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.
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9 * as published by the Free Software Foundation; either version 2
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14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with HELM; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place - Suite 330, Boston,
22 * For details, see the HELM World-Wide-Web page,
23 * http://cs.unibo.it/helm/.
26 (* $Id: destructTactic.ml 9774 2009-05-15 19:37:08Z sacerdot $ *)
29 open Continuationals.Stack
33 if debug then (fun x -> prerr_endline (Lazy.force x)) else (fun _ -> ())
39 "z" ^ string_of_int !i
43 let id = if id = "_" then fresh_name () else id in
44 CicNotationPt.Ident (id,None)
47 let rec mk_prods l t =
50 | hd::tl -> CicNotationPt.Binder (`Forall, (mk_id hd, None), mk_prods tl t)
57 | l -> CicNotationPt.Appl l
60 let rec iter f n acc =
62 else iter f (n-1) (f n acc)
65 let subst_metasenv_and_fix_names status =
66 let u,h,metasenv, subst,o = status#obj in
68 NCicUntrusted.map_obj_kind ~skip_body:true
69 (NCicUntrusted.apply_subst subst []) o
71 status#set_obj(u,h,NCicUntrusted.apply_subst_metasenv subst metasenv,subst,o)
74 (* input: nome della variabile riscritta
75 * output: lista dei nomi delle variabili il cui tipo dipende dall'input *)
76 let cascade_select_in_ctx ~subst ctx iname =
78 let lctx, rctx = HExtlib.split_nth (iname - 1) ctx in
79 let lctx = List.rev lctx in
80 let rec rm_last = function
82 | hd::tl -> hd::(rm_last tl)
85 let indices,_ = List.fold_left
86 (fun (acc,context) item ->
89 | n,(NCic.Decl s | NCic.Def (s,_))
90 when not (List.for_all (fun x -> NCicTypeChecker.does_not_occur ~subst context (x-1) x s) acc) ->
91 List.iter (fun m -> prerr_endline ("acc has " ^ (string_of_int m))) acc;
92 prerr_endline ("acc occurs in the type of " ^ n);
93 (1::List.map ((+) 1) acc, item::context)
94 | _ -> (List.map ((+) 1) acc, item::context))
97 List.iter (fun n -> prerr_endline (string_of_int n)) indices;
98 let indices = rm_last indices in
99 let res = List.map (fun n -> let s,_ = List.nth ctx (n-1) in s) indices in
101 List.iter (fun n -> prerr_endline n) res;
102 prerr_endline (NCicPp.ppcontext ~metasenv:[] ~subst ctx);
106 let rec mk_fresh_name ctx firstch n =
107 let candidate = (String.make 1 firstch) ^ (string_of_int n) in
108 if (List.for_all (fun (s,_) -> s <> candidate) ctx) then candidate
109 else mk_fresh_name ctx firstch (n+1)
112 let arg_list nleft t =
113 let rec drop_prods n t =
116 | NCic.Prod (_,_,ta) -> drop_prods (n-1) ta
117 | _ -> raise (Failure "drop_prods")
119 let rec aux = function
120 | NCic.Prod (_,so,ta) -> so::aux ta
122 in aux (drop_prods nleft t)
125 let nargs it nleft consno =
126 prerr_endline (Printf.sprintf "nargs %d %d" nleft consno);
127 let _,indname,_,cl = it in
128 let _,_,t_k = List.nth cl consno in
129 List.length (arg_list nleft t_k) ;;
131 let default_pattern = "",0,(None,[],Some CicNotationPt.UserInput);;
133 (* returns the discrimination = injection+contradiction principle *)
134 (* FIXME: mi riservo di considerare tipi con parametri sx alla fine *)
136 let mk_discriminator it nleft status =
137 let _,indname,_,cl = it in
140 let mk_eq tys ts us es n =
141 (* eqty = Tn u0 e0...un-1 en-1 *)
143 (List.nth tys n :: iter (fun i acc ->
148 (* params = [T0;t0;...;Tn;tn;u0;e0;un-1;en-1] *)
149 let params = iter (fun i acc ->
151 List.nth ts i :: acc) n
154 List.nth es i:: acc) (n-1) []) in
155 mk_appl [mk_id "eq"; eqty;
156 mk_appl (mk_id ("R" ^ string_of_int n) :: params);
162 let _,name,_ = List.nth cl j in
166 let branch i j ts us =
167 let nargs = nargs it nleft i in
168 let es = List.map (fun x -> mk_id ("e" ^ string_of_int x)) (HExtlib.list_seq 0 nargs) in
170 (fun x -> CicNotationPt.Implicit (`Tagged ("T" ^ (string_of_int x))))
171 (HExtlib.list_seq 0 nargs) in
174 CicNotationPt.Binder (`Lambda, (mk_id ("x" ^ string_of_int i), None),
175 CicNotationPt.Binder (`Lambda, (mk_id ("p" ^ string_of_int i), None),
177 (mk_appl [mk_id "eq"; CicNotationPt.Implicit `JustOne;
178 mk_appl (mk_id (kname it i)::
179 List.map (fun x -> mk_id ("x" ^string_of_int x))
180 (HExtlib.list_seq 0 (List.length ts)));
181 mk_appl (mk_id (kname it j)::us)])]
183 (** CicNotationPt.Binder (`Lambda, (mk_id "e",
186 CicNotationPt.Implicit `JustOne;
187 mk_appl (mk_id (kname it i)::ts);
188 mk_appl (mk_id (kname it j)::us)])),
189 let ts = ts @ [mk_id "e"] in
192 CicNotationPt.Implicit `JustOne;
193 mk_appl (mk_id (kname it j)::us)] in
194 let us = us @ [refl2] in *)
195 CicNotationPt.Binder (`Forall, (mk_id "P", Some (CicNotationPt.Sort (`NType "1") )),
197 CicNotationPt.Binder (`Forall, (mk_id "_",
198 Some (iter (fun i acc ->
199 CicNotationPt.Binder (`Forall, (List.nth es i, Some (mk_eq tys ts us es i)), acc))
201 (** (CicNotationPt.Binder (`Forall, (mk_id "_",
202 Some (mk_eq tys ts us es nargs)),*)
203 (mk_id "P"))), mk_id "P")
207 let inner i ts = CicNotationPt.Case
209 (*Some (CicNotationPt.Binder (`Lambda, (mk_id "y",None),
210 CicNotationPt.Binder (`Forall, (mk_id "_", Some
211 (mk_appl [mk_id "eq";CicNotationPt.Implicit
212 `JustOne;(*CicNotationPt.Implicit `JustOne*)
213 mk_appl (mk_id (kname it i)::ts);mk_id "y"])),
214 CicNotationPt.Implicit `JustOne )))*)
218 let nargs_kty = nargs it nleft j in
219 let us = iter (fun m acc -> mk_id ("u" ^ (string_of_int m))::acc)
220 (nargs_kty - 1) [] in
222 iter (fun _ acc -> None::acc) (nargs_kty - 1) [] in
223 CicNotationPt.Pattern (kname it j,
225 List.combine us nones),
227 (HExtlib.list_seq 0 (List.length cl)))
229 let outer = CicNotationPt.Case
234 let nargs_kty = nargs it nleft i in
235 let ts = iter (fun m acc -> mk_id ("t" ^ (string_of_int m))::acc)
236 (nargs_kty - 1) [] in
238 iter (fun _ acc -> None::acc) (nargs_kty - 1) [] in
239 CicNotationPt.Pattern (kname it i,
241 List.combine ts nones),
243 (HExtlib.list_seq 0 (List.length cl))) in
244 let principle = CicNotationPt.Binder (`Lambda, (mk_id "x", (*Some (mk_id indname)*) None),
245 CicNotationPt.Binder (`Lambda, (mk_id "y", (*Some (mk_id indname)*) None), outer))
247 pp (lazy ("discriminator = " ^ (CicNotationPp.pp_term principle)));
252 let hd_of_term = function
253 | NCic.Appl (hd::_) -> hd
257 let name_of_rel ~context rel =
258 let s, _ = List.nth context (rel-1) in s
261 (* let lookup_in_ctx ~context n =
262 List.nth context ((List.length context) - n - 1)
265 let discriminate_tac ~context cur_eq status =
266 pp (lazy (Printf.sprintf "discriminate: equation %s" (name_of_rel ~context cur_eq)));
268 let dbranch it leftno consno =
269 prerr_endline (Printf.sprintf "dbranch %d %d" leftno consno);
270 let nlist = HExtlib.list_seq 0 (nargs it leftno consno) in
271 (* (\forall ...\forall P.\forall DH : ( ... = ... -> P). P) *)
272 let params = List.map (fun x -> prerr_endline (Printf.sprintf "dbranch param a%d" x); NTactics.intro_tac ("a" ^ string_of_int x)) nlist in
273 NTactics.reduce_tac ~reduction:(`Normalize true) ~where:default_pattern::
275 NTactics.intro_tac "P";
276 NTactics.intro_tac "DH";
277 NTactics.apply_tac ("",0,mk_id "DH");
278 NTactics.apply_tac ("",0,mk_id "refl");
280 let dbranches it leftno =
281 prerr_endline (Printf.sprintf "dbranches %d" leftno);
283 let nbranches = List.length cl in
284 let branches = iter (fun n acc ->
285 let m = nbranches - n - 1 in
286 if m = 0 then (prerr_endline "no shift"; acc @ (dbranch it leftno m))
287 else (prerr_endline "sì shift"; acc @ NTactics.shift_tac :: (dbranch it
290 if nbranches > 1 then
291 (prerr_endline "sì branch";
292 NTactics.branch_tac:: branches @ [NTactics.merge_tac])
294 (prerr_endline "no branch";
298 let eq_name,(NCic.Decl s | NCic.Def (s,_)) = List.nth context (cur_eq-1) in
299 let _,ctx' = HExtlib.split_nth cur_eq context in
300 let status, s = NTacStatus.whd status ctx' (mk_cic_term ctx' s) in
301 let status, s = term_of_cic_term status s ctx' in
302 let status, leftno, it =
303 let it, t1, t2 = match s with
304 | NCic.Appl [_;it;t1;t2] -> it,t1,t2
305 | _ -> assert false in
306 (* XXX: serve? ho già fatto whd *)
307 let status, it = whd status ctx' (mk_cic_term ctx' it) in
308 let status, it = term_of_cic_term status it ctx' in
309 let _uri,indtyno,its = match it with
310 | NCic.Const (NReference.Ref (uri, NReference.Ind (_,indtyno,_)) as r)
311 | NCic.Appl (NCic.Const
312 (NReference.Ref (uri, NReference.Ind (_,indtyno,_)) as r)::_) ->
313 uri, indtyno, NCicEnvironment.get_checked_indtys r
314 | _ -> prerr_endline ("discriminate: indty =" ^ NCicPp.ppterm
315 ~metasenv:[] ~subst:[] ~context:[] it) ; assert false in
316 let _,leftno,its,_,_ = its in
317 status, leftno, List.nth its indtyno
321 let _,_,arity,_ = it in
322 List.length (arg_list 0 arity) in
323 let _,itname,_,_ = it in
324 let params = List.map (fun x -> "a" ^ string_of_int x) (HExtlib.list_seq 1 (itnargs+1)) in
325 let print_tac s status = pp s ; status in
328 let status, discr = mk_discriminator it leftno status in
329 NTactics.cut_tac ("",0, mk_prods params (CicNotationPt.Binder (`Forall, (mk_id "x",
330 Some (mk_appl (List.map mk_id (itname::params)))),
331 CicNotationPt.Binder (`Forall, (mk_id "y", None),
332 CicNotationPt.Binder (`Forall, (mk_id "e",
333 Some (mk_appl [mk_id "eq";CicNotationPt.Implicit `JustOne; mk_id "x"; mk_id "y"])),
334 mk_appl [discr; mk_id "x"; mk_id "y"(*;mk_id "e"*)])))))
337 print_tac (lazy "ci sono");
338 NTactics.reduce_tac ~reduction:(`Normalize true) ~where:default_pattern]
339 @ List.map (fun x -> NTactics.intro_tac x) params @
340 [NTactics.intro_tac "x";
341 NTactics.intro_tac "y";
342 NTactics.intro_tac "Deq";
343 print_tac (lazy "ci sono 2");
344 NTactics.rewrite_tac ~dir:`RightToLeft ~what:("",0,mk_id "Deq") ~where:default_pattern;
345 NTactics.cases_tac ~what:("",0,mk_id "x") ~where:default_pattern]
346 @ dbranches it leftno @
348 print_tac (lazy "ci sono 3");
349 NTactics.intro_tac "#discriminate";
350 NTactics.apply_tac ("",0,mk_appl ([mk_id "#discriminate"]@
351 HExtlib.mk_list (CicNotationPt.Implicit `JustOne) (List.length params + 2) @
353 NTactics.reduce_tac ~reduction:(`Normalize true) ~where:default_pattern;
354 NTactics.clear_tac ["#discriminate"];
359 let subst_tac ~context ~dir cur_eq =
361 let eq_name,(NCic.Decl s | NCic.Def (s,_)) = List.nth context (cur_eq-1) in
362 let _,ctx' = HExtlib.split_nth cur_eq context in
363 let status, s = NTacStatus.whd status ctx' (mk_cic_term ctx' s) in
364 let status, s = term_of_cic_term status s ctx' in
365 pp (lazy (Printf.sprintf "subst: equation %s" eq_name));
366 let l, r = match s with
367 | NCic.Appl [_;_;t1;t2] -> t1,t2
368 | _ -> assert false in
369 let var = match dir with
371 | `RightToLeft -> r in
372 let var = match var with
374 | _ -> assert false in
375 let names_to_gen, _ =
376 cascade_select_in_ctx ~subst:(get_subst status) context (var+cur_eq) in
377 let names_to_gen = match names_to_gen with [] -> [] | _::tl -> tl in
379 NTactics.generalize_tac
380 ~where:("",0,(Some (mk_id x),[], Some CicNotationPt.UserInput)) in
381 NTactics.block_tac ((List.map gen_tac names_to_gen)@
382 [NTactics.clear_tac names_to_gen;
383 NTactics.rewrite_tac ~dir
384 ~what:("",0,mk_id eq_name) ~where:default_pattern;
385 NTactics.reduce_tac ~reduction:(`Normalize true)
386 ~where:default_pattern;
387 NTactics.clear_tac [eq_name]]@
388 (List.map NTactics.intro_tac (List.rev names_to_gen))) status
391 let clearid_tac ~context cur_eq =
393 let eq_name,(NCic.Decl s | NCic.Def (s,_)) = List.nth context (cur_eq-1) in
394 let _,ctx' = HExtlib.split_nth cur_eq context in
395 let status, s = NTacStatus.whd status ctx' (mk_cic_term ctx' s) in
396 let status, s = term_of_cic_term status s ctx' in
397 pp (lazy (Printf.sprintf "clearid: equation %s" eq_name));
398 let names_to_gen, _ =
399 cascade_select_in_ctx ~subst:(get_subst status) context cur_eq in
400 let names_to_gen = names_to_gen @ [eq_name] in
402 NTactics.generalize_tac
403 ~where:("",0,(Some (mk_id x),[], Some CicNotationPt.UserInput)) in
404 NTactics.block_tac ((List.map gen_tac names_to_gen)@
405 [NTactics.clear_tac names_to_gen;
406 NTactics.apply_tac ("",0, mk_appl [mk_id "streicherK";
407 CicNotationPt.Implicit `JustOne;
408 CicNotationPt.Implicit `JustOne;
409 CicNotationPt.Implicit `JustOne;
410 CicNotationPt.Implicit `JustOne]);
411 NTactics.reduce_tac ~reduction:(`Normalize true)
412 ~where:default_pattern] @
413 (let names_to_intro =
414 match List.rev names_to_gen with
417 List.map NTactics.intro_tac names_to_intro)) status
420 let get_ctx st goal =
421 ctx_of (get_goalty st goal)
424 (* = select + classify *)
425 let select_eq ctx acc status goal =
426 let classify ~subst ctx' l r =
427 (* FIXME: metasenv *)
428 if NCicReduction.are_convertible ~metasenv:[] ~subst ctx' l r
429 then status, `Identity
430 else status, (match hd_of_term l, hd_of_term r with
431 | NCic.Const (NReference.Ref (_,NReference.Con (_,ki,nleft)) as kref),
432 NCic.Const (NReference.Ref (_,NReference.Con (_,kj,_))) ->
433 if ki != kj then `Discriminate (0,true)
435 let rit = NReference.mk_indty true kref in
436 let _,_,its,_,itno = NCicEnvironment.get_checked_indtys rit in
437 let it = List.nth its itno in
438 let newprods = nargs it nleft (ki-1) in
439 `Discriminate (newprods, false)
441 when NCicTypeChecker.does_not_occur ~subst ctx' (j-1) j r ->
444 when NCicTypeChecker.does_not_occur ~subst ctx' (j-1) j l ->
446 | (NCic.Rel _, _ | _, NCic.Rel _ ) -> `Cycle
450 let index = List.length ctx - i in
451 pp (lazy ("provo classify di index = " ^string_of_int index));
452 match (List.nth ctx (index - 1)) with
453 | n, (NCic.Decl ty | NCic.Def (ty,_)) ->
454 (let _,ctx_ty = HExtlib.split_nth index ctx in
455 let status, ty = NTacStatus.whd status ctx_ty (mk_cic_term ctx_ty ty) in
456 let status, ty = term_of_cic_term status ty ctx_ty in
457 pp (lazy (Printf.sprintf "select_eq tries %s" (NCicPp.ppterm ~context:ctx_ty ~subst:[] ~metasenv:[] ty)));
459 | NCic.Appl [NCic.Const (NReference.Ref (u,_)) ;_;l;r] when NUri.name_of_uri u = "eq" ->
460 (let status, kind = classify ~subst:(get_subst status) ctx_ty l r in
463 let status, goalty = term_of_cic_term status (get_goalty status goal) ctx in
464 status, Some (List.length ctx - i), kind
465 | `Cycle | `Blob -> aux (i+1) (* XXX: skip cyclic/blob equations for now *)
467 if (List.for_all (fun x -> x <> n) acc) then
468 status, Some (List.length ctx - i), kind
471 with Failure _ | Invalid_argument _ -> status, None, `Blob
475 let rec destruct_tac0 nprods acc status goal =
476 let ctx = get_ctx status goal in
477 let subst = get_subst status in
478 let get_newgoal os ns ogoal =
479 let go, gc = NTactics.compare_statuses ~past:os ~present:ns in
480 let go' = ([ogoal] @- gc) @+ go in
481 match go' with [] -> assert false | g::_ -> g
483 let status, selection, kind = select_eq ctx acc status goal in
484 pp (lazy ("destruct: acc is " ^ String.concat "," acc ));
485 match selection, kind with
487 pp (lazy (Printf.sprintf "destruct: nprods is %d, no selection, context is %s" nprods (NCicPp.ppcontext ~metasenv:[] ~subst ctx)));
489 let status' = NTactics.exec (NTactics.intro_tac (mk_fresh_name ctx 'e' 0)) status goal in
490 destruct_tac0 (nprods-1) acc status' (get_newgoal status status' goal)
493 | Some cur_eq, `Discriminate (newprods,conflict) ->
494 pp (lazy (Printf.sprintf "destruct: discriminate - nprods is %d, selection is %d, context is %s" nprods cur_eq (NCicPp.ppcontext ~metasenv:[] ~subst ctx)));
495 let status' = NTactics.exec (discriminate_tac ~context:ctx cur_eq) status goal in
496 if conflict then status'
497 else destruct_tac0 (nprods+newprods)
498 (name_of_rel ~context:ctx cur_eq::acc) status' (get_newgoal status status' goal)
499 | Some cur_eq, `Subst dir ->
500 pp (lazy (Printf.sprintf "destruct: subst - nprods is %d, selection is %d, context is %s" nprods cur_eq (NCicPp.ppcontext ~metasenv:[] ~subst ctx)));
501 let status' = NTactics.exec (subst_tac ~context:ctx ~dir cur_eq) status goal in
502 pp (lazy (Printf.sprintf " ctx after subst = %s" (NCicPp.ppcontext ~metasenv:[] ~subst (get_ctx status' (get_newgoal status status' goal)))));
503 let eq_name,_ = List.nth ctx (cur_eq-1) in
504 destruct_tac0 nprods (List.filter (fun x -> x <> eq_name) acc) status' (get_newgoal status status' goal)
505 | Some cur_eq, `Identity ->
506 pp (lazy (Printf.sprintf "destruct: identity - nprods is %d, selection is %d, context is %s" nprods cur_eq (NCicPp.ppcontext ~metasenv:[] ~subst ctx)));
507 let eq_name,_ = List.nth ctx (cur_eq-1) in
508 let status' = NTactics.exec (clearid_tac ~context:ctx cur_eq) status goal in
509 destruct_tac0 nprods (List.filter (fun x -> x <> eq_name) acc) status' (get_newgoal status status' goal)
510 | Some cur_eq, `Cycle -> (* TODO, should never happen *)
511 pp (lazy (Printf.sprintf "destruct: cycle - nprods is %d, selection is %d, context is %s" nprods cur_eq (NCicPp.ppcontext ~metasenv:[] ~subst ctx)));
513 | Some cur_eq, `Blob ->
514 pp (lazy (Printf.sprintf "destruct: blob - nprods is %d, selection is %d, context is %s" nprods cur_eq (NCicPp.ppcontext ~metasenv:[] ~subst ctx)));
518 let destruct_tac s = NTactics.distribute_tac (destruct_tac0 0 []) s;;