(* Title: HOL/Tools/Sledgehammer/sledgehammer_filter.ML
Author: Jia Meng, Cambridge University Computer Laboratory and NICTA
Author: Jasmin Blanchette, TU Muenchen
Sledgehammer's relevance filter.
*)
signature SLEDGEHAMMER_FILTER =
sig
datatype locality = General | Intro | Elim | Simp | Local | Assum | Chained
type relevance_fudge =
{local_const_multiplier : real,
worse_irrel_freq : real,
higher_order_irrel_weight : real,
abs_rel_weight : real,
abs_irrel_weight : real,
skolem_irrel_weight : real,
theory_const_rel_weight : real,
theory_const_irrel_weight : real,
chained_const_irrel_weight : real,
intro_bonus : real,
elim_bonus : real,
simp_bonus : real,
local_bonus : real,
assum_bonus : real,
chained_bonus : real,
max_imperfect : real,
max_imperfect_exp : real,
threshold_divisor : real,
ridiculous_threshold : real}
type relevance_override =
{add : (Facts.ref * Attrib.src list) list,
del : (Facts.ref * Attrib.src list) list,
only : bool}
val trace : bool Config.T
val new_monomorphizer : bool Config.T
val ignore_no_atp : bool Config.T
val instantiate_inducts : bool Config.T
val is_locality_global : locality -> bool
val fact_from_ref :
Proof.context -> unit Symtab.table -> thm list
-> Facts.ref * Attrib.src list -> ((string * locality) * thm) list
val all_facts :
Proof.context -> 'a Symtab.table -> bool -> (term -> bool) -> thm list
-> thm list -> (((unit -> string) * locality) * (bool * thm)) list
val const_names_in_fact :
theory -> (string * typ -> term list -> bool * term list) -> term
-> string list
val relevant_facts :
Proof.context -> real * real -> int -> (term -> bool)
-> (string * typ -> term list -> bool * term list) -> relevance_fudge
-> relevance_override -> thm list -> term list -> term
-> ((string * locality) * thm) list
end;
structure Sledgehammer_Filter : SLEDGEHAMMER_FILTER =
struct
open Sledgehammer_Util
val trace =
Attrib.setup_config_bool @{binding sledgehammer_filter_trace} (K false)
fun trace_msg ctxt msg = if Config.get ctxt trace then tracing (msg ()) else ()
(* experimental features *)
val new_monomorphizer =
Attrib.setup_config_bool @{binding sledgehammer_new_monomorphizer} (K false)
val ignore_no_atp =
Attrib.setup_config_bool @{binding sledgehammer_ignore_no_atp} (K false)
val instantiate_inducts =
Attrib.setup_config_bool @{binding sledgehammer_instantiate_inducts} (K false)
datatype locality = General | Intro | Elim | Simp | Local | Assum | Chained
(* (quasi-)underapproximation of the truth *)
fun is_locality_global Local = false
| is_locality_global Assum = false
| is_locality_global Chained = false
| is_locality_global _ = true
type relevance_fudge =
{local_const_multiplier : real,
worse_irrel_freq : real,
higher_order_irrel_weight : real,
abs_rel_weight : real,
abs_irrel_weight : real,
skolem_irrel_weight : real,
theory_const_rel_weight : real,
theory_const_irrel_weight : real,
chained_const_irrel_weight : real,
intro_bonus : real,
elim_bonus : real,
simp_bonus : real,
local_bonus : real,
assum_bonus : real,
chained_bonus : real,
max_imperfect : real,
max_imperfect_exp : real,
threshold_divisor : real,
ridiculous_threshold : real}
type relevance_override =
{add : (Facts.ref * Attrib.src list) list,
del : (Facts.ref * Attrib.src list) list,
only : bool}
val sledgehammer_prefix = "Sledgehammer" ^ Long_Name.separator
val abs_name = sledgehammer_prefix ^ "abs"
val skolem_prefix = sledgehammer_prefix ^ "sko"
val theory_const_suffix = Long_Name.separator ^ " 1"
fun needs_quoting reserved s =
Symtab.defined reserved s orelse
exists (not o Lexicon.is_identifier) (Long_Name.explode s)
fun make_name reserved multi j name =
(name |> needs_quoting reserved name ? quote) ^
(if multi then "(" ^ string_of_int j ^ ")" else "")
fun explode_interval _ (Facts.FromTo (i, j)) = i upto j
| explode_interval max (Facts.From i) = i upto i + max - 1
| explode_interval _ (Facts.Single i) = [i]
val backquote =
raw_explode #> map (fn "`" => "\\`" | s => s) #> implode #> enclose "`" "`"
fun fact_from_ref ctxt reserved chained_ths (xthm as (xref, args)) =
let
val ths = Attrib.eval_thms ctxt [xthm]
val bracket =
map (enclose "[" "]" o Pretty.str_of o Args.pretty_src ctxt) args
|> implode
fun nth_name j =
case xref of
Facts.Fact s => backquote s ^ bracket
| Facts.Named (("", _), _) => "[" ^ bracket ^ "]"
| Facts.Named ((name, _), NONE) =>
make_name reserved (length ths > 1) (j + 1) name ^ bracket
| Facts.Named ((name, _), SOME intervals) =>
make_name reserved true
(nth (maps (explode_interval (length ths)) intervals) j) name ^
bracket
in
(ths, (0, []))
|-> fold (fn th => fn (j, rest) =>
(j + 1, ((nth_name j,
if member Thm.eq_thm chained_ths th then Chained
else General), th) :: rest))
|> snd
end
(* This is a terrible hack. Free variables are sometimes code as "M__" when they
are displayed as "M" and we want to avoid clashes with these. But sometimes
it's even worse: "Ma__" encodes "M". So we simply reserve all prefixes of all
free variables. In the worse case scenario, where the fact won't be resolved
correctly, the user can fix it manually, e.g., by naming the fact in
question. Ideally we would need nothing of it, but backticks just don't work
with schematic variables. *)
fun all_prefixes_of s =
map (fn i => String.extract (s, 0, SOME i)) (1 upto size s - 1)
fun close_form t =
(t, [] |> Term.add_free_names t |> maps all_prefixes_of)
|> fold (fn ((s, i), T) => fn (t', taken) =>
let val s' = Name.variant taken s in
((if fastype_of t' = HOLogic.boolT then HOLogic.all_const
else Term.all) T
$ Abs (s', T, abstract_over (Var ((s, i), T), t')),
s' :: taken)
end)
(Term.add_vars t [] |> sort_wrt (fst o fst))
|> fst
fun string_for_term ctxt t =
Print_Mode.setmp (filter (curry (op =) Symbol.xsymbolsN)
(print_mode_value ())) (Syntax.string_of_term ctxt) t
|> String.translate (fn c => if Char.isPrint c then str c else "")
|> simplify_spaces
(** Structural induction rules **)
fun struct_induct_rule_on th =
case Logic.strip_horn (prop_of th) of
(prems, @{const Trueprop}
$ ((p as Var ((p_name, 0), _)) $ (a as Var (_, ind_T)))) =>
if not (is_TVar ind_T) andalso length prems > 1 andalso
exists (exists_subterm (curry (op aconv) p)) prems andalso
not (exists (exists_subterm (curry (op aconv) a)) prems) then
SOME (p_name, ind_T)
else
NONE
| _ => NONE
fun instantiate_induct_rule ctxt concl_prop p_name ((name, loc), (multi, th))
ind_x =
let
fun varify_noninducts (t as Free (s, T)) =
if (s, T) = ind_x orelse can dest_funT T then t else Var ((s, 0), T)
| varify_noninducts t = t
val p_inst =
concl_prop |> map_aterms varify_noninducts |> close_form
|> lambda (Free ind_x)
|> string_for_term ctxt
in
((fn () => name () ^ "[where " ^ p_name ^ " = " ^ quote p_inst ^ "]", loc),
(multi, th |> read_instantiate ctxt [((p_name, 0), p_inst)]))
end
fun type_match thy (T1, T2) =
(Sign.typ_match thy (T2, T1) Vartab.empty; true)
handle Type.TYPE_MATCH => false
fun instantiate_if_induct_rule ctxt stmt stmt_xs (ax as (_, (_, th))) =
case struct_induct_rule_on th of
SOME (p_name, ind_T) =>
let val thy = Proof_Context.theory_of ctxt in
stmt_xs |> filter (fn (_, T) => type_match thy (T, ind_T))
|> map_filter (try (instantiate_induct_rule ctxt stmt p_name ax))
end
| NONE => [ax]
(***************************************************************)
(* Relevance Filtering *)
(***************************************************************)
(*** constants with types ***)
fun order_of_type (Type (@{type_name fun}, [T1, @{typ bool}])) =
order_of_type T1 (* cheat: pretend sets are first-order *)
| order_of_type (Type (@{type_name fun}, [T1, T2])) =
Int.max (order_of_type T1 + 1, order_of_type T2)
| order_of_type (Type (_, Ts)) = fold (Integer.max o order_of_type) Ts 0
| order_of_type _ = 0
(* An abstraction of Isabelle types and first-order terms *)
datatype pattern = PVar | PApp of string * pattern list
datatype ptype = PType of int * pattern list
fun string_for_pattern PVar = "_"
| string_for_pattern (PApp (s, ps)) =
if null ps then s else s ^ string_for_patterns ps
and string_for_patterns ps = "(" ^ commas (map string_for_pattern ps) ^ ")"
fun string_for_ptype (PType (_, ps)) = string_for_patterns ps
(*Is the second type an instance of the first one?*)
fun match_pattern (PVar, _) = true
| match_pattern (PApp _, PVar) = false
| match_pattern (PApp (s, ps), PApp (t, qs)) =
s = t andalso match_patterns (ps, qs)
and match_patterns (_, []) = true
| match_patterns ([], _) = false
| match_patterns (p :: ps, q :: qs) =
match_pattern (p, q) andalso match_patterns (ps, qs)
fun match_ptype (PType (_, ps), PType (_, qs)) = match_patterns (ps, qs)
(* Is there a unifiable constant? *)
fun pconst_mem f consts (s, ps) =
exists (curry (match_ptype o f) ps)
(map snd (filter (curry (op =) s o fst) consts))
fun pconst_hyper_mem f const_tab (s, ps) =
exists (curry (match_ptype o f) ps) (these (Symtab.lookup const_tab s))
fun pattern_for_type (Type (s, Ts)) = PApp (s, map pattern_for_type Ts)
| pattern_for_type (TFree (s, _)) = PApp (s, [])
| pattern_for_type (TVar _) = PVar
(* Pairs a constant with the list of its type instantiations. *)
fun ptype thy const x =
(if const then map pattern_for_type (these (try (Sign.const_typargs thy) x))
else [])
fun rich_ptype thy const (s, T) =
PType (order_of_type T, ptype thy const (s, T))
fun rich_pconst thy const (s, T) = (s, rich_ptype thy const (s, T))
fun string_for_hyper_pconst (s, ps) =
s ^ "{" ^ commas (map string_for_ptype ps) ^ "}"
(* Add a pconstant to the table, but a [] entry means a standard
connective, which we ignore.*)
fun add_pconst_to_table also_skolem (s, p) =
if (not also_skolem andalso String.isPrefix skolem_prefix s) then I
else Symtab.map_default (s, [p]) (insert (op =) p)
(* Set constants tend to pull in too many irrelevant facts. We limit the damage
by treating them more or less as if they were built-in but add their
definition at the end. *)
val set_consts =
[(@{const_name Collect}, @{thms Collect_def}),
(@{const_name Set.member}, @{thms mem_def})]
val is_set_const = AList.defined (op =) set_consts
fun add_pconsts_in_term thy is_built_in_const also_skolems pos =
let
val flip = Option.map not
(* We include free variables, as well as constants, to handle locales. For
each quantifiers that must necessarily be skolemized by the automatic
prover, we introduce a fresh constant to simulate the effect of
Skolemization. *)
fun do_const const ext_arg (x as (s, _)) ts =
let val (built_in, ts) = is_built_in_const x ts in
if is_set_const s then
fold (do_term ext_arg) ts
else
(not built_in
? add_pconst_to_table also_skolems (rich_pconst thy const x))
#> fold (do_term false) ts
end
and do_term ext_arg t =
case strip_comb t of
(Const x, ts) => do_const true ext_arg x ts
| (Free x, ts) => do_const false ext_arg x ts
| (Abs (_, T, t'), ts) =>
((null ts andalso not ext_arg)
(* Since lambdas on the right-hand side of equalities are usually
extensionalized later by "extensionalize_term", we don't penalize
them here. *)
? add_pconst_to_table true (abs_name, PType (order_of_type T + 1, [])))
#> fold (do_term false) (t' :: ts)
| (_, ts) => fold (do_term false) ts
fun do_quantifier will_surely_be_skolemized abs_T body_t =
do_formula pos body_t
#> (if also_skolems andalso will_surely_be_skolemized then
add_pconst_to_table true
(gensym skolem_prefix, PType (order_of_type abs_T, []))
else
I)
and do_term_or_formula ext_arg T =
if T = HOLogic.boolT then do_formula NONE else do_term ext_arg
and do_formula pos t =
case t of
Const (@{const_name all}, _) $ Abs (_, T, t') =>
do_quantifier (pos = SOME false) T t'
| @{const "==>"} $ t1 $ t2 =>
do_formula (flip pos) t1 #> do_formula pos t2
| Const (@{const_name "=="}, Type (_, [T, _])) $ t1 $ t2 =>
do_term_or_formula false T t1 #> do_term_or_formula true T t2
| @{const Trueprop} $ t1 => do_formula pos t1
| @{const False} => I
| @{const True} => I
| @{const Not} $ t1 => do_formula (flip pos) t1
| Const (@{const_name All}, _) $ Abs (_, T, t') =>
do_quantifier (pos = SOME false) T t'
| Const (@{const_name Ex}, _) $ Abs (_, T, t') =>
do_quantifier (pos = SOME true) T t'
| @{const HOL.conj} $ t1 $ t2 => fold (do_formula pos) [t1, t2]
| @{const HOL.disj} $ t1 $ t2 => fold (do_formula pos) [t1, t2]
| @{const HOL.implies} $ t1 $ t2 =>
do_formula (flip pos) t1 #> do_formula pos t2
| Const (@{const_name HOL.eq}, Type (_, [T, _])) $ t1 $ t2 =>
do_term_or_formula false T t1 #> do_term_or_formula true T t2
| Const (@{const_name If}, Type (_, [_, Type (_, [T, _])]))
$ t1 $ t2 $ t3 =>
do_formula NONE t1 #> fold (do_term_or_formula false T) [t2, t3]
| Const (@{const_name Ex1}, _) $ Abs (_, T, t') =>
do_quantifier (is_some pos) T t'
| Const (@{const_name Ball}, _) $ t1 $ Abs (_, T, t') =>
do_quantifier (pos = SOME false) T
(HOLogic.mk_imp (incr_boundvars 1 t1 $ Bound 0, t'))
| Const (@{const_name Bex}, _) $ t1 $ Abs (_, T, t') =>
do_quantifier (pos = SOME true) T
(HOLogic.mk_conj (incr_boundvars 1 t1 $ Bound 0, t'))
| (t0 as Const (_, @{typ bool})) $ t1 =>
do_term false t0 #> do_formula pos t1 (* theory constant *)
| _ => do_term false t
in do_formula pos end
(*Inserts a dummy "constant" referring to the theory name, so that relevance
takes the given theory into account.*)
fun theory_constify ({theory_const_rel_weight, theory_const_irrel_weight, ...}
: relevance_fudge) thy_name t =
if exists (curry (op <) 0.0) [theory_const_rel_weight,
theory_const_irrel_weight] then
Const (thy_name ^ theory_const_suffix, @{typ bool}) $ t
else
t
fun theory_const_prop_of fudge th =
theory_constify fudge (Context.theory_name (theory_of_thm th)) (prop_of th)
(**** Constant / Type Frequencies ****)
(* A two-dimensional symbol table counts frequencies of constants. It's keyed
first by constant name and second by its list of type instantiations. For the
latter, we need a linear ordering on "pattern list". *)
fun pattern_ord p =
case p of
(PVar, PVar) => EQUAL
| (PVar, PApp _) => LESS
| (PApp _, PVar) => GREATER
| (PApp q1, PApp q2) =>
prod_ord fast_string_ord (dict_ord pattern_ord) (q1, q2)
fun ptype_ord (PType p, PType q) =
prod_ord (dict_ord pattern_ord) int_ord (swap p, swap q)
structure PType_Tab = Table(type key = ptype val ord = ptype_ord)
fun count_fact_consts thy fudge =
let
fun do_const const (s, T) ts =
(* Two-dimensional table update. Constant maps to types maps to count. *)
PType_Tab.map_default (rich_ptype thy const (s, T), 0) (Integer.add 1)
|> Symtab.map_default (s, PType_Tab.empty)
#> fold do_term ts
and do_term t =
case strip_comb t of
(Const x, ts) => do_const true x ts
| (Free x, ts) => do_const false x ts
| (Abs (_, _, t'), ts) => fold do_term (t' :: ts)
| (_, ts) => fold do_term ts
in do_term o theory_const_prop_of fudge o snd end
(**** Actual Filtering Code ****)
fun pow_int _ 0 = 1.0
| pow_int x 1 = x
| pow_int x n = if n > 0 then x * pow_int x (n - 1) else pow_int x (n + 1) / x
(*The frequency of a constant is the sum of those of all instances of its type.*)
fun pconst_freq match const_tab (c, ps) =
PType_Tab.fold (fn (qs, m) => match (ps, qs) ? Integer.add m)
(the (Symtab.lookup const_tab c)) 0
(* A surprising number of theorems contain only a few significant constants.
These include all induction rules, and other general theorems. *)
(* "log" seems best in practice. A constant function of one ignores the constant
frequencies. Rare constants give more points if they are relevant than less
rare ones. *)
fun rel_weight_for _ freq = 1.0 + 2.0 / Math.ln (Real.fromInt freq + 1.0)
(* Irrelevant constants are treated differently. We associate lower penalties to
very rare constants and very common ones -- the former because they can't
lead to the inclusion of too many new facts, and the latter because they are
so common as to be of little interest. *)
fun irrel_weight_for ({worse_irrel_freq, higher_order_irrel_weight, ...}
: relevance_fudge) order freq =
let val (k, x) = worse_irrel_freq |> `Real.ceil in
(if freq < k then Math.ln (Real.fromInt (freq + 1)) / Math.ln x
else rel_weight_for order freq / rel_weight_for order k)
* pow_int higher_order_irrel_weight (order - 1)
end
fun multiplier_for_const_name local_const_multiplier s =
if String.isSubstring "." s then 1.0 else local_const_multiplier
(* Computes a constant's weight, as determined by its frequency. *)
fun generic_pconst_weight local_const_multiplier abs_weight skolem_weight
theory_const_weight chained_const_weight weight_for f
const_tab chained_const_tab (c as (s, PType (m, _))) =
if s = abs_name then
abs_weight
else if String.isPrefix skolem_prefix s then
skolem_weight
else if String.isSuffix theory_const_suffix s then
theory_const_weight
else
multiplier_for_const_name local_const_multiplier s
* weight_for m (pconst_freq (match_ptype o f) const_tab c)
|> (if chained_const_weight < 1.0 andalso
pconst_hyper_mem I chained_const_tab c then
curry (op *) chained_const_weight
else
I)
fun rel_pconst_weight ({local_const_multiplier, abs_rel_weight,
theory_const_rel_weight, ...} : relevance_fudge)
const_tab =
generic_pconst_weight local_const_multiplier abs_rel_weight 0.0
theory_const_rel_weight 0.0 rel_weight_for I const_tab
Symtab.empty
fun irrel_pconst_weight (fudge as {local_const_multiplier, abs_irrel_weight,
skolem_irrel_weight,
theory_const_irrel_weight,
chained_const_irrel_weight, ...})
const_tab chained_const_tab =
generic_pconst_weight local_const_multiplier abs_irrel_weight
skolem_irrel_weight theory_const_irrel_weight
chained_const_irrel_weight (irrel_weight_for fudge) swap
const_tab chained_const_tab
fun locality_bonus (_ : relevance_fudge) General = 0.0
| locality_bonus {intro_bonus, ...} Intro = intro_bonus
| locality_bonus {elim_bonus, ...} Elim = elim_bonus
| locality_bonus {simp_bonus, ...} Simp = simp_bonus
| locality_bonus {local_bonus, ...} Local = local_bonus
| locality_bonus {assum_bonus, ...} Assum = assum_bonus
| locality_bonus {chained_bonus, ...} Chained = chained_bonus
fun is_odd_const_name s =
s = abs_name orelse String.isPrefix skolem_prefix s orelse
String.isSuffix theory_const_suffix s
fun fact_weight fudge loc const_tab relevant_consts chained_consts fact_consts =
case fact_consts |> List.partition (pconst_hyper_mem I relevant_consts)
||> filter_out (pconst_hyper_mem swap relevant_consts) of
([], _) => 0.0
| (rel, irrel) =>
if forall (forall (is_odd_const_name o fst)) [rel, irrel] then
0.0
else
let
val irrel = irrel |> filter_out (pconst_mem swap rel)
val rel_weight =
0.0 |> fold (curry (op +) o rel_pconst_weight fudge const_tab) rel
val irrel_weight =
~ (locality_bonus fudge loc)
|> fold (curry (op +)
o irrel_pconst_weight fudge const_tab chained_consts) irrel
val res = rel_weight / (rel_weight + irrel_weight)
in if Real.isFinite res then res else 0.0 end
fun pconsts_in_fact thy is_built_in_const t =
Symtab.fold (fn (s, pss) => fold (cons o pair s) pss)
(Symtab.empty |> add_pconsts_in_term thy is_built_in_const true
(SOME true) t) []
fun pair_consts_fact thy is_built_in_const fudge fact =
case fact |> snd |> theory_const_prop_of fudge
|> pconsts_in_fact thy is_built_in_const of
[] => NONE
| consts => SOME ((fact, consts), NONE)
val const_names_in_fact = map fst ooo pconsts_in_fact
type annotated_thm =
(((unit -> string) * locality) * thm) * (string * ptype) list
fun take_most_relevant ctxt max_relevant remaining_max
({max_imperfect, max_imperfect_exp, ...} : relevance_fudge)
(candidates : (annotated_thm * real) list) =
let
val max_imperfect =
Real.ceil (Math.pow (max_imperfect,
Math.pow (Real.fromInt remaining_max
/ Real.fromInt max_relevant, max_imperfect_exp)))
val (perfect, imperfect) =
candidates |> sort (Real.compare o swap o pairself snd)
|> take_prefix (fn (_, w) => w > 0.99999)
val ((accepts, more_rejects), rejects) =
chop max_imperfect imperfect |>> append perfect |>> chop remaining_max
in
trace_msg ctxt (fn () =>
"Actually passed (" ^ string_of_int (length accepts) ^ " of " ^
string_of_int (length candidates) ^ "): " ^
(accepts |> map (fn ((((name, _), _), _), weight) =>
name () ^ " [" ^ Real.toString weight ^ "]")
|> commas));
(accepts, more_rejects @ rejects)
end
fun if_empty_replace_with_locality thy is_built_in_const facts loc tab =
if Symtab.is_empty tab then
Symtab.empty
|> fold (add_pconsts_in_term thy is_built_in_const false (SOME false))
(map_filter (fn ((_, loc'), th) =>
if loc' = loc then SOME (prop_of th) else NONE)
facts)
else
tab
fun consider_arities is_built_in_const th =
let
fun aux _ _ NONE = NONE
| aux t args (SOME tab) =
case t of
t1 $ t2 => SOME tab |> aux t1 (t2 :: args) |> aux t2 []
| Const (x as (s, _)) =>
(if is_built_in_const x args |> fst then
SOME tab
else case Symtab.lookup tab s of
NONE => SOME (Symtab.update (s, length args) tab)
| SOME n => if n = length args then SOME tab else NONE)
| _ => SOME tab
in aux (prop_of th) [] end
(* FIXME: This is currently only useful for polymorphic type systems. *)
fun could_benefit_from_ext is_built_in_const facts =
fold (consider_arities is_built_in_const o snd) facts (SOME Symtab.empty)
|> is_none
fun relevance_filter ctxt threshold0 decay max_relevant is_built_in_const
(fudge as {threshold_divisor, ridiculous_threshold, ...})
({add, del, ...} : relevance_override) facts chained_ts hyp_ts concl_t =
let
val thy = Proof_Context.theory_of ctxt
val const_tab = fold (count_fact_consts thy fudge) facts Symtab.empty
val add_pconsts = add_pconsts_in_term thy is_built_in_const false o SOME
val chained_const_tab = Symtab.empty |> fold (add_pconsts true) chained_ts
val goal_const_tab =
Symtab.empty |> fold (add_pconsts true) hyp_ts
|> add_pconsts false concl_t
|> (fn tab => if Symtab.is_empty tab then chained_const_tab else tab)
|> fold (if_empty_replace_with_locality thy is_built_in_const facts)
[Chained, Assum, Local]
val add_ths = Attrib.eval_thms ctxt add
val del_ths = Attrib.eval_thms ctxt del
val facts = facts |> filter_out (member Thm.eq_thm del_ths o snd)
fun iter j remaining_max threshold rel_const_tab hopeless hopeful =
let
fun relevant [] _ [] =
(* Nothing has been added this iteration. *)
if j = 0 andalso threshold >= ridiculous_threshold then
(* First iteration? Try again. *)
iter 0 max_relevant (threshold / threshold_divisor) rel_const_tab
hopeless hopeful
else
[]
| relevant candidates rejects [] =
let
val (accepts, more_rejects) =
take_most_relevant ctxt max_relevant remaining_max fudge
candidates
val rel_const_tab' =
rel_const_tab
|> fold (add_pconst_to_table false) (maps (snd o fst) accepts)
fun is_dirty (c, _) =
Symtab.lookup rel_const_tab' c <> Symtab.lookup rel_const_tab c
val (hopeful_rejects, hopeless_rejects) =
(rejects @ hopeless, ([], []))
|-> fold (fn (ax as (_, consts), old_weight) =>
if exists is_dirty consts then
apfst (cons (ax, NONE))
else
apsnd (cons (ax, old_weight)))
|>> append (more_rejects
|> map (fn (ax as (_, consts), old_weight) =>
(ax, if exists is_dirty consts then NONE
else SOME old_weight)))
val threshold =
1.0 - (1.0 - threshold)
* Math.pow (decay, Real.fromInt (length accepts))
val remaining_max = remaining_max - length accepts
in
trace_msg ctxt (fn () => "New or updated constants: " ^
commas (rel_const_tab' |> Symtab.dest
|> subtract (op =) (rel_const_tab |> Symtab.dest)
|> map string_for_hyper_pconst));
map (fst o fst) accepts @
(if remaining_max = 0 then
[]
else
iter (j + 1) remaining_max threshold rel_const_tab'
hopeless_rejects hopeful_rejects)
end
| relevant candidates rejects
(((ax as (((_, loc), _), fact_consts)), cached_weight)
:: hopeful) =
let
val weight =
case cached_weight of
SOME w => w
| NONE => fact_weight fudge loc const_tab rel_const_tab
chained_const_tab fact_consts
in
if weight >= threshold then
relevant ((ax, weight) :: candidates) rejects hopeful
else
relevant candidates ((ax, weight) :: rejects) hopeful
end
in
trace_msg ctxt (fn () =>
"ITERATION " ^ string_of_int j ^ ": current threshold: " ^
Real.toString threshold ^ ", constants: " ^
commas (rel_const_tab |> Symtab.dest
|> filter (curry (op <>) [] o snd)
|> map string_for_hyper_pconst));
relevant [] [] hopeful
end
fun prepend_facts ths accepts =
((facts |> filter (member Thm.eq_thm ths o snd)) @
(accepts |> filter_out (member Thm.eq_thm ths o snd)))
|> take max_relevant
fun append_facts ths accepts =
let val add = facts |> filter (member Thm.eq_thm ths o snd) in
(accepts |> filter_out (member Thm.eq_thm ths o snd)
|> take (max_relevant - length add)) @
add
end
fun uses_const s t =
fold_aterms (curry (fn (Const (s', _), false) => s' = s | (_, b) => b)) t
false
fun maybe_add_set_const (s, ths) accepts =
accepts |> (if exists (uses_const s o prop_of o snd) accepts orelse
exists (uses_const s) (concl_t :: hyp_ts) then
append_facts ths
else
I)
in
facts |> map_filter (pair_consts_fact thy is_built_in_const fudge)
|> iter 0 max_relevant threshold0 goal_const_tab []
|> not (null add_ths) ? prepend_facts add_ths
|> (fn accepts =>
accepts |> could_benefit_from_ext is_built_in_const accepts
? append_facts @{thms ext}
|> fold maybe_add_set_const set_consts)
|> tap (fn accepts => trace_msg ctxt (fn () =>
"Total relevant: " ^ string_of_int (length accepts)))
end
(***************************************************************)
(* Retrieving and filtering lemmas *)
(***************************************************************)
(*** retrieve lemmas and filter them ***)
(*Reject theorems with names like "List.filter.filter_list_def" or
"Accessible_Part.acc.defs", as these are definitions arising from packages.*)
fun is_package_def a =
let val names = Long_Name.explode a in
(length names > 2 andalso not (hd names = "local") andalso
String.isSuffix "_def" a) orelse String.isSuffix "_defs" a
end
fun mk_fact_table g f xs =
fold (Termtab.update o `(g o prop_of o f)) xs Termtab.empty
fun uniquify xs = Termtab.fold (cons o snd) (mk_fact_table I snd xs) []
(* FIXME: put other record thms here, or declare as "no_atp" *)
fun multi_base_blacklist ctxt =
["defs", "select_defs", "update_defs", "split", "splits", "split_asm",
"cases", "ext_cases", "eq.simps", "eq.refl", "nchotomy", "case_cong",
"weak_case_cong"]
|> not (Config.get ctxt instantiate_inducts) ? append ["induct", "inducts"]
|> map (prefix ".")
val max_lambda_nesting = 3
fun term_has_too_many_lambdas max (t1 $ t2) =
exists (term_has_too_many_lambdas max) [t1, t2]
| term_has_too_many_lambdas max (Abs (_, _, t)) =
max = 0 orelse term_has_too_many_lambdas (max - 1) t
| term_has_too_many_lambdas _ _ = false
(* Don't count nested lambdas at the level of formulas, since they are
quantifiers. *)
fun formula_has_too_many_lambdas Ts (Abs (_, T, t)) =
formula_has_too_many_lambdas (T :: Ts) t
| formula_has_too_many_lambdas Ts t =
if member (op =) [HOLogic.boolT, propT] (fastype_of1 (Ts, t)) then
exists (formula_has_too_many_lambdas Ts) (#2 (strip_comb t))
else
term_has_too_many_lambdas max_lambda_nesting t
(* The max apply depth of any "metis" call in "Metis_Examples" (on 2007-10-31)
was 11. *)
val max_apply_depth = 15
fun apply_depth (f $ t) = Int.max (apply_depth f, apply_depth t + 1)
| apply_depth (Abs (_, _, t)) = apply_depth t
| apply_depth _ = 0
fun is_formula_too_complex t =
apply_depth t > max_apply_depth orelse formula_has_too_many_lambdas [] t
(* FIXME: Extend to "Meson" and "Metis" *)
val exists_sledgehammer_const =
exists_Const (fn (s, _) => String.isPrefix sledgehammer_prefix s)
(* FIXME: make more reliable *)
val exists_low_level_class_const =
exists_Const (fn (s, _) =>
String.isSubstring (Long_Name.separator ^ "class" ^ Long_Name.separator) s)
fun is_metastrange_theorem th =
case head_of (concl_of th) of
Const (a, _) => (a <> @{const_name Trueprop} andalso
a <> @{const_name "=="})
| _ => false
fun is_that_fact th =
String.isSuffix (Long_Name.separator ^ Obtain.thatN) (Thm.get_name_hint th)
andalso exists_subterm (fn Free (s, _) => s = Name.skolem Auto_Bind.thesisN
| _ => false) (prop_of th)
val type_has_top_sort =
exists_subtype (fn TFree (_, []) => true | TVar (_, []) => true | _ => false)
(**** Predicates to detect unwanted facts (prolific or likely to cause
unsoundness) ****)
fun is_theorem_bad_for_atps is_appropriate_prop thm =
let val t = prop_of thm in
not (is_appropriate_prop t) orelse is_formula_too_complex t orelse
exists_type type_has_top_sort t orelse exists_sledgehammer_const t orelse
exists_low_level_class_const t orelse is_metastrange_theorem thm orelse
is_that_fact thm
end
fun meta_equify (@{const Trueprop}
$ (Const (@{const_name HOL.eq}, Type (_, [T, _])) $ t1 $ t2)) =
Const (@{const_name "=="}, T --> T --> @{typ prop}) $ t1 $ t2
| meta_equify t = t
val normalize_simp_prop =
meta_equify
#> map_aterms (fn Var ((s, _), T) => Var ((s, 0), T) | t => t)
#> map_types (map_type_tvar (fn ((s, _), S) => TVar ((s, 0), S)))
fun clasimpset_rules_of ctxt =
let
val {safeIs, safeEs, hazIs, hazEs, ...} = ctxt |> claset_of |> Classical.rep_cs
val intros = Item_Net.content safeIs @ Item_Net.content hazIs
val elims = map Classical.classical_rule (Item_Net.content safeEs @ Item_Net.content hazEs)
val simps = ctxt |> simpset_of |> dest_ss |> #simps
in
(mk_fact_table I I intros,
mk_fact_table I I elims,
mk_fact_table normalize_simp_prop snd simps)
end
fun all_facts ctxt reserved really_all is_appropriate_prop add_ths chained_ths =
let
val thy = Proof_Context.theory_of ctxt
val global_facts = Global_Theory.facts_of thy
val local_facts = Proof_Context.facts_of ctxt
val named_locals = local_facts |> Facts.dest_static []
val assms = Assumption.all_assms_of ctxt
fun is_assum th = exists (fn ct => prop_of th aconv term_of ct) assms
val is_chained = member Thm.eq_thm chained_ths
val (intros, elims, simps) = clasimpset_rules_of ctxt
fun locality_of_theorem global th =
if is_chained th then
Chained
else if global then
let val t = prop_of th in
if Termtab.defined intros t then Intro
else if Termtab.defined elims t then Elim
else if Termtab.defined simps (normalize_simp_prop t) then Simp
else General
end
else
if is_assum th then Assum else Local
fun is_good_unnamed_local th =
not (Thm.has_name_hint th) andalso
forall (fn (_, ths) => not (member Thm.eq_thm ths th)) named_locals
val unnamed_locals =
union Thm.eq_thm (Facts.props local_facts) chained_ths
|> filter is_good_unnamed_local |> map (pair "" o single)
val full_space =
Name_Space.merge (Facts.space_of global_facts, Facts.space_of local_facts)
fun add_facts global foldx facts =
foldx (fn (name0, ths) =>
if not really_all andalso name0 <> "" andalso
forall (not o member Thm.eq_thm add_ths) ths andalso
(Facts.is_concealed facts name0 orelse
(not (Config.get ctxt ignore_no_atp) andalso
is_package_def name0) orelse
exists (fn s => String.isSuffix s name0)
(multi_base_blacklist ctxt) orelse
String.isSuffix "_def_raw" (* FIXME: crude hack *) name0) then
I
else
let
val multi = length ths > 1
val backquote_thm =
backquote o string_for_term ctxt o close_form o prop_of
fun check_thms a =
case try (Proof_Context.get_thms ctxt) a of
NONE => false
| SOME ths' => Thm.eq_thms (ths, ths')
in
pair 1
#> fold (fn th => fn (j, rest) =>
(j + 1,
if not (member Thm.eq_thm add_ths th) andalso
is_theorem_bad_for_atps is_appropriate_prop th then
rest
else
(((fn () =>
if name0 = "" then
th |> backquote_thm
else
[Facts.extern ctxt facts name0,
Name_Space.extern ctxt full_space name0,
name0]
|> find_first check_thms
|> (fn SOME name =>
make_name reserved multi j name
| NONE => "")),
locality_of_theorem global th),
(multi, th)) :: rest)) ths
#> snd
end)
in
[] |> add_facts false fold local_facts (unnamed_locals @ named_locals)
|> add_facts true Facts.fold_static global_facts global_facts
end
(* The single-name theorems go after the multiple-name ones, so that single
names are preferred when both are available. *)
fun rearrange_facts ctxt only =
List.partition (fst o snd) #> op @ #> map (apsnd snd)
#> (not (Config.get ctxt ignore_no_atp) andalso not only)
? filter_out (No_ATPs.member ctxt o snd)
fun external_frees t =
[] |> Term.add_frees t |> filter_out (can Name.dest_internal o fst)
fun relevant_facts ctxt (threshold0, threshold1) max_relevant
is_appropriate_prop is_built_in_const fudge
(override as {add, only, ...}) chained_ths hyp_ts concl_t =
let
val thy = Proof_Context.theory_of ctxt
val decay = Math.pow ((1.0 - threshold1) / (1.0 - threshold0),
1.0 / Real.fromInt (max_relevant + 1))
val add_ths = Attrib.eval_thms ctxt add
val reserved = reserved_isar_keyword_table ()
val ind_stmt =
Logic.list_implies (hyp_ts |> filter_out (null o external_frees), concl_t)
|> Object_Logic.atomize_term thy
val ind_stmt_xs = external_frees ind_stmt
val facts =
(if only then
maps (map (fn ((name, loc), th) => ((K name, loc), (true, th)))
o fact_from_ref ctxt reserved chained_ths) add
else
all_facts ctxt reserved false is_appropriate_prop add_ths chained_ths)
|> Config.get ctxt instantiate_inducts
? maps (instantiate_if_induct_rule ctxt ind_stmt ind_stmt_xs)
|> rearrange_facts ctxt only
|> uniquify
in
trace_msg ctxt (fn () => "Considering " ^ string_of_int (length facts) ^
" facts");
(if only orelse threshold1 < 0.0 then
facts
else if threshold0 > 1.0 orelse threshold0 > threshold1 orelse
max_relevant = 0 then
[]
else
relevance_filter ctxt threshold0 decay max_relevant is_built_in_const
fudge override facts (chained_ths |> map prop_of) hyp_ts
(concl_t |> theory_constify fudge (Context.theory_name thy)))
|> map (apfst (apfst (fn f => f ())))
end
end;