE
| new_timeout (SOME timeout) run_time =
Int.min (Time.toMilliseconds timeout,
Time.toMilliseconds run_time + slack_msecs)
|> Time.fromMilliseconds |> SOME
(* The linear algorithm usually outperforms the binary algorithm when over 60%
of the facts are actually needed. The binary algorithm is much more
appropriate for provers that cannot return the list of used facts and hence
returns all facts as used. Since we cannot know in advance how many facts are
actually needed, we heuristically set the threshold to 10 facts. *)
val binary_min_facts =
Attrib.setup_config_int @{binding sledgehammer_minimize_binary_min_facts}
(K 20)
val auto_minimize_min_facts =
Attrib.setup_config_int @{binding sledgehammer_auto_minimize_min_facts}
(fn generic => Config.get_generic generic binary_min_facts)
val auto_minimize_max_time =
Attrib.setup_config_real @{binding sledgehammer_auto_minimize_max_time}
(K 5.0)
fun linear_minimize test timeout result xs =
let
fun min _ [] p = p
| min timeout (x :: xs) (seen, result) =
case test timeout (xs @ seen) of
result as {outcome = NONE, used_facts, run_time, ...}
: prover_result =>
min (new_timeout timeout run_time)
(filter_used_facts true used_facts xs)
(filter_used_facts false used_facts seen, result)
| _ => min timeout xs (x :: seen, result)
in min timeout xs ([], result) end
fun binary_minimize test timeout result xs =
let
fun min depth (result as {run_time, ...} : prover_result) sup
(xs as _ :: _ :: _) =
let
val (l0, r0) = chop (length xs div 2) xs
(*
val _ = warning (replicate_string depth " " ^ "{ " ^
"sup: " ^ n_facts (map fst sup))
val _ = warning (replicate_string depth " " ^ " " ^
"xs: " ^ n_facts (map fst xs))
val _ = warning (replicate_string depth " " ^ " " ^
"l0: " ^ n_facts (map fst l0))
val _ = warning (replicate_string depth " " ^ " " ^
"r0: " ^ n_facts (map fst r0))
*)
val depth = depth + 1
val timeout = new_timeout timeout run_time
in
case test timeout (sup @ l0) of
result as {outcome = NONE, used_facts, ...} =>
min depth result (filter_used_facts true used_facts sup)
(filter_used_facts true used_facts l0)
| _ =>
case test timeout (sup @ r0) of
result as {outcome = NONE, used_facts, ...} =>
min depth result (filter_used_facts true used_facts sup)
(filter_used_facts true used_facts r0)
| _ =>
let
val (sup_r0, (l, result)) = min depth result (sup @ r0) l0
val (sup, r0) =
(sup, r0)
|> pairself (filter_used_facts true (map fst sup_r0))
val (sup_l, (r, result)) = min depth result (sup @ l) r0
val sup = sup |> filter_used_facts true (map fst sup_l)
in (sup, (l @ r, result)) end
end
(*
|> tap (fn _ => warning (replicate_string depth " " ^ "}"))
*)
| min _ result sup xs = (sup, (xs, result))
in
case snd (min 0 result [] xs) of
([x], result as {run_time, ...}) =>
(case test (new_timeout timeout run_time) [] of
result as {outcome = NONE, ...} => ([], result)
| _ => ([x], result))
| p => p
end
fun minimize_facts do_learn prover_name (params as {learn, timeout, ...}) silent
i n state goal preplay0 facts =
let
val ctxt = Proof.context_of state
val prover =
get_prover ctxt (if silent then Auto_Minimize else Minimize) prover_name
fun test timeout = test_facts params silent prover timeout i n state goal
val (chained, non_chained) = List.partition is_fact_chained facts
(* Push chained facts to the back, so that they are less likely to be
kicked out by the linear minimization algorithm. *)
val facts = non_chained @ chained
in
(print silent (fn () => "Sledgehammer minimizer: " ^
quote prover_name ^ ".");
case test timeout facts of
result as {outcome = NONE, used_facts, run_time, ...} =>
let
val facts = filter_used_facts true used_facts facts
val min =
if length facts >= Config.get ctxt binary_min_facts then
binary_minimize
else
linear_minimize
val (min_facts, {preplay, message, message_tail, ...}) =
min test (new_timeout timeout run_time) result facts
in
print silent (fn () => cat_lines
["Minimized to " ^ n_facts (map fst min_facts)] ^
(case min_facts |> filter is_fact_chained |> length of
0 => ""
| n => "\n(including " ^ string_of_int n ^ " chained)") ^ ".");
(if learn then do_learn (maps snd min_facts) else ());
(SOME min_facts,
(if is_some preplay0 andalso length min_facts = length facts then
the preplay0
else
preplay,
message, message_tail))
end
| {outcome = SOME TimedOut, preplay, ...} =>
(NONE,
(preplay,
fn _ =>
"Timeout: You can increase the time limit using the \"timeout\" \
\option (e.g., \"timeout = " ^
string_of_int (10 + Time.toMilliseconds
(timeout |> the_default (seconds 60.0)) div 1000) ^
"\").", ""))
| {preplay, message, ...} =>
(NONE, (preplay, prefix "Prover error: " o message, "")))
handle ERROR msg =>
(NONE, (Lazy.value (Play_Failed plain_metis), fn _ => "Error: " ^ msg, ""))
end
fun adjust_reconstructor_params override_params
({debug, verbose, overlord, spy, blocking, provers, type_enc, strict,
lam_trans, uncurried_aliases, learn, fact_filter, max_facts,
fact_thresholds, max_mono_iters, max_new_mono_instances, isar_proofs,
isar_compress, isar_try0, slice, minimize, timeout, preplay_timeout,
expect} : params) =
let
fun lookup_override name default_value =
case AList.lookup (op =) override_params name of
SOME [s] => SOME s
| _ => default_value
(* Only those options that reconstructors are interested in are considered
here. *)
val type_enc = lookup_override "type_enc" type_enc
val lam_trans = lookup_override "lam_trans" lam_trans
in
{debug = debug, verbose = verbose, overlord = overlord, spy = spy, blocking = blocking,
provers = provers, type_enc = type_enc, strict = strict, lam_trans = lam_trans,
uncurried_aliases = uncurried_aliases, learn = learn, fact_filter = fact_filter,
max_facts = max_facts, fact_thresholds = fact_thresholds, max_mono_iters = max_mono_iters,
max_new_mono_instances = max_new_mono_instances, isar_proofs = isar_proofs,
isar_compress = isar_compress, isar_try0 = isar_try0, slice = slice, minimize = minimize,
timeout = timeout, preplay_timeout = preplay_timeout, expect = expect}
end
fun maybe_minimize ctxt mode do_learn name
(params as {verbose, isar_proofs, minimize, ...})
({state, goal, subgoal, subgoal_count, ...} : prover_problem)
(result as {outcome, used_facts, used_from, run_time, preplay, message,
message_tail} : prover_result) =
if is_some outcome orelse null used_facts then
result
else
let
val num_facts = length used_facts
val ((perhaps_minimize, (minimize_name, params)), preplay) =
if mode = Normal then
if num_facts >= Config.get ctxt auto_minimize_min_facts then
((true, (name, params)), preplay)
else
let
fun can_min_fast_enough time =
0.001
* Real.fromInt ((num_facts + 1) * Time.toMilliseconds time)
<= Config.get ctxt auto_minimize_max_time
fun prover_fast_enough () = can_min_fast_enough run_time
in
(case Lazy.force preplay of
Played (reconstr as Metis _, timeout) =>
if isar_proofs = SOME true then
(* Cheat: Assume the selected ATP is as fast as "metis" for
the goal it proved itself. *)
(can_min_fast_enough timeout,
(isar_proof_reconstructor ctxt name, params))
else if can_min_fast_enough timeout then
(true, extract_reconstructor params reconstr
||> (fn override_params =>
adjust_reconstructor_params override_params
params))
else
(prover_fast_enough (), (name, params))
| Played (SMT, timeout) =>
(* Cheat: Assume the original prover is as fast as "smt" for
the goal it proved itself *)
(can_min_fast_enough timeout, (name, params))
| _ => (prover_fast_enough (), (name, params)),
preplay)
end
else
((false, (name, params)), preplay)
val minimize = minimize |> the_default perhaps_minimize
val (used_facts, (preplay, message, _)) =
if minimize then
minimize_facts do_learn minimize_name params
(not verbose orelse (mode <> Normal andalso mode <> MaSh)) subgoal
subgoal_count state goal (SOME preplay)
(filter_used_facts true used_facts (map (apsnd single) used_from))
|>> Option.map (map fst)
else
(SOME used_facts, (preplay, message, ""))
in
case used_facts of
SOME used_facts =>
{outcome = NONE, used_facts = used_facts, used_from = used_from,
run_time = run_time, preplay = preplay, message = message,
message_tail = message_tail}
| NONE => result
end
fun get_minimizing_prover ctxt mode do_learn name params minimize_command
problem =
get_prover ctxt mode name params minimize_command problem
|> maybe_minimize ctxt mode do_learn name params problem
fun run_minimize (params as {provers, ...}) do_learn i refs state =
let
val ctxt = Proof.context_of state
val {goal, facts = chained_ths, ...} = Proof.goal state
val reserved = reserved_isar_keyword_table ()
val css = clasimpset_rule_table_of ctxt
val facts = refs |> maps (map (apsnd single) o fact_of_ref ctxt reserved chained_ths css)
in
case subgoal_count state of
0 => Output.urgent_message "No subgoal!"
| n => case provers of
[] => error "No prover is set."
| prover :: _ =>
(kill_provers ();
minimize_facts do_learn prover params false i n state goal NONE facts
|> (fn (_, (preplay, message, message_tail)) =>
message (Lazy.force preplay) ^ message_tail
|> Output.urgent_message))
end
end;