(* Title: Pure/variable.ML
Author: Makarius
Fixed type/term variables and polymorphic term abbreviations.
*)
signature VARIABLE =
sig
val names_of: Proof.context -> Name.context
val binds_of: Proof.context -> (typ * term) Vartab.table
val maxidx_of: Proof.context -> int
val constraints_of: Proof.context -> typ Vartab.table * sort Vartab.table
val is_declared: Proof.context -> string -> bool
val check_name: binding -> string
val default_type: Proof.context -> string -> typ option
val def_type: Proof.context -> bool -> indexname -> typ option
val def_sort: Proof.context -> indexname -> sort option
val declare_maxidx: int -> Proof.context -> Proof.context
val declare_names: term -> Proof.context -> Proof.context
val declare_constraints: term -> Proof.context -> Proof.context
val declare_internal: term -> Proof.context -> Proof.context
val declare_term: term -> Proof.context -> Proof.context
val declare_typ: typ -> Proof.context -> Proof.context
val declare_prf: Proofterm.proof -> Proof.context -> Proof.context
val declare_thm: thm -> Proof.context -> Proof.context
val variant_frees: Proof.context -> term list -> (string * 'a) list -> (string * 'a) list
val bind_term: indexname * term -> Proof.context -> Proof.context
val unbind_term: indexname -> Proof.context -> Proof.context
val maybe_bind_term: indexname * term option -> Proof.context -> Proof.context
val expand_binds: Proof.context -> term -> term
val lookup_const: Proof.context -> string -> string option
val is_const: Proof.context -> string -> bool
val declare_const: string * string -> Proof.context -> Proof.context
val next_bound: string * typ -> Proof.context -> term * Proof.context
val revert_bounds: Proof.context -> term -> term
val is_body: Proof.context -> bool
val set_body: bool -> Proof.context -> Proof.context
val restore_body: Proof.context -> Proof.context -> Proof.context
val improper_fixes: Proof.context -> Proof.context
val restore_proper_fixes: Proof.context -> Proof.context -> Proof.context
val is_improper: Proof.context -> string -> bool
val is_fixed: Proof.context -> string -> bool
val is_newly_fixed: Proof.context -> Proof.context -> string -> bool
val fixed_ord: Proof.context -> string * string -> order
val intern_fixed: Proof.context -> string -> string
val lookup_fixed: Proof.context -> string -> string option
val revert_fixed: Proof.context -> string -> string
val markup_fixed: Proof.context -> string -> Markup.T
val markup: Proof.context -> string -> Markup.T
val markup_entity_def: Proof.context -> string -> Markup.T
val dest_fixes: Proof.context -> (string * string) list
val add_fixed_names: Proof.context -> term -> string list -> string list
val add_fixed: Proof.context -> term -> (string * typ) list -> (string * typ) list
val add_newly_fixed: Proof.context -> Proof.context ->
term -> (string * typ) list -> (string * typ) list
val add_free_names: Proof.context -> term -> string list -> string list
val add_frees: Proof.context -> term -> (string * typ) list -> (string * typ) list
val add_fixes_binding: binding list -> Proof.context -> string list * Proof.context
val add_fixes: string list -> Proof.context -> string list * Proof.context
val add_fixes_direct: string list -> Proof.context -> Proof.context
val fix_dummy_patterns: term -> Proof.context -> term * Proof.context
val variant_fixes: string list -> Proof.context -> string list * Proof.context
val gen_all: Proof.context -> thm -> thm
val export_terms: Proof.context -> Proof.context -> term list -> term list
val exportT_terms: Proof.context -> Proof.context -> term list -> term list
val exportT: Proof.context -> Proof.context -> thm list -> thm list
val export_prf: Proof.context -> Proof.context -> Proofterm.proof -> Proofterm.proof
val export: Proof.context -> Proof.context -> thm list -> thm list
val export_morphism: Proof.context -> Proof.context -> morphism
val invent_types: sort list -> Proof.context -> (string * sort) list * Proof.context
val importT_inst: term list -> Proof.context -> ((indexname * sort) * typ) list * Proof.context
val import_inst: bool -> term list -> Proof.context ->
(((indexname * sort) * typ) list * ((indexname * typ) * term) list) * Proof.context
val importT_terms: term list -> Proof.context -> term list * Proof.context
val import_terms: bool -> term list -> Proof.context -> term list * Proof.context
val importT: thm list -> Proof.context ->
(((indexname * sort) * ctyp) list * thm list) * Proof.context
val import_prf: bool -> Proofterm.proof -> Proof.context -> Proofterm.proof * Proof.context
val import: bool -> thm list -> Proof.context ->
((((indexname * sort) * ctyp) list * ((indexname * typ) * cterm) list) * thm list) * Proof.context
val import_vars: Proof.context -> thm -> thm
val tradeT: (Proof.context -> thm list -> thm list) -> Proof.context -> thm list -> thm list
val trade: (Proof.context -> thm list -> thm list) -> Proof.context -> thm list -> thm list
val is_bound_focus: Proof.context -> bool
val set_bound_focus: bool -> Proof.context -> Proof.context
val restore_bound_focus: Proof.context -> Proof.context -> Proof.context
val focus_params: binding list option -> term -> Proof.context ->
(string list * (string * typ) list) * Proof.context
val focus: binding list option -> term -> Proof.context ->
((string * (string * typ)) list * term) * Proof.context
val focus_cterm: binding list option -> cterm -> Proof.context ->
((string * cterm) list * cterm) * Proof.context
val focus_subgoal: binding list option -> int -> thm -> Proof.context ->
((string * cterm) list * cterm) * Proof.context
val warn_extra_tfrees: Proof.context -> Proof.context -> unit
val polymorphic_types: Proof.context -> term list -> (indexname * sort) list * term list
val polymorphic: Proof.context -> term list -> term list
end;
structure Variable: VARIABLE =
struct
(** local context data **)
type fixes = (string * bool) Name_Space.table;
val empty_fixes: fixes = Name_Space.empty_table Markup.fixedN;
datatype data = Data of
{names: Name.context, (*type/term variable names*)
consts: string Symtab.table, (*consts within the local scope*)
bounds: int * ((string * typ) * string) list, (*next index, internal name, type, external name*)
fixes: fixes, (*term fixes -- global name space, intern ~> extern*)
binds: (typ * term) Vartab.table, (*term bindings*)
type_occs: string list Symtab.table, (*type variables -- possibly within term variables*)
maxidx: int, (*maximum var index*)
constraints:
typ Vartab.table * (*type constraints*)
sort Vartab.table}; (*default sorts*)
fun make_data (names, consts, bounds, fixes, binds, type_occs, maxidx, constraints) =
Data {names = names, consts = consts, bounds = bounds, fixes = fixes, binds = binds,
type_occs = type_occs, maxidx = maxidx, constraints = constraints};
val empty_data =
make_data (Name.context, Symtab.empty, (0, []), empty_fixes, Vartab.empty,
Symtab.empty, ~1, (Vartab.empty, Vartab.empty));
structure Data = Proof_Data
(
type T = data;
fun init _ = empty_data;
);
fun map_data f =
Data.map (fn Data {names, consts, bounds, fixes, binds, type_occs, maxidx, constraints} =>
make_data (f (names, consts, bounds, fixes, binds, type_occs, maxidx, constraints)));
fun map_names f =
map_data (fn (names, consts, bounds, fixes, binds, type_occs, maxidx, constraints) =>
(f names, consts, bounds, fixes, binds, type_occs, maxidx, constraints));
fun map_consts f =
map_data (fn (names, consts, bounds, fixes, binds, type_occs, maxidx, constraints) =>
(names, f consts, bounds, fixes, binds, type_occs, maxidx, constraints));
fun map_bounds f =
map_data (fn (names, consts, bounds, fixes, binds, type_occs, maxidx, constraints) =>
(names, consts, f bounds, fixes, binds, type_occs, maxidx, constraints));
fun map_fixes f =
map_data (fn (names, consts, bounds, fixes, binds, type_occs, maxidx, constraints) =>
(names, consts, bounds, f fixes, binds, type_occs, maxidx, constraints));
fun map_binds f =
map_data (fn (names, consts, bounds, fixes, binds, type_occs, maxidx, constraints) =>
(names, consts, bounds, fixes, f binds, type_occs, maxidx, constraints));
fun map_type_occs f =
map_data (fn (names, consts, bounds, fixes, binds, type_occs, maxidx, constraints) =>
(names, consts, bounds, fixes, binds, f type_occs, maxidx, constraints));
fun map_maxidx f =
map_data (fn (names, consts, bounds, fixes, binds, type_occs, maxidx, constraints) =>
(names, consts, bounds, fixes, binds, type_occs, f maxidx, constraints));
fun map_constraints f =
map_data (fn (names, consts, bounds, fixes, binds, type_occs, maxidx, constraints) =>
(names, consts, bounds, fixes, binds, type_occs, maxidx, f constraints));
fun rep_data ctxt = Data.get ctxt |> (fn Data rep => rep);
val names_of = #names o rep_data;
val fixes_of = #fixes o rep_data;
val fixes_space = Name_Space.space_of_table o fixes_of;
val binds_of = #binds o rep_data;
val type_occs_of = #type_occs o rep_data;
val maxidx_of = #maxidx o rep_data;
val constraints_of = #constraints o rep_data;
val is_declared = Name.is_declared o names_of;
val check_name = Name_Space.base_name o tap Binding.check;
(** declarations **)
(* default sorts and types *)
fun default_type ctxt x = Vartab.lookup (#1 (constraints_of ctxt)) (x, ~1);
fun def_type ctxt pattern xi =
let val {binds, constraints = (types, _), ...} = rep_data ctxt in
(case Vartab.lookup types xi of
NONE =>
if pattern then NONE
else Vartab.lookup binds xi |> Option.map (Type.mark_polymorphic o #1)
| some => some)
end;
val def_sort = Vartab.lookup o #2 o constraints_of;
(* maxidx *)
val declare_maxidx = map_maxidx o Integer.max;
(* names *)
fun declare_type_names t =
map_names (fold_types (fold_atyps Term.declare_typ_names) t) #>
map_maxidx (fold_types Term.maxidx_typ t);
fun declare_names t =
declare_type_names t #>
map_names (fold_aterms Term.declare_term_frees t) #>
map_maxidx (Term.maxidx_term t);
(* type occurrences *)
fun decl_type_occsT T = fold_atyps (fn TFree (a, _) => Symtab.default (a, []) | _ => I) T;
val decl_type_occs = fold_term_types
(fn Free (x, _) => fold_atyps (fn TFree (a, _) => Symtab.insert_list (op =) (a, x) | _ => I)
| _ => decl_type_occsT);
val declare_type_occsT = map_type_occs o fold_types decl_type_occsT;
val declare_type_occs = map_type_occs o decl_type_occs;
(* constraints *)
fun constrain_tvar (xi, raw_S) =
let val S = #2 (Term_Position.decode_positionS raw_S)
in if S = dummyS then Vartab.delete_safe xi else Vartab.update (xi, S) end;
fun declare_constraints t = map_constraints (fn (types, sorts) =>
let
val types' = fold_aterms
(fn Free (x, T) => Vartab.update ((x, ~1), T)
| Var v => Vartab.update v
| _ => I) t types;
val sorts' = (fold_types o fold_atyps)
(fn TFree (x, S) => constrain_tvar ((x, ~1), S)
| TVar v => constrain_tvar v
| _ => I) t sorts;
in (types', sorts') end)
#> declare_type_occsT t
#> declare_type_names t;
(* common declarations *)
fun declare_internal t =
declare_names t #>
declare_type_occs t #>
Thm.declare_term_sorts t;
fun declare_term t =
declare_internal t #>
declare_constraints t;
val declare_typ = declare_term o Logic.mk_type;
val declare_prf = Proofterm.fold_proof_terms declare_internal (declare_internal o Logic.mk_type);
val declare_thm = Thm.fold_terms declare_internal;
(* renaming term/type frees *)
fun variant_frees ctxt ts frees =
let
val names = names_of (fold declare_names ts ctxt);
val xs = fst (fold_map Name.variant (map #1 frees) names);
in xs ~~ map snd frees end;
(** term bindings **)
fun bind_term ((x, i), t) =
let
val u = Term.close_schematic_term t;
val U = Term.fastype_of u;
in declare_term u #> map_binds (Vartab.update ((x, i), (U, u))) end;
val unbind_term = map_binds o Vartab.delete_safe;
fun maybe_bind_term (xi, SOME t) = bind_term (xi, t)
| maybe_bind_term (xi, NONE) = unbind_term xi;
fun expand_binds ctxt =
let
val binds = binds_of ctxt;
val get = fn Var (xi, _) => Vartab.lookup binds xi | _ => NONE;
in Envir.beta_norm o Envir.expand_term get end;
(** consts **)
val lookup_const = Symtab.lookup o #consts o rep_data;
val is_const = is_some oo lookup_const;
val declare_fixed = map_consts o Symtab.delete_safe;
val declare_const = map_consts o Symtab.update;
(** bounds **)
fun next_bound (a, T) ctxt =
let
val b = Name.bound (#1 (#bounds (rep_data ctxt)));
val ctxt' = ctxt |> map_bounds (fn (next, bounds) => (next + 1, ((b, T), a) :: bounds));
in (Free (b, T), ctxt') end;
fun revert_bounds ctxt t =
(case #2 (#bounds (rep_data ctxt)) of
[] => t
| bounds =>
let
val names = Term.declare_term_names t (names_of ctxt);
val xs = rev (#1 (fold_map Name.variant (rev (map #2 bounds)) names));
fun subst ((b, T), _) x' = (Free (b, T), Syntax_Trans.mark_bound_abs (x', T));
in Term.subst_atomic (map2 subst bounds xs) t end);
(** fixes **)
(* inner body mode *)
val inner_body = Config.declare_bool ("inner_body", \<^here>) (K false);
val is_body = Config.apply inner_body;
val set_body = Config.put inner_body;
val restore_body = set_body o is_body;
(* proper mode *)
val proper_fixes = Config.declare_bool ("proper_fixes", \<^here>) (K true);
val improper_fixes = Config.put proper_fixes false;
val restore_proper_fixes = Config.put proper_fixes o Config.apply proper_fixes;
fun is_improper ctxt x =
(case Name_Space.lookup (fixes_of ctxt) x of
SOME (_, proper) => not proper
| NONE => false);
(* specialized name space *)
val is_fixed = Name_Space.defined o fixes_of;
fun is_newly_fixed inner outer = is_fixed inner andf (not o is_fixed outer);
val fixed_ord = Name_Space.entry_ord o fixes_space;
val intern_fixed = Name_Space.intern o fixes_space;
fun lookup_fixed ctxt x =
let val x' = intern_fixed ctxt x
in if is_fixed ctxt x' then SOME x' else NONE end;
fun revert_fixed ctxt x =
(case Name_Space.lookup (fixes_of ctxt) x of
SOME (x', _) => if intern_fixed ctxt x' = x then x' else x
| NONE => x);
fun markup_fixed ctxt x =
Name_Space.markup (fixes_space ctxt) x
|> Markup.name (revert_fixed ctxt x);
fun markup ctxt x =
if is_improper ctxt x then Markup.improper
else if Name.is_skolem x then Markup.skolem
else Markup.free;
val markup_entity_def = Name_Space.markup_def o fixes_space;
fun dest_fixes ctxt =
Name_Space.fold_table (fn (x, (y, _)) => cons (y, x)) (fixes_of ctxt) []
|> sort (Name_Space.entry_ord (fixes_space ctxt) o apply2 #2);
(* collect variables *)
fun add_free_names ctxt =
fold_aterms (fn Free (x, _) => not (is_fixed ctxt x) ? insert (op =) x | _ => I);
fun add_frees ctxt =
fold_aterms (fn Free (x, T) => not (is_fixed ctxt x) ? insert (op =) (x, T) | _ => I);
fun add_fixed_names ctxt =
fold_aterms (fn Free (x, _) => is_fixed ctxt x ? insert (op =) x | _ => I);
fun add_fixed ctxt =
fold_aterms (fn Free (x, T) => is_fixed ctxt x ? insert (op =) (x, T) | _ => I);
fun add_newly_fixed ctxt' ctxt =
fold_aterms (fn Free (x, T) => is_newly_fixed ctxt' ctxt x ? insert (op =) (x, T) | _ => I);
(* declarations *)
local
fun err_dups dups =
error ("Duplicate fixed variable(s): " ^ commas (map Binding.print dups));
fun new_fixed ((x, x'), pos) ctxt =
if is_some (lookup_fixed ctxt x') then err_dups [Binding.make (x, pos)]
else
let
val proper = Config.get ctxt proper_fixes;
val context = Context.Proof ctxt
|> Name_Space.map_naming (K Name_Space.global_naming)
|> Context_Position.set_visible_generic false;
in
ctxt
|> map_fixes
(Name_Space.define context true (Binding.make (x', pos), (x, proper)) #> snd #>
Name_Space.alias_table Name_Space.global_naming (Binding.make (x, pos)) x')
|> declare_fixed x
|> declare_constraints (Syntax.free x')
end;
fun new_fixes names' xs xs' ps =
map_names (K names') #>
fold new_fixed ((xs ~~ xs') ~~ ps) #>
pair xs';
in
fun add_fixes_binding bs ctxt =
let
val _ =
(case filter (Name.is_skolem o Binding.name_of) bs of
[] => ()
| bads => error ("Illegal internal Skolem constant(s): " ^ commas (map Binding.print bads)));
val _ =
(case duplicates (op = o apply2 Binding.name_of) bs of
[] => ()
| dups => err_dups dups);
val xs = map check_name bs;
val names = names_of ctxt;
val (xs', names') =
if is_body ctxt then fold_map Name.variant xs names |>> map Name.skolem
else (xs, fold Name.declare xs names);
in ctxt |> new_fixes names' xs xs' (map Binding.pos_of bs) end;
fun bound_fixes xs ctxt =
let
val (xs', ctxt') = fold_map next_bound xs ctxt;
val no_ps = replicate (length xs) Position.none;
in ctxt' |> new_fixes (names_of ctxt') (map #1 xs) (map (#1 o dest_Free) xs') no_ps end;
fun variant_fixes raw_xs ctxt =
let
val names = names_of ctxt;
val xs = map (fn x => Name.clean x |> Name.is_internal x ? Name.internal) raw_xs;
val (xs', names') = fold_map Name.variant xs names |>> (is_body ctxt ? map Name.skolem);
val no_ps = replicate (length xs) Position.none;
in ctxt |> new_fixes names' xs xs' no_ps end;
end;
val add_fixes = add_fixes_binding o map Binding.name;
fun add_fixes_direct xs ctxt = ctxt
|> set_body false
|> (snd o add_fixes xs)
|> restore_body ctxt;
(* dummy patterns *)
fun fix_dummy_patterns (Const ("Pure.dummy_pattern", T)) ctxt =
let val ([x], ctxt') = ctxt |> set_body true |> add_fixes [Name.uu_] ||> restore_body ctxt
in (Free (x, T), ctxt') end
| fix_dummy_patterns (Abs (x, T, b)) ctxt =
let val (b', ctxt') = fix_dummy_patterns b ctxt
in (Abs (x, T, b'), ctxt') end
| fix_dummy_patterns (t $ u) ctxt =
let
val (t', ctxt') = fix_dummy_patterns t ctxt;
val (u', ctxt'') = fix_dummy_patterns u ctxt';
in (t' $ u', ctxt'') end
| fix_dummy_patterns a ctxt = (a, ctxt);
(** export -- generalize type/term variables (beware of closure sizes) **)
fun gen_all ctxt th =
let
val i = Thm.maxidx_thm th (maxidx_of ctxt) + 1;
fun gen (x, T) = Thm.forall_elim (Thm.cterm_of ctxt (Var ((x, i), T)));
in fold gen (Drule.outer_params (Thm.prop_of th)) th end;
fun export_inst inner outer =
let
val declared_outer = is_declared outer;
val still_fixed = not o is_newly_fixed inner outer;
val gen_fixes =
Name_Space.fold_table (fn (y, _) => not (is_fixed outer y) ? cons y)
(fixes_of inner) [];
val type_occs_inner = type_occs_of inner;
fun gen_fixesT ts =
Symtab.fold (fn (a, xs) =>
if declared_outer a orelse exists still_fixed xs
then I else cons a) (fold decl_type_occs ts type_occs_inner) [];
in (gen_fixesT, gen_fixes) end;
fun exportT_inst inner outer = #1 (export_inst inner outer);
fun exportT_terms inner outer =
let
val mk_tfrees = exportT_inst inner outer;
val maxidx = maxidx_of outer;
in
fn ts => ts |> map
(Term_Subst.generalize (mk_tfrees ts, [])
(fold (Term.fold_types Term.maxidx_typ) ts maxidx + 1))
end;
fun export_terms inner outer =
let
val (mk_tfrees, tfrees) = export_inst inner outer;
val maxidx = maxidx_of outer;
in
fn ts => ts |> map
(Term_Subst.generalize (mk_tfrees ts, tfrees)
(fold Term.maxidx_term ts maxidx + 1))
end;
fun export_prf inner outer prf =
let
val (mk_tfrees, frees) = export_inst (declare_prf prf inner) outer;
val tfrees = mk_tfrees [];
val maxidx = maxidx_of outer;
val idx = Proofterm.maxidx_proof prf maxidx + 1;
val gen_term = Term_Subst.generalize_same (tfrees, frees) idx;
val gen_typ = Term_Subst.generalizeT_same tfrees idx;
in Same.commit (Proofterm.map_proof_terms_same gen_term gen_typ) prf end;
fun gen_export (mk_tfrees, frees) maxidx ths =
let
val tfrees = mk_tfrees (map Thm.full_prop_of ths);
val idx = fold Thm.maxidx_thm ths maxidx + 1;
in map (Thm.generalize (tfrees, frees) idx) ths end;
fun exportT inner outer = gen_export (exportT_inst inner outer, []) (maxidx_of outer);
fun export inner outer = gen_export (export_inst inner outer) (maxidx_of outer);
fun export_morphism inner outer =
let
val fact = export inner outer;
val term = singleton (export_terms inner outer);
val typ = Logic.type_map term;
in
Morphism.transfer_morphism' inner $>
Morphism.transfer_morphism' outer $>
Morphism.morphism "Variable.export" {binding = [], typ = [typ], term = [term], fact = [fact]}
end;
(** import -- fix schematic type/term variables **)
fun invent_types Ss ctxt =
let
val tfrees = Name.invent (names_of ctxt) Name.aT (length Ss) ~~ Ss;
val ctxt' = fold (declare_constraints o Logic.mk_type o TFree) tfrees ctxt;
in (tfrees, ctxt') end;
fun importT_inst ts ctxt =
let
val tvars = rev (fold Term.add_tvars ts []);
val (tfrees, ctxt') = invent_types (map #2 tvars) ctxt;
in (tvars ~~ map TFree tfrees, ctxt') end;
fun import_inst is_open ts ctxt =
let
val ren = Name.clean #> (if is_open then I else Name.internal);
val (instT, ctxt') = importT_inst ts ctxt;
val vars = map (apsnd (Term_Subst.instantiateT instT)) (rev (fold Term.add_vars ts []));
val (xs, ctxt'') = variant_fixes (map (ren o #1 o #1) vars) ctxt';
val inst = vars ~~ map Free (xs ~~ map #2 vars);
in ((instT, inst), ctxt'') end;
fun importT_terms ts ctxt =
let val (instT, ctxt') = importT_inst ts ctxt
in (map (Term_Subst.instantiate (instT, [])) ts, ctxt') end;
fun import_terms is_open ts ctxt =
let val (inst, ctxt') = import_inst is_open ts ctxt
in (map (Term_Subst.instantiate inst) ts, ctxt') end;
fun importT ths ctxt =
let
val (instT, ctxt') = importT_inst (map Thm.full_prop_of ths) ctxt;
val instT' = map (apsnd (Thm.ctyp_of ctxt')) instT;
val ths' = map (Thm.instantiate (instT', [])) ths;
in ((instT', ths'), ctxt') end;
fun import_prf is_open prf ctxt =
let
val ts = rev (Proofterm.fold_proof_terms cons (cons o Logic.mk_type) prf []);
val (insts, ctxt') = import_inst is_open ts ctxt;
in (Proofterm.instantiate insts prf, ctxt') end;
fun import is_open ths ctxt =
let
val ((instT, inst), ctxt') = import_inst is_open (map Thm.full_prop_of ths) ctxt;
val insts' =
(map (apsnd (Thm.ctyp_of ctxt')) instT,
map (apsnd (Thm.cterm_of ctxt')) inst);
val ths' = map (Thm.instantiate insts') ths;
in ((insts', ths'), ctxt') end;
fun import_vars ctxt th =
let val ((_, [th']), _) = ctxt |> set_body false |> import true [th];
in th' end;
(* import/export *)
fun gen_trade imp exp f ctxt ths =
let val ((_, ths'), ctxt') = imp ths ctxt
in exp ctxt' ctxt (f ctxt' ths') end;
val tradeT = gen_trade importT exportT;
val trade = gen_trade (import true) export;
(* focus on outermost parameters: \<And>x y z. B *)
val bound_focus = Config.declare_bool ("bound_focus", \<^here>) (K false);
val is_bound_focus = Config.apply bound_focus;
val set_bound_focus = Config.put bound_focus;
val restore_bound_focus = set_bound_focus o is_bound_focus;
fun focus_params bindings t ctxt =
let
val ps = Term.variant_frees t (Term.strip_all_vars t); (*as they are printed :-*)
val (xs, Ts) = split_list ps;
val (xs', ctxt') =
(case bindings of
SOME bs => ctxt |> set_body true |> add_fixes_binding bs ||> restore_body ctxt
| NONE => if is_bound_focus ctxt then bound_fixes ps ctxt else variant_fixes xs ctxt);
val ps' = xs' ~~ Ts;
val ctxt'' = ctxt' |> fold (declare_constraints o Free) ps';
in ((xs, ps'), ctxt'') end;
fun focus bindings t ctxt =
let
val ((xs, ps), ctxt') = focus_params bindings t ctxt;
val t' = Term.subst_bounds (rev (map Free ps), Term.strip_all_body t);
in (((xs ~~ ps), t'), ctxt') end;
fun forall_elim_prop t prop =
Thm.beta_conversion false (Thm.apply (Thm.dest_arg prop) t)
|> Thm.cprop_of |> Thm.dest_arg;
fun focus_cterm bindings goal ctxt =
let
val ((xs, ps), ctxt') = focus_params bindings (Thm.term_of goal) ctxt;
val ps' = map (Thm.cterm_of ctxt' o Free) ps;
val goal' = fold forall_elim_prop ps' goal;
in ((xs ~~ ps', goal'), ctxt') end;
fun focus_subgoal bindings i st =
let
val all_vars = Thm.fold_terms Term.add_vars st [];
in
fold (unbind_term o #1) all_vars #>
fold (declare_constraints o Var) all_vars #>
focus_cterm bindings (Thm.cprem_of st i)
end;
(** implicit polymorphism **)
(* warn_extra_tfrees *)
fun warn_extra_tfrees ctxt1 ctxt2 =
let
fun occs_typ a = Term.exists_subtype (fn TFree (b, _) => a = b | _ => false);
fun occs_free a x =
(case def_type ctxt1 false (x, ~1) of
SOME T => if occs_typ a T then I else cons (a, x)
| NONE => cons (a, x));
val occs1 = type_occs_of ctxt1;
val occs2 = type_occs_of ctxt2;
val extras = Symtab.fold (fn (a, xs) =>
if Symtab.defined occs1 a then I else fold (occs_free a) xs) occs2 [];
val tfrees = map #1 extras |> sort_distinct string_ord;
val frees = map #2 extras |> sort_distinct string_ord;
in
if null extras orelse not (Context_Position.is_visible ctxt2) then ()
else warning ("Introduced fixed type variable(s): " ^ commas tfrees ^ " in " ^
space_implode " or " (map quote frees))
end;
(* polymorphic terms *)
fun polymorphic_types ctxt ts =
let
val ctxt' = fold declare_term ts ctxt;
val occs = type_occs_of ctxt;
val occs' = type_occs_of ctxt';
val types = Symtab.fold (fn (a, _) => if Symtab.defined occs a then I else cons a) occs' [];
val idx = maxidx_of ctxt' + 1;
val Ts' = (fold o fold_types o fold_atyps)
(fn T as TFree _ =>
(case Term_Subst.generalizeT types idx T of TVar v => insert (op =) v | _ => I)
| _ => I) ts [];
val ts' = map (Term_Subst.generalize (types, []) idx) ts;
in (rev Ts', ts') end;
fun polymorphic ctxt ts = snd (polymorphic_types ctxt ts);
end;