correctly add extra facts to lemmas (cf. conjecture and hypotheses) in Z3 Isar proofs
(* Title: HOL/Tools/Sledgehammer/sledgehammer_prover_smt.ML
Author: Fabian Immler, TU Muenchen
Author: Makarius
Author: Jasmin Blanchette, TU Muenchen
SMT solvers as Sledgehammer provers.
*)
signature SLEDGEHAMMER_PROVER_SMT =
sig
type stature = ATP_Problem_Generate.stature
type mode = Sledgehammer_Prover.mode
type prover = Sledgehammer_Prover.prover
val smt_builtins : bool Config.T
val smt_triggers : bool Config.T
val smt_weights : bool Config.T
val smt_weight_min_facts : int Config.T
val smt_min_weight : int Config.T
val smt_max_weight : int Config.T
val smt_max_weight_index : int Config.T
val smt_weight_curve : (int -> int) Unsynchronized.ref
val smt_max_slices : int Config.T
val smt_slice_fact_frac : real Config.T
val smt_slice_time_frac : real Config.T
val smt_slice_min_secs : int Config.T
val is_smt_prover : Proof.context -> string -> bool
val run_smt_solver : mode -> string -> prover
end;
structure Sledgehammer_Prover_SMT : SLEDGEHAMMER_PROVER_SMT =
struct
open ATP_Util
open ATP_Proof
open ATP_Systems
open ATP_Problem_Generate
open ATP_Proof_Reconstruct
open Sledgehammer_Util
open Sledgehammer_Proof_Methods
open Sledgehammer_Prover
val smt_builtins = Attrib.setup_config_bool @{binding sledgehammer_smt_builtins} (K true)
val smt_triggers = Attrib.setup_config_bool @{binding sledgehammer_smt_triggers} (K true)
val smt_weights = Attrib.setup_config_bool @{binding sledgehammer_smt_weights} (K true)
val smt_weight_min_facts =
Attrib.setup_config_int @{binding sledgehammer_smt_weight_min_facts} (K 20)
fun is_smt_prover ctxt = member (op =) (SMT_Solver.available_solvers_of ctxt)
(* FUDGE *)
val smt_min_weight = Attrib.setup_config_int @{binding sledgehammer_smt_min_weight} (K 0)
val smt_max_weight = Attrib.setup_config_int @{binding sledgehammer_smt_max_weight} (K 10)
val smt_max_weight_index =
Attrib.setup_config_int @{binding sledgehammer_smt_max_weight_index} (K 200)
val smt_weight_curve = Unsynchronized.ref (fn x : int => x * x)
fun smt_fact_weight ctxt j num_facts =
if Config.get ctxt smt_weights andalso num_facts >= Config.get ctxt smt_weight_min_facts then
let
val min = Config.get ctxt smt_min_weight
val max = Config.get ctxt smt_max_weight
val max_index = Config.get ctxt smt_max_weight_index
val curve = !smt_weight_curve
in
SOME (max - (max - min + 1) * curve (Int.max (0, max_index - j - 1)) div curve max_index)
end
else
NONE
fun weight_smt_fact ctxt num_facts ((info, th), j) =
let val thy = Proof_Context.theory_of ctxt in
(info, (smt_fact_weight ctxt j num_facts, Thm.transfer thy th (* TODO: needed? *)))
end
(* "SMT_Failure.Abnormal_Termination" carries the solver's return code. Until these are sorted out
properly in the SMT module, we must interpret these here. *)
val z3_failures =
[(101, OutOfResources),
(103, MalformedInput),
(110, MalformedInput),
(112, TimedOut)]
val unix_failures =
[(138, Crashed),
(139, Crashed)]
val smt_failures = z3_failures @ unix_failures
fun failure_of_smt_failure (SMT_Failure.Counterexample {is_real_cex, ...}) =
if is_real_cex then Unprovable else GaveUp
| failure_of_smt_failure SMT_Failure.Time_Out = TimedOut
| failure_of_smt_failure (SMT_Failure.Abnormal_Termination code) =
(case AList.lookup (op =) smt_failures code of
SOME failure => failure
| NONE => UnknownError ("Abnormal termination with exit code " ^ string_of_int code ^ "."))
| failure_of_smt_failure SMT_Failure.Out_Of_Memory = OutOfResources
| failure_of_smt_failure (SMT_Failure.Other_Failure s) = UnknownError s
(* FUDGE *)
val smt_max_slices = Attrib.setup_config_int @{binding sledgehammer_smt_max_slices} (K 8)
val smt_slice_fact_frac =
Attrib.setup_config_real @{binding sledgehammer_smt_slice_fact_frac} (K 0.667)
val smt_slice_time_frac =
Attrib.setup_config_real @{binding sledgehammer_smt_slice_time_frac} (K 0.333)
val smt_slice_min_secs = Attrib.setup_config_int @{binding sledgehammer_smt_slice_min_secs} (K 3)
val is_boring_builtin_typ =
not o exists_subtype (member (op =) [@{typ nat}, @{typ int}, HOLogic.realT])
fun smt_filter_loop name ({debug, overlord, max_mono_iters, max_new_mono_instances, timeout, slice,
...} : params) state goal i =
let
fun repair_context ctxt =
ctxt |> Context.proof_map (SMT_Config.select_solver name)
|> Config.put SMT_Config.verbose debug
|> (if overlord then
Config.put SMT_Config.debug_files
(overlord_file_location_of_prover name |> (fn (path, name) => path ^ "/" ^ name))
else
I)
|> Config.put SMT_Config.infer_triggers (Config.get ctxt smt_triggers)
|> not (Config.get ctxt smt_builtins)
? (SMT_Builtin.filter_builtins is_boring_builtin_typ
#> Config.put SMT_Config.datatypes false)
|> repair_monomorph_context max_mono_iters default_max_mono_iters max_new_mono_instances
default_max_new_mono_instances
val state = Proof.map_context (repair_context) state
val ctxt = Proof.context_of state
val max_slices = if slice then Config.get ctxt smt_max_slices else 1
fun do_slice timeout slice outcome0 time_so_far
(weighted_factss as (fact_filter, weighted_facts) :: _) =
let
val timer = Timer.startRealTimer ()
val slice_timeout =
if slice < max_slices then
let val ms = Time.toMilliseconds timeout in
Int.min (ms, Int.max (1000 * Config.get ctxt smt_slice_min_secs,
Real.ceil (Config.get ctxt smt_slice_time_frac * Real.fromInt ms)))
|> Time.fromMilliseconds
end
else
timeout
val num_facts = length weighted_facts
val _ =
if debug then
quote name ^ " slice " ^ string_of_int slice ^ " with " ^ string_of_int num_facts ^
" fact" ^ plural_s num_facts ^ " for " ^ string_of_time slice_timeout
|> Output.urgent_message
else
()
val birth = Timer.checkRealTimer timer
val _ = if debug then Output.urgent_message "Invoking SMT solver..." else ()
val (outcome, used_facts) =
SMT_Solver.smt_filter_preprocess ctxt [] goal weighted_facts i
|> SMT_Solver.smt_filter_apply slice_timeout
|> (fn {outcome, used_facts} => (outcome, used_facts))
handle exn =>
if Exn.is_interrupt exn then reraise exn
else (Runtime.exn_message exn |> SMT_Failure.Other_Failure |> SOME, [])
val death = Timer.checkRealTimer timer
val outcome0 = if is_none outcome0 then SOME outcome else outcome0
val time_so_far = Time.+ (time_so_far, Time.- (death, birth))
val too_many_facts_perhaps =
(case outcome of
NONE => false
| SOME (SMT_Failure.Counterexample _) => false
| SOME SMT_Failure.Time_Out => slice_timeout <> timeout
| SOME (SMT_Failure.Abnormal_Termination _) => true (* kind of *)
| SOME SMT_Failure.Out_Of_Memory => true
| SOME (SMT_Failure.Other_Failure _) => true)
val timeout = Time.- (timeout, Timer.checkRealTimer timer)
in
if too_many_facts_perhaps andalso slice < max_slices andalso num_facts > 0 andalso
Time.> (timeout, Time.zeroTime) then
let
val new_num_facts =
Real.ceil (Config.get ctxt smt_slice_fact_frac * Real.fromInt num_facts)
val weighted_factss as (new_fact_filter, _) :: _ =
weighted_factss
|> (fn (x :: xs) => xs @ [x])
|> app_hd (apsnd (take new_num_facts))
val show_filter = fact_filter <> new_fact_filter
fun num_of_facts fact_filter num_facts =
string_of_int num_facts ^ (if show_filter then " " ^ quote fact_filter else "") ^
" fact" ^ plural_s num_facts
val _ =
if debug then
quote name ^ " invoked with " ^
num_of_facts fact_filter num_facts ^ ": " ^
string_of_atp_failure (failure_of_smt_failure (the outcome)) ^
" Retrying with " ^ num_of_facts new_fact_filter new_num_facts ^
"..."
|> Output.urgent_message
else
()
in
do_slice timeout (slice + 1) outcome0 time_so_far weighted_factss
end
else
{outcome = if is_none outcome then NONE else the outcome0, used_facts = used_facts,
used_from = map (apsnd snd) weighted_facts, run_time = time_so_far}
end
in
do_slice timeout 1 NONE Time.zeroTime
end
fun run_smt_solver mode name (params as {debug, verbose, smt_proofs, preplay_timeout, ...})
minimize_command ({state, goal, subgoal, subgoal_count, factss, ...} : prover_problem) =
let
val thy = Proof.theory_of state
val ctxt = Proof.context_of state
fun weight_facts facts =
let val num_facts = length facts in
map (weight_smt_fact ctxt num_facts) (facts ~~ (0 upto num_facts - 1))
end
val weighted_factss = factss |> map (apsnd weight_facts)
val {outcome, used_facts = used_pairs, used_from, run_time} =
smt_filter_loop name params state goal subgoal weighted_factss
val used_facts = used_pairs |> map fst
val outcome = outcome |> Option.map failure_of_smt_failure
val (preplay, message, message_tail) =
(case outcome of
NONE =>
(Lazy.lazy (fn () =>
play_one_line_proof mode debug verbose preplay_timeout used_pairs state subgoal
SMT2_Method (bunch_of_proof_methods (smt_proofs <> SOME false) false liftingN)),
fn preplay =>
let
val one_line_params =
(preplay, proof_banner mode name, used_facts,
choose_minimize_command thy params minimize_command name preplay, subgoal,
subgoal_count)
val num_chained = length (#facts (Proof.goal state))
in
one_line_proof_text ctxt num_chained one_line_params
end,
if verbose then "\nSMT solver real CPU time: " ^ string_of_time run_time ^ "." else "")
| SOME failure =>
(Lazy.value (Metis_Method (NONE, NONE), Play_Failed),
fn _ => string_of_atp_failure failure, ""))
in
{outcome = outcome, used_facts = used_facts, used_from = used_from, run_time = run_time,
preplay = preplay, message = message, message_tail = message_tail}
end
end;