1 (* Copyright (C) 2002, HELM Team.
3 * This file is part of HELM, an Hypertextual, Electronic
4 * Library of Mathematics, developed at the Computer Science
5 * Department, University of Bologna, Italy.
7 * HELM is free software; you can redistribute it and/or
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15 * GNU General Public License for more details.
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22 * For details, see the HELM World-Wide-Web page,
23 * http://cs.unibo.it/helm/.
30 module P = PrimitiveTactics
32 module CR = CicReduction
33 module PST = ProofEngineStructuralRules
34 module PET = ProofEngineTypes
35 module CTC = CicTypeChecker
37 module S = CicSubstitution
38 module RT = ReductionTactics
39 module PEH = ProofEngineHelpers
40 module ET = EqualityTactics
41 module DTI = DoubleTypeInference
42 module FNG = FreshNamesGenerator
46 if debug then (fun x -> prerr_endline (Lazy.force x)) else (fun _ -> ())
48 (* funzione generale di rilocazione dei riferimenti locali *)
50 let relocate_term map t =
51 let rec map_xnss k xnss =
52 let imap (uri, t) = uri, map_term k t in
57 | Some t -> Some (map_term k t)
61 let imap (name, i, ty, bo) = name, i, map_term k ty, map_term (k + len) bo in
63 and map_cfs len k cfs =
64 let imap (name, ty, bo) = name, map_term k ty, map_term (k + len) bo in
66 and map_term k = function
67 | C.Rel m -> if m < k then C.Rel m else C.Rel (map (m - k))
69 | C.Implicit _ as t -> t
70 | C.Var (uri, xnss) -> C.Var (uri, map_xnss k xnss)
71 | C.Const (uri, xnss) -> C.Const (uri, map_xnss k xnss)
72 | C.MutInd (uri, tyno, xnss) -> C.MutInd (uri, tyno, map_xnss k xnss)
73 | C.MutConstruct (uri, tyno, consno, xnss) ->
74 C.MutConstruct (uri, tyno, consno, map_xnss k xnss)
75 | C.Meta (i, mss) -> C.Meta(i, map_mss k mss)
76 | C.Cast (te, ty) -> C.Cast (map_term k te, map_term k ty)
77 | C.Appl ts -> C.Appl (List.map (map_term k) ts)
78 | C.MutCase (sp, i, outty, t, pl) ->
79 C.MutCase (sp, i, map_term k outty, map_term k t, List.map (map_term k) pl)
80 | C.Prod (n, s, t) -> C.Prod (n, map_term k s, map_term (succ k) t)
81 | C.Lambda (n, s, t) -> C.Lambda (n, map_term k s, map_term (succ k) t)
82 | C.LetIn (n, s, t) -> C.LetIn (n, map_term k s, map_term (succ k) t)
83 | C.Fix (i, fs) -> C.Fix (i, map_fs (List.length fs) k fs)
84 | C.CoFix (i, cfs) -> C.CoFix (i, map_cfs (List.length cfs) k cfs)
90 let after continuation aftermap beforemap =
91 continuation ~map:(fun n -> aftermap (beforemap n))
93 let after2 continuation aftermap beforemap ~map =
94 continuation ~map:(fun n -> map (aftermap (beforemap n)))
96 (* term ha tipo t1=t2; funziona solo se t1 e t2 hanno in testa costruttori
99 let discriminate_tac ~term =
101 match LibraryObjects.true_URI () with
103 | None -> raise (PET.Fail (lazy "You need to register the default \"true\" definition first. Please use the \"default\" command")) in
105 match LibraryObjects.false_URI () with
107 | None -> raise (PET.Fail (lazy "You need to register the default \"false\" definition first. Please use the \"default\" command")) in
108 let fail msg = raise (PET.Fail (lazy ("Discriminate: " ^ msg))) in
109 let find_discriminating_consno t1 t2 =
112 | C.MutConstruct _, C.MutConstruct _ when t1 = t2 -> None
113 | C.Appl ((C.MutConstruct _ as constr1) :: args1),
114 C.Appl ((C.MutConstruct _ as constr2) :: args2)
115 when constr1 = constr2 ->
116 let rec aux_list l1 l2 =
119 | hd1 :: tl1, hd2 :: tl2 ->
120 (match aux hd1 hd2 with
121 | None -> aux_list tl1 tl2
122 | Some _ as res -> res)
123 | _ -> (* same constructor applied to a different number of args *)
127 | ((C.MutConstruct (_,_,consno1,subst1)),
128 (C.MutConstruct (_,_,consno2,subst2)))
129 | ((C.MutConstruct (_,_,consno1,subst1)),
130 (C.Appl ((C.MutConstruct (_,_,consno2,subst2)) :: _)))
131 | ((C.Appl ((C.MutConstruct (_,_,consno1,subst1)) :: _)),
132 (C.MutConstruct (_,_,consno2,subst2)))
133 | ((C.Appl ((C.MutConstruct (_,_,consno1,subst1)) :: _)),
134 (C.Appl ((C.MutConstruct (_,_,consno2,subst2)) :: _)))
135 when (consno1 <> consno2) || (subst1 <> subst2) ->
137 | _ -> fail "not a discriminable equality"
141 let mk_branches_and_outtype turi typeno consno context args =
142 (* a list of "True" except for the element in position consno which
144 match fst (CicEnvironment.get_obj CU.empty_ugraph turi) with
145 | C.InductiveDefinition (ind_type_list,_,paramsno,_) ->
146 let _,_,rty,constructor_list = List.nth ind_type_list typeno in
147 let false_constr_id,_ = List.nth constructor_list (consno - 1) in
151 (* dubbio: e' corretto ridurre in questo context ??? *)
152 let red_ty = CR.whd context cty in
155 | C.Prod (_,_,target) when (k <= paramsno) ->
156 S.subst (List.nth args (k-1))
158 | C.Prod (binder,source,target) when (k > paramsno) ->
159 C.Lambda (binder, source, (aux target (k+1)))
161 if (id = false_constr_id)
162 then (C.MutInd(false_URI,0,[]))
163 else (C.MutInd(true_URI,0,[]))
165 (S.lift 1 (aux red_ty 1)))
169 let rec mk_lambdas rev_left_args =
171 0, args, C.Prod (_,so,ta) ->
173 (C.Name (incr seed; "x" ^ string_of_int !seed),
175 mk_lambdas rev_left_args (0,args,ta))
176 | 0, args, C.Sort _ ->
180 | n -> C.Rel n :: mk_rels (n - 1) in
181 let argsno = List.length args in
184 (if argsno + List.length rev_left_args > 0 then
186 (C.MutInd (turi, typeno, []) ::
188 (S.lift (argsno + 1))
189 (List.rev rev_left_args)) @
192 C.MutInd (turi,typeno,[])),
194 | 0, _, _ -> assert false (* seriously screwed up *)
195 | n, he::tl, C.Prod (_,_,ta) ->
196 mk_lambdas (he::rev_left_args)(n-1,tl,S.subst he ta)
198 assert false (* we should probably reduce in some context *)
200 mk_lambdas [] (paramsno, args, rty)
205 let discriminate'_tac ~term status =
206 let (proof, goal) = status in
207 let _,metasenv,_subst,_,_, _ = proof in
208 let _,context,_ = CicUtil.lookup_meta goal metasenv in
210 CTC.type_of_aux' metasenv context term CU.empty_ugraph
213 | C.Appl [(C.MutInd (equri, 0, [])) ; tty ; t1 ; t2]
214 when LibraryObjects.is_eq_URI equri ->
215 let turi,typeno,exp_named_subst,args =
217 | (C.MutInd (turi,typeno,exp_named_subst)) ->
218 turi,typeno,exp_named_subst,[]
219 | (C.Appl (C.MutInd (turi,typeno,exp_named_subst)::args)) ->
220 turi,typeno,exp_named_subst,args
221 | _ -> fail "not a discriminable equality"
224 match find_discriminating_consno t1 t2 with
225 | Some consno -> consno
226 | None -> fail "discriminating terms are structurally equal"
228 let branches,outtype =
229 mk_branches_and_outtype turi typeno consno context args
233 ~start:(EliminationTactics.elim_type_tac (C.MutInd (false_URI, 0, [])))
238 ~pattern:(PET.conclusion_pattern None)
241 C.Lambda ( C.Name "x", tty,
242 C.MutCase (turi, typeno, outtype, (C.Rel 1), branches));
248 (ET.rewrite_simpl_tac
249 ~direction:`RightToLeft
250 ~pattern:(PET.conclusion_pattern None)
253 (IntroductionTactics.constructor_tac ~n:1)))) status
254 | _ -> fail "not an equality"
256 PET.mk_tactic (discriminate'_tac ~term)
259 PET.Fail (lazy "Injection: not an equality")
260 let exn_nothingtodo =
261 PET.Fail (lazy "Nothing to do")
262 let exn_discrnonind =
263 PET.Fail (lazy "Discriminate: object is not an Inductive Definition: it's imposible")
264 let exn_injwronggoal =
265 PET.Fail (lazy "Injection: goal after cut is not correct")
267 PET.Fail (lazy "Injection: not an equality over elements of an inductive type")
270 let names = List.map (function Some (n,_) -> Some n | None -> None) ctx in
273 let clear_term first_time lterm =
274 let clear_term status =
275 let (proof, goal) = status in
276 let _,metasenv,_subst,_,_, _ = proof in
277 let _,context,_ = CicUtil.lookup_meta goal metasenv in
278 let term, metasenv, _ugraph = lterm context metasenv CU.empty_ugraph in
279 debug_print (lazy ("\nclear di: " ^ pp context term));
280 debug_print (lazy ("nel contesto:\n" ^ CicPp.ppcontext context));
281 let g () = if first_time then raise exn_nothingtodo else T.id_tac in
282 let tactic = match term with
284 begin match List.nth context (pred n) with
285 | Some (C.Name id, _) ->
286 T.if_ ~fail:(g ()) ~start:(PST.clear ~hyps:[id]) ~continuation:T.id_tac
291 PET.apply_tactic tactic status
293 PET.mk_tactic clear_term
295 let simpl_in_term context = function
297 let name = match List.nth context (pred i) with
298 | Some (Cic.Name s, Cic.Def _) -> s
299 | Some (Cic.Name s, Cic.Decl _) -> s
302 RT.simpl_tac ~pattern:(None,[name,Cic.Implicit (Some `Hole)],None)
305 let mk_fresh_name metasenv context name typ =
306 let name = C.Name name in
307 match FNG.mk_fresh_name ~subst:[] metasenv context name ~typ with
309 | C.Anonymous -> assert false
311 let exists context = function
312 | C.Rel i -> List.nth context (pred i) <> None
315 let rec recur_on_child_tac name =
316 let recur_on_child status =
317 let (proof, goal) = status in
318 let _, metasenv, _subst, _, _, _ = proof in
319 let _, context, _ = CicUtil.lookup_meta goal metasenv in
320 debug_print (lazy ("\nrecur_on_child su: " ^ name));
321 debug_print (lazy ("nel contesto:\n" ^ CicPp.ppcontext context));
322 let rec search_name i = function
324 | Some (Cic.Name n, _) :: _ when n = name ->
325 destruct ~first_time:false ~term:(Cic.Rel i)
326 | _ :: tl -> search_name (succ i) tl
328 PET.apply_tactic (search_name 1 context) status
330 PET.mk_tactic recur_on_child
332 and injection_tac ~lterm ~i ~continuation =
333 let give_name seed = function
334 | C.Name _ as name -> name
335 | C.Anonymous -> C.Name (incr seed; "y" ^ string_of_int !seed)
337 let rec mk_rels = function | 0 -> [] | n -> C.Rel n :: (mk_rels (n - 1)) in
338 let injection_tac status =
339 let (proof, goal) = status in
340 (* precondizione: t1 e t2 hanno in testa lo stesso costruttore ma
341 * differiscono (o potrebbero differire?) nell'i-esimo parametro
343 let _,metasenv,_subst,_,_, _ = proof in
344 let _,context,_ = CicUtil.lookup_meta goal metasenv in
345 let term, metasenv, _ugraph = lterm context metasenv CU.empty_ugraph in
347 CTC.type_of_aux' metasenv context term CU.empty_ugraph
349 debug_print (lazy ("\ninjection su : " ^ pp context termty));
350 match termty with (* an equality *)
351 | C.Appl [(C.MutInd (equri, 0, [])) ; tty ; t1 ; t2]
352 when LibraryObjects.is_eq_URI equri ->
353 let turi,typeno,ens,params =
354 match tty with (* some inductive type *)
355 | C.MutInd (turi,typeno,ens) -> turi,typeno,ens,[]
356 | C.Appl (C.MutInd (turi,typeno,ens)::params) -> turi,typeno,ens,params
357 | _ -> raise exn_noneqind
359 let t1',t2',consno = (* sono i due sottotermini che differiscono *)
361 | C.Appl ((C.MutConstruct (uri1,typeno1,consno1,ens1))::applist1),
362 C.Appl ((C.MutConstruct (uri2,typeno2,consno2,ens2))::applist2)
363 when (uri1 = uri2) && (typeno1 = typeno2) &&
364 (consno1 = consno2) && (ens1 = ens2) ->
365 (* controllo ridondante *)
366 List.nth applist1 (pred i),List.nth applist2 (pred i),consno2
369 let tty',_ = CTC.type_of_aux' metasenv context t1' CU.empty_ugraph in
370 let patterns,outtype =
371 match fst (CicEnvironment.get_obj CU.empty_ugraph turi) with
372 | C.InductiveDefinition (ind_type_list,_,paramsno,_)->
373 let left_params, right_params = HExtlib.split_nth paramsno params in
374 let _,_,_,constructor_list = List.nth ind_type_list typeno in
375 let i_constr_id,_ = List.nth constructor_list (consno - 1) in
379 (function (id,cty) ->
380 let reduced_cty = CR.whd context cty in
381 let rec aux k = function
382 | C.Prod (_,_,tgt) when k <= paramsno ->
383 let left = List.nth left_params (k-1) in
384 aux (k+1) (S.subst left tgt)
385 | C.Prod (binder,source,target) when k > paramsno ->
386 let binder' = give_name seed binder in
387 C.Lambda (binder',source,(aux (k+1) target))
389 let nr_param_constr = k - paramsno - 1 in
390 if id = i_constr_id then C.Rel (k - i)
391 else S.lift nr_param_constr t1'
392 (* + 1 per liftare anche il lambda aggiunto
393 * esternamente al case *)
394 in S.lift 1 (aux 1 reduced_cty))
397 (* this code should be taken from cases_tac *)
400 let rec to_lambdas te head =
401 match CR.whd context te with
402 | C.Prod (binder,so,ta) ->
403 let binder' = give_name seed binder in
404 C.Lambda (binder',so,to_lambdas ta head)
407 let rec skip_prods params te =
408 match params, CR.whd context te with
410 | left::tl, C.Prod (_,_,ta) ->
411 skip_prods tl (S.subst left ta)
412 | _, _ -> assert false
416 List.fold_left (fun x y -> S.subst y x) tty left_params
418 (* non lift, ma subst coi left! *)
419 match S.lift 1 tty with
420 | C.MutInd _ as tty' -> tty'
422 let keep,abstract = HExtlib.split_nth (paramsno +1) l in
423 let keep = List.map (S.lift paramsno) keep in
424 C.Appl (keep@mk_rels (List.length abstract))
427 match ind_type_list with
430 (* this is in general wrong, do as in cases_tac *)
431 to_lambdas (skip_prods left_params ty)
433 (C.Name "cased", abstracted_tty,
434 (* here we should capture right parameters *)
435 (* 1 for his Lambda, one for the Lambda outside the match
436 * and then one for each to_lambda *)
437 S.lift (2+List.length right_params) tty'))
440 | _ -> raise exn_discrnonind
442 let cutted = C.Appl [C.MutInd (equri,0,[]) ; tty' ; t1' ; t2'] in
444 C.Appl [ C.Lambda (C.Name "x", tty,
445 C.MutCase (turi,typeno,outtype,C.Rel 1,patterns)) ; t1]
447 (* check if cutted and changed are well typed and if t1' ~ changed *)
450 let _,g = CTC.type_of_aux' metasenv context cutted
453 let _,g = CTC.type_of_aux' metasenv context changed g in
454 fst (CR.are_convertible ~metasenv context t1' changed g)
456 | CTC.TypeCheckerFailure _ -> false
458 if not go_on then begin
459 HLog.warn "destruct: injection failed";
460 PET.apply_tactic continuation status
462 let fill_cut_tac term =
463 let fill_cut status =
464 debug_print (lazy "riempio il cut");
465 let (proof, goal) = status in
466 let _,metasenv,_subst,_,_, _ = proof in
467 let _,context,gty = CicUtil.lookup_meta goal metasenv in
468 let gty = Unshare.unshare gty in
469 let new_t1' = match gty with
470 | (C.Appl (C.MutInd (_,_,_)::_::t::_)) -> t
471 | _ -> raise exn_injwronggoal
473 debug_print (lazy ("metto: " ^ pp context changed));
474 debug_print (lazy ("al posto di: " ^ pp context new_t1'));
475 debug_print (lazy ("nel goal: " ^ pp context gty));
476 debug_print (lazy ("nel contesto:\n" ^ CicPp.ppcontext context));
477 debug_print (lazy ("e poi rewrite con: "^pp context term));
478 let tac = T.seq ~tactics:[
480 ~pattern:(None, [], Some (PEH.pattern_of ~term:gty [new_t1']))
481 (fun _ m u -> changed,m,u);
483 ~direction:`LeftToRight
484 ~pattern:(PET.conclusion_pattern None)
488 PET.apply_tactic tac status
490 PET.mk_tactic fill_cut
492 debug_print (lazy ("CUT: " ^ pp context cutted));
493 let name = mk_fresh_name metasenv context "Hcut" cutted in
494 let mk_fresh_name_callback = PEH.namer_of [Some name] in
495 debug_print (lazy ("figlio: " ^ name));
497 T.thens ~start: (P.cut_tac ~mk_fresh_name_callback cutted)
499 T.seq ~tactics:[continuation; recur_on_child_tac name];
503 PET.apply_tactic tactic status
504 | _ -> raise exn_noneq
506 PET.mk_tactic injection_tac
508 and subst_tac ~lterm ~direction ~where ~continuation =
509 let subst_tac status =
510 let (proof, goal) = status in
511 let _,metasenv,_subst,_,_, _ = proof in
512 let _,context,_ = CicUtil.lookup_meta goal metasenv in
513 let term, metasenv, _ugraph = lterm context metasenv CU.empty_ugraph in
514 debug_print (lazy ("\nsubst " ^ (match direction with `LeftToRight -> "->" | `RightToLeft -> "<-") ^ " di: " ^ pp context term));
515 let tactic = match where with
517 debug_print (lazy ("nella conclusione"));
518 let pattern = PET.conclusion_pattern None in
519 let tactic = ET.rewrite_tac ~direction ~pattern term [] in
520 T.then_ ~start:(T.try_tactic ~tactic) ~continuation
522 debug_print (lazy ("nella premessa: " ^ name));
523 let pattern = None, [name, PET.hole], None in
524 let start = ET.rewrite_tac ~direction ~pattern term [] in
526 T.seq ~tactics:[continuation; recur_on_child_tac name]
528 debug_print (lazy ("figlio: " ^ name));
529 T.if_ ~start ~continuation:ok_tactic ~fail:continuation
531 PET.apply_tactic tactic status
533 PET.mk_tactic subst_tac
535 (* ~term vive nel contesto della tattica una volta ~mappato
536 * ~continuation riceve la mappa assoluta
538 and destruct ~first_time ~term =
539 let are_convertible hd1 hd2 metasenv context =
540 fst (CR.are_convertible ~metasenv context hd1 hd2 CU.empty_ugraph)
542 let destruct status =
543 let (proof, goal) = status in
544 let _,metasenv,_subst, _,_, _ = proof in
545 let _,context,_ = CicUtil.lookup_meta goal metasenv in
546 debug_print (lazy ("\ndestruct di: " ^ pp context term));
547 debug_print (lazy ("nel contesto:\n" ^ CicPp.ppcontext context));
549 CTC.type_of_aux' metasenv context term CU.empty_ugraph
551 debug_print (lazy ("\ndestruct su: " ^ pp context termty));
552 let mk_lterm term c m ug =
553 let distance = List.length c - List.length context in
554 S.lift distance term, m, ug
556 let lterm = mk_lterm term in
557 let mk_subst_chain direction index with_what what =
558 let k = match term with C.Rel i -> i | _ -> -1 in
559 let rec traverse_context first_time j = function
563 clear_term first_time lterm;
564 clear_term false (mk_lterm what);
565 clear_term false (mk_lterm with_what)
568 subst_tac ~direction ~lterm ~where:None ~continuation
569 | Some (C.Name name, _) :: tl when j < index && j <> k ->
570 debug_print (lazy ("\nsubst programmata: cosa: " ^ string_of_int index ^ ", dove: " ^ string_of_int j));
571 subst_tac ~direction ~lterm ~where:(Some name)
572 ~continuation:(traverse_context false (succ j) tl)
573 | _ :: tl -> traverse_context first_time (succ j) tl
575 traverse_context first_time 1 context
577 let tac = match termty with
578 | C.Appl [(C.MutInd (equri, 0, [])) ; tty ; t1 ; t2]
579 when LibraryObjects.is_eq_URI equri ->
580 begin match t1,t2 with
584 when t1 = t2 -> clear_term first_time lterm
585 | C.Appl (C.MutConstruct _ as mc1 :: applist1),
586 C.Appl (C.MutConstruct _ as mc2 :: applist2)
588 let rec traverse_list first_time i l1 l2 =
590 | [], [] -> clear_term first_time lterm
591 | hd1 :: tl1, hd2 :: tl2 ->
592 if are_convertible hd1 hd2 metasenv context then
593 traverse_list first_time (succ i) tl1 tl2
595 injection_tac ~i ~lterm ~continuation:
596 (traverse_list false (succ i) tl1 tl2)
598 (* i 2 termini hanno in testa lo stesso costruttore,
599 * ma applicato a un numero diverso di termini *)
601 traverse_list first_time 1 applist1 applist2
602 (* discriminate part *)
603 | C.MutConstruct (_,_,consno1,ens1),
604 C.MutConstruct (_,_,consno2,ens2)
605 | C.MutConstruct (_,_,consno1,ens1),
606 C.Appl ((C.MutConstruct (_,_,consno2,ens2))::_)
607 | C.Appl ((C.MutConstruct (_,_,consno1,ens1))::_),
608 C.MutConstruct (_,_,consno2,ens2)
609 | C.Appl ((C.MutConstruct (_,_,consno1,ens1))::_),
610 C.Appl ((C.MutConstruct (_,_,consno2,ens2))::_)
611 when (consno1 <> consno2) || (ens1 <> ens2) ->
612 discriminate_tac ~term
614 | C.Rel _, C.Rel _ when t1 = t2 ->
616 clear_term first_time lterm;
617 clear_term false (mk_lterm t1)
619 | C.Rel i1, C.Rel i2 when i1 < i2 ->
620 mk_subst_chain `LeftToRight i1 t2 t1
621 | C.Rel i1, C.Rel i2 when i1 > i2 ->
622 mk_subst_chain `RightToLeft i2 t1 t2
623 | C.Rel i1, _ when DTI.does_not_occur i1 t2 ->
624 mk_subst_chain `LeftToRight i1 t2 t1
625 | _, C.Rel i2 when DTI.does_not_occur i2 t1 ->
626 mk_subst_chain `RightToLeft i2 t1 t2
628 | _ when not first_time -> T.id_tac
629 | _ (* when first_time *) ->
630 T.then_ ~start:(simpl_in_term context term)
631 ~continuation:(destruct ~first_time:false ~term)
633 | _ when not first_time -> T.id_tac
634 | _ (* when first_time *) -> raise exn_nothingtodo
636 PET.apply_tactic tac status
638 PET.mk_tactic destruct
640 let lazy_destruct_tac ~first_time ~lterm =
641 let lazy_destruct status =
642 let (proof, goal) = status in
643 let _,metasenv,_subst,_,_, _ = proof in
644 let _,context,_ = CicUtil.lookup_meta goal metasenv in
645 let term, _, _ = lterm context metasenv CU.empty_ugraph in
647 if exists context term then destruct ~first_time ~term else T.id_tac
649 PET.apply_tactic tactic status
651 PET.mk_tactic lazy_destruct
653 (* destruct performs either injection or discriminate *)
654 (* equivalent to Coq's "analyze equality" *)
655 let destruct_tac = function
656 | Some term -> destruct ~first_time:true ~term
658 let destruct_all status =
659 let (proof, goal) = status in
660 let _,metasenv,_subst,_,_, _ = proof in
661 let _,context,_ = CicUtil.lookup_meta goal metasenv in
662 let mk_lterm term c m ug =
663 let distance = List.length c - List.length context in
664 S.lift distance term, m, ug
666 let rec mk_tactics first_time i tacs = function
667 | [] -> List.rev tacs
669 let lterm = mk_lterm (C.Rel i) in
670 let tacs = lazy_destruct_tac ~first_time ~lterm :: tacs in
671 mk_tactics false (succ i) tacs tl
672 | _ :: tl -> mk_tactics first_time (succ i) tacs tl
674 let tactics = mk_tactics false 1 [] context in
675 PET.apply_tactic (T.seq ~tactics) status
677 PET.mk_tactic destruct_all