1 (* Title: Pure/Isar/proof_context.ML
2 Author: Markus Wenzel, TU Muenchen
4 The key concept of Isar proof contexts: elevates primitive local
5 reasoning Gamma |- phi to a structured concept, with generic context
6 elements. See also structure Variable and Assumption.
9 signature PROOF_CONTEXT =
11 val theory_of: Proof.context -> theory
12 val init_global: theory -> Proof.context
14 val mode_default: mode
16 val mode_pattern: mode
17 val mode_schematic: mode
19 val set_mode: mode -> Proof.context -> Proof.context
20 val get_mode: Proof.context -> mode
21 val restore_mode: Proof.context -> Proof.context -> Proof.context
22 val abbrev_mode: Proof.context -> bool
23 val set_stmt: bool -> Proof.context -> Proof.context
24 val local_naming: Name_Space.naming
25 val map_naming: (Name_Space.naming -> Name_Space.naming) -> Proof.context -> Proof.context
26 val naming_of: Proof.context -> Name_Space.naming
27 val restore_naming: Proof.context -> Proof.context -> Proof.context
28 val full_name: Proof.context -> binding -> string
29 val syntax_of: Proof.context -> Local_Syntax.T
30 val syn_of: Proof.context -> Syntax.syntax
31 val tsig_of: Proof.context -> Type.tsig
32 val set_defsort: sort -> Proof.context -> Proof.context
33 val default_sort: Proof.context -> indexname -> sort
34 val consts_of: Proof.context -> Consts.T
35 val the_const_constraint: Proof.context -> string -> typ
36 val set_syntax_mode: Syntax.mode -> Proof.context -> Proof.context
37 val restore_syntax_mode: Proof.context -> Proof.context -> Proof.context
38 val facts_of: Proof.context -> Facts.T
39 val cases_of: Proof.context -> (string * (Rule_Cases.T * bool)) list
40 val class_space: Proof.context -> Name_Space.T
41 val type_space: Proof.context -> Name_Space.T
42 val const_space: Proof.context -> Name_Space.T
43 val intern_class: Proof.context -> xstring -> string
44 val intern_type: Proof.context -> xstring -> string
45 val intern_const: Proof.context -> xstring -> string
46 val extern_class: Proof.context -> string -> xstring
47 val extern_type: Proof.context -> string -> xstring
48 val extern_const: Proof.context -> string -> xstring
49 val transfer_syntax: theory -> Proof.context -> Proof.context
50 val transfer: theory -> Proof.context -> Proof.context
51 val background_theory: (theory -> theory) -> Proof.context -> Proof.context
52 val background_theory_result: (theory -> 'a * theory) -> Proof.context -> 'a * Proof.context
53 val extern_fact: Proof.context -> string -> xstring
54 val pretty_term_abbrev: Proof.context -> term -> Pretty.T
55 val pretty_fact_aux: Proof.context -> bool -> string * thm list -> Pretty.T
56 val pretty_fact: Proof.context -> string * thm list -> Pretty.T
57 val read_class: Proof.context -> xstring -> class
58 val read_arity: Proof.context -> xstring * string list * string -> arity
59 val cert_arity: Proof.context -> arity -> arity
60 val read_typ: Proof.context -> string -> typ
61 val read_typ_syntax: Proof.context -> string -> typ
62 val read_typ_abbrev: Proof.context -> string -> typ
63 val cert_typ: Proof.context -> typ -> typ
64 val cert_typ_syntax: Proof.context -> typ -> typ
65 val cert_typ_abbrev: Proof.context -> typ -> typ
66 val infer_type: Proof.context -> string * typ -> typ
67 val inferred_param: string -> Proof.context -> typ * Proof.context
68 val inferred_fixes: Proof.context -> (string * typ) list * Proof.context
69 val read_type_name: Proof.context -> bool -> string -> typ
70 val read_type_name_proper: Proof.context -> bool -> string -> typ
71 val read_const_proper: Proof.context -> bool -> string -> term
72 val read_const: Proof.context -> bool -> typ -> string -> term
73 val allow_dummies: Proof.context -> Proof.context
74 val get_sort: Proof.context -> (indexname * sort) list -> indexname -> sort
75 val check_tvar: Proof.context -> indexname * sort -> indexname * sort
76 val check_tfree: Proof.context -> string * sort -> string * sort
77 val intern_skolem: Proof.context -> string -> string option
78 val read_term_pattern: Proof.context -> string -> term
79 val read_term_schematic: Proof.context -> string -> term
80 val read_term_abbrev: Proof.context -> string -> term
81 val show_abbrevs_raw: Config.raw
82 val show_abbrevs: bool Config.T
83 val expand_abbrevs: Proof.context -> term -> term
84 val cert_term: Proof.context -> term -> term
85 val cert_prop: Proof.context -> term -> term
86 val def_type: Proof.context -> indexname -> typ option
87 val goal_export: Proof.context -> Proof.context -> thm list -> thm list
88 val export: Proof.context -> Proof.context -> thm list -> thm list
89 val export_morphism: Proof.context -> Proof.context -> morphism
90 val norm_export_morphism: Proof.context -> Proof.context -> morphism
91 val bind_terms: (indexname * term option) list -> Proof.context -> Proof.context
92 val auto_bind_goal: term list -> Proof.context -> Proof.context
93 val auto_bind_facts: term list -> Proof.context -> Proof.context
94 val match_bind: bool -> (string list * string) list -> Proof.context -> term list * Proof.context
95 val match_bind_i: bool -> (term list * term) list -> Proof.context -> term list * Proof.context
96 val read_propp: (string * string list) list list -> Proof.context ->
97 (term * term list) list list * Proof.context
98 val cert_propp: (term * term list) list list -> Proof.context ->
99 (term * term list) list list * Proof.context
100 val read_propp_schematic: (string * string list) list list -> Proof.context ->
101 (term * term list) list list * Proof.context
102 val cert_propp_schematic: (term * term list) list list -> Proof.context ->
103 (term * term list) list list * Proof.context
104 val bind_propp: (string * string list) list list -> Proof.context ->
105 (term list list * (Proof.context -> Proof.context)) * Proof.context
106 val bind_propp_i: (term * term list) list list -> Proof.context ->
107 (term list list * (Proof.context -> Proof.context)) * Proof.context
108 val bind_propp_schematic: (string * string list) list list -> Proof.context ->
109 (term list list * (Proof.context -> Proof.context)) * Proof.context
110 val bind_propp_schematic_i: (term * term list) list list -> Proof.context ->
111 (term list list * (Proof.context -> Proof.context)) * Proof.context
112 val fact_tac: thm list -> int -> tactic
113 val some_fact_tac: Proof.context -> int -> tactic
114 val get_fact: Proof.context -> Facts.ref -> thm list
115 val get_fact_single: Proof.context -> Facts.ref -> thm
116 val get_thms: Proof.context -> xstring -> thm list
117 val get_thm: Proof.context -> xstring -> thm
118 val note_thmss: string -> (Thm.binding * (thm list * attribute list) list) list ->
119 Proof.context -> (string * thm list) list * Proof.context
120 val put_thms: bool -> string * thm list option -> Proof.context -> Proof.context
121 val read_vars: (binding * string option * mixfix) list -> Proof.context ->
122 (binding * typ option * mixfix) list * Proof.context
123 val cert_vars: (binding * typ option * mixfix) list -> Proof.context ->
124 (binding * typ option * mixfix) list * Proof.context
125 val add_fixes: (binding * typ option * mixfix) list -> Proof.context ->
126 string list * Proof.context
127 val add_assms: Assumption.export ->
128 (Thm.binding * (string * string list) list) list ->
129 Proof.context -> (string * thm list) list * Proof.context
130 val add_assms_i: Assumption.export ->
131 (Thm.binding * (term * term list) list) list ->
132 Proof.context -> (string * thm list) list * Proof.context
133 val add_cases: bool -> (string * Rule_Cases.T option) list -> Proof.context -> Proof.context
134 val apply_case: Rule_Cases.T -> Proof.context -> (string * term list) list * Proof.context
135 val get_case: Proof.context -> string -> binding option list -> Rule_Cases.T
136 val type_notation: bool -> Syntax.mode -> (typ * mixfix) list -> Proof.context -> Proof.context
137 val notation: bool -> Syntax.mode -> (term * mixfix) list -> Proof.context -> Proof.context
138 val target_type_notation: bool -> Syntax.mode -> (typ * mixfix) list -> morphism ->
139 Context.generic -> Context.generic
140 val target_notation: bool -> Syntax.mode -> (term * mixfix) list -> morphism ->
141 Context.generic -> Context.generic
142 val class_alias: binding -> class -> Proof.context -> Proof.context
143 val type_alias: binding -> string -> Proof.context -> Proof.context
144 val const_alias: binding -> string -> Proof.context -> Proof.context
145 val add_const_constraint: string * typ option -> Proof.context -> Proof.context
146 val add_abbrev: string -> binding * term -> Proof.context -> (term * term) * Proof.context
147 val revert_abbrev: string -> string -> Proof.context -> Proof.context
148 val print_syntax: Proof.context -> unit
149 val print_abbrevs: Proof.context -> unit
150 val print_binds: Proof.context -> unit
151 val print_lthms: Proof.context -> unit
152 val print_cases: Proof.context -> unit
153 val debug: bool Config.T
154 val verbose: bool Config.T
155 val pretty_ctxt: Proof.context -> Pretty.T list
156 val pretty_context: Proof.context -> Pretty.T list
159 structure Proof_Context: PROOF_CONTEXT =
162 val theory_of = Proof_Context.theory_of;
163 val init_global = Proof_Context.init_global;
167 (** inner syntax mode **)
171 {stmt: bool, (*inner statement mode*)
172 pattern: bool, (*pattern binding schematic variables*)
173 schematic: bool, (*term referencing loose schematic variables*)
174 abbrev: bool}; (*abbrev mode -- no normalization*)
176 fun make_mode (stmt, pattern, schematic, abbrev) =
177 Mode {stmt = stmt, pattern = pattern, schematic = schematic, abbrev = abbrev};
179 val mode_default = make_mode (false, false, false, false);
180 val mode_stmt = make_mode (true, false, false, false);
181 val mode_pattern = make_mode (false, true, false, false);
182 val mode_schematic = make_mode (false, false, true, false);
183 val mode_abbrev = make_mode (false, false, false, true);
187 (** Isar proof context information **)
191 {mode: mode, (*inner syntax mode*)
192 naming: Name_Space.naming, (*local naming conventions*)
193 syntax: Local_Syntax.T, (*local syntax*)
194 tsig: Type.tsig * Type.tsig, (*local/global type signature -- local name space / defsort only*)
195 consts: Consts.T * Consts.T, (*local/global consts -- local name space / abbrevs only*)
196 facts: Facts.T, (*local facts*)
197 cases: (string * (Rule_Cases.T * bool)) list}; (*named case contexts*)
199 fun make_ctxt (mode, naming, syntax, tsig, consts, facts, cases) =
200 Ctxt {mode = mode, naming = naming, syntax = syntax,
201 tsig = tsig, consts = consts, facts = facts, cases = cases};
203 val local_naming = Name_Space.default_naming |> Name_Space.add_path "local";
205 structure Data = Proof_Data
209 make_ctxt (mode_default, local_naming, Local_Syntax.init thy,
210 (Sign.tsig_of thy, Sign.tsig_of thy),
211 (Sign.consts_of thy, Sign.consts_of thy), Facts.empty, []);
214 fun rep_context ctxt = Data.get ctxt |> (fn Ctxt args => args);
217 Data.map (fn Ctxt {mode, naming, syntax, tsig, consts, facts, cases} =>
218 make_ctxt (f (mode, naming, syntax, tsig, consts, facts, cases)));
220 fun set_mode mode = map_context (fn (_, naming, syntax, tsig, consts, facts, cases) =>
221 (mode, naming, syntax, tsig, consts, facts, cases));
224 map_context (fn (Mode {stmt, pattern, schematic, abbrev}, naming, syntax, tsig, consts, facts, cases) =>
225 (make_mode (f (stmt, pattern, schematic, abbrev)), naming, syntax, tsig, consts, facts, cases));
228 map_context (fn (mode, naming, syntax, tsig, consts, facts, cases) =>
229 (mode, f naming, syntax, tsig, consts, facts, cases));
232 map_context (fn (mode, naming, syntax, tsig, consts, facts, cases) =>
233 (mode, naming, f syntax, tsig, consts, facts, cases));
236 map_context (fn (mode, naming, syntax, tsig, consts, facts, cases) =>
237 (mode, naming, syntax, f tsig, consts, facts, cases));
240 map_context (fn (mode, naming, syntax, tsig, consts, facts, cases) =>
241 (mode, naming, syntax, tsig, f consts, facts, cases));
244 map_context (fn (mode, naming, syntax, tsig, consts, facts, cases) =>
245 (mode, naming, syntax, tsig, consts, f facts, cases));
248 map_context (fn (mode, naming, syntax, tsig, consts, facts, cases) =>
249 (mode, naming, syntax, tsig, consts, facts, f cases));
251 val get_mode = #mode o rep_context;
252 val restore_mode = set_mode o get_mode;
253 val abbrev_mode = get_mode #> (fn Mode {abbrev, ...} => abbrev);
256 map_mode (fn (_, pattern, schematic, abbrev) => (stmt, pattern, schematic, abbrev));
258 val naming_of = #naming o rep_context;
259 val restore_naming = map_naming o K o naming_of
260 val full_name = Name_Space.full_name o naming_of;
262 val syntax_of = #syntax o rep_context;
263 val syn_of = Local_Syntax.syn_of o syntax_of;
264 val set_syntax_mode = map_syntax o Local_Syntax.set_mode;
265 val restore_syntax_mode = map_syntax o Local_Syntax.restore_mode o syntax_of;
267 val tsig_of = #1 o #tsig o rep_context;
268 val set_defsort = map_tsig o apfst o Type.set_defsort;
269 fun default_sort ctxt = the_default (Type.defaultS (tsig_of ctxt)) o Variable.def_sort ctxt;
271 val consts_of = #1 o #consts o rep_context;
272 val the_const_constraint = Consts.the_constraint o consts_of;
274 val facts_of = #facts o rep_context;
275 val cases_of = #cases o rep_context;
280 val class_space = Type.class_space o tsig_of;
281 val type_space = Type.type_space o tsig_of;
282 val const_space = Consts.space_of o consts_of;
284 val intern_class = Name_Space.intern o class_space;
285 val intern_type = Name_Space.intern o type_space;
286 val intern_const = Name_Space.intern o const_space;
288 fun extern_class ctxt = Name_Space.extern ctxt (class_space ctxt);
289 fun extern_type ctxt = Name_Space.extern ctxt (type_space ctxt);
290 fun extern_const ctxt = Name_Space.extern ctxt (const_space ctxt);
293 (* theory transfer *)
295 fun transfer_syntax thy ctxt = ctxt |>
296 map_syntax (Local_Syntax.rebuild thy) |>
297 map_tsig (fn tsig as (local_tsig, global_tsig) =>
298 let val thy_tsig = Sign.tsig_of thy in
299 if Type.eq_tsig (thy_tsig, global_tsig) then tsig
300 else (Type.merge_tsig ctxt (local_tsig, thy_tsig), thy_tsig)
302 map_consts (fn consts as (local_consts, global_consts) =>
303 let val thy_consts = Sign.consts_of thy in
304 if Consts.eq_consts (thy_consts, global_consts) then consts
305 else (Consts.merge (local_consts, thy_consts), thy_consts)
308 fun transfer thy = Context.raw_transfer thy #> transfer_syntax thy;
310 fun background_theory f ctxt = transfer (f (theory_of ctxt)) ctxt;
312 fun background_theory_result f ctxt =
313 let val (res, thy') = f (theory_of ctxt)
314 in (res, ctxt |> transfer thy') end;
318 (** pretty printing **)
322 fun which_facts ctxt name =
324 val local_facts = facts_of ctxt;
325 val global_facts = Global_Theory.facts_of (theory_of ctxt);
327 if is_some (Facts.lookup (Context.Proof ctxt) local_facts name)
328 then local_facts else global_facts
331 fun markup_fact ctxt name = Name_Space.markup (Facts.space_of (which_facts ctxt name)) name;
333 fun extern_fact ctxt name = Facts.extern ctxt (which_facts ctxt name) name;
338 fun pretty_term_abbrev ctxt = Syntax.pretty_term (set_mode mode_abbrev ctxt);
340 fun pretty_fact_name ctxt a =
341 Pretty.block [Pretty.mark_str (markup_fact ctxt a, extern_fact ctxt a), Pretty.str ":"];
343 fun pretty_fact_aux ctxt flag ("", ths) =
344 Display.pretty_thms_aux ctxt flag ths
345 | pretty_fact_aux ctxt flag (a, [th]) = Pretty.block
346 [pretty_fact_name ctxt a, Pretty.brk 1, Display.pretty_thm_aux ctxt flag th]
347 | pretty_fact_aux ctxt flag (a, ths) = Pretty.block
348 (Pretty.fbreaks (pretty_fact_name ctxt a :: map (Display.pretty_thm_aux ctxt flag) ths));
350 fun pretty_fact ctxt = pretty_fact_aux ctxt true;
354 (** prepare types **)
358 fun read_class ctxt text =
360 val tsig = tsig_of ctxt;
361 val (syms, pos) = Syntax.read_token text;
362 val c = Type.cert_class tsig (Type.intern_class tsig (Symbol_Pos.content syms))
363 handle TYPE (msg, _, _) => error (msg ^ Position.str_of pos);
364 val _ = Context_Position.report ctxt pos (Name_Space.markup (Type.class_space tsig) c);
372 fun prep_arity prep_tycon prep_sort ctxt (t, Ss, S) =
373 let val arity = (prep_tycon ctxt t, map (prep_sort ctxt) Ss, prep_sort ctxt S)
374 in Type.add_arity ctxt arity (tsig_of ctxt); arity end;
378 val read_arity = prep_arity intern_type Syntax.read_sort;
379 val cert_arity = prep_arity (K I) (Type.cert_sort o tsig_of);
386 fun read_typ_mode mode ctxt s =
387 Syntax.read_typ (Type.set_mode mode ctxt) s;
389 val read_typ = read_typ_mode Type.mode_default;
390 val read_typ_syntax = read_typ_mode Type.mode_syntax;
391 val read_typ_abbrev = read_typ_mode Type.mode_abbrev;
394 fun cert_typ_mode mode ctxt T =
395 Type.cert_typ_mode mode (tsig_of ctxt) T
396 handle TYPE (msg, _, _) => error msg;
398 val cert_typ = cert_typ_mode Type.mode_default;
399 val cert_typ_syntax = cert_typ_mode Type.mode_syntax;
400 val cert_typ_abbrev = cert_typ_mode Type.mode_abbrev;
404 (** prepare variables **)
406 (* check Skolem constants *)
408 fun no_skolem internal x =
409 if can Name.dest_skolem x then
410 error ("Illegal reference to internal Skolem constant: " ^ quote x)
411 else if not internal andalso can Name.dest_internal x then
412 error ("Illegal reference to internal variable: " ^ quote x)
417 (** prepare terms and propositions **)
419 (* inferred types of parameters *)
421 fun infer_type ctxt x =
422 Term.fastype_of (singleton (Syntax.check_terms (set_mode mode_schematic ctxt)) (Free x));
424 fun inferred_param x ctxt =
425 let val T = infer_type ctxt (x, dummyT)
426 in (T, ctxt |> Variable.declare_term (Free (x, T))) end;
428 fun inferred_fixes ctxt =
430 val xs = map #2 (Variable.dest_fixes ctxt);
431 val (Ts, ctxt') = fold_map inferred_param xs ctxt;
432 in (xs ~~ Ts, ctxt') end;
435 (* type and constant names *)
439 val token_content = Syntax.read_token #>> Symbol_Pos.content;
441 fun prep_const_proper ctxt strict (c, pos) =
443 fun err msg = error (msg ^ Position.str_of pos);
444 val consts = consts_of ctxt;
445 val t as Const (d, _) =
446 (case Variable.lookup_const ctxt c of
448 Const (d, Consts.type_scheme (consts_of ctxt) d handle TYPE (msg, _, _) => err msg)
449 | NONE => Consts.read_const consts (c, pos));
451 if strict then ignore (Consts.the_const consts d) handle TYPE (msg, _, _) => err msg
453 val _ = Context_Position.report ctxt pos (Name_Space.markup (Consts.space_of consts) d);
458 fun read_type_name ctxt strict text =
460 val tsig = tsig_of ctxt;
461 val (c, pos) = token_content text;
463 if Lexicon.is_tid c then
464 (Context_Position.report ctxt pos Markup.tfree;
465 TFree (c, default_sort ctxt (c, ~1)))
468 val d = intern_type ctxt c;
469 val decl = Type.the_decl tsig (d, pos);
470 fun err () = error ("Bad type name: " ^ quote d ^ Position.str_of pos);
473 Type.LogicalType n => n
474 | Type.Abbreviation (vs, _, _) => if strict then err () else length vs
475 | Type.Nonterminal => if strict then err () else 0);
476 val _ = Context_Position.report ctxt pos (Name_Space.markup (Type.type_space tsig) d);
477 in Type (d, replicate args dummyT) end
480 fun read_type_name_proper ctxt strict text =
481 (case read_type_name ctxt strict text of
483 | T => error ("Not a type constructor: " ^ Syntax.string_of_typ ctxt T));
486 fun read_const_proper ctxt strict = prep_const_proper ctxt strict o token_content;
488 fun read_const ctxt strict ty text =
490 val (c, pos) = token_content text;
491 val _ = no_skolem false c;
493 (case (Variable.lookup_fixed ctxt c, Variable.is_const ctxt c) of
495 (Context_Position.report ctxt pos
496 (Markup.name x (if can Name.dest_skolem x then Markup.skolem else Markup.free));
497 Free (x, infer_type ctxt (x, ty)))
498 | _ => prep_const_proper ctxt strict (c, pos))
504 (* skolem variables *)
506 fun intern_skolem ctxt x =
508 val _ = no_skolem false x;
509 val sko = Variable.lookup_fixed ctxt x;
510 val is_const = can (read_const_proper ctxt false) x orelse Long_Name.is_qualified x;
511 val is_declared = is_some (Variable.def_type ctxt false (x, ~1));
513 if Variable.is_const ctxt x then NONE
514 else if is_some sko then sko
515 else if not is_const orelse is_declared then SOME x
522 fun read_term_mode mode ctxt = Syntax.read_term (set_mode mode ctxt);
524 val read_term_pattern = read_term_mode mode_pattern;
525 val read_term_schematic = read_term_mode mode_schematic;
526 val read_term_abbrev = read_term_mode mode_abbrev;
529 (* local abbreviations *)
533 fun certify_consts ctxt = Consts.certify (Context.pretty ctxt) (tsig_of ctxt)
534 (not (abbrev_mode ctxt)) (consts_of ctxt);
536 fun expand_binds ctxt =
538 val Mode {pattern, schematic, ...} = get_mode ctxt;
540 fun reject_schematic (t as Var _) =
541 error ("Unbound schematic variable: " ^ Syntax.string_of_term ctxt t)
542 | reject_schematic (Abs (_, _, t)) = reject_schematic t
543 | reject_schematic (t $ u) = (reject_schematic t; reject_schematic u)
544 | reject_schematic _ = ();
547 else Variable.expand_binds ctxt #> (if schematic then I else tap reject_schematic)
552 fun expand_abbrevs ctxt = certify_consts ctxt #> expand_binds ctxt;
556 val show_abbrevs_raw = Config.declare "show_abbrevs" (fn _ => Config.Bool true);
557 val show_abbrevs = Config.bool show_abbrevs_raw;
559 fun contract_abbrevs ctxt t =
561 val thy = theory_of ctxt;
562 val consts = consts_of ctxt;
563 val Mode {abbrev, ...} = get_mode ctxt;
564 val retrieve = Consts.retrieve_abbrevs consts (print_mode_value () @ [""]);
565 fun match_abbrev u = Option.map #1 (get_first (Pattern.match_rew thy u) (retrieve u));
567 if abbrev orelse not (Config.get ctxt show_abbrevs) orelse not (can Term.type_of t) then t
568 else Pattern.rewrite_term_top thy [] [match_abbrev] t
574 fun prepare_patternT ctxt T =
576 val Mode {pattern, schematic, ...} = get_mode ctxt;
578 pattern orelse schematic orelse
579 T |> Term.exists_subtype
580 (fn T as TVar (xi, _) =>
581 not (Type_Infer.is_param xi) andalso
582 error ("Illegal schematic type variable: " ^ Syntax.string_of_typ ctxt T)
589 val dummies = Config.bool (Config.declare "Proof_Context.dummies" (K (Config.Bool false)));
591 fun check_dummies ctxt t =
592 if Config.get ctxt dummies then t
593 else Term.no_dummy_patterns t handle TERM _ => error "Illegal dummy pattern(s) in term";
595 fun prepare_dummies ts = #1 (fold_map Term.replace_dummy_patterns ts 1);
599 val allow_dummies = Config.put dummies true;
601 fun prepare_patterns ctxt =
602 let val Mode {pattern, ...} = get_mode ctxt in
603 Type_Infer.fixate ctxt #>
604 pattern ? Variable.polymorphic ctxt #>
605 (map o Term.map_types) (prepare_patternT ctxt) #>
606 (if pattern then prepare_dummies else map (check_dummies ctxt))
612 (* sort constraints *)
614 fun get_sort ctxt raw_text =
616 val tsig = tsig_of ctxt;
618 val text = distinct (op =) (map (apsnd (Type.minimize_sort tsig)) raw_text);
620 (case duplicates (eq_fst (op =)) text of
622 | dups => error ("Inconsistent sort constraints for type variable(s) "
623 ^ commas_quote (map (Term.string_of_vname' o fst) dups)));
626 (case AList.lookup (op =) text xi of
628 | SOME S => if S = dummyS then NONE else SOME S);
631 (case (lookup xi, Variable.def_sort ctxt xi) of
632 (NONE, NONE) => Type.defaultS tsig
633 | (NONE, SOME S) => S
634 | (SOME S, NONE) => S
635 | (SOME S, SOME S') =>
636 if Type.eq_sort tsig (S, S') then S'
637 else error ("Sort constraint " ^ Syntax.string_of_sort ctxt S ^
638 " inconsistent with default " ^ Syntax.string_of_sort ctxt S' ^
639 " for type variable " ^ quote (Term.string_of_vname' xi)));
642 fun check_tvar ctxt (xi, S) = (xi, get_sort ctxt [(xi, S)] xi);
643 fun check_tfree ctxt (x, S) = apfst fst (check_tvar ctxt ((x, ~1), S));
650 fun gen_cert prop ctxt t =
652 |> expand_abbrevs ctxt
654 #1 (Sign.certify' prop (Context.pretty ctxt) false (consts_of ctxt) (theory_of ctxt) t')
655 handle TYPE (msg, _, _) => error msg | TERM (msg, _) => error msg);
659 val cert_term = gen_cert false;
660 val cert_prop = gen_cert true;
668 let val Mode {pattern, ...} = get_mode ctxt
669 in Variable.def_type ctxt pattern end;
673 fun standard_typ_check ctxt =
674 map (cert_typ_mode (Type.get_mode ctxt) ctxt) #>
675 map (prepare_patternT ctxt);
677 fun standard_term_uncheck ctxt =
678 map (contract_abbrevs ctxt);
683 (Syntax.add_typ_check 0 "standard" standard_typ_check #>
684 Syntax.add_term_check 100 "fixate" prepare_patterns #>
685 Syntax.add_term_uncheck 0 "standard" standard_term_uncheck);
691 (** export results **)
693 fun common_export is_goal inner outer =
694 map (Assumption.export is_goal inner outer) #>
695 Variable.export inner outer;
697 val goal_export = common_export true;
698 val export = common_export false;
700 fun export_morphism inner outer =
701 Assumption.export_morphism inner outer $>
702 Variable.export_morphism inner outer;
704 fun norm_export_morphism inner outer =
705 export_morphism inner outer $>
706 Morphism.thm_morphism Goal.norm_result;
710 (** term bindings **)
714 fun simult_matches ctxt (t, pats) =
715 (case Seq.pull (Unify.matchers (theory_of ctxt) (map (rpair t) pats)) of
716 NONE => error "Pattern match failed!"
717 | SOME (env, _) => Vartab.fold (fn (v, (_, t)) => cons (v, t)) (Envir.term_env env) []);
722 val bind_terms = fold (fn (xi, t) => fn ctxt =>
724 |> Variable.bind_term (xi, Option.map (cert_term (set_mode mode_default ctxt)) t));
729 fun drop_schematic (b as (xi, SOME t)) = if Term.exists_subterm is_Var t then (xi, NONE) else b
730 | drop_schematic b = b;
732 fun auto_bind f ts ctxt = ctxt |> bind_terms (map drop_schematic (f (theory_of ctxt) ts));
734 val auto_bind_goal = auto_bind Auto_Bind.goal;
735 val auto_bind_facts = auto_bind Auto_Bind.facts;
742 fun gen_bind prep_terms gen raw_binds ctxt =
744 fun prep_bind (raw_pats, t) ctxt1 =
746 val T = Term.fastype_of t;
747 val ctxt2 = Variable.declare_term t ctxt1;
748 val pats = prep_terms (set_mode mode_pattern ctxt2) T raw_pats;
749 val binds = simult_matches ctxt2 (t, pats);
750 in (binds, ctxt2) end;
752 val ts = prep_terms ctxt dummyT (map snd raw_binds);
753 val (binds, ctxt') = apfst flat (fold_map prep_bind (map fst raw_binds ~~ ts) ctxt);
755 if gen then map #1 binds ~~ Variable.exportT_terms ctxt' ctxt (map #2 binds)
757 val binds'' = map (apsnd SOME) binds';
759 tap (Variable.warn_extra_tfrees ctxt)
761 ctxt (*sic!*) |> fold Variable.declare_term (map #2 binds') |> bind_terms binds''
762 else ctxt' |> bind_terms binds'');
767 fun read_terms ctxt T =
768 map (Syntax.parse_term ctxt #> Type.constraint T) #> Syntax.check_terms ctxt;
770 val match_bind = gen_bind read_terms;
771 val match_bind_i = gen_bind (fn ctxt => fn _ => map (cert_term ctxt));
776 (* propositions with patterns *)
780 fun prep_propp mode prep_props args context =
782 fun prep (_, raw_pats) (ctxt, prop :: props) =
783 let val ctxt' = Variable.declare_term prop ctxt
784 in ((prop, prep_props (set_mode mode_pattern ctxt') raw_pats), (ctxt', props)) end;
786 val (propp, (context', _)) =
787 (fold_map o fold_map) prep args
788 (context, prep_props (set_mode mode context) (maps (map fst) args));
789 in (propp, context') end;
791 fun gen_bind_propp mode parse_prop raw_args ctxt =
793 val (args, ctxt') = prep_propp mode parse_prop raw_args ctxt;
794 val binds = flat (flat (map (map (simult_matches ctxt')) args));
795 val propss = map (map #1) args;
797 (*generalize result: context evaluated now, binds added later*)
798 val gen = Variable.exportT_terms ctxt' ctxt;
799 fun gen_binds c = c |> bind_terms (map #1 binds ~~ map SOME (gen (map #2 binds)));
800 in ((propss, gen_binds), ctxt' |> bind_terms (map (apsnd SOME) binds)) end;
804 val read_propp = prep_propp mode_default Syntax.read_props;
805 val cert_propp = prep_propp mode_default (map o cert_prop);
806 val read_propp_schematic = prep_propp mode_schematic Syntax.read_props;
807 val cert_propp_schematic = prep_propp mode_schematic (map o cert_prop);
809 val bind_propp = gen_bind_propp mode_default Syntax.read_props;
810 val bind_propp_i = gen_bind_propp mode_default (map o cert_prop);
811 val bind_propp_schematic = gen_bind_propp mode_schematic Syntax.read_props;
812 val bind_propp_schematic_i = gen_bind_propp mode_schematic (map o cert_prop);
822 fun comp_incr_tac [] _ = no_tac
823 | comp_incr_tac (th :: ths) i =
824 (fn st => Goal.compose_hhf_tac (Drule.incr_indexes st th) i st) APPEND comp_incr_tac ths i;
826 fun fact_tac facts = Goal.norm_hhf_tac THEN' comp_incr_tac facts;
828 fun potential_facts ctxt prop =
829 Facts.could_unify (facts_of ctxt) (Term.strip_all_body prop);
831 fun some_fact_tac ctxt = SUBGOAL (fn (goal, i) => fact_tac (potential_facts ctxt goal) i);
838 fun retrieve_thms pick ctxt (Facts.Fact s) =
840 val (_, pos) = Syntax.read_token s;
842 Syntax.read_prop (ctxt |> set_mode mode_default |> allow_dummies) s
843 |> singleton (Variable.polymorphic ctxt);
844 fun err msg = error (msg ^ Position.str_of pos ^ ":\n" ^ Syntax.string_of_term ctxt prop);
846 val (prop', _) = Term.replace_dummy_patterns prop (Variable.maxidx_of ctxt + 1);
848 Goal.prove ctxt [] [] prop' (K (ALLGOALS (fact_tac [th])));
849 val results = map_filter (try prove_fact) (potential_facts ctxt prop');
851 (case distinct Thm.eq_thm_prop results of
853 | [] => err "Failed to retrieve literal fact"
854 | _ => err "Ambiguous specification of literal fact");
856 | retrieve_thms pick ctxt xthmref =
858 val thy = theory_of ctxt;
859 val local_facts = facts_of ctxt;
860 val thmref = Facts.map_name_of_ref (Facts.intern local_facts) xthmref;
861 val name = Facts.name_of_ref thmref;
862 val pos = Facts.pos_of_ref xthmref;
864 if name = "" then [Thm.transfer thy Drule.dummy_thm]
866 (case Facts.lookup (Context.Proof ctxt) local_facts name of
868 (Context_Position.report ctxt pos
869 (Name_Space.markup (Facts.space_of local_facts) name);
870 map (Thm.transfer thy) (Facts.select thmref ths))
871 | NONE => Global_Theory.get_fact (Context.Proof ctxt) thy xthmref);
872 in pick name thms end;
876 val get_fact = retrieve_thms (K I);
877 val get_fact_single = retrieve_thms Facts.the_single;
879 fun get_thms ctxt = get_fact ctxt o Facts.named;
880 fun get_thm ctxt = get_fact_single ctxt o Facts.named;
889 fun update_thms _ (b, NONE) ctxt = ctxt |> map_facts (Facts.del (full_name ctxt b))
890 | update_thms do_props (b, SOME ths) ctxt = ctxt |> map_facts
891 (Facts.add_local ctxt do_props (naming_of ctxt) (b, ths) #> snd);
895 fun note_thmss kind = fold_map (fn ((b, more_attrs), raw_facts) => fn ctxt =>
897 val name = full_name ctxt b;
898 val facts = Global_Theory.name_thmss false name raw_facts;
899 fun app (th, attrs) x =
900 swap (Library.foldl_map
901 (Thm.proof_attributes (surround (Thm.kind kind) (attrs @ more_attrs))) (x, th));
902 val (res, ctxt') = fold_map app facts ctxt;
903 val thms = Global_Theory.name_thms false false name (flat res);
904 val Mode {stmt, ...} = get_mode ctxt;
905 in ((name, thms), ctxt' |> update_thms stmt (b, SOME thms)) end);
907 fun put_thms do_props thms ctxt = ctxt
908 |> map_naming (K local_naming)
909 |> Context_Position.set_visible false
910 |> update_thms do_props (apfst Binding.name thms)
911 |> Context_Position.restore_visible ctxt
912 |> restore_naming ctxt;
918 (** basic logical entities **)
922 fun declare_var (x, opt_T, mx) ctxt =
923 let val T = (case opt_T of SOME T => T | NONE => Mixfix.mixfixT mx)
924 in ((x, T, mx), ctxt |> Variable.declare_constraints (Free (x, T))) end;
928 fun prep_vars prep_typ internal =
929 fold_map (fn (b, raw_T, mx) => fn ctxt =>
931 val x = Variable.check_name b;
932 val _ = Lexicon.is_identifier (no_skolem internal x) orelse
933 error ("Illegal variable name: " ^ Binding.print b);
937 else Type.no_tvars T handle TYPE (msg, _, _) => error msg;
938 val opt_T = Option.map (cond_tvars o cert_typ ctxt o prep_typ ctxt) raw_T;
939 val (_, ctxt') = ctxt |> declare_var (x, opt_T, mx);
940 in ((b, opt_T, mx), ctxt') end);
944 val read_vars = prep_vars Syntax.parse_typ false;
945 val cert_vars = prep_vars (K I) true;
954 fun type_syntax (Type (c, args), mx) =
955 SOME (Local_Syntax.Type, (Lexicon.mark_type c, Mixfix.make_type (length args), mx))
956 | type_syntax _ = NONE;
958 fun const_syntax _ (Free (x, T), mx) = SOME (Local_Syntax.Fixed, (x, T, mx))
959 | const_syntax ctxt (Const (c, _), mx) =
960 (case try (Consts.type_scheme (consts_of ctxt)) c of
961 SOME T => SOME (Local_Syntax.Const, (Lexicon.mark_const c, T, mx))
963 | const_syntax _ _ = NONE;
965 fun gen_notation syntax add mode args ctxt =
967 (Local_Syntax.update_modesyntax (theory_of ctxt) add mode (map_filter (syntax ctxt) args));
971 val type_notation = gen_notation (K type_syntax);
972 val notation = gen_notation const_syntax;
974 fun target_type_notation add mode args phi =
976 val args' = args |> map_filter (fn (T, mx) =>
978 val T' = Morphism.typ phi T;
979 val similar = (case (T, T') of (Type (c, _), Type (c', _)) => c = c' | _ => false);
980 in if similar then SOME (T', mx) else NONE end);
981 in Context.mapping (Sign.type_notation add mode args') (type_notation add mode args') end;
983 fun target_notation add mode args phi =
985 val args' = args |> map_filter (fn (t, mx) =>
986 let val t' = Morphism.term phi t
987 in if Term.aconv_untyped (t, t') then SOME (t', mx) else NONE end);
988 in Context.mapping (Sign.notation add mode args') (notation add mode args') end;
995 fun class_alias b c ctxt = (map_tsig o apfst) (Type.class_alias (naming_of ctxt) b c) ctxt;
996 fun type_alias b c ctxt = (map_tsig o apfst) (Type.type_alias (naming_of ctxt) b c) ctxt;
997 fun const_alias b c ctxt = (map_consts o apfst) (Consts.alias (naming_of ctxt) b c) ctxt;
1000 (* local constants *)
1002 fun add_const_constraint (c, opt_T) ctxt =
1005 let val T = cert_typ ctxt raw_T
1006 in cert_term ctxt (Const (c, T)); T end;
1007 in ctxt |> (map_consts o apfst) (Consts.constrain (c, Option.map prepT opt_T)) end;
1009 fun add_abbrev mode (b, raw_t) ctxt =
1011 val t0 = cert_term (ctxt |> set_mode mode_abbrev) raw_t
1012 handle ERROR msg => cat_error msg ("in constant abbreviation " ^ Binding.print b);
1013 val [t] = Variable.exportT_terms (Variable.declare_term t0 ctxt) ctxt [t0];
1014 val ((lhs, rhs), consts') = consts_of ctxt
1015 |> Consts.abbreviate ctxt (tsig_of ctxt) (naming_of ctxt) mode (b, t);
1018 |> (map_consts o apfst) (K consts')
1019 |> Variable.declare_term rhs
1023 fun revert_abbrev mode c = (map_consts o apfst) (Consts.revert_abbrev mode c);
1028 fun add_fixes raw_vars ctxt =
1030 val thy = theory_of ctxt;
1031 val vars = #1 (cert_vars raw_vars ctxt);
1034 |> Variable.add_fixes_binding (map #1 vars)
1036 fold_map declare_var (map2 (fn x => fn (_, T, mx) => (x, T, mx)) xs vars)
1037 #-> (map_syntax o Local_Syntax.add_syntax thy o map (pair Local_Syntax.Fixed))
1047 fun gen_assms prepp exp args ctxt =
1049 val cert = Thm.cterm_of (theory_of ctxt);
1050 val ((propss, _), ctxt1) = prepp (map snd args) ctxt;
1051 val _ = Variable.warn_extra_tfrees ctxt ctxt1;
1052 val (premss, ctxt2) = fold_burrow (Assumption.add_assms exp o map cert) propss ctxt1;
1055 |> auto_bind_facts (flat propss)
1056 |> note_thmss "" (map fst args ~~ map (map (fn th => ([th], []))) premss)
1061 val add_assms = gen_assms bind_propp;
1062 val add_assms_i = gen_assms bind_propp_i;
1072 fun rem_case name = remove (fn (x: string, (y, _)) => x = y) name;
1074 fun add_case _ ("", _) cases = cases
1075 | add_case _ (name, NONE) cases = rem_case name cases
1076 | add_case is_proper (name, SOME c) cases = (name, (c, is_proper)) :: rem_case name cases;
1078 fun prep_case name fxs c =
1080 fun replace (opt_x :: xs) ((y, T) :: ys) = (the_default y opt_x, T) :: replace xs ys
1081 | replace [] ys = ys
1082 | replace (_ :: _) [] = error ("Too many parameters for case " ^ quote name);
1083 val Rule_Cases.Case {fixes, assumes, binds, cases} = c;
1084 val fixes' = replace fxs fixes;
1085 val binds' = map drop_schematic binds;
1087 if null (fold (Term.add_tvarsT o snd) fixes []) andalso
1088 null (fold (fold Term.add_vars o snd) assumes []) then
1089 Rule_Cases.Case {fixes = fixes', assumes = assumes, binds = binds', cases = cases}
1090 else error ("Illegal schematic variable(s) in case " ^ quote name)
1093 fun fix (b, T) ctxt =
1094 let val ([x], ctxt') = add_fixes [(b, SOME T, NoSyn)] ctxt
1095 in (Free (x, T), ctxt') end;
1099 fun add_cases is_proper = map_cases o fold (add_case is_proper);
1101 fun case_result c ctxt =
1103 val Rule_Cases.Case {fixes, ...} = c;
1104 val (ts, ctxt') = ctxt |> fold_map fix fixes;
1105 val Rule_Cases.Case {assumes, binds, cases, ...} = Rule_Cases.apply ts c;
1108 |> bind_terms (map drop_schematic binds)
1109 |> add_cases true (map (apsnd SOME) cases)
1110 |> pair (assumes, (binds, cases))
1113 val apply_case = apfst fst oo case_result;
1115 fun get_case ctxt name xs =
1116 (case AList.lookup (op =) (cases_of ctxt) name of
1117 NONE => error ("Unknown case: " ^ quote name)
1118 | SOME (c, _) => prep_case name xs c);
1124 (** print context information **)
1128 val print_syntax = Syntax.print_syntax o syn_of;
1133 fun pretty_abbrevs show_globals ctxt =
1135 val ((space, consts), (_, globals)) =
1136 pairself (#constants o Consts.dest) (#consts (rep_context ctxt));
1137 fun add_abbr (_, (_, NONE)) = I
1138 | add_abbr (c, (T, SOME t)) =
1139 if not show_globals andalso Symtab.defined globals c then I
1140 else cons (c, Logic.mk_equals (Const (c, T), t));
1142 Name_Space.extern_table ctxt (space, Symtab.make (Symtab.fold add_abbr consts []));
1144 if null abbrevs then []
1145 else [Pretty.big_list "abbreviations:" (map (pretty_term_abbrev ctxt o #2) abbrevs)]
1148 val print_abbrevs = Pretty.writeln o Pretty.chunks o pretty_abbrevs true;
1153 fun pretty_binds ctxt =
1155 val binds = Variable.binds_of ctxt;
1156 fun prt_bind (xi, (T, t)) = pretty_term_abbrev ctxt (Logic.mk_equals (Var (xi, T), t));
1158 if Vartab.is_empty binds then []
1159 else [Pretty.big_list "term bindings:" (map prt_bind (Vartab.dest binds))]
1162 val print_binds = Pretty.writeln o Pretty.chunks o pretty_binds;
1165 (* local theorems *)
1167 fun pretty_lthms ctxt =
1169 val local_facts = facts_of ctxt;
1170 val props = Facts.props local_facts;
1172 (if null props then [] else [("<unnamed>", props)]) @
1173 Facts.dest_static [] local_facts;
1175 if null facts then []
1176 else [Pretty.big_list "facts:" (map #1 (sort_wrt (#1 o #2) (map (`(pretty_fact ctxt)) facts)))]
1179 val print_lthms = Pretty.writeln o Pretty.chunks o pretty_lthms;
1182 (* local contexts *)
1186 fun pretty_case (name, (fixes, ((asms, (lets, cs)), ctxt))) =
1188 val prt_term = Syntax.pretty_term ctxt;
1190 fun prt_let (xi, t) = Pretty.block
1191 [Pretty.quote (prt_term (Var (xi, Term.fastype_of t))), Pretty.str " =", Pretty.brk 1,
1192 Pretty.quote (prt_term t)];
1194 fun prt_asm (a, ts) = Pretty.block (Pretty.breaks
1195 ((if a = "" then [] else [Pretty.str (a ^ ":")]) @ map (Pretty.quote o prt_term) ts));
1197 fun prt_sect _ _ _ [] = []
1198 | prt_sect s sep prt xs =
1199 [Pretty.block (Pretty.breaks (Pretty.str s ::
1200 flat (separate sep (map (single o prt) xs))))];
1202 Pretty.block (Pretty.fbreaks
1203 (Pretty.str (name ^ ":") ::
1204 prt_sect "fix" [] (Pretty.str o Binding.name_of o fst) fixes @
1205 prt_sect "let" [Pretty.str "and"] prt_let
1206 (map_filter (fn (xi, SOME t) => SOME (xi, t) | _ => NONE) lets) @
1207 (if forall (null o #2) asms then []
1208 else prt_sect "assume" [Pretty.str "and"] prt_asm asms) @
1209 prt_sect "subcases:" [] (Pretty.str o fst) cs))
1214 fun pretty_cases ctxt =
1216 fun add_case (_, (_, false)) = I
1217 | add_case (name, (c as Rule_Cases.Case {fixes, ...}, true)) =
1218 cons (name, (fixes, case_result c ctxt));
1219 val cases = fold add_case (cases_of ctxt) [];
1221 if null cases then []
1222 else [Pretty.big_list "cases:" (map pretty_case cases)]
1225 val print_cases = Pretty.writeln o Pretty.chunks o pretty_cases;
1232 val debug = Config.bool (Config.declare "Proof_Context.debug" (K (Config.Bool false)));
1233 val verbose = Config.bool (Config.declare "Proof_Context.verbose" (K (Config.Bool false)));
1235 fun pretty_ctxt ctxt =
1236 if not (Config.get ctxt debug) then []
1239 val prt_term = Syntax.pretty_term ctxt;
1242 val {structs, ...} = Local_Syntax.idents_of (syntax_of ctxt);
1244 if null structs then []
1245 else [Pretty.block (Pretty.str "structures:" :: Pretty.brk 1 ::
1246 Pretty.commas (map Pretty.str structs))];
1249 fun prt_fix (x, x') =
1250 if x = x' then Pretty.str x
1251 else Pretty.block [Pretty.str x, Pretty.str " =", Pretty.brk 1, prt_term (Syntax.free x')];
1253 filter_out ((can Name.dest_internal orf member (op =) structs) o #1)
1254 (Variable.dest_fixes ctxt);
1256 if null fixes then []
1257 else [Pretty.block (Pretty.str "fixed variables:" :: Pretty.brk 1 ::
1258 Pretty.commas (map prt_fix fixes))];
1261 val prems = Assumption.all_prems_of ctxt;
1263 if null prems then []
1264 else [Pretty.big_list "prems:" (map (Display.pretty_thm ctxt) prems)];
1265 in prt_structs @ prt_fixes @ prt_prems end;
1270 fun pretty_context ctxt =
1272 val verbose = Config.get ctxt verbose;
1273 fun verb f x = if verbose then f (x ()) else [];
1275 val prt_term = Syntax.pretty_term ctxt;
1276 val prt_typ = Syntax.pretty_typ ctxt;
1277 val prt_sort = Syntax.pretty_sort ctxt;
1280 val pretty_thy = Pretty.block
1281 [Pretty.str "theory:", Pretty.brk 1, Context.pretty_thy (theory_of ctxt)];
1284 fun prt_atom prt prtT (x, X) = Pretty.block
1285 [prt x, Pretty.str " ::", Pretty.brk 1, prtT X];
1287 fun prt_var (x, ~1) = prt_term (Syntax.free x)
1288 | prt_var xi = prt_term (Syntax.var xi);
1290 fun prt_varT (x, ~1) = prt_typ (TFree (x, []))
1291 | prt_varT xi = prt_typ (TVar (xi, []));
1293 val prt_defT = prt_atom prt_var prt_typ;
1294 val prt_defS = prt_atom prt_varT prt_sort;
1296 val (types, sorts) = Variable.constraints_of ctxt;
1298 verb single (K pretty_thy) @
1300 verb (pretty_abbrevs false) (K ctxt) @
1301 verb pretty_binds (K ctxt) @
1302 verb pretty_lthms (K ctxt) @
1303 verb pretty_cases (K ctxt) @
1304 verb single (fn () => Pretty.big_list "type constraints:" (map prt_defT (Vartab.dest types))) @
1305 verb single (fn () => Pretty.big_list "default sorts:" (map prt_defS (Vartab.dest sorts)))
1310 val show_abbrevs = Proof_Context.show_abbrevs;