1(*  Title:      HOL/Tools/Transfer/transfer.ML
2    Author:     Brian Huffman, TU Muenchen
3    Author:     Ondrej Kuncar, TU Muenchen
4
5Generic theorem transfer method.
6*)
7
8signature TRANSFER =
9sig
10  type pred_data
11  val mk_pred_data: thm -> thm -> thm list -> pred_data
12  val rel_eq_onp: pred_data -> thm
13  val pred_def: pred_data -> thm
14  val pred_simps: pred_data -> thm list
15  val update_pred_simps: thm list -> pred_data -> pred_data
16
17  val bottom_rewr_conv: thm list -> conv
18  val top_rewr_conv: thm list -> conv
19  val top_sweep_rewr_conv: thm list -> conv
20
21  val prep_conv: conv
22  val fold_relator_eqs_conv: Proof.context -> conv
23  val unfold_relator_eqs_conv: Proof.context -> conv
24  val get_transfer_raw: Proof.context -> thm list
25  val get_relator_eq: Proof.context -> thm list
26  val retrieve_relator_eq: Proof.context -> term -> thm list
27  val get_sym_relator_eq: Proof.context -> thm list
28  val get_relator_eq_raw: Proof.context -> thm list
29  val get_relator_domain: Proof.context -> thm list
30  val morph_pred_data: morphism -> pred_data -> pred_data
31  val lookup_pred_data: Proof.context -> string -> pred_data option
32  val update_pred_data: string -> pred_data -> Context.generic -> Context.generic
33  val is_compound_lhs: Proof.context -> term -> bool
34  val is_compound_rhs: Proof.context -> term -> bool
35  val transfer_add: attribute
36  val transfer_del: attribute
37  val transfer_raw_add: thm -> Context.generic -> Context.generic
38  val transfer_raw_del: thm -> Context.generic -> Context.generic
39  val transferred_attribute: thm list -> attribute
40  val untransferred_attribute: thm list -> attribute
41  val prep_transfer_domain_thm: Proof.context -> thm -> thm
42  val transfer_domain_add: attribute
43  val transfer_domain_del: attribute
44  val transfer_rule_of_term: Proof.context -> bool -> term -> thm
45  val transfer_rule_of_lhs: Proof.context -> term -> thm
46  val eq_tac: Proof.context -> int -> tactic
47  val transfer_start_tac: bool -> Proof.context -> int -> tactic
48  val transfer_prover_start_tac: Proof.context -> int -> tactic
49  val transfer_step_tac: Proof.context -> int -> tactic
50  val transfer_end_tac: Proof.context -> int -> tactic
51  val transfer_prover_end_tac: Proof.context -> int -> tactic
52  val transfer_tac: bool -> Proof.context -> int -> tactic
53  val transfer_prover_tac: Proof.context -> int -> tactic
54  val gen_frees_tac: (string * typ) list -> Proof.context -> int -> tactic
55end
56
57structure Transfer : TRANSFER =
58struct
59
60fun bottom_rewr_conv rewrs = Conv.bottom_conv (K (Conv.try_conv (Conv.rewrs_conv rewrs))) \<^context>
61fun top_rewr_conv rewrs = Conv.top_conv (K (Conv.try_conv (Conv.rewrs_conv rewrs))) \<^context>
62fun top_sweep_rewr_conv rewrs = Conv.top_sweep_conv (K (Conv.rewrs_conv rewrs)) \<^context>
63
64(** Theory Data **)
65
66val compound_xhs_empty_net = Item_Net.init (Thm.eq_thm_prop o apply2 snd) (single o fst);
67val rewr_rules = Item_Net.init Thm.eq_thm_prop (single o fst o HOLogic.dest_eq
68  o HOLogic.dest_Trueprop o Thm.concl_of);
69
70datatype pred_data = PRED_DATA of {pred_def: thm, rel_eq_onp: thm, pred_simps: thm list}
71
72fun mk_pred_data pred_def rel_eq_onp pred_simps = PRED_DATA {pred_def = pred_def, 
73  rel_eq_onp = rel_eq_onp, pred_simps = pred_simps}
74
75fun map_pred_data' f1 f2 f3 (PRED_DATA {pred_def, rel_eq_onp, pred_simps}) =
76  PRED_DATA {pred_def = f1 pred_def, rel_eq_onp = f2 rel_eq_onp, pred_simps = f3 pred_simps}
77
78fun rep_pred_data (PRED_DATA p) = p
79val rel_eq_onp = #rel_eq_onp o rep_pred_data
80val pred_def = #pred_def o rep_pred_data
81val pred_simps = #pred_simps o rep_pred_data
82fun update_pred_simps new_pred_data = map_pred_data' I I (K new_pred_data)
83
84
85structure Data = Generic_Data
86(
87  type T =
88    { transfer_raw : thm Item_Net.T,
89      known_frees : (string * typ) list,
90      compound_lhs : (term * thm) Item_Net.T,
91      compound_rhs : (term * thm) Item_Net.T,
92      relator_eq : thm Item_Net.T,
93      relator_eq_raw : thm Item_Net.T,
94      relator_domain : thm Item_Net.T,
95      pred_data : pred_data Symtab.table }
96  val empty =
97    { transfer_raw = Thm.intro_rules,
98      known_frees = [],
99      compound_lhs = compound_xhs_empty_net,
100      compound_rhs = compound_xhs_empty_net,
101      relator_eq = rewr_rules,
102      relator_eq_raw = Thm.full_rules,
103      relator_domain = Thm.full_rules,
104      pred_data = Symtab.empty }
105  val extend = I
106  fun merge
107    ( { transfer_raw = t1, known_frees = k1,
108        compound_lhs = l1,
109        compound_rhs = c1, relator_eq = r1,
110        relator_eq_raw = rw1, relator_domain = rd1,
111        pred_data = pd1 },
112      { transfer_raw = t2, known_frees = k2,
113        compound_lhs = l2,
114        compound_rhs = c2, relator_eq = r2,
115        relator_eq_raw = rw2, relator_domain = rd2,
116        pred_data = pd2 } ) =
117    { transfer_raw = Item_Net.merge (t1, t2),
118      known_frees = Library.merge (op =) (k1, k2),
119      compound_lhs = Item_Net.merge (l1, l2),
120      compound_rhs = Item_Net.merge (c1, c2),
121      relator_eq = Item_Net.merge (r1, r2),
122      relator_eq_raw = Item_Net.merge (rw1, rw2),
123      relator_domain = Item_Net.merge (rd1, rd2),
124      pred_data = Symtab.merge (K true) (pd1, pd2) }
125)
126
127fun get_net_content f ctxt =
128  Item_Net.content (f (Data.get (Context.Proof ctxt)))
129  |> map (Thm.transfer' ctxt)
130
131val get_transfer_raw = get_net_content #transfer_raw
132
133val get_known_frees = #known_frees o Data.get o Context.Proof
134
135fun is_compound f ctxt t =
136  Item_Net.retrieve (f (Data.get (Context.Proof ctxt))) t
137  |> exists (fn (pat, _) => Pattern.matches (Proof_Context.theory_of ctxt) (pat, t));
138
139val is_compound_lhs = is_compound #compound_lhs
140val is_compound_rhs = is_compound #compound_rhs
141
142val get_relator_eq = get_net_content #relator_eq #> map safe_mk_meta_eq
143
144fun retrieve_relator_eq ctxt t =
145  Item_Net.retrieve (#relator_eq (Data.get (Context.Proof ctxt))) t
146  |> map (Thm.transfer' ctxt)
147
148val get_sym_relator_eq = get_net_content #relator_eq #> map (safe_mk_meta_eq #> Thm.symmetric)
149
150val get_relator_eq_raw = get_net_content #relator_eq_raw
151
152val get_relator_domain = get_net_content #relator_domain
153
154val get_pred_data = #pred_data o Data.get o Context.Proof
155
156fun map_data f1 f2 f3 f4 f5 f6 f7 f8
157  { transfer_raw, known_frees, compound_lhs, compound_rhs,
158    relator_eq, relator_eq_raw, relator_domain, pred_data } =
159  { transfer_raw = f1 transfer_raw,
160    known_frees = f2 known_frees,
161    compound_lhs = f3 compound_lhs,
162    compound_rhs = f4 compound_rhs,
163    relator_eq = f5 relator_eq,
164    relator_eq_raw = f6 relator_eq_raw,
165    relator_domain = f7 relator_domain,
166    pred_data = f8 pred_data }
167
168fun map_transfer_raw   f = map_data f I I I I I I I
169fun map_known_frees    f = map_data I f I I I I I I
170fun map_compound_lhs   f = map_data I I f I I I I I
171fun map_compound_rhs   f = map_data I I I f I I I I
172fun map_relator_eq     f = map_data I I I I f I I I
173fun map_relator_eq_raw f = map_data I I I I I f I I
174fun map_relator_domain f = map_data I I I I I I f I
175fun map_pred_data      f = map_data I I I I I I I f
176
177val add_transfer_thm =
178  Thm.trim_context #> (fn thm => Data.map
179    (map_transfer_raw (Item_Net.update thm) o
180     map_compound_lhs
181       (case HOLogic.dest_Trueprop (Thm.concl_of thm) of
182          Const (\<^const_name>\<open>Rel\<close>, _) $ _ $ (lhs as (_ $ _)) $ _ =>
183            Item_Net.update (lhs, thm)
184        | _ => I) o
185     map_compound_rhs
186       (case HOLogic.dest_Trueprop (Thm.concl_of thm) of
187          Const (\<^const_name>\<open>Rel\<close>, _) $ _ $ _ $ (rhs as (_ $ _)) =>
188            Item_Net.update (rhs, thm)
189        | _ => I) o
190     map_known_frees (Term.add_frees (Thm.concl_of thm))))
191
192fun del_transfer_thm thm = Data.map
193  (map_transfer_raw (Item_Net.remove thm) o
194   map_compound_lhs
195     (case HOLogic.dest_Trueprop (Thm.concl_of thm) of
196        Const (\<^const_name>\<open>Rel\<close>, _) $ _ $ (lhs as (_ $ _)) $ _ =>
197          Item_Net.remove (lhs, thm)
198      | _ => I) o
199   map_compound_rhs
200     (case HOLogic.dest_Trueprop (Thm.concl_of thm) of
201        Const (\<^const_name>\<open>Rel\<close>, _) $ _ $ _ $ (rhs as (_ $ _)) =>
202          Item_Net.remove (rhs, thm)
203      | _ => I))
204
205fun transfer_raw_add thm ctxt = add_transfer_thm thm ctxt
206fun transfer_raw_del thm ctxt = del_transfer_thm thm ctxt
207
208(** Conversions **)
209
210fun transfer_rel_conv conv =
211  Conv.concl_conv ~1 (HOLogic.Trueprop_conv (Conv.fun2_conv (Conv.arg_conv conv)))
212
213val Rel_rule = Thm.symmetric @{thm Rel_def}
214
215fun Rel_conv ct =
216  let val (cT, cT') = Thm.dest_funT (Thm.ctyp_of_cterm ct)
217      val (cU, _) = Thm.dest_funT cT'
218  in Thm.instantiate' [SOME cT, SOME cU] [SOME ct] Rel_rule end
219
220(* Conversion to preprocess a transfer rule *)
221fun safe_Rel_conv ct =
222  Conv.try_conv (HOLogic.Trueprop_conv (Conv.fun_conv (Conv.fun_conv Rel_conv))) ct
223
224fun prep_conv ct = (
225      Conv.implies_conv safe_Rel_conv prep_conv
226      else_conv
227      safe_Rel_conv
228      else_conv
229      Conv.all_conv) ct
230
231fun fold_relator_eqs_conv ctxt ct = (bottom_rewr_conv (get_relator_eq ctxt)) ct;
232fun unfold_relator_eqs_conv ctxt ct = (top_rewr_conv (get_sym_relator_eq ctxt)) ct;
233
234
235(** Replacing explicit equalities with is_equality premises **)
236
237fun mk_is_equality t =
238  Const (\<^const_name>\<open>is_equality\<close>, Term.fastype_of t --> HOLogic.boolT) $ t
239
240fun gen_abstract_equalities ctxt (dest : term -> term * (term -> term)) thm =
241  let
242    val prop = Thm.prop_of thm
243    val (t, mk_prop') = dest prop
244    (* Only consider "(=)" at non-base types *)
245    fun is_eq (Const (\<^const_name>\<open>HOL.eq\<close>, Type ("fun", [T, _]))) =
246        (case T of Type (_, []) => false | _ => true)
247      | is_eq _ = false
248    val add_eqs = Term.fold_aterms (fn t => if is_eq t then insert (op =) t else I)
249    val eq_consts = rev (add_eqs t [])
250    val eqTs = map (snd o dest_Const) eq_consts
251    val used = Term.add_free_names prop []
252    val names = map (K "") eqTs |> Name.variant_list used
253    val frees = map Free (names ~~ eqTs)
254    val prems = map (HOLogic.mk_Trueprop o mk_is_equality) frees
255    val prop1 = mk_prop' (Term.subst_atomic (eq_consts ~~ frees) t)
256    val prop2 = fold Logic.all frees (Logic.list_implies (prems, prop1))
257    val cprop = Thm.cterm_of ctxt prop2
258    val equal_thm = Raw_Simplifier.rewrite ctxt false @{thms is_equality_lemma} cprop
259    fun forall_elim thm = Thm.forall_elim_vars (Thm.maxidx_of thm + 1) thm
260  in
261    forall_elim (thm COMP (equal_thm COMP @{thm equal_elim_rule2}))
262  end
263    handle TERM _ => thm
264
265fun abstract_equalities_transfer ctxt thm =
266  let
267    fun dest prop =
268      let
269        val prems = Logic.strip_imp_prems prop
270        val concl = HOLogic.dest_Trueprop (Logic.strip_imp_concl prop)
271        val ((rel, x), y) = apfst Term.dest_comb (Term.dest_comb concl)
272      in
273        (rel, fn rel' =>
274          Logic.list_implies (prems, HOLogic.mk_Trueprop (rel' $ x $ y)))
275      end
276    val contracted_eq_thm =
277      Conv.fconv_rule (transfer_rel_conv (fold_relator_eqs_conv ctxt)) thm
278      handle CTERM _ => thm
279  in
280    gen_abstract_equalities ctxt dest contracted_eq_thm
281  end
282
283fun abstract_equalities_relator_eq ctxt rel_eq_thm =
284  gen_abstract_equalities ctxt (fn x => (x, I))
285    (rel_eq_thm RS @{thm is_equality_def [THEN iffD2]})
286
287fun abstract_equalities_domain ctxt thm =
288  let
289    fun dest prop =
290      let
291        val prems = Logic.strip_imp_prems prop
292        val concl = HOLogic.dest_Trueprop (Logic.strip_imp_concl prop)
293        val ((eq, dom), y) = apfst Term.dest_comb (Term.dest_comb concl)
294      in
295        (dom, fn dom' => Logic.list_implies (prems, HOLogic.mk_Trueprop (eq $ dom' $ y)))
296      end
297    fun transfer_rel_conv conv =
298      Conv.concl_conv ~1 (HOLogic.Trueprop_conv (Conv.arg1_conv (Conv.arg_conv conv)))
299    val contracted_eq_thm =
300      Conv.fconv_rule (transfer_rel_conv (fold_relator_eqs_conv ctxt)) thm
301  in
302    gen_abstract_equalities ctxt dest contracted_eq_thm
303  end
304
305
306(** Replacing explicit Domainp predicates with Domainp assumptions **)
307
308fun mk_Domainp_assm (T, R) =
309  HOLogic.mk_eq ((Const (\<^const_name>\<open>Domainp\<close>, Term.fastype_of T --> Term.fastype_of R) $ T), R)
310
311fun fold_Domainp f (t as Const (\<^const_name>\<open>Domainp\<close>,_) $ (Var (_,_))) = f t
312  | fold_Domainp f (t $ u) = fold_Domainp f t #> fold_Domainp f u
313  | fold_Domainp f (Abs (_, _, t)) = fold_Domainp f t
314  | fold_Domainp _ _ = I
315
316fun subst_terms tab t =
317  let
318    val t' = Termtab.lookup tab t
319  in
320    case t' of
321      SOME t' => t'
322      | NONE =>
323        (case t of
324          u $ v => (subst_terms tab u) $ (subst_terms tab v)
325          | Abs (a, T, t) => Abs (a, T, subst_terms tab t)
326          | t => t)
327  end
328
329fun gen_abstract_domains ctxt (dest : term -> term * (term -> term)) thm =
330  let
331    val prop = Thm.prop_of thm
332    val (t, mk_prop') = dest prop
333    val Domainp_tms = rev (fold_Domainp (fn t => insert op= t) t [])
334    val Domainp_Ts = map (snd o dest_funT o snd o dest_Const o fst o dest_comb) Domainp_tms
335    val used = Term.add_free_names t []
336    val rels = map (snd o dest_comb) Domainp_tms
337    val rel_names = map (fst o fst o dest_Var) rels
338    val names = map (fn name => ("D" ^ name)) rel_names |> Name.variant_list used
339    val frees = map Free (names ~~ Domainp_Ts)
340    val prems = map (HOLogic.mk_Trueprop o mk_Domainp_assm) (rels ~~ frees);
341    val t' = subst_terms (fold Termtab.update (Domainp_tms ~~ frees) Termtab.empty) t
342    val prop1 = fold Logic.all frees (Logic.list_implies (prems, mk_prop' t'))
343    val prop2 = Logic.list_rename_params (rev names) prop1
344    val cprop = Thm.cterm_of ctxt prop2
345    val equal_thm = Raw_Simplifier.rewrite ctxt false @{thms Domainp_lemma} cprop
346    fun forall_elim thm = Thm.forall_elim_vars (Thm.maxidx_of thm + 1) thm;
347  in
348    forall_elim (thm COMP (equal_thm COMP @{thm equal_elim_rule2}))
349  end
350  handle TERM _ => thm
351
352fun abstract_domains_transfer ctxt thm =
353  let
354    fun dest prop =
355      let
356        val prems = Logic.strip_imp_prems prop
357        val concl = HOLogic.dest_Trueprop (Logic.strip_imp_concl prop)
358        val ((rel, x), y) = apfst Term.dest_comb (Term.dest_comb concl)
359      in
360        (x, fn x' =>
361          Logic.list_implies (prems, HOLogic.mk_Trueprop (rel $ x' $ y)))
362      end
363  in
364    gen_abstract_domains ctxt dest thm
365  end
366
367fun abstract_domains_relator_domain ctxt thm =
368  let
369    fun dest prop =
370      let
371        val prems = Logic.strip_imp_prems prop
372        val concl = HOLogic.dest_Trueprop (Logic.strip_imp_concl prop)
373        val ((rel, x), y) = apfst Term.dest_comb (Term.dest_comb concl)
374      in
375        (y, fn y' =>
376          Logic.list_implies (prems, HOLogic.mk_Trueprop (rel $ x $ y')))
377      end
378  in
379    gen_abstract_domains ctxt dest thm
380  end
381
382fun detect_transfer_rules thm =
383  let
384    fun is_transfer_rule tm = case (HOLogic.dest_Trueprop tm) of
385      (Const (\<^const_name>\<open>HOL.eq\<close>, _)) $ ((Const (\<^const_name>\<open>Domainp\<close>, _)) $ _) $ _ => false
386      | _ $ _ $ _ => true
387      | _ => false
388    fun safe_transfer_rule_conv ctm =
389      if is_transfer_rule (Thm.term_of ctm) then safe_Rel_conv ctm else Conv.all_conv ctm
390  in
391    Conv.fconv_rule (Conv.prems_conv ~1 safe_transfer_rule_conv) thm
392  end
393
394(** Adding transfer domain rules **)
395
396fun prep_transfer_domain_thm ctxt =
397  abstract_equalities_domain ctxt o detect_transfer_rules
398
399fun add_transfer_domain_thm thm ctxt =
400  (add_transfer_thm o prep_transfer_domain_thm (Context.proof_of ctxt)) thm ctxt
401
402fun del_transfer_domain_thm thm ctxt =
403  (del_transfer_thm o prep_transfer_domain_thm (Context.proof_of ctxt)) thm ctxt
404
405(** Transfer proof method **)
406
407val post_simps =
408  @{thms transfer_forall_eq [symmetric]
409    transfer_implies_eq [symmetric] transfer_bforall_unfold}
410
411fun gen_frees_tac keepers ctxt = SUBGOAL (fn (t, i) =>
412  let
413    val keepers = keepers @ get_known_frees ctxt
414    val vs = rev (Term.add_frees t [])
415    val vs' = filter_out (member (op =) keepers) vs
416  in
417    Induct.arbitrary_tac ctxt 0 vs' i
418  end)
419
420fun mk_relT (T, U) = T --> U --> HOLogic.boolT
421
422fun mk_Rel t =
423  let val T = fastype_of t
424  in Const (\<^const_name>\<open>Transfer.Rel\<close>, T --> T) $ t end
425
426fun transfer_rule_of_terms (prj : typ * typ -> typ) ctxt tab t u =
427  let
428    (* precondition: prj(T,U) must consist of only TFrees and type "fun" *)
429    fun rel (T as Type ("fun", [T1, T2])) (U as Type ("fun", [U1, U2])) =
430          let
431            val r1 = rel T1 U1
432            val r2 = rel T2 U2
433            val rT = fastype_of r1 --> fastype_of r2 --> mk_relT (T, U)
434          in
435            Const (\<^const_name>\<open>rel_fun\<close>, rT) $ r1 $ r2
436          end
437      | rel T U =
438          let
439            val (a, _) = dest_TFree (prj (T, U))
440          in
441            Free (the (AList.lookup (op =) tab a), mk_relT (T, U))
442          end
443    fun zip _ thms (Bound i) (Bound _) = (nth thms i, [])
444      | zip ctxt thms (Abs (x, T, t)) (Abs (y, U, u)) =
445          let
446            val ([x', y'], ctxt') = Variable.variant_fixes [x, y] ctxt
447            val prop = mk_Rel (rel T U) $ Free (x', T) $ Free (y', U)
448            val cprop = Thm.cterm_of ctxt' (HOLogic.mk_Trueprop prop)
449            val thm0 = Thm.assume cprop
450            val (thm1, hyps) = zip ctxt' (thm0 :: thms) t u
451            val ((r1, x), y) = apfst Thm.dest_comb (Thm.dest_comb (Thm.dest_arg cprop))
452            val r2 = Thm.dest_fun2 (Thm.dest_arg (Thm.cprop_of thm1))
453            val (a1, (b1, _)) = apsnd Thm.dest_funT (Thm.dest_funT (Thm.ctyp_of_cterm r1))
454            val (a2, (b2, _)) = apsnd Thm.dest_funT (Thm.dest_funT (Thm.ctyp_of_cterm r2))
455            val tinsts = [SOME a1, SOME b1, SOME a2, SOME b2]
456            val insts = [SOME (Thm.dest_arg r1), SOME (Thm.dest_arg r2)]
457            val rule = Thm.instantiate' tinsts insts @{thm Rel_abs}
458            val thm2 = Thm.forall_intr x (Thm.forall_intr y (Thm.implies_intr cprop thm1))
459          in
460            (thm2 COMP rule, hyps)
461          end
462      | zip ctxt thms (f $ t) (g $ u) =
463          let
464            val (thm1, hyps1) = zip ctxt thms f g
465            val (thm2, hyps2) = zip ctxt thms t u
466          in
467            (thm2 RS (thm1 RS @{thm Rel_app}), hyps1 @ hyps2)
468          end
469      | zip _ _ t u =
470          let
471            val T = fastype_of t
472            val U = fastype_of u
473            val prop = mk_Rel (rel T U) $ t $ u
474            val cprop = Thm.cterm_of ctxt (HOLogic.mk_Trueprop prop)
475          in
476            (Thm.assume cprop, [cprop])
477          end
478    val r = mk_Rel (rel (fastype_of t) (fastype_of u))
479    val goal = HOLogic.mk_Trueprop (r $ t $ u)
480    val rename = Thm.trivial (Thm.cterm_of ctxt goal)
481    val (thm, hyps) = zip ctxt [] t u
482  in
483    Drule.implies_intr_list hyps (thm RS rename)
484  end
485
486(* create a lambda term of the same shape as the given term *)
487fun skeleton is_atom =
488  let
489    fun dummy ctxt =
490      let val (c, ctxt') = yield_singleton Variable.variant_fixes "a" ctxt
491      in (Free (c, dummyT), ctxt') end
492    fun skel (Bound i) ctxt = (Bound i, ctxt)
493      | skel (Abs (x, _, t)) ctxt =
494          let val (t', ctxt) = skel t ctxt
495          in (Abs (x, dummyT, t'), ctxt) end
496      | skel (tu as t $ u) ctxt =
497          if is_atom tu andalso not (Term.is_open tu) then dummy ctxt
498          else
499            let
500              val (t', ctxt) = skel t ctxt
501              val (u', ctxt) = skel u ctxt
502            in (t' $ u', ctxt) end
503      | skel _ ctxt = dummy ctxt
504  in
505    fn ctxt => fn t =>
506      fst (skel t ctxt) |> Syntax.check_term ctxt  (* FIXME avoid syntax operation!? *)
507  end
508
509(** Monotonicity analysis **)
510
511(* TODO: Put extensible table in theory data *)
512val monotab =
513  Symtab.make
514    [(\<^const_name>\<open>transfer_implies\<close>, [~1, 1]),
515     (\<^const_name>\<open>transfer_forall\<close>, [1])(*,
516     (@{const_name implies}, [~1, 1]),
517     (@{const_name All}, [1])*)]
518
519(*
520Function bool_insts determines the set of boolean-relation variables
521that can be instantiated to implies, rev_implies, or iff.
522
523Invariants: bool_insts p (t, u) requires that
524  u :: _ => _ => ... => bool, and
525  t is a skeleton of u
526*)
527fun bool_insts p (t, u) =
528  let
529    fun strip2 (t1 $ t2, u1 $ u2, tus) =
530        strip2 (t1, u1, (t2, u2) :: tus)
531      | strip2 x = x
532    fun or3 ((a, b, c), (x, y, z)) = (a orelse x, b orelse y, c orelse z)
533    fun go Ts p (Abs (_, T, t), Abs (_, _, u)) tab = go (T :: Ts) p (t, u) tab
534      | go Ts p (t, u) tab =
535        let
536          val (a, _) = dest_TFree (Term.body_type (Term.fastype_of1 (Ts, t)))
537          val (_, tf, tus) = strip2 (t, u, [])
538          val ps_opt = case tf of Const (c, _) => Symtab.lookup monotab c | _ => NONE
539          val tab1 =
540            case ps_opt of
541              SOME ps =>
542              let
543                val ps' = map (fn x => p * x) (take (length tus) ps)
544              in
545                fold I (map2 (go Ts) ps' tus) tab
546              end
547            | NONE => tab
548          val tab2 = Symtab.make [(a, (p >= 0, p <= 0, is_none ps_opt))]
549        in
550          Symtab.join (K or3) (tab1, tab2)
551        end
552    val tab = go [] p (t, u) Symtab.empty
553    fun f (a, (true, false, false)) = SOME (a, \<^const>\<open>implies\<close>)
554      | f (a, (false, true, false)) = SOME (a, \<^const>\<open>rev_implies\<close>)
555      | f (a, (true, true, _))      = SOME (a, HOLogic.eq_const HOLogic.boolT)
556      | f _                         = NONE
557  in
558    map_filter f (Symtab.dest tab)
559  end
560
561fun transfer_rule_of_term ctxt equiv t =
562  let
563    val s = skeleton (is_compound_rhs ctxt) ctxt t
564    val frees = map fst (Term.add_frees s [])
565    val tfrees = map fst (Term.add_tfrees s [])
566    fun prep a = "R" ^ Library.unprefix "'" a
567    val (rnames, ctxt') = Variable.variant_fixes (map prep tfrees) ctxt
568    val tab = tfrees ~~ rnames
569    fun prep a = the (AList.lookup (op =) tab a)
570    val thm = transfer_rule_of_terms fst ctxt' tab s t
571    val binsts = bool_insts (if equiv then 0 else 1) (s, t)
572    val idx = Thm.maxidx_of thm + 1
573    fun tinst (a, _) = (((a, idx), \<^sort>\<open>type\<close>), \<^ctyp>\<open>bool\<close>)
574    fun inst (a, t) =
575      ((Name.clean_index (prep a, idx), \<^typ>\<open>bool \<Rightarrow> bool \<Rightarrow> bool\<close>), Thm.cterm_of ctxt' t)
576  in
577    thm
578    |> Thm.generalize (tfrees, rnames @ frees) idx
579    |> Thm.instantiate (map tinst binsts, map inst binsts)
580  end
581
582fun transfer_rule_of_lhs ctxt t =
583  let
584    val s = skeleton (is_compound_lhs ctxt) ctxt t
585    val frees = map fst (Term.add_frees s [])
586    val tfrees = map fst (Term.add_tfrees s [])
587    fun prep a = "R" ^ Library.unprefix "'" a
588    val (rnames, ctxt') = Variable.variant_fixes (map prep tfrees) ctxt
589    val tab = tfrees ~~ rnames
590    fun prep a = the (AList.lookup (op =) tab a)
591    val thm = transfer_rule_of_terms snd ctxt' tab t s
592    val binsts = bool_insts 1 (s, t)
593    val idx = Thm.maxidx_of thm + 1
594    fun tinst (a, _) = (((a, idx), \<^sort>\<open>type\<close>), \<^ctyp>\<open>bool\<close>)
595    fun inst (a, t) =
596      ((Name.clean_index (prep a, idx), \<^typ>\<open>bool \<Rightarrow> bool \<Rightarrow> bool\<close>), Thm.cterm_of ctxt' t)
597  in
598    thm
599    |> Thm.generalize (tfrees, rnames @ frees) idx
600    |> Thm.instantiate (map tinst binsts, map inst binsts)
601  end
602
603fun eq_rules_tac ctxt eq_rules =
604  TRY o REPEAT_ALL_NEW (resolve_tac ctxt eq_rules)
605  THEN_ALL_NEW resolve_tac ctxt @{thms is_equality_eq}
606
607fun eq_tac ctxt = eq_rules_tac ctxt (get_relator_eq_raw ctxt)
608
609fun transfer_step_tac ctxt =
610  REPEAT_ALL_NEW (resolve_tac ctxt (get_transfer_raw ctxt))
611  THEN_ALL_NEW (DETERM o eq_rules_tac ctxt (get_relator_eq_raw ctxt))
612
613fun transfer_start_tac equiv ctxt i =
614    let
615      val pre_simps = @{thms transfer_forall_eq transfer_implies_eq}
616      val start_rule =
617        if equiv then @{thm transfer_start} else @{thm transfer_start'}
618      val err_msg = "Transfer failed to convert goal to an object-logic formula"
619      fun main_tac (t, i) =
620        resolve_tac ctxt [start_rule] i THEN
621        (resolve_tac ctxt [transfer_rule_of_term ctxt equiv (HOLogic.dest_Trueprop t)]) (i + 1)
622          handle TERM (_, ts) => raise TERM (err_msg, ts)
623    in
624      EVERY
625        [rewrite_goal_tac ctxt pre_simps i THEN
626         SUBGOAL main_tac i]
627    end;
628
629fun transfer_prover_start_tac ctxt = SUBGOAL (fn (t, i) =>
630  let
631    val rhs = (snd o Term.dest_comb o HOLogic.dest_Trueprop) t
632    val rule1 = transfer_rule_of_term ctxt false rhs
633    val expand_eqs_in_rel_conv = transfer_rel_conv (unfold_relator_eqs_conv ctxt)
634  in
635    EVERY
636      [CONVERSION prep_conv i,
637       CONVERSION expand_eqs_in_rel_conv i,
638       resolve_tac ctxt @{thms transfer_prover_start} i,
639       resolve_tac ctxt [rule1] (i + 1)]
640  end);
641
642fun transfer_end_tac ctxt i =
643  let
644    val post_simps = @{thms transfer_forall_eq [symmetric]
645      transfer_implies_eq [symmetric] transfer_bforall_unfold}
646  in
647    EVERY [rewrite_goal_tac ctxt post_simps i,
648           Goal.norm_hhf_tac ctxt i]
649  end;
650
651fun transfer_prover_end_tac ctxt i = resolve_tac ctxt @{thms refl} i
652
653local 
654  infix 1 THEN_ALL_BUT_FIRST_NEW
655  fun (tac1 THEN_ALL_BUT_FIRST_NEW tac2) i st =
656    st |> (tac1 i THEN (fn st' =>
657      Seq.INTERVAL tac2 (i + 1) (i + Thm.nprems_of st' - Thm.nprems_of st) st'));
658in
659  fun transfer_tac equiv ctxt i =
660    let
661      val rules = get_transfer_raw ctxt
662      val eq_rules = get_relator_eq_raw ctxt
663      (* allow unsolved subgoals only for standard transfer method, not for transfer' *)
664      val end_tac = if equiv then K all_tac else K no_tac
665  
666      fun transfer_search_tac i =
667        (SOLVED'
668          (REPEAT_ALL_NEW (resolve_tac ctxt rules) THEN_ALL_NEW
669            (DETERM o eq_rules_tac ctxt eq_rules))
670          ORELSE' end_tac) i
671     in
672       (transfer_start_tac equiv ctxt 
673        THEN_ALL_BUT_FIRST_NEW transfer_search_tac
674        THEN' transfer_end_tac ctxt) i
675     end
676
677  fun transfer_prover_tac ctxt i = 
678    let
679      val rules = get_transfer_raw ctxt
680      val eq_rules = get_relator_eq_raw ctxt
681  
682      fun transfer_prover_search_tac i = 
683        (REPEAT_ALL_NEW (resolve_tac ctxt rules) THEN_ALL_NEW
684          (DETERM o eq_rules_tac ctxt eq_rules)) i
685    in
686      (transfer_prover_start_tac ctxt 
687       THEN_ALL_BUT_FIRST_NEW transfer_prover_search_tac
688       THEN' transfer_prover_end_tac ctxt) i
689    end
690end;
691
692(** Transfer attribute **)
693
694fun transferred ctxt extra_rules thm =
695  let
696    val rules = extra_rules @ get_transfer_raw ctxt
697    val eq_rules = get_relator_eq_raw ctxt
698    val pre_simps = @{thms transfer_forall_eq transfer_implies_eq}
699    val thm1 = Drule.forall_intr_vars thm
700    val instT =
701      rev (Term.add_tvars (Thm.full_prop_of thm1) [])
702      |> map (fn v as ((a, _), S) => (v, Thm.ctyp_of ctxt (TFree (a, S))))
703    val thm2 = thm1
704      |> Thm.instantiate (instT, [])
705      |> Raw_Simplifier.rewrite_rule ctxt pre_simps
706    val ctxt' = Variable.declare_names (Thm.full_prop_of thm2) ctxt
707    val rule = transfer_rule_of_lhs ctxt' (HOLogic.dest_Trueprop (Thm.concl_of thm2))
708  in
709    Goal.prove_internal ctxt' []
710      (Thm.cterm_of ctxt' (HOLogic.mk_Trueprop (Var (("P", 0), \<^typ>\<open>bool\<close>))))
711      (fn _ =>
712        resolve_tac ctxt' [thm2 RS @{thm transfer_start'}, thm2 RS @{thm transfer_start}] 1 THEN
713        (resolve_tac ctxt' [rule]
714          THEN_ALL_NEW
715            (SOLVED' (REPEAT_ALL_NEW (resolve_tac ctxt' rules)
716              THEN_ALL_NEW (DETERM o eq_rules_tac ctxt' eq_rules)))) 1
717          handle TERM (_, ts) =>
718            raise TERM ("Transfer failed to convert goal to an object-logic formula", ts))
719    |> Raw_Simplifier.rewrite_rule ctxt' post_simps
720    |> Simplifier.norm_hhf ctxt'
721    |> Drule.generalize (map (fst o dest_TFree o Thm.typ_of o snd) instT, [])
722    |> Drule.zero_var_indexes
723  end
724(*
725    handle THM _ => thm
726*)
727
728fun untransferred ctxt extra_rules thm =
729  let
730    val rules = extra_rules @ get_transfer_raw ctxt
731    val eq_rules = get_relator_eq_raw ctxt
732    val pre_simps = @{thms transfer_forall_eq transfer_implies_eq}
733    val thm1 = Drule.forall_intr_vars thm
734    val instT =
735      rev (Term.add_tvars (Thm.full_prop_of thm1) [])
736      |> map (fn v as ((a, _), S) => (v, Thm.ctyp_of ctxt (TFree (a, S))))
737    val thm2 = thm1
738      |> Thm.instantiate (instT, [])
739      |> Raw_Simplifier.rewrite_rule ctxt pre_simps
740    val ctxt' = Variable.declare_names (Thm.full_prop_of thm2) ctxt
741    val t = HOLogic.dest_Trueprop (Thm.concl_of thm2)
742    val rule = transfer_rule_of_term ctxt' true t
743  in
744    Goal.prove_internal ctxt' []
745      (Thm.cterm_of ctxt' (HOLogic.mk_Trueprop (Var (("P", 0), \<^typ>\<open>bool\<close>))))
746      (fn _ =>
747        resolve_tac ctxt' [thm2 RS @{thm untransfer_start}] 1 THEN
748        (resolve_tac ctxt' [rule]
749          THEN_ALL_NEW
750            (SOLVED' (REPEAT_ALL_NEW (resolve_tac ctxt' rules)
751              THEN_ALL_NEW (DETERM o eq_rules_tac ctxt' eq_rules)))) 1
752          handle TERM (_, ts) =>
753            raise TERM ("Transfer failed to convert goal to an object-logic formula", ts))
754    |> Raw_Simplifier.rewrite_rule ctxt' post_simps
755    |> Simplifier.norm_hhf ctxt'
756    |> Drule.generalize (map (fst o dest_TFree o Thm.typ_of o snd) instT, [])
757    |> Drule.zero_var_indexes
758  end
759
760(** Methods and attributes **)
761
762val free = Args.context -- Args.term >> (fn (_, Free v) => v | (ctxt, t) =>
763  error ("Bad free variable: " ^ Syntax.string_of_term ctxt t))
764
765val fixing = Scan.optional (Scan.lift (Args.$$$ "fixing" -- Args.colon)
766  |-- Scan.repeat free) []
767
768val reverse_prems = fn _ => PRIMITIVE (fn thm => fold_rev (fn i => Thm.permute_prems i 1) 
769    (0 upto Thm.nprems_of thm - 1) thm);
770  
771fun transfer_start_method equiv : (Proof.context -> Proof.method) context_parser =
772  fixing >> (fn vs => fn ctxt =>
773    SIMPLE_METHOD' (gen_frees_tac vs ctxt THEN' transfer_start_tac equiv ctxt
774    THEN' reverse_prems));
775
776fun transfer_method equiv : (Proof.context -> Proof.method) context_parser =
777  fixing >> (fn vs => fn ctxt =>
778    SIMPLE_METHOD' (gen_frees_tac vs ctxt THEN' transfer_tac equiv ctxt))
779
780val transfer_prover_start_method : (Proof.context -> Proof.method) context_parser =
781  Scan.succeed (fn ctxt => SIMPLE_METHOD' (transfer_prover_start_tac ctxt THEN' reverse_prems))
782
783val transfer_prover_method : (Proof.context -> Proof.method) context_parser =
784  Scan.succeed (fn ctxt => SIMPLE_METHOD' (transfer_prover_tac ctxt))
785
786(* Attribute for transfer rules *)
787
788fun prep_rule ctxt =
789  abstract_domains_transfer ctxt o abstract_equalities_transfer ctxt o Conv.fconv_rule prep_conv
790
791val transfer_add =
792  Thm.declaration_attribute (fn thm => fn ctxt =>
793    (add_transfer_thm o prep_rule (Context.proof_of ctxt)) thm ctxt)
794
795val transfer_del =
796  Thm.declaration_attribute (fn thm => fn ctxt =>
797    (del_transfer_thm o prep_rule (Context.proof_of ctxt)) thm ctxt)
798
799val transfer_attribute =
800  Attrib.add_del transfer_add transfer_del
801
802(* Attributes for transfer domain rules *)
803
804val transfer_domain_add = Thm.declaration_attribute add_transfer_domain_thm
805
806val transfer_domain_del = Thm.declaration_attribute del_transfer_domain_thm
807
808val transfer_domain_attribute =
809  Attrib.add_del transfer_domain_add transfer_domain_del
810
811(* Attributes for transferred rules *)
812
813fun transferred_attribute thms =
814  Thm.rule_attribute thms (fn context => transferred (Context.proof_of context) thms)
815
816fun untransferred_attribute thms =
817  Thm.rule_attribute thms (fn context => untransferred (Context.proof_of context) thms)
818
819val transferred_attribute_parser =
820  Attrib.thms >> transferred_attribute
821
822val untransferred_attribute_parser =
823  Attrib.thms >> untransferred_attribute
824
825fun morph_pred_data phi = 
826  let
827    val morph_thm = Morphism.thm phi
828  in
829    map_pred_data' morph_thm morph_thm (map morph_thm)
830  end
831
832fun lookup_pred_data ctxt type_name =
833  Symtab.lookup (get_pred_data ctxt) type_name
834  |> Option.map (morph_pred_data (Morphism.transfer_morphism' ctxt))
835
836fun update_pred_data type_name qinfo ctxt =
837  Data.map (map_pred_data (Symtab.update (type_name, qinfo))) ctxt
838
839(* Theory setup *)
840
841val _ =
842  Theory.setup
843    let
844      val name = \<^binding>\<open>relator_eq\<close>
845      fun add_thm thm context =
846        context
847        |> Data.map (map_relator_eq (Item_Net.update (Thm.trim_context thm)))
848        |> Data.map (map_relator_eq_raw
849            (Item_Net.update
850              (Thm.trim_context (abstract_equalities_relator_eq (Context.proof_of context) thm))))
851      fun del_thm thm context = context
852        |> Data.map (map_relator_eq (Item_Net.remove thm))
853        |> Data.map (map_relator_eq_raw
854            (Item_Net.remove (abstract_equalities_relator_eq (Context.proof_of context) thm)))
855      val add = Thm.declaration_attribute add_thm
856      val del = Thm.declaration_attribute del_thm
857      val text = "declaration of relator equality rule (used by transfer method)"
858      val content = Item_Net.content o #relator_eq o Data.get
859    in
860      Attrib.setup name (Attrib.add_del add del) text
861      #> Global_Theory.add_thms_dynamic (name, content)
862    end
863
864val _ =
865  Theory.setup
866    let
867      val name = \<^binding>\<open>relator_domain\<close>
868      fun add_thm thm context =
869        let
870          val thm' = thm
871            |> abstract_domains_relator_domain (Context.proof_of context)
872            |> Thm.trim_context
873        in
874          context
875          |> Data.map (map_relator_domain (Item_Net.update thm'))
876          |> add_transfer_domain_thm thm'
877        end
878      fun del_thm thm context =
879        let
880          val thm' = abstract_domains_relator_domain (Context.proof_of context) thm
881        in
882          context
883          |> Data.map (map_relator_domain (Item_Net.remove thm'))
884          |> del_transfer_domain_thm thm'
885        end
886      val add = Thm.declaration_attribute add_thm
887      val del = Thm.declaration_attribute del_thm
888      val text = "declaration of relator domain rule (used by transfer method)"
889      val content = Item_Net.content o #relator_domain o Data.get
890    in
891      Attrib.setup name (Attrib.add_del add del) text
892      #> Global_Theory.add_thms_dynamic (name, content)
893    end
894
895val _ =
896  Theory.setup
897    (Attrib.setup \<^binding>\<open>transfer_rule\<close> transfer_attribute
898       "transfer rule for transfer method"
899    #> Global_Theory.add_thms_dynamic
900       (\<^binding>\<open>transfer_raw\<close>, Item_Net.content o #transfer_raw o Data.get)
901    #> Attrib.setup \<^binding>\<open>transfer_domain_rule\<close> transfer_domain_attribute
902       "transfer domain rule for transfer method"
903    #> Attrib.setup \<^binding>\<open>transferred\<close> transferred_attribute_parser
904       "raw theorem transferred to abstract theorem using transfer rules"
905    #> Attrib.setup \<^binding>\<open>untransferred\<close> untransferred_attribute_parser
906       "abstract theorem transferred to raw theorem using transfer rules"
907    #> Global_Theory.add_thms_dynamic
908       (\<^binding>\<open>relator_eq_raw\<close>, Item_Net.content o #relator_eq_raw o Data.get)
909    #> Method.setup \<^binding>\<open>transfer_start\<close> (transfer_start_method true)
910       "firtst step in the transfer algorithm (for debugging transfer)"
911    #> Method.setup \<^binding>\<open>transfer_start'\<close> (transfer_start_method false)
912       "firtst step in the transfer algorithm (for debugging transfer)"
913    #> Method.setup \<^binding>\<open>transfer_prover_start\<close> transfer_prover_start_method
914       "firtst step in the transfer_prover algorithm (for debugging transfer_prover)"
915    #> Method.setup \<^binding>\<open>transfer_step\<close>
916       (Scan.succeed (fn ctxt => SIMPLE_METHOD' (transfer_step_tac ctxt)))
917       "step in the search for transfer rules (for debugging transfer and transfer_prover)"
918    #> Method.setup \<^binding>\<open>transfer_end\<close>
919       (Scan.succeed (fn ctxt => SIMPLE_METHOD' (transfer_end_tac ctxt)))
920       "last step in the transfer algorithm (for debugging transfer)"
921    #> Method.setup \<^binding>\<open>transfer_prover_end\<close>
922       (Scan.succeed (fn ctxt => SIMPLE_METHOD' (transfer_prover_end_tac ctxt)))
923       "last step in the transfer_prover algorithm (for debugging transfer_prover)"
924    #> Method.setup \<^binding>\<open>transfer\<close> (transfer_method true)
925       "generic theorem transfer method"
926    #> Method.setup \<^binding>\<open>transfer'\<close> (transfer_method false)
927       "generic theorem transfer method"
928    #> Method.setup \<^binding>\<open>transfer_prover\<close> transfer_prover_method
929       "for proving transfer rules")
930end
931