(* Title: HOL/Tools/Sledgehammer/sledgehammer_util.ML
Author: Jasmin Blanchette, TU Muenchen
General-purpose functions used by the Sledgehammer modules.
*)
signature SLEDGEHAMMER_UTIL =
sig
val plural_s : int -> string
val serial_commas : string -> string list -> string list
val simplify_spaces : string -> string
val parse_bool_option : bool -> string -> string -> bool option
val parse_time_option : string -> string -> Time.time option
val string_from_time : Time.time -> string
val nat_subscript : int -> string
val unyxml : string -> string
val maybe_quote : string -> string
val typ_of_dtyp :
Datatype_Aux.descr -> (Datatype_Aux.dtyp * typ) list -> Datatype_Aux.dtyp
-> typ
val varify_type : Proof.context -> typ -> typ
val instantiate_type : theory -> typ -> typ -> typ -> typ
val varify_and_instantiate_type : Proof.context -> typ -> typ -> typ -> typ
val monomorphic_term : Type.tyenv -> term -> term
val eta_expand : typ list -> term -> int -> term
val transform_elim_term : term -> term
val specialize_type : theory -> (string * typ) -> term -> term
val subgoal_count : Proof.state -> int
val strip_subgoal : thm -> int -> (string * typ) list * term list * term
val reserved_isar_keyword_table : unit -> unit Symtab.table
end;
structure Sledgehammer_Util : SLEDGEHAMMER_UTIL =
struct
fun plural_s n = if n = 1 then "" else "s"
fun serial_commas _ [] = ["??"]
| serial_commas _ [s] = [s]
| serial_commas conj [s1, s2] = [s1, conj, s2]
| serial_commas conj [s1, s2, s3] = [s1 ^ ",", s2 ^ ",", conj, s3]
| serial_commas conj (s :: ss) = s ^ "," :: serial_commas conj ss
val simplify_spaces = ATP_Proof.strip_spaces (K true)
fun parse_bool_option option name s =
(case s of
"smart" => if option then NONE else raise Option
| "false" => SOME false
| "true" => SOME true
| "" => SOME true
| _ => raise Option)
handle Option.Option =>
let val ss = map quote ((option ? cons "smart") ["true", "false"]) in
error ("Parameter " ^ quote name ^ " must be assigned " ^
space_implode " " (serial_commas "or" ss) ^ ".")
end
val has_junk =
exists (fn s => not (Symbol.is_digit s) andalso s <> ".") o raw_explode (* FIXME Symbol.explode (?) *)
fun parse_time_option _ "none" = NONE
| parse_time_option name s =
let val secs = if has_junk s then NONE else Real.fromString s in
if is_none secs orelse Real.<= (the secs, 0.0) then
error ("Parameter " ^ quote name ^ " must be assigned a positive \
\number of seconds (e.g., \"60\", \"0.5\") or \"none\".")
else
SOME (seconds (the secs))
end
fun string_from_time t =
string_of_real (0.01 * Real.fromInt (Time.toMilliseconds t div 10)) ^ " s"
val subscript = implode o map (prefix "\<^isub>") o raw_explode (* FIXME Symbol.explode (?) *)
fun nat_subscript n =
n |> string_of_int |> print_mode_active Symbol.xsymbolsN ? subscript
val unyxml = XML.content_of o YXML.parse_body
val is_long_identifier = forall Lexicon.is_identifier o space_explode "."
fun maybe_quote y =
let val s = unyxml y in
y |> ((not (is_long_identifier (perhaps (try (unprefix "'")) s)) andalso
not (is_long_identifier (perhaps (try (unprefix "?")) s))) orelse
Keyword.is_keyword s) ? quote
end
fun typ_of_dtyp _ typ_assoc (Datatype_Aux.DtTFree a) =
the (AList.lookup (op =) typ_assoc (Datatype_Aux.DtTFree a))
| typ_of_dtyp descr typ_assoc (Datatype_Aux.DtType (s, Us)) =
Type (s, map (typ_of_dtyp descr typ_assoc) Us)
| typ_of_dtyp descr typ_assoc (Datatype_Aux.DtRec i) =
let val (s, ds, _) = the (AList.lookup (op =) descr i) in
Type (s, map (typ_of_dtyp descr typ_assoc) ds)
end
fun varify_type ctxt T =
Variable.polymorphic_types ctxt [Const (@{const_name undefined}, T)]
|> snd |> the_single |> dest_Const |> snd
(* TODO: use "Term_Subst.instantiateT" instead? *)
fun instantiate_type thy T1 T1' T2 =
Same.commit (Envir.subst_type_same
(Sign.typ_match thy (T1, T1') Vartab.empty)) T2
handle Type.TYPE_MATCH => raise TYPE ("instantiate_type", [T1, T1'], [])
fun varify_and_instantiate_type ctxt T1 T1' T2 =
let val thy = Proof_Context.theory_of ctxt in
instantiate_type thy (varify_type ctxt T1) T1' (varify_type ctxt T2)
end
fun monomorphic_term subst t =
map_types (map_type_tvar (fn v =>
case Type.lookup subst v of
SOME typ => typ
| NONE => raise TERM ("monomorphic_term: uninstanitated schematic type \
\variable", [t]))) t
fun eta_expand _ t 0 = t
| eta_expand Ts (Abs (s, T, t')) n =
Abs (s, T, eta_expand (T :: Ts) t' (n - 1))
| eta_expand Ts t n =
fold_rev (fn T => fn t' => Abs ("x" ^ nat_subscript n, T, t'))
(List.take (binder_types (fastype_of1 (Ts, t)), n))
(list_comb (incr_boundvars n t, map Bound (n - 1 downto 0)))
(* Converts an elim-rule into an equivalent theorem that does not have the
predicate variable. Leaves other theorems unchanged. We simply instantiate
the conclusion variable to False. (Cf. "transform_elim_theorem" in
"Meson_Clausify".) *)
fun transform_elim_term t =
case Logic.strip_imp_concl t of
@{const Trueprop} $ Var (z, @{typ bool}) =>
subst_Vars [(z, @{const False})] t
| Var (z, @{typ prop}) => subst_Vars [(z, @{prop False})] t
| _ => t
fun specialize_type thy (s, T) t =
let
fun subst_for (Const (s', T')) =
if s = s' then
SOME (Sign.typ_match thy (T', T) Vartab.empty)
handle Type.TYPE_MATCH => NONE
else
NONE
| subst_for (t1 $ t2) =
(case subst_for t1 of SOME x => SOME x | NONE => subst_for t2)
| subst_for (Abs (_, _, t')) = subst_for t'
| subst_for _ = NONE
in
case subst_for t of
SOME subst => monomorphic_term subst t
| NONE => raise Type.TYPE_MATCH
end
val subgoal_count = Logic.count_prems o prop_of o #goal o Proof.goal
fun strip_subgoal goal i =
let
val (t, frees) = Logic.goal_params (prop_of goal) i
val hyp_ts = t |> Logic.strip_assums_hyp |> map (curry subst_bounds frees)
val concl_t = t |> Logic.strip_assums_concl |> curry subst_bounds frees
in (rev (map dest_Free frees), hyp_ts, concl_t) end
fun reserved_isar_keyword_table () =
union (op =) (Keyword.dest_keywords ()) (Keyword.dest_commands ())
|> map (rpair ()) |> Symtab.make
end;