2 ||M|| This file is part of HELM, an Hypertextual, Electronic
3 ||A|| Library of Mathematics, developed at the Computer Science
4 ||T|| Department, University of Bologna, Italy.
6 ||T|| HELM is free software; you can redistribute it and/or
7 ||A|| modify it under the terms of the GNU General Public License
8 \ / version 2 or (at your option) any later version.
9 \ / This software is distributed as is, NO WARRANTY.
10 V_______________________________________________________________ *)
14 exception UnificationFailure of string Lazy.t;;
15 exception Uncertain of string Lazy.t;;
16 exception AssertFailure of string Lazy.t;;
17 exception KeepReducing of string Lazy.t;;
18 exception KeepReducingThis of
19 string Lazy.t * (NCicReduction.machine * bool) *
20 (NCicReduction.machine * bool) ;;
22 let (===) x y = Pervasives.compare x y = 0 ;;
24 let mk_msg metasenv subst context t1 t2 =
26 "Can't unify " ^ NCicPp.ppterm ~metasenv ~subst ~context t1 ^
27 " with " ^ NCicPp.ppterm ~metasenv ~subst ~context t2))
29 let mk_appl ~upto hd tl =
30 NCicReduction.head_beta_reduce ~upto
32 | NCic.Appl l -> NCic.Appl (l@tl)
33 | _ -> NCic.Appl (hd :: tl))
36 exception WrongShape;;
38 let eta_reduce subst t =
39 let delift_if_not_occur body =
41 Some (NCicSubstitution.psubst ~avoid_beta_redexes:true
42 (fun () -> raise WrongShape) [()] body)
43 with WrongShape -> None
45 let rec eat_lambdas ctx = function
46 | NCic.Lambda (name, src, tgt) ->
47 eat_lambdas ((name, src) :: ctx) tgt
48 | NCic.Meta (i,lc) as t->
50 let _,_,t,_ = NCicUtils.lookup_subst i subst in
51 let t = NCicSubstitution.subst_meta lc t in
53 with Not_found -> ctx, t)
56 let context_body = eat_lambdas [] t in
57 let rec aux = function
59 | (name, src)::ctx, (NCic.Appl (hd::[NCic.Rel 1]) as bo) ->
60 (match delift_if_not_occur hd with
61 | None -> aux (ctx,NCic.Lambda(name,src, bo))
62 | Some bo -> aux (ctx,bo))
63 | (name, src)::ctx, (NCic.Appl args as bo)
64 when HExtlib.list_last args = NCic.Rel 1 ->
65 let args, _ = HExtlib.split_nth (List.length args - 1) args in
66 (match delift_if_not_occur (NCic.Appl args) with
67 | None -> aux (ctx,NCic.Lambda(name,src, bo))
68 | Some bo -> aux (ctx,bo))
69 | (name, src) :: ctx, t ->
70 aux (ctx,NCic.Lambda(name,src, t))
76 module Ref = NReference;;
78 let debug = ref false;;
83 prerr_endline (Printf.sprintf "%-20s" !indent ^ " " ^ Lazy.force s)
88 let time1 = Unix.gettimeofday () in
89 indent := !indent ^ String.make 1 c;
90 times := time1 :: !times;
91 prerr_endline ("{{{" ^ !indent ^ " ")
97 let time2 = Unix.gettimeofday () in
99 match !times with time1::tl -> times := tl; time1 | [] -> assert false in
100 prerr_endline ("}}} " ^ string_of_float (time2 -. time1));
102 | Some e -> prerr_endline ("exception raised: " ^ Printexc.to_string e)
105 indent := String.sub !indent 0 (String.length !indent -1)
107 Invalid_argument _ -> indent := "??"; ()
111 let ppcontext ~metasenv ~subst c =
112 "\nctx:\n"^ NCicPp.ppcontext ~metasenv ~subst c
114 let ppmetasenv ~subst m = "\nmenv:\n" ^ NCicPp.ppmetasenv ~subst m;;
116 let ppcontext ~metasenv:_metasenv ~subst:_subst _context = "";;
117 let ppmetasenv ~subst:_subst _metasenv = "";;
118 let ppterm ~metasenv ~subst ~context = NCicPp.ppterm ~metasenv ~subst ~context;;
119 (* let ppterm ~metasenv:_ ~subst:_ ~context:_ _ = "";; *)
121 let is_locked n subst =
123 match NCicUtils.lookup_subst n subst with
124 | tag, _,_,_ when NCicMetaSubst.is_out_scope_tag tag -> true
126 with NCicUtils.Subst_not_found _ -> false
129 let rec mk_irl stop base =
130 if base > stop then []
131 else (NCic.Rel base) :: mk_irl stop (base+1)
134 (* the argument must be a term in whd *)
135 let rec could_reduce =
138 | C.Appl (C.Const (Ref.Ref (_,Ref.Fix (_,recno,_)))::args)
139 when List.length args > recno -> could_reduce (List.nth args recno)
140 | C.Match (_,_,arg,_) -> could_reduce arg
141 | C.Appl (he::_) -> could_reduce he
142 | C.Sort _ | C.Rel _ | C.Prod _ | C.Lambda _ | C.Const _ -> false
143 | C.Appl [] | C.LetIn _ | C.Implicit _ -> assert false
146 let rec lambda_intros rdb metasenv subst context argsno ty =
147 pp (lazy ("LAMBDA INTROS: " ^ ppterm ~metasenv ~subst ~context ty));
150 let metasenv, _, bo, _ =
151 NCicMetaSubst.mk_meta metasenv context ~with_type:ty `IsTerm
155 (match NCicReduction.whd ~subst context ty with
158 lambda_intros rdb metasenv subst
159 ((n,C.Decl so)::context) (argsno - 1) ta
161 metasenv,C.Lambda (n,so,bo)
165 let unopt exc = function None -> raise exc | Some x -> x ;;
167 let fix metasenv subst is_sup test_eq_only exc t =
168 (*D*) inside 'f'; try let rc =
169 pp (lazy (NCicPp.ppterm ~metasenv ~subst ~context:[] t));
170 let rec aux test_eq_only metasenv = function
171 | NCic.Prod (n,so,ta) ->
172 let metasenv,so = aux true metasenv so in
173 let metasenv,ta = aux test_eq_only metasenv ta in
174 metasenv,NCic.Prod (n,so,ta)
175 | NCic.Sort (NCic.Type [(`CProp|`Type),_]) as orig when test_eq_only ->
177 | NCic.Sort (NCic.Type _) when test_eq_only -> raise exc
178 | NCic.Sort (NCic.Type u) when is_sup ->
179 metasenv, NCic.Sort (NCic.Type (unopt exc (NCicEnvironment.sup u)))
180 | NCic.Sort (NCic.Type u) ->
181 metasenv, NCic.Sort (NCic.Type
182 (unopt exc (NCicEnvironment.inf ~strict:false u)))
183 | NCic.Meta (n,_) as orig ->
185 let _,_,_,_ = NCicUtils.lookup_subst n subst in metasenv,orig
186 with NCicUtils.Subst_not_found _ ->
187 let metasenv, _ = NCicMetaSubst.extend_meta metasenv n in
190 NCicUntrusted.map_term_fold_a (fun _ x -> x) test_eq_only aux metasenv t
192 aux test_eq_only metasenv t
193 (*D*) in outside None; rc with exn -> outside (Some exn); raise exn
196 let metasenv_to_subst n (kind,context,ty) metasenv subst =
197 let infos,metasenv = List.partition (fun (n',_) -> n = n') metasenv in
198 let attrs,octx,oty = match infos with [_,infos] -> infos | _ -> assert false in
199 if octx=context && oty=ty then
200 (n,(NCicUntrusted.set_kind kind attrs, octx, oty))::metasenv,subst
202 let metasenv, _, bo, _ =
203 NCicMetaSubst.mk_meta metasenv context ~attrs ~with_type:ty kind in
204 let subst = (n,(NCicUntrusted.set_kind kind attrs,octx,bo,oty))::subst in
208 let rec sortfy exc metasenv subst context t =
209 let t = NCicReduction.whd ~subst context t in
212 | NCic.Sort _ -> metasenv, subst
214 let attrs, context, ty = NCicUtils.lookup_meta n metasenv in
215 let kind = NCicUntrusted.kind_of_meta attrs in
216 if kind = `IsSort then
220 | NCic.Implicit (`Typeof _) ->
221 metasenv_to_subst n (`IsSort,[],ty) metasenv subst
223 let metasenv,subst,ty = sortfy exc metasenv subst context ty in
224 metasenv_to_subst n (`IsSort,[],ty) metasenv subst)
225 | NCic.Implicit _ -> assert false
230 let tipify exc metasenv subst context t ty =
232 match NCicUntrusted.kind_of_meta attrs with
233 `IsType | `IsSort -> true
236 let rec optimize_meta metasenv subst =
240 let attrs,_,_ = NCicUtils.lookup_meta n metasenv in
241 if is_type attrs then
245 NCicUntrusted.replace_in_metasenv n
246 (fun attrs,cc,ty -> NCicUntrusted.set_kind `IsType attrs, cc, ty)
251 NCicUtils.Meta_not_found _ ->
252 let attrs, _,bo,_ = NCicUtils.lookup_subst n subst in
253 if is_type attrs then
257 NCicUntrusted.replace_in_subst n
258 (fun attrs,cc,bo,ty->NCicUntrusted.set_kind `IsType attrs,cc,bo,ty)
261 optimize_meta metasenv subst (NCicSubstitution.subst_meta lc bo))
262 | _ -> metasenv,subst,false
264 let metasenv,subst,b = optimize_meta metasenv subst t in
268 let metasenv,subst,_ = sortfy exc metasenv subst context ty in
272 let rec instantiate rdb test_eq_only metasenv subst context n lc t swap =
273 (*D*) inside 'I'; try let rc =
274 pp (lazy(string_of_int n^" :=?= "^ppterm ~metasenv ~subst ~context t));
276 UnificationFailure (mk_msg metasenv subst context (NCic.Meta (n,lc)) t) in
277 let move_to_subst i ((_,cc,t,_) as infos) metasenv subst =
278 let metasenv = List.remove_assoc i metasenv in
279 pp(lazy(string_of_int n ^ " :==> "^ ppterm ~metasenv ~subst ~context:cc t));
280 metasenv, (i,infos) :: subst
282 let delift_to_subst test_eq_only n lc (attrs,cc,ty) t context metasenv subst =
283 pp (lazy(string_of_int n ^ " := 111 = "^
284 ppterm ~metasenv ~subst ~context t));
285 let (metasenv, subst), t =
288 ~unify:(fun m s c t1 t2 ->
291 try Some (unify rdb test_eq_only m s c t1 t2 )
292 with UnificationFailure _ | Uncertain _ -> None
295 metasenv subst context n lc t
296 with NCicMetaSubst.Uncertain msg ->
297 pp (lazy ("delift is uncertain: " ^ Lazy.force msg));
298 raise (Uncertain msg)
299 | NCicMetaSubst.MetaSubstFailure msg ->
300 pp (lazy ("delift fails: " ^ Lazy.force msg));
301 raise (UnificationFailure msg)
303 pp (lazy(string_of_int n ^ " := 222 = "^
304 ppterm ~metasenv ~subst ~context:cc t^ppmetasenv ~subst metasenv));
305 (* Unifying the types may have already instantiated n. *)
307 let _, _,oldt,_ = NCicUtils.lookup_subst n subst in
308 let oldt = NCicSubstitution.subst_meta lc oldt in
309 let t = NCicSubstitution.subst_meta lc t in
310 (* conjecture: always fail --> occur check *)
311 unify rdb test_eq_only metasenv subst context t oldt
312 with NCicUtils.Subst_not_found _ ->
313 move_to_subst n (attrs,cc,t,ty) metasenv subst
315 let attrs,cc,ty = NCicUtils.lookup_meta n metasenv in
316 let kind = NCicUntrusted.kind_of_meta attrs in
317 let metasenv,t = fix metasenv subst swap test_eq_only exc t in
318 let ty_t = NCicTypeChecker.typeof ~metasenv ~subst context t in
319 let metasenv,subst,t =
321 `IsSort -> sortfy exc metasenv subst context t
322 | `IsType -> tipify exc metasenv subst context t ty_t
323 | `IsTerm -> metasenv,subst,t in
327 NCic.Implicit (`Typeof _), NCic.Sort _ ->
328 move_to_subst n (attrs,cc,t,ty_t) metasenv subst
329 | NCic.Sort (NCic.Type u1), NCic.Sort s ->
332 NCic.Type u2, false ->
334 (unopt exc (NCicEnvironment.inf ~strict:false
335 (unopt exc (NCicEnvironment.inf ~strict:true u1) @ u2))))
336 | NCic.Type u2, true ->
337 if NCicEnvironment.universe_lt u2 u1 then
338 NCic.Sort (NCic.Type u2)
340 | NCic.Prop,_ -> NCic.Sort NCic.Prop
342 move_to_subst n (attrs,cc,s,ty) metasenv subst
343 | NCic.Implicit (`Typeof _), NCic.Meta _ ->
344 move_to_subst n (attrs,cc,t,ty_t) metasenv subst
346 | NCic.Meta _, NCic.Sort _ ->
347 pp (lazy ("On the types: " ^
348 ppterm ~metasenv ~subst ~context ty ^ "=<=" ^
349 ppterm ~metasenv ~subst ~context ty_t));
350 let metasenv, subst =
351 unify rdb false metasenv subst context ty_t ty in
352 delift_to_subst test_eq_only n lc (attrs,cc,ty) t
353 context metasenv subst
358 NCic.Implicit (`Typeof _), _ ->
359 let (metasenv, subst), ty_t =
362 ~unify:(fun m s c t1 t2 ->
364 let res = try Some (unify rdb test_eq_only m s c t1 t2 )
365 with UnificationFailure _ | Uncertain _ -> None
368 metasenv subst context n lc ty_t
369 with NCicMetaSubst.Uncertain msg ->
370 pp (lazy ("delift is uncertain: " ^ Lazy.force msg));
371 raise (Uncertain msg)
372 | NCicMetaSubst.MetaSubstFailure msg ->
373 pp (lazy ("delift fails: " ^ Lazy.force msg));
374 raise (UnificationFailure msg)
376 delift_to_subst test_eq_only n lc (attrs,cc,ty_t) t context metasenv
379 let lty = NCicSubstitution.subst_meta lc ty in
380 pp (lazy ("On the types: " ^
381 ppterm ~metasenv ~subst ~context lty ^ "=<=" ^
382 ppterm ~metasenv ~subst ~context ty_t));
383 let metasenv, subst =
384 unify rdb false metasenv subst context ty_t lty
386 delift_to_subst test_eq_only n lc (attrs,cc,ty) t context metasenv
389 | kind, ty, NCic.Meta(m,lcm), _ when List.mem_assoc m subst ->
390 let at,ccm,bo,tym = NCicUtils.lookup_subst m subst in
391 if NCicMetaSubst.is_out_scope_tag at then
393 (* Case meta vs out-scope *)
395 let ty_t, ccm, kindm =
396 NCicSubstitution.subst_meta lcm tym, ccm,
397 NCicUntrusted.kind_of_meta at in
398 let lty = NCicSubstitution.subst_meta lc ty in
399 pp (lazy ("On the types: " ^
400 ppterm ~metasenv ~subst ~context lty ^ "=<=" ^
401 ppterm ~metasenv ~subst ~context ty_t));
402 let metasenv, subst =
403 unify rdb false metasenv subst context ty_t lty in
404 (*CSC: here I should call kindfy, but it fails since the second
405 meta in in the susbt, not the metasenv! *)
406 (* let metasenv,subst,t = kindfy exc metasenv subst ccm m lcm ty_t kindm kind in *)
407 delift_to_subst test_eq_only n lc attrs cc t ty context metasenv subst
410 let bo = NCicSubstitution.subst_meta lcm bo in
411 instantiate rdb test_eq_only metasenv subst context n lc bo swap
413 (*D*) in outside None; rc with exn -> outside (Some exn); raise exn
415 and unify rdb test_eq_only metasenv subst context t1 t2 =
416 (*D*) inside 'U'; try let rc =
417 let fo_unif test_eq_only metasenv subst (norm1,t1) (norm2,t2) =
418 (*D*) inside 'F'; try let rc =
419 pp (lazy(" " ^ ppterm ~metasenv ~subst ~context t1 ^ " ==?== " ^
420 ppterm ~metasenv ~subst ~context t2 ^ ppmetasenv
422 pp (lazy(" " ^ ppterm ~metasenv ~subst:[] ~context t1 ^ " ==??== " ^
423 ppterm ~metasenv ~subst:[] ~context t2 ^ ppmetasenv
427 (* CSC: To speed up Oliboni's stuff. Why is it necessary, anyway?
429 NCicUntrusted.metas_of_term subst context t1 = [] &&
430 NCicUntrusted.metas_of_term subst context t2 = []
432 if NCicReduction.are_convertible ~metasenv ~subst context t1 t2 then
435 raise (UnificationFailure (lazy "Closed terms not convertible"))
439 | C.Appl [_], _ | _, C.Appl [_] | C.Appl [], _ | _, C.Appl []
440 | C.Appl (C.Appl _::_), _ | _, C.Appl (C.Appl _::_) ->
441 prerr_endline "Appl [Appl _;_] or Appl [] or Appl [_] invariant";
443 | (C.Sort (C.Type a), C.Sort (C.Type b)) when not test_eq_only ->
444 if NCicEnvironment.universe_leq a b then metasenv, subst
445 else raise (UnificationFailure (mk_msg metasenv subst context t1 t2))
446 | (C.Sort (C.Type a), C.Sort (C.Type b)) ->
447 if NCicEnvironment.universe_eq a b then metasenv, subst
448 else raise (UnificationFailure (mk_msg metasenv subst context t1 t2))
449 | (C.Sort C.Prop,C.Sort (C.Type _)) ->
450 if (not test_eq_only) then metasenv, subst
451 else raise (UnificationFailure (mk_msg metasenv subst context t1 t2))
453 | (C.Lambda (name1,s1,t1), C.Lambda(_,s2,t2))
454 | (C.Prod (name1,s1,t1), C.Prod(_,s2,t2)) ->
455 let metasenv, subst = unify rdb true metasenv subst context s1 s2 in
456 unify rdb test_eq_only metasenv subst ((name1, C.Decl s1)::context) t1 t2
457 | (C.LetIn (name1,ty1,s1,t1), C.LetIn(_,ty2,s2,t2)) ->
458 let metasenv,subst=unify rdb test_eq_only metasenv subst context ty1 ty2 in
459 let metasenv,subst=unify rdb test_eq_only metasenv subst context s1 s2 in
460 let context = (name1, C.Def (s1,ty1))::context in
461 unify rdb test_eq_only metasenv subst context t1 t2
463 | (C.Meta (n1,(s1,l1 as lc1)),C.Meta (n2,(s2,l2 as lc2))) when n1 = n2 ->
465 let l1 = NCicUtils.expand_local_context l1 in
466 let l2 = NCicUtils.expand_local_context l2 in
467 let metasenv, subst, to_restrict, _ =
469 (fun t1 t2 (metasenv, subst, to_restrict, i) ->
471 let metasenv, subst =
472 unify rdb test_eq_only metasenv subst context
473 (NCicSubstitution.lift s1 t1) (NCicSubstitution.lift s2 t2)
475 metasenv, subst, to_restrict, i-1
476 with UnificationFailure _ | Uncertain _ ->
477 metasenv, subst, i::to_restrict, i-1)
478 l1 l2 (metasenv, subst, [], List.length l1)
480 if to_restrict <> [] then
481 let metasenv, subst, _ =
482 NCicMetaSubst.restrict metasenv subst n1 to_restrict
487 | Invalid_argument _ -> assert false
488 | NCicMetaSubst.MetaSubstFailure msg ->
490 let _,_,term,_ = NCicUtils.lookup_subst n1 subst in
491 let term1 = NCicSubstitution.subst_meta lc1 term in
492 let term2 = NCicSubstitution.subst_meta lc2 term in
493 unify rdb test_eq_only metasenv subst context term1 term2
494 with NCicUtils.Subst_not_found _-> raise (UnificationFailure msg))
496 | NCic.Appl (NCic.Meta (i,_)::_ as l1),
497 NCic.Appl (NCic.Meta (j,_)::_ as l2) when i=j ->
500 (fun (metasenv, subst) t1 t2 ->
501 unify rdb test_eq_only metasenv subst context t1 t2)
502 (metasenv,subst) l1 l2
503 with Invalid_argument _ ->
504 raise (UnificationFailure (mk_msg metasenv subst context t1 t2)))
506 | _, NCic.Meta (n, _) when is_locked n subst ->
507 (let (metasenv, subst), i =
508 match NCicReduction.whd ~subst context t1 with
509 | NCic.Appl (NCic.Meta (i,l) as meta :: args) ->
510 let metasenv, lambda_Mj =
511 lambda_intros rdb metasenv subst context (List.length args)
512 (NCicTypeChecker.typeof ~metasenv ~subst context meta)
514 unify rdb test_eq_only metasenv subst context
515 (C.Meta (i,l)) lambda_Mj,
517 | NCic.Meta (i,_) -> (metasenv, subst), i
519 raise (UnificationFailure (lazy "Locked term vs non
520 flexible term; probably not saturated enough yet!"))
522 let t1 = NCicReduction.whd ~subst context t1 in
524 match t1 with NCic.Meta (j,l) -> j, l | _ -> assert false
526 let metasenv, subst =
527 instantiate rdb test_eq_only metasenv subst context j lj t2 true
529 (* We need to remove the out_scope_tags to avoid propagation of
530 them that triggers again the ad-hoc case *)
532 List.map (fun (i,(tag,ctx,bo,ty)) ->
535 (function `InScope | `OutScope _ -> false | _ -> true) tag
541 let name, ctx, term, ty = NCicUtils.lookup_subst i subst in
542 let term = eta_reduce subst term in
543 let subst = List.filter (fun (j,_) -> j <> i) subst in
544 metasenv, ((i, (name, ctx, term, ty)) :: subst)
545 with Not_found -> assert false))
547 | C.Meta (n,lc), t when List.mem_assoc n subst ->
548 let _,_,term,_ = NCicUtils.lookup_subst n subst in
549 let term = NCicSubstitution.subst_meta lc term in
550 unify rdb test_eq_only metasenv subst context term t
552 | t, C.Meta (n,lc) when List.mem_assoc n subst ->
553 let _,_,term,_ = NCicUtils.lookup_subst n subst in
554 let term = NCicSubstitution.subst_meta lc term in
555 unify rdb test_eq_only metasenv subst context t term
557 | NCic.Appl (NCic.Meta (i,l)::args), _ when List.mem_assoc i subst ->
558 let _,_,term,_ = NCicUtils.lookup_subst i subst in
559 let term = NCicSubstitution.subst_meta l term in
560 unify rdb test_eq_only metasenv subst context
561 (mk_appl ~upto:(List.length args) term args) t2
563 | _, NCic.Appl (NCic.Meta (i,l)::args) when List.mem_assoc i subst ->
564 let _,_,term,_ = NCicUtils.lookup_subst i subst in
565 let term = NCicSubstitution.subst_meta l term in
566 unify rdb test_eq_only metasenv subst context t1
567 (mk_appl ~upto:(List.length args) term args)
569 | C.Meta (n,lc), t ->
570 instantiate rdb test_eq_only metasenv subst context n lc
571 (NCicReduction.head_beta_reduce ~subst t) false
573 | t, C.Meta (n,lc) ->
574 instantiate rdb test_eq_only metasenv subst context n lc
575 (NCicReduction.head_beta_reduce ~subst t) true
577 | NCic.Appl (NCic.Meta (i,l) as meta :: args), _ ->
578 let metasenv, lambda_Mj =
579 lambda_intros rdb metasenv subst context (List.length args)
580 (NCicTypeChecker.typeof ~metasenv ~subst context meta)
582 let metasenv, subst =
584 unify rdb test_eq_only metasenv subst context
585 (C.Meta (i,l)) lambda_Mj
586 with UnificationFailure msg | Uncertain msg when not norm2->
587 (* failure: let's try again argument vs argument *)
588 raise (KeepReducing msg)
590 let metasenv, subst =
591 unify rdb test_eq_only metasenv subst context t1 t2
594 let name, ctx, term, ty = NCicUtils.lookup_subst i subst in
595 let term = eta_reduce subst term in
596 let subst = List.filter (fun (j,_) -> j <> i) subst in
597 metasenv, ((i, (name, ctx, term, ty)) :: subst)
598 with Not_found -> assert false)
600 | _, NCic.Appl (NCic.Meta (i,l) as meta :: args) ->
601 let metasenv, lambda_Mj =
602 lambda_intros rdb metasenv subst context (List.length args)
603 (NCicTypeChecker.typeof ~metasenv ~subst context meta)
605 let metasenv, subst =
607 unify rdb test_eq_only metasenv subst context
608 lambda_Mj (C.Meta (i,l))
609 with UnificationFailure msg | Uncertain msg when not norm1 ->
610 (* failure: let's try again argument vs argument *)
611 raise (KeepReducing msg)
613 let metasenv, subst =
614 unify rdb test_eq_only metasenv subst context t1 t2
617 let name, ctx, term, ty = NCicUtils.lookup_subst i subst in
618 let term = eta_reduce subst term in
619 let subst = List.filter (fun (j,_) -> j <> i) subst in
620 metasenv, ((i, (name, ctx, term, ty)) :: subst)
621 with Not_found -> assert false)
623 (* processing this case here we avoid a useless small delta step *)
624 | (C.Appl ((C.Const r1) as _hd1::tl1), C.Appl (C.Const r2::tl2))
626 let relevance = NCicEnvironment.get_relevance r1 in
627 let metasenv, subst, _ =
630 (fun (metasenv, subst, relevance) t1 t2 ->
632 match relevance with b::tl -> b,tl | _ -> true, [] in
633 let metasenv, subst =
634 try unify rdb test_eq_only metasenv subst context t1 t2
635 with UnificationFailure _ | Uncertain _ when not b ->
638 metasenv, subst, relevance)
639 (metasenv, subst, relevance) tl1 tl2
641 Invalid_argument _ ->
642 raise (Uncertain (mk_msg metasenv subst context t1 t2))
643 | UnificationFailure _ | Uncertain _ when not (norm1 && norm2) ->
644 raise (KeepReducing (mk_msg metasenv subst context t1 t2))
645 | KeepReducing _ | KeepReducingThis _ -> assert false
649 | (C.Match (Ref.Ref (_,Ref.Ind (_,tyno,_)) as ref1,outtype1,term1,pl1),
650 C.Match (ref2,outtype2,term2,pl2)) ->
651 let _,_,itl,_,_ = NCicEnvironment.get_checked_indtys ref1 in
652 let _,_,ty,_ = List.nth itl tyno in
653 let rec remove_prods ~subst context ty =
654 let ty = NCicReduction.whd ~subst context ty in
657 | C.Prod (name,so,ta) ->
658 remove_prods ~subst ((name,(C.Decl so))::context) ta
662 match remove_prods ~subst [] ty with
663 | C.Sort C.Prop -> true
666 if not (Ref.eq ref1 ref2) then
667 raise (Uncertain (mk_msg metasenv subst context t1 t2))
669 let metasenv, subst =
670 unify rdb test_eq_only metasenv subst context outtype1 outtype2 in
671 let metasenv, subst =
672 try unify rdb test_eq_only metasenv subst context term1 term2
673 with UnificationFailure _ | Uncertain _ when is_prop ->
678 (fun (metasenv,subst) ->
679 unify rdb test_eq_only metasenv subst context)
680 (metasenv, subst) pl1 pl2
681 with Invalid_argument _ -> assert false)
682 | (C.Implicit _, _) | (_, C.Implicit _) -> assert false
683 | _ when norm1 && norm2 ->
684 if (could_reduce t1 || could_reduce t2) then
685 raise (Uncertain (mk_msg metasenv subst context t1 t2))
687 raise (UnificationFailure (mk_msg metasenv subst context t1 t2))
688 | _ -> raise (KeepReducing (mk_msg metasenv subst context t1 t2))
689 (*D*) in outside None; rc with exn -> outside (Some exn); raise exn
691 let try_hints metasenv subst (_,t1 as mt1) (_,t2 as mt2) (* exc*) =
692 (*D*) inside 'H'; try let rc =
693 pp(lazy ("\nProblema:\n" ^
694 ppterm ~metasenv ~subst ~context t1 ^ " =?= " ^
695 ppterm ~metasenv ~subst ~context t2));
697 NCicUnifHint.look_for_hint rdb metasenv subst context t1 t2
699 let rec cand_iter = function
700 | [] -> None (* raise exc *)
701 | (metasenv,(c1,c2),premises)::tl ->
702 pp (lazy ("\nProvo il candidato:\n" ^
706 ppterm ~metasenv ~subst ~context a ^ " =?= " ^
707 ppterm ~metasenv ~subst ~context b) premises) ^
708 "\n-------------------------------------------\n"^
709 ppterm ~metasenv ~subst ~context c1 ^ " = " ^
710 ppterm ~metasenv ~subst ~context c2));
712 (*D*) inside 'K'; try let rc =
714 fo_unif test_eq_only metasenv subst mt1 (false,c1) in
716 fo_unif test_eq_only metasenv subst (false,c2) mt2 in
719 (fun (metasenv, subst) (x,y) ->
720 unify rdb test_eq_only metasenv subst context x y)
721 (metasenv, subst) premises
723 pp(lazy("FUNZIONA!"));
724 Some (metasenv, subst)
725 (*D*) in outside None; rc with exn -> outside (Some exn); raise exn
727 KeepReducing _ | UnificationFailure _ | Uncertain _ -> cand_iter tl
728 | KeepReducingThis _ -> assert false
731 (*D*) in outside None; rc with exn -> outside (Some exn); raise exn
733 let put_in_whd m1 m2 =
734 NCicReduction.reduce_machine ~delta:max_int ~subst context m1,
735 NCicReduction.reduce_machine ~delta:max_int ~subst context m2
737 let fo_unif_w_hints test_eq_only metasenv subst (_,t1 as m1) (_,t2 as m2) =
738 try fo_unif test_eq_only metasenv subst m1 m2
740 | UnificationFailure _ as exn -> raise exn
741 | KeepReducing _ | Uncertain _ as exn ->
742 let (t1,norm1 as tm1),(t2,norm2 as tm2) =
743 put_in_whd (0,[],t1,[]) (0,[],t2,[])
746 try_hints metasenv subst
747 (norm1,NCicReduction.unwind t1) (norm2,NCicReduction.unwind t2)
752 | KeepReducing msg -> raise (KeepReducingThis (msg,tm1,tm2))
753 | Uncertain _ as exn -> raise exn
756 let height_of = function
757 | NCic.Const (Ref.Ref (_,Ref.Def h))
758 | NCic.Const (Ref.Ref (_,Ref.Fix (_,_,h)))
759 | NCic.Appl(NCic.Const(Ref.Ref(_,Ref.Def h))::_)
760 | NCic.Appl(NCic.Const(Ref.Ref(_,Ref.Fix (_,_,h)))::_) -> h
763 let small_delta_step ~subst
764 ((_,_,t1,_ as m1, norm1) as x1) ((_,_,t2,_ as m2, norm2) as x2)
766 assert (not (norm1 && norm2));
768 x1,NCicReduction.reduce_machine ~delta:0 ~subst context m2
770 NCicReduction.reduce_machine ~delta:0 ~subst context m1,x2
772 let h1 = height_of t1 in
773 let h2 = height_of t2 in
774 let delta = if h1 = h2 then max 0 (h1 -1) else min h1 h2 in
775 NCicReduction.reduce_machine ~delta ~subst context m1,
776 NCicReduction.reduce_machine ~delta ~subst context m2
778 let rec unif_machines metasenv subst =
780 | ((k1,e1,t1,s1),norm1 as m1),((k2,e2,t2,s2),norm2 as m2) ->
781 (*D*) inside 'M'; try let rc =
783 ppterm ~metasenv ~subst ~context
784 (NCicReduction.unwind (k1,e1,t1,s1)) ^
786 ppterm ~metasenv ~subst ~context
787 (NCicReduction.unwind (k2,e2,t2,s2))));
788 pp (lazy (string_of_bool norm1 ^ " ?? " ^ string_of_bool norm2));
789 let relevance = [] (* TO BE UNDERSTOOD
791 | C.Const r -> NCicEnvironment.get_relevance r
793 let unif_from_stack t1 t2 b metasenv subst =
795 let t1 = NCicReduction.from_stack ~delta:max_int t1 in
796 let t2 = NCicReduction.from_stack ~delta:max_int t2 in
797 unif_machines metasenv subst (put_in_whd t1 t2)
798 with UnificationFailure _ | Uncertain _ when not b ->
801 let rec check_stack l1 l2 r todo =
803 | x1::tl1, x2::tl2, r::tr-> check_stack tl1 tl2 tr ((x1,x2,r)::todo)
804 | x1::tl1, x2::tl2, []-> check_stack tl1 tl2 [] ((x1,x2,true)::todo)
806 NCicReduction.unwind (k1,e1,t1,List.rev l1),
807 NCicReduction.unwind (k2,e2,t2,List.rev l2),
810 let hh1,hh2,todo=check_stack (List.rev s1) (List.rev s2) relevance [] in
813 fo_unif_w_hints test_eq_only metasenv subst (norm1,hh1) (norm2,hh2) in
815 (fun (metasenv,subst) (x1,x2,r) ->
816 unif_from_stack x1 x2 r metasenv subst
817 ) (metasenv,subst) todo
819 | KeepReducing _ -> assert false
820 | KeepReducingThis _ ->
821 assert (not (norm1 && norm2));
822 unif_machines metasenv subst (small_delta_step ~subst m1 m2)
823 | UnificationFailure _ | Uncertain _ when (not (norm1 && norm2))
824 -> unif_machines metasenv subst (small_delta_step ~subst m1 m2)
825 | UnificationFailure msg
826 when could_reduce (NCicReduction.unwind (fst m1))
827 || could_reduce (NCicReduction.unwind (fst m2))
828 -> raise (Uncertain msg)
829 (*D*) in outside None; rc with exn -> outside (Some exn); raise exn
831 try fo_unif_w_hints test_eq_only metasenv subst (false,t1) (false,t2)
833 | KeepReducingThis (msg,tm1,tm2) ->
835 unif_machines metasenv subst (tm1,tm2)
837 | UnificationFailure _ -> raise (UnificationFailure msg)
838 | Uncertain _ -> raise (Uncertain msg)
839 | KeepReducing _ -> assert false)
840 | KeepReducing _ -> assert false
842 (*D*) in outside None; rc with KeepReducing _ -> assert false | exn -> outside (Some exn); raise exn
844 and delift_type_wrt_terms rdb metasenv subst context t args =
845 let lc = List.rev args @ mk_irl (List.length context) (List.length args+1) in
846 let (metasenv, subst), t =
849 ~unify:(fun m s c t1 t2 ->
852 try Some (unify rdb false m s c t1 t2 )
853 with UnificationFailure _ | Uncertain _ -> None
856 metasenv subst context 0 (0,NCic.Ctx lc) t
858 NCicMetaSubst.MetaSubstFailure _
859 | NCicMetaSubst.Uncertain _ -> (metasenv, subst), t
865 let unify rdb ?(test_eq_only=false) =
867 unify rdb test_eq_only;;
870 fix m s true false (UnificationFailure (lazy "no sup"))