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;;
19 ref (fun _ ?localise _ _ _ _ _ -> ignore localise; assert false);;
20 let set_refiner_typeof f = refiner_typeof := f
23 let (===) x y = Pervasives.compare x y = 0 ;;
25 let uncert_exc metasenv subst context t1 t2 =
27 "Can't unify " ^ NCicPp.ppterm ~metasenv ~subst ~context t1 ^
28 " with " ^ NCicPp.ppterm ~metasenv ~subst ~context t2))
31 let fail_exc metasenv subst context t1 t2 =
32 UnificationFailure (lazy (
33 "Can't unify " ^ NCicPp.ppterm ~metasenv ~subst ~context t1 ^
34 " with " ^ NCicPp.ppterm ~metasenv ~subst ~context t2));
37 let mk_appl ~upto hd tl =
38 NCicReduction.head_beta_reduce ~upto
40 | NCic.Appl l -> NCic.Appl (l@tl)
41 | _ -> NCic.Appl (hd :: tl))
44 exception WrongShape;;
46 let eta_reduce subst t =
47 let delift_if_not_occur body =
49 Some (NCicSubstitution.psubst ~avoid_beta_redexes:true
50 (fun () -> raise WrongShape) [()] body)
51 with WrongShape -> None
53 let rec eat_lambdas ctx = function
54 | NCic.Lambda (name, src, tgt) ->
55 eat_lambdas ((name, src) :: ctx) tgt
56 | NCic.Meta (i,lc) as t->
58 let _,_,t,_ = NCicUtils.lookup_subst i subst in
59 let t = NCicSubstitution.subst_meta lc t in
61 with Not_found -> ctx, t)
64 let context_body = eat_lambdas [] t in
65 let rec aux = function
67 | (name, src)::ctx, (NCic.Appl (hd::[NCic.Rel 1]) as bo) ->
68 (match delift_if_not_occur hd with
69 | None -> aux (ctx,NCic.Lambda(name,src, bo))
70 | Some bo -> aux (ctx,bo))
71 | (name, src)::ctx, (NCic.Appl args as bo)
72 when HExtlib.list_last args = NCic.Rel 1 ->
73 let args, _ = HExtlib.split_nth (List.length args - 1) args in
74 (match delift_if_not_occur (NCic.Appl args) with
75 | None -> aux (ctx,NCic.Lambda(name,src, bo))
76 | Some bo -> aux (ctx,bo))
77 | (name, src) :: ctx, t ->
78 aux (ctx,NCic.Lambda(name,src, t))
84 module Ref = NReference;;
87 let inside c = indent := !indent ^ String.make 1 c;;
90 indent := String.sub !indent 0 (String.length !indent -1)
92 Invalid_argument _ -> indent := "??"; ()
96 prerr_endline (Printf.sprintf "%-20s" !indent ^ " " ^ Lazy.force s)
101 let ppcontext ~metasenv ~subst c =
102 "\nctx:\n"^ NCicPp.ppcontext ~metasenv ~subst c
104 let ppmetasenv ~subst m = "\nmenv:\n" ^ NCicPp.ppmetasenv ~subst m;;
106 let ppcontext ~metasenv:_metasenv ~subst:_subst _context = "";;
107 let ppmetasenv ~subst:_subst _metasenv = "";;
109 let fix_sorts swap exc t =
110 let rec aux () = function
111 | NCic.Sort (NCic.Type u) as orig ->
113 match NCicEnvironment.sup u with
115 prerr_endline ("no sup for " ^ NCicPp.ppterm ~metasenv:[] ~subst:[] ~context:[] orig) ;
117 | Some u1 -> if u = u1 then orig else NCic.Sort (NCic.Type u1)
119 NCic.Sort (NCic.Type (
120 match NCicEnvironment.sup NCicEnvironment.type0 with
122 | _ -> assert false))
123 | NCic.Meta _ as orig -> orig
124 | t -> NCicUtils.map (fun _ _ -> ()) () aux t
129 let is_locked n subst =
131 match NCicUtils.lookup_subst n subst with
132 | Some tag, _,_,_ when NCicMetaSubst.is_out_scope_tag tag -> true
134 with NCicUtils.Subst_not_found _ -> false
140 | n -> NCic.Rel n :: mk_irl (n-1)
143 let rec lambda_intros rdb metasenv subst context t args =
144 let tty = NCicTypeChecker.typeof ~metasenv ~subst context t in
147 (fun arg -> arg, NCicTypeChecker.typeof ~metasenv ~subst context arg) args in
148 let context_of_args = context in
149 let rec mk_lambda metasenv subst context n processed_args = function
151 let metasenv, _, bo, _ =
152 NCicMetaSubst.mk_meta metasenv context
153 (`WithType (NCicSubstitution.lift n tty))
157 let metasenv, subst, telescopic_ty =
158 (* XXX if processed_args = [] then metasenv, subst, ty else *)
159 delift_type_wrt_terms rdb metasenv subst context_of_args ty
160 (List.rev processed_args)
162 let name = "HBeta"^string_of_int n in
163 let metasenv, subst, bo =
164 mk_lambda metasenv subst ((name,NCic.Decl telescopic_ty)::context) (n+1)
165 (arg::processed_args) tail
167 metasenv, subst, NCic.Lambda (name, telescopic_ty, bo)
169 let rc = mk_lambda metasenv subst context 0 [] argsty in
172 and instantiate rdb test_eq_only metasenv subst context n lc t swap =
173 (*D*) inside 'I'; try let rc =
174 pp (lazy(string_of_int n ^ " :=?= "^
175 NCicPp.ppterm ~metasenv ~subst ~context t));
176 let unify test_eq_only m s c t1 t2 =
177 if swap then unify rdb test_eq_only m s c t2 t1
178 else unify rdb test_eq_only m s c t1 t2
180 let name, ctx, ty = NCicUtils.lookup_meta n metasenv in
181 let metasenv, subst, t =
183 | NCic.Implicit (`Typeof _) ->
185 (* fix_sorts swap metasenv subst context (NCic.Meta(n,lc)) t *)
188 "typeof: " ^ NCicPp.ppterm ~metasenv ~subst ~context t ^
189 ppcontext ~metasenv ~subst context ^
190 ppmetasenv ~subst metasenv));
191 let exc_to_be = fail_exc metasenv subst context (NCic.Meta (n,lc)) t in
193 try t, NCicTypeChecker.typeof ~subst ~metasenv context t
195 | NCicTypeChecker.AssertFailure msg ->
196 (pp (lazy "fine typeof (fallimento)");
197 let ft = fix_sorts swap exc_to_be t in
199 (prerr_endline ( ("ILLTYPED: " ^
200 NCicPp.ppterm ~metasenv ~subst ~context t
201 ^ "\nBECAUSE:" ^ Lazy.force msg ^
202 ppcontext ~metasenv ~subst context ^
203 ppmetasenv ~subst metasenv
208 pp (lazy ("typeof: " ^
209 NCicPp.ppterm ~metasenv ~subst ~context ft));
210 ft, NCicTypeChecker.typeof ~subst ~metasenv context ft
211 with NCicTypeChecker.AssertFailure _ ->
213 | NCicTypeChecker.TypeCheckerFailure msg ->
214 prerr_endline (Lazy.force msg);
217 let lty = NCicSubstitution.subst_meta lc ty in
220 raise (UnificationFailure
221 (lazy "trying to unify a term with a type"))
223 pp (lazy ("On the types: " ^
224 NCicPp.ppterm ~metasenv ~subst ~context:ctx ty ^ " ~~~ " ^
225 NCicPp.ppterm ~metasenv ~subst ~context lty ^ " === "
226 ^ NCicPp.ppterm ~metasenv ~subst ~context ty_t));
229 unify test_eq_only metasenv subst context lty ty_t
230 with NCicEnvironment.BadConstraint _ as exc ->
231 let ty_t = fix_sorts swap exc_to_be ty_t in
232 try unify test_eq_only metasenv subst context lty ty_t
233 with _ -> raise exc in
236 pp (lazy(string_of_int n ^ " := 111 = "^
237 NCicPp.ppterm ~metasenv ~subst ~context t));
238 let (metasenv, subst), t =
241 ~unify:(fun m s c t1 t2 ->
244 try Some (unify test_eq_only m s c t1 t2 )
245 with UnificationFailure _ | Uncertain _ -> None
248 metasenv subst context n lc t
249 with NCicMetaSubst.Uncertain msg ->
250 pp (lazy ("delift fails: " ^ Lazy.force msg));
251 raise (Uncertain msg)
252 | NCicMetaSubst.MetaSubstFailure msg ->
253 pp (lazy ("delift fails: " ^ Lazy.force msg));
254 raise (UnificationFailure msg)
256 pp (lazy(string_of_int n ^ " := 222 = "^
257 NCicPp.ppterm ~metasenv ~subst ~context:ctx t
258 ^ ppmetasenv ~subst metasenv));
259 (* Unifying the types may have already instantiated n. *)
261 let _, _,oldt,_ = NCicUtils.lookup_subst n subst in
262 let oldt = NCicSubstitution.subst_meta lc oldt in
263 let t = NCicSubstitution.subst_meta lc t in
264 (* conjecture: always fail --> occur check *)
265 unify test_eq_only metasenv subst context oldt t
266 with NCicUtils.Subst_not_found _ ->
267 (* by cumulativity when unify(?,Type_i)
268 * we could ? := Type_j with j <= i... *)
269 let subst = (n, (name, ctx, t, ty)) :: subst in
270 pp (lazy ("?"^string_of_int n^" := "^NCicPp.ppterm
271 ~metasenv ~subst ~context (NCicSubstitution.subst_meta lc t)));
273 List.filter (fun (m,_) -> not (n = m)) metasenv
276 (*D*) in outside(); rc with exn -> outside (); raise exn
278 and unify rdb test_eq_only metasenv subst context t1 t2 =
279 (*D*) inside 'U'; try let rc =
280 let fo_unif test_eq_only metasenv subst t1 t2 =
281 (*D*) inside 'F'; try let rc =
282 pp (lazy(" " ^ NCicPp.ppterm ~metasenv ~subst ~context t1 ^ " ==?== " ^
283 NCicPp.ppterm ~metasenv ~subst ~context t2 ^ ppmetasenv
289 | C.Appl [_], _ | _, C.Appl [_] | C.Appl [], _ | _, C.Appl []
290 | C.Appl (C.Appl _::_), _ | _, C.Appl (C.Appl _::_) ->
291 prerr_endline "Appl [Appl _;_] or Appl [] or Appl [_] invariant";
293 | (C.Sort (C.Type a), C.Sort (C.Type b)) when not test_eq_only ->
294 if NCicEnvironment.universe_leq a b then metasenv, subst
295 else raise (fail_exc metasenv subst context t1 t2)
296 | (C.Sort (C.Type a), C.Sort (C.Type b)) ->
297 if NCicEnvironment.universe_eq a b then metasenv, subst
298 else raise (fail_exc metasenv subst context t1 t2)
299 | (C.Sort C.Prop,C.Sort (C.Type _)) ->
300 if (not test_eq_only) then metasenv, subst
301 else raise (fail_exc metasenv subst context t1 t2)
303 | (C.Lambda (name1,s1,t1), C.Lambda(_,s2,t2))
304 | (C.Prod (name1,s1,t1), C.Prod(_,s2,t2)) ->
305 let metasenv, subst = unify rdb true metasenv subst context s1 s2 in
306 unify rdb test_eq_only metasenv subst ((name1, C.Decl s1)::context) t1 t2
307 | (C.LetIn (name1,ty1,s1,t1), C.LetIn(_,ty2,s2,t2)) ->
308 let metasenv,subst=unify rdb test_eq_only metasenv subst context ty1 ty2 in
309 let metasenv,subst=unify rdb test_eq_only metasenv subst context s1 s2 in
310 let context = (name1, C.Def (s1,ty1))::context in
311 unify rdb test_eq_only metasenv subst context t1 t2
313 | (C.Meta (n1,(s1,l1 as lc1)),C.Meta (n2,(s2,l2 as lc2))) when n1 = n2 ->
315 let l1 = NCicUtils.expand_local_context l1 in
316 let l2 = NCicUtils.expand_local_context l2 in
317 let metasenv, subst, to_restrict, _ =
319 (fun t1 t2 (metasenv, subst, to_restrict, i) ->
321 let metasenv, subst =
322 unify rdb test_eq_only metasenv subst context
323 (NCicSubstitution.lift s1 t1) (NCicSubstitution.lift s2 t2)
325 metasenv, subst, to_restrict, i-1
326 with UnificationFailure _ | Uncertain _ ->
327 metasenv, subst, i::to_restrict, i-1)
328 l1 l2 (metasenv, subst, [], List.length l1)
330 if to_restrict <> [] then
331 let metasenv, subst, _ =
332 NCicMetaSubst.restrict metasenv subst n1 to_restrict
337 | Invalid_argument _ -> assert false
338 | NCicMetaSubst.MetaSubstFailure msg ->
340 let _,_,term,_ = NCicUtils.lookup_subst n1 subst in
341 let term1 = NCicSubstitution.subst_meta lc1 term in
342 let term2 = NCicSubstitution.subst_meta lc2 term in
343 unify rdb test_eq_only metasenv subst context term1 term2
344 with NCicUtils.Subst_not_found _-> raise (UnificationFailure msg))
346 | _, NCic.Meta (n, _) when is_locked n subst ->
347 (let (metasenv, subst), i =
348 match NCicReduction.whd ~subst context t1 with
349 | NCic.Appl (NCic.Meta (i,l)::args) ->
350 let metasenv, subst, lambda_Mj =
351 lambda_intros rdb metasenv subst context t1 args
353 unify rdb test_eq_only metasenv subst context
354 (C.Meta (i,l)) lambda_Mj,
356 | NCic.Meta (i,_) -> (metasenv, subst), i
358 raise (UnificationFailure (lazy "Locked term vs non
359 flexible term; probably not saturated enough yet!"))
361 let t1 = NCicReduction.whd ~subst context t1 in
363 match t1 with NCic.Meta (j,l) -> j, l | _ -> assert false
365 let metasenv, subst =
366 instantiate rdb test_eq_only metasenv subst context j lj t2 true
368 (* We need to remove the out_scope_tags to avoid propagation of
369 them that triggers again the ad-hoc case *)
371 List.map (fun (i,(tag,ctx,bo,ty)) ->
375 tag = NCicMetaSubst.in_scope_tag
376 || NCicMetaSubst.is_out_scope_tag tag -> None
383 let name, ctx, term, ty = NCicUtils.lookup_subst i subst in
384 let term = eta_reduce subst term in
385 let subst = List.filter (fun (j,_) -> j <> i) subst in
386 metasenv, ((i, (name, ctx, term, ty)) :: subst)
387 with Not_found -> assert false))
389 | C.Meta (n,lc), t ->
391 let _,_,term,_ = NCicUtils.lookup_subst n subst in
392 let term = NCicSubstitution.subst_meta lc term in
393 unify rdb test_eq_only metasenv subst context term t
394 with NCicUtils.Subst_not_found _->
395 instantiate rdb test_eq_only metasenv subst context n lc
396 (NCicReduction.head_beta_reduce ~subst t) false)
398 | t, C.Meta (n,lc) ->
400 let _,_,term,_ = NCicUtils.lookup_subst n subst in
401 let term = NCicSubstitution.subst_meta lc term in
402 unify rdb test_eq_only metasenv subst context t term
403 with NCicUtils.Subst_not_found _->
404 instantiate rdb test_eq_only metasenv subst context n lc
405 (NCicReduction.head_beta_reduce ~subst t) true)
407 | NCic.Appl (NCic.Meta (i,l)::args), _ when List.mem_assoc i subst ->
408 let _,_,term,_ = NCicUtils.lookup_subst i subst in
409 let term = NCicSubstitution.subst_meta l term in
410 unify rdb test_eq_only metasenv subst context
411 (mk_appl ~upto:(List.length args) term args) t2
413 | _, NCic.Appl (NCic.Meta (i,l)::args) when List.mem_assoc i subst ->
414 let _,_,term,_ = NCicUtils.lookup_subst i subst in
415 let term = NCicSubstitution.subst_meta l term in
416 unify rdb test_eq_only metasenv subst context t1
417 (mk_appl ~upto:(List.length args) term args)
419 | NCic.Appl (NCic.Meta (i,_)::_ as l1),
420 NCic.Appl (NCic.Meta (j,_)::_ as l2) when i=j ->
423 (fun (metasenv, subst) t1 t2 ->
424 unify rdb test_eq_only metasenv subst context t1 t2)
425 (metasenv,subst) l1 l2
426 with Invalid_argument _ ->
427 raise (fail_exc metasenv subst context t1 t2))
429 | NCic.Appl (NCic.Meta (i,l)::args), _ ->
430 let metasenv, subst, lambda_Mj =
431 lambda_intros rdb metasenv subst context t1 args
433 let metasenv, subst =
434 unify rdb test_eq_only metasenv subst context
435 (C.Meta (i,l)) lambda_Mj
437 let metasenv, subst =
438 unify rdb test_eq_only metasenv subst context t1 t2
441 let name, ctx, term, ty = NCicUtils.lookup_subst i subst in
442 let term = eta_reduce subst term in
443 let subst = List.filter (fun (j,_) -> j <> i) subst in
444 metasenv, ((i, (name, ctx, term, ty)) :: subst)
445 with Not_found -> assert false)
447 | _, NCic.Appl (NCic.Meta (i,l)::args) ->
448 let metasenv, subst, lambda_Mj =
449 lambda_intros rdb metasenv subst context t2 args
451 let metasenv, subst =
452 unify rdb test_eq_only metasenv subst context
453 lambda_Mj (C.Meta (i,l))
455 let metasenv, subst =
456 unify rdb test_eq_only metasenv subst context t1 t2
459 let name, ctx, term, ty = NCicUtils.lookup_subst i subst in
460 let term = eta_reduce subst term in
461 let subst = List.filter (fun (j,_) -> j <> i) subst in
462 metasenv, ((i, (name, ctx, term, ty)) :: subst)
463 with Not_found -> assert false)
465 (* processing this case here we avoid a useless small delta step *)
466 | (C.Appl ((C.Const r1) as _hd1::tl1), C.Appl (C.Const r2::tl2))
468 let relevance = NCicEnvironment.get_relevance r1 in
469 let relevance = match r1 with
470 | Ref.Ref (_,Ref.Con (_,_,lno)) ->
472 try snd (HExtlib.split_nth lno relevance)
475 HExtlib.mk_list false lno @ relevance
478 let metasenv, subst, _ =
481 (fun (metasenv, subst, relevance) t1 t2 ->
483 match relevance with b::tl -> b,tl | _ -> true, [] in
484 let metasenv, subst =
485 try unify rdb test_eq_only metasenv subst context t1 t2
486 with UnificationFailure _ | Uncertain _ when not b ->
489 metasenv, subst, relevance)
490 (metasenv, subst, relevance) tl1 tl2
491 with Invalid_argument _ ->
492 raise (uncert_exc metasenv subst context t1 t2)
496 | (C.Match (Ref.Ref (_,Ref.Ind (_,tyno,_)) as ref1,outtype1,term1,pl1),
497 C.Match (ref2,outtype2,term2,pl2)) ->
498 let _,_,itl,_,_ = NCicEnvironment.get_checked_indtys ref1 in
499 let _,_,ty,_ = List.nth itl tyno in
500 let rec remove_prods ~subst context ty =
501 let ty = NCicReduction.whd ~subst context ty in
504 | C.Prod (name,so,ta) ->
505 remove_prods ~subst ((name,(C.Decl so))::context) ta
509 match remove_prods ~subst [] ty with
510 | C.Sort C.Prop -> true
513 if not (Ref.eq ref1 ref2) then
514 raise (uncert_exc metasenv subst context t1 t2)
516 let metasenv, subst =
517 unify rdb test_eq_only metasenv subst context outtype1 outtype2 in
518 let metasenv, subst =
519 try unify rdb test_eq_only metasenv subst context term1 term2
520 with UnificationFailure _ | Uncertain _ when is_prop ->
525 (fun (metasenv,subst) ->
526 unify rdb test_eq_only metasenv subst context)
527 (metasenv, subst) pl1 pl2
528 with Invalid_argument _ ->
529 raise (uncert_exc metasenv subst context t1 t2))
530 | (C.Implicit _, _) | (_, C.Implicit _) -> assert false
531 | _ when NCicUntrusted.metas_of_term subst context t1 = [] &&
532 NCicUntrusted.metas_of_term subst context t2 = [] ->
533 raise (fail_exc metasenv subst context t1 t2)
534 | _ -> raise (uncert_exc metasenv subst context t1 t2)
535 (*D*) in outside(); rc with exn -> outside (); raise exn
537 let try_hints metasenv subst t1 t2 (* exc*) =
539 prerr_endline ("\nProblema:\n" ^
540 NCicPp.ppterm ~metasenv ~subst ~context t1 ^ " =?= " ^
541 NCicPp.ppterm ~metasenv ~subst ~context t2);
544 NCicUnifHint.look_for_hint rdb metasenv subst context t1 t2
546 let rec cand_iter = function
547 | [] -> None (* raise exc *)
548 | (metasenv,(c1,c2),premises)::tl ->
550 prerr_endline ("\nProvo il candidato:\n" ^
554 NCicPp.ppterm ~metasenv ~subst ~context a ^ " =?= " ^
555 NCicPp.ppterm ~metasenv ~subst ~context b) premises) ^
556 "\n-------------------------------------------\n"^
557 NCicPp.ppterm ~metasenv ~subst ~context c1 ^ " = " ^
558 NCicPp.ppterm ~metasenv ~subst ~context c2);
562 fo_unif test_eq_only metasenv subst t1 c1 in
564 fo_unif test_eq_only metasenv subst c2 t2 in
567 (fun (metasenv, subst) (x,y) ->
568 unify rdb test_eq_only metasenv subst context x y)
569 (metasenv, subst) premises
571 Some (metasenv, subst)
573 UnificationFailure _ | Uncertain _ ->
578 let height_of = function
579 | NCic.Const (Ref.Ref (_,Ref.Def h))
580 | NCic.Const (Ref.Ref (_,Ref.Fix (_,_,h)))
581 | NCic.Appl(NCic.Const(Ref.Ref(_,Ref.Def h))::_)
582 | NCic.Appl(NCic.Const(Ref.Ref(_,Ref.Fix (_,_,h)))::_) -> h
585 let put_in_whd m1 m2 =
586 NCicReduction.reduce_machine ~delta:max_int ~subst context m1,
587 NCicReduction.reduce_machine ~delta:max_int ~subst context m2
589 let small_delta_step ~subst
590 ((_,_,t1,_ as m1, norm1) as x1) ((_,_,t2,_ as m2, norm2) as x2)
592 assert (not (norm1 && norm2));
594 x1,NCicReduction.reduce_machine ~delta:(height_of t2 -1) ~subst context m2
596 NCicReduction.reduce_machine ~delta:(height_of t1 -1) ~subst context m1,x2
598 let h1 = height_of t1 in
599 let h2 = height_of t2 in
600 let delta = if h1 = h2 then max 0 (h1 -1) else min h1 h2 in
601 NCicReduction.reduce_machine ~delta ~subst context m1,
602 NCicReduction.reduce_machine ~delta ~subst context m2
604 let rec unif_machines metasenv subst =
606 | ((k1,e1,t1,s1),norm1 as m1),((k2,e2,t2,s2),norm2 as m2) ->
607 (*D*) inside 'M'; try let rc =
609 NCicPp.ppterm ~metasenv ~subst ~context
610 (NCicReduction.unwind (k1,e1,t1,s1)) ^
612 NCicPp.ppterm ~metasenv ~subst ~context
613 (NCicReduction.unwind (k2,e2,t2,s2))));
614 pp (lazy (string_of_bool norm1 ^ " ?? " ^ string_of_bool norm2));
615 let relevance = [] (* TO BE UNDERSTOOD
617 | C.Const r -> NCicEnvironment.get_relevance r
619 let unif_from_stack t1 t2 b metasenv subst =
621 let t1 = NCicReduction.from_stack ~delta:max_int t1 in
622 let t2 = NCicReduction.from_stack ~delta:max_int t2 in
623 unif_machines metasenv subst (put_in_whd t1 t2)
624 with UnificationFailure _ | Uncertain _ when not b ->
627 let rec check_stack l1 l2 r todo =
629 | x1::tl1, x2::tl2, r::tr-> check_stack tl1 tl2 tr ((x1,x2,r)::todo)
630 | x1::tl1, x2::tl2, []-> check_stack tl1 tl2 [] ((x1,x2,true)::todo)
632 NCicReduction.unwind (k1,e1,t1,List.rev l1),
633 NCicReduction.unwind (k2,e2,t2,List.rev l2),
636 let hh1,hh2,todo=check_stack (List.rev s1) (List.rev s2) relevance [] in
638 let metasenv,subst = fo_unif test_eq_only metasenv subst hh1 hh2 in
640 (fun (metasenv,subst) (x1,x2,r) ->
641 unif_from_stack x1 x2 r metasenv subst
642 ) (metasenv,subst) todo
643 with UnificationFailure _ | Uncertain _ when not (norm1 && norm2) ->
644 unif_machines metasenv subst (small_delta_step ~subst m1 m2)
645 (*D*) in outside(); rc with exn -> outside (); raise exn
647 try fo_unif test_eq_only metasenv subst t1 t2
649 | UnificationFailure msg as exn ->
651 unif_machines metasenv subst
652 (put_in_whd (0,[],t1,[]) (0,[],t2,[]))
654 | UnificationFailure _ -> raise (UnificationFailure msg)
655 | Uncertain _ -> raise exn)
656 | Uncertain msg as exn ->
657 match try_hints metasenv subst t1 t2 with
661 unif_machines metasenv subst
662 (put_in_whd (0,[],t1,[]) (0,[],t2,[]))
664 | UnificationFailure _ -> raise (UnificationFailure msg)
665 | Uncertain _ -> raise exn
666 (*D*) in outside(); rc with exn -> outside (); raise exn
668 and delift_type_wrt_terms rdb metasenv subst context t args =
669 let metasenv, _, instance, _ =
670 NCicMetaSubst.mk_meta metasenv context `Type in
671 let meta_applied = NCicUntrusted.mk_appl instance args in
672 let metasenv,subst,meta_applied,_ =
673 !refiner_typeof ((rdb:> NRstatus.status)#set_coerc_db NCicCoercion.empty_db)
674 metasenv subst context meta_applied None
676 let metasenv, subst =
677 unify rdb true metasenv subst context meta_applied t in
678 let t = NCicSubstitution.lift (List.length args) instance in
679 let t = NCicUntrusted.mk_appl t (mk_irl (List.length args)) in
684 let unify rdb ?(test_eq_only=false) =
686 unify rdb test_eq_only;;
688 let fix_sorts = fix_sorts true (UnificationFailure (lazy "no sup"));;