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 = NCicPp.ppcontext;;
102 let ppmetasenv = NCicPp.ppmetasenv;;
104 let ppcontext ~metasenv:_metasenv ~subst:_subst _context = "...";;
105 let ppmetasenv ~subst:_subst _metasenv = "...";;
107 let fix_sorts swap exc t =
108 let rec aux () = function
109 | NCic.Sort (NCic.Type u) as orig ->
111 match NCicEnvironment.sup u with
113 prerr_endline ("no sup for " ^ NCicPp.ppterm ~metasenv:[] ~subst:[] ~context:[] orig) ;
115 | Some u1 -> if u = u1 then orig else NCic.Sort (NCic.Type u1)
117 NCic.Sort (NCic.Type (
118 match NCicEnvironment.sup NCicEnvironment.type0 with
120 | _ -> assert false))
121 | NCic.Meta _ as orig -> orig
122 | t -> NCicUtils.map (fun _ _ -> ()) () aux t
127 let is_locked n subst =
129 match NCicUtils.lookup_subst n subst with
130 | Some tag, _,_,_ when NCicMetaSubst.is_out_scope_tag tag -> true
132 with NCicUtils.Subst_not_found _ -> false
138 | n -> NCic.Rel n :: mk_irl (n-1)
141 let rec lambda_intros rdb metasenv subst context t args =
142 let tty = NCicTypeChecker.typeof ~metasenv ~subst context t in
145 (fun arg -> arg, NCicTypeChecker.typeof ~metasenv ~subst context arg) args in
146 let context_of_args = context in
147 let rec mk_lambda metasenv subst context n processed_args = function
149 let metasenv, _, bo, _ =
150 NCicMetaSubst.mk_meta metasenv context
151 (`WithType (NCicSubstitution.lift n tty))
155 let metasenv, subst, telescopic_ty =
156 delift_term_wrt_terms rdb metasenv subst context_of_args ty
157 (List.rev processed_args)
159 let name = "HBeta"^string_of_int n in
160 let metasenv, subst, bo =
161 mk_lambda metasenv subst ((name,NCic.Decl telescopic_ty)::context) (n+1)
162 (arg::processed_args) tail
164 metasenv, subst, NCic.Lambda (name, telescopic_ty, bo)
166 mk_lambda metasenv subst context 0 [] argsty
168 and instantiate rdb test_eq_only metasenv subst context n lc t swap =
169 (*D*) inside 'I'; try let rc =
170 pp (lazy(string_of_int n ^ " :=?= "^
171 NCicPp.ppterm ~metasenv ~subst ~context t));
172 let unify test_eq_only m s c t1 t2 =
173 if swap then unify rdb test_eq_only m s c t2 t1
174 else unify rdb test_eq_only m s c t1 t2
176 let name, ctx, ty = NCicUtils.lookup_meta n metasenv in
177 let metasenv, subst, t =
179 | NCic.Implicit (`Typeof _) ->
181 (* fix_sorts swap metasenv subst context (NCic.Meta(n,lc)) t *)
184 "typeof: " ^ NCicPp.ppterm ~metasenv ~subst ~context t ^ "\nctx:\n"^
185 ppcontext ~metasenv ~subst context ^ "\nmenv:\n"^
186 ppmetasenv ~subst metasenv));
187 let exc_to_be = fail_exc metasenv subst context (NCic.Meta (n,lc)) t in
189 try t, NCicTypeChecker.typeof ~subst ~metasenv context t
191 | NCicTypeChecker.AssertFailure msg ->
192 (pp (lazy "fine typeof (fallimento)");
193 let ft = fix_sorts swap exc_to_be t in
195 (prerr_endline ( ("ILLTYPED: " ^
196 NCicPp.ppterm ~metasenv ~subst ~context t
197 ^ "\nBECAUSE:" ^ Lazy.force msg ^ "\nCONTEXT:\n" ^
198 ppcontext ~metasenv ~subst context ^ "\nMENV:\n" ^
199 ppmetasenv ~subst metasenv
204 pp (lazy ("typeof: " ^
205 NCicPp.ppterm ~metasenv ~subst ~context ft));
206 ft, NCicTypeChecker.typeof ~subst ~metasenv context ft
207 with NCicTypeChecker.AssertFailure _ ->
209 | NCicTypeChecker.TypeCheckerFailure msg ->
210 prerr_endline (Lazy.force msg);
213 let lty = NCicSubstitution.subst_meta lc ty in
216 raise (UnificationFailure
217 (lazy "trying to unify a term with a type"))
219 pp (lazy ("On the types: " ^
220 NCicPp.ppterm ~metasenv ~subst ~context:ctx ty ^ " ~~~ " ^
221 NCicPp.ppterm ~metasenv ~subst ~context lty ^ " === "
222 ^ NCicPp.ppterm ~metasenv ~subst ~context ty_t));
225 unify test_eq_only metasenv subst context lty ty_t
226 with NCicEnvironment.BadConstraint _ as exc ->
227 let ty_t = fix_sorts swap exc_to_be ty_t in
228 try unify test_eq_only metasenv subst context lty ty_t
229 with _ -> raise exc in
232 pp (lazy(string_of_int n ^ " := 111 = "^
233 NCicPp.ppterm ~metasenv ~subst ~context t));
234 let (metasenv, subst), t =
237 ~unify:(fun m s c t1 t2 ->
240 try Some (unify test_eq_only m s c t1 t2 )
241 with UnificationFailure _ | Uncertain _ -> None
244 metasenv subst context n lc t
245 with NCicMetaSubst.Uncertain msg ->
246 pp (lazy ("delift fails: " ^ Lazy.force msg));
247 raise (Uncertain msg)
248 | NCicMetaSubst.MetaSubstFailure msg ->
249 pp (lazy ("delift fails: " ^ Lazy.force msg));
250 raise (UnificationFailure msg)
252 pp (lazy(string_of_int n ^ " := 222 = "^
253 NCicPp.ppterm ~metasenv ~subst ~context:ctx t
254 ^ "\n" ^ ppmetasenv ~subst metasenv));
255 (* Unifying the types may have already instantiated n. *)
257 let _, _,oldt,_ = NCicUtils.lookup_subst n subst in
258 let oldt = NCicSubstitution.subst_meta lc oldt in
259 let t = NCicSubstitution.subst_meta lc t in
260 (* conjecture: always fail --> occur check *)
261 unify test_eq_only metasenv subst context oldt t
262 with NCicUtils.Subst_not_found _ ->
263 (* by cumulativity when unify(?,Type_i)
264 * we could ? := Type_j with j <= i... *)
265 let subst = (n, (name, ctx, t, ty)) :: subst in
266 pp (lazy ("?"^string_of_int n^" := "^NCicPp.ppterm
267 ~metasenv ~subst ~context (NCicSubstitution.subst_meta lc t)));
269 List.filter (fun (m,_) -> not (n = m)) metasenv
272 (*D*) in outside(); rc with exn -> outside (); raise exn
274 and unify rdb test_eq_only metasenv subst context t1 t2 =
275 (*D*) inside 'U'; try let rc =
276 let fo_unif test_eq_only metasenv subst t1 t2 =
277 (*D*) inside 'F'; try let rc =
278 pp (lazy(" " ^ NCicPp.ppterm ~metasenv ~subst ~context t1 ^ " ==?== " ^
279 NCicPp.ppterm ~metasenv ~subst ~context t2 ^ "\n" ^ ppmetasenv
285 | C.Appl [_], _ | _, C.Appl [_] | C.Appl [], _ | _, C.Appl []
286 | C.Appl (C.Appl _::_), _ | _, C.Appl (C.Appl _::_) ->
287 prerr_endline "Appl [Appl _;_] or Appl [] or Appl [_] invariant";
289 | (C.Sort (C.Type a), C.Sort (C.Type b)) when not test_eq_only ->
290 if NCicEnvironment.universe_leq a b then metasenv, subst
291 else raise (fail_exc metasenv subst context t1 t2)
292 | (C.Sort (C.Type a), C.Sort (C.Type b)) ->
293 if NCicEnvironment.universe_eq a b then metasenv, subst
294 else raise (fail_exc metasenv subst context t1 t2)
295 | (C.Sort C.Prop,C.Sort (C.Type _)) ->
296 if (not test_eq_only) then metasenv, subst
297 else raise (fail_exc metasenv subst context t1 t2)
299 | (C.Lambda (name1,s1,t1), C.Lambda(_,s2,t2))
300 | (C.Prod (name1,s1,t1), C.Prod(_,s2,t2)) ->
301 let metasenv, subst = unify rdb true metasenv subst context s1 s2 in
302 unify rdb test_eq_only metasenv subst ((name1, C.Decl s1)::context) t1 t2
303 | (C.LetIn (name1,ty1,s1,t1), C.LetIn(_,ty2,s2,t2)) ->
304 let metasenv,subst=unify rdb test_eq_only metasenv subst context ty1 ty2 in
305 let metasenv,subst=unify rdb test_eq_only metasenv subst context s1 s2 in
306 let context = (name1, C.Def (s1,ty1))::context in
307 unify rdb test_eq_only metasenv subst context t1 t2
309 | (C.Meta (n1,(s1,l1 as lc1)),C.Meta (n2,(s2,l2 as lc2))) when n1 = n2 ->
311 let l1 = NCicUtils.expand_local_context l1 in
312 let l2 = NCicUtils.expand_local_context l2 in
313 let metasenv, subst, to_restrict, _ =
315 (fun t1 t2 (metasenv, subst, to_restrict, i) ->
317 let metasenv, subst =
318 unify rdb test_eq_only metasenv subst context
319 (NCicSubstitution.lift s1 t1) (NCicSubstitution.lift s2 t2)
321 metasenv, subst, to_restrict, i-1
322 with UnificationFailure _ | Uncertain _ ->
323 metasenv, subst, i::to_restrict, i-1)
324 l1 l2 (metasenv, subst, [], List.length l1)
326 if to_restrict <> [] then
327 let metasenv, subst, _ =
328 NCicMetaSubst.restrict metasenv subst n1 to_restrict
333 | Invalid_argument _ -> assert false
334 | NCicMetaSubst.MetaSubstFailure msg ->
336 let _,_,term,_ = NCicUtils.lookup_subst n1 subst in
337 let term1 = NCicSubstitution.subst_meta lc1 term in
338 let term2 = NCicSubstitution.subst_meta lc2 term in
339 unify rdb test_eq_only metasenv subst context term1 term2
340 with NCicUtils.Subst_not_found _-> raise (UnificationFailure msg))
342 | _, NCic.Meta (n, _) when is_locked n subst ->
343 (let (metasenv, subst), i =
344 match NCicReduction.whd ~subst context t1 with
345 | NCic.Appl (NCic.Meta (i,l)::args) ->
346 let metasenv, subst, lambda_Mj =
347 lambda_intros rdb metasenv subst context t1 args
349 unify rdb test_eq_only metasenv subst context
350 (C.Meta (i,l)) lambda_Mj,
352 | NCic.Meta (i,_) -> (metasenv, subst), i
354 raise (UnificationFailure (lazy "Locked term vs non
355 flexible term; probably not saturated enough yet!"))
357 let t1 = NCicReduction.whd ~subst context t1 in
359 match t1 with NCic.Meta (j,l) -> j, l | _ -> assert false
361 let metasenv, subst =
362 instantiate rdb test_eq_only metasenv subst context j lj t2 true
364 (* We need to remove the out_scope_tags to avoid propagation of
365 them that triggers again the ad-hoc case *)
367 List.map (fun (i,(tag,ctx,bo,ty)) ->
371 tag = NCicMetaSubst.in_scope_tag
372 || NCicMetaSubst.is_out_scope_tag tag -> None
379 let name, ctx, term, ty = NCicUtils.lookup_subst i subst in
380 let term = eta_reduce subst term in
381 let subst = List.filter (fun (j,_) -> j <> i) subst in
382 metasenv, ((i, (name, ctx, term, ty)) :: subst)
383 with Not_found -> assert false))
385 | C.Meta (n,lc), t ->
387 let _,_,term,_ = NCicUtils.lookup_subst n subst in
388 let term = NCicSubstitution.subst_meta lc term in
389 unify rdb test_eq_only metasenv subst context term t
390 with NCicUtils.Subst_not_found _->
391 instantiate rdb test_eq_only metasenv subst context n lc
392 (NCicReduction.head_beta_reduce ~subst t) false)
394 | t, C.Meta (n,lc) ->
396 let _,_,term,_ = NCicUtils.lookup_subst n subst in
397 let term = NCicSubstitution.subst_meta lc term in
398 unify rdb test_eq_only metasenv subst context t term
399 with NCicUtils.Subst_not_found _->
400 instantiate rdb test_eq_only metasenv subst context n lc
401 (NCicReduction.head_beta_reduce ~subst t) true)
403 | NCic.Appl (NCic.Meta (i,l)::args), _ when List.mem_assoc i subst ->
404 let _,_,term,_ = NCicUtils.lookup_subst i subst in
405 let term = NCicSubstitution.subst_meta l term in
406 unify rdb test_eq_only metasenv subst context
407 (mk_appl ~upto:(List.length args) term args) t2
409 | _, NCic.Appl (NCic.Meta (i,l)::args) when List.mem_assoc i subst ->
410 let _,_,term,_ = NCicUtils.lookup_subst i subst in
411 let term = NCicSubstitution.subst_meta l term in
412 unify rdb test_eq_only metasenv subst context t1
413 (mk_appl ~upto:(List.length args) term args)
415 | NCic.Appl (NCic.Meta (i,_)::_ as l1),
416 NCic.Appl (NCic.Meta (j,_)::_ as l2) when i=j ->
419 (fun (metasenv, subst) t1 t2 ->
420 unify rdb test_eq_only metasenv subst context t1 t2)
421 (metasenv,subst) l1 l2
422 with Invalid_argument _ ->
423 raise (fail_exc metasenv subst context t1 t2))
425 | NCic.Appl (NCic.Meta (i,l)::args), _ ->
426 let metasenv, subst, lambda_Mj =
427 lambda_intros rdb metasenv subst context t1 args
429 let metasenv, subst =
430 unify rdb test_eq_only metasenv subst context
431 (C.Meta (i,l)) lambda_Mj
433 let metasenv, subst =
434 unify rdb test_eq_only metasenv subst context t1 t2
437 let name, ctx, term, ty = NCicUtils.lookup_subst i subst in
438 let term = eta_reduce subst term in
439 let subst = List.filter (fun (j,_) -> j <> i) subst in
440 metasenv, ((i, (name, ctx, term, ty)) :: subst)
441 with Not_found -> assert false)
443 | _, NCic.Appl (NCic.Meta (i,l)::args) ->
444 let metasenv, subst, lambda_Mj =
445 lambda_intros rdb metasenv subst context t2 args
447 let metasenv, subst =
448 unify rdb test_eq_only metasenv subst context
449 lambda_Mj (C.Meta (i,l))
451 let metasenv, subst =
452 unify rdb test_eq_only metasenv subst context t1 t2
455 let name, ctx, term, ty = NCicUtils.lookup_subst i subst in
456 let term = eta_reduce subst term in
457 let subst = List.filter (fun (j,_) -> j <> i) subst in
458 metasenv, ((i, (name, ctx, term, ty)) :: subst)
459 with Not_found -> assert false)
461 (* processing this case here we avoid a useless small delta step *)
462 | (C.Appl ((C.Const r1) as _hd1::tl1), C.Appl (C.Const r2::tl2))
464 let relevance = NCicEnvironment.get_relevance r1 in
465 let relevance = match r1 with
466 | Ref.Ref (_,Ref.Con (_,_,lno)) ->
468 try snd (HExtlib.split_nth lno relevance)
471 HExtlib.mk_list false lno @ relevance
474 let metasenv, subst, _ =
477 (fun (metasenv, subst, relevance) t1 t2 ->
479 match relevance with b::tl -> b,tl | _ -> true, [] in
480 let metasenv, subst =
481 try unify rdb test_eq_only metasenv subst context t1 t2
482 with UnificationFailure _ | Uncertain _ when not b ->
485 metasenv, subst, relevance)
486 (metasenv, subst, relevance) tl1 tl2
487 with Invalid_argument _ ->
488 raise (uncert_exc metasenv subst context t1 t2)
492 | (C.Match (Ref.Ref (_,Ref.Ind (_,tyno,_)) as ref1,outtype1,term1,pl1),
493 C.Match (ref2,outtype2,term2,pl2)) ->
494 let _,_,itl,_,_ = NCicEnvironment.get_checked_indtys ref1 in
495 let _,_,ty,_ = List.nth itl tyno in
496 let rec remove_prods ~subst context ty =
497 let ty = NCicReduction.whd ~subst context ty in
500 | C.Prod (name,so,ta) ->
501 remove_prods ~subst ((name,(C.Decl so))::context) ta
505 match remove_prods ~subst [] ty with
506 | C.Sort C.Prop -> true
509 if not (Ref.eq ref1 ref2) then
510 raise (uncert_exc metasenv subst context t1 t2)
512 let metasenv, subst =
513 unify rdb test_eq_only metasenv subst context outtype1 outtype2 in
514 let metasenv, subst =
515 try unify rdb test_eq_only metasenv subst context term1 term2
516 with UnificationFailure _ | Uncertain _ when is_prop ->
521 (fun (metasenv,subst) ->
522 unify rdb test_eq_only metasenv subst context)
523 (metasenv, subst) pl1 pl2
524 with Invalid_argument _ ->
525 raise (uncert_exc metasenv subst context t1 t2))
526 | (C.Implicit _, _) | (_, C.Implicit _) -> assert false
527 | _ when NCicUntrusted.metas_of_term subst context t1 = [] &&
528 NCicUntrusted.metas_of_term subst context t2 = [] ->
529 raise (fail_exc metasenv subst context t1 t2)
530 | _ -> raise (uncert_exc metasenv subst context t1 t2)
531 (*D*) in outside(); rc with exn -> outside (); raise exn
533 let try_hints metasenv subst t1 t2 (* exc*) =
535 prerr_endline ("\nProblema:\n" ^
536 NCicPp.ppterm ~metasenv ~subst ~context t1 ^ " =?= " ^
537 NCicPp.ppterm ~metasenv ~subst ~context t2);
540 NCicUnifHint.look_for_hint rdb metasenv subst context t1 t2
542 let rec cand_iter = function
543 | [] -> None (* raise exc *)
544 | (metasenv,(c1,c2),premises)::tl ->
546 prerr_endline ("\nProvo il candidato:\n" ^
550 NCicPp.ppterm ~metasenv ~subst ~context a ^ " =?= " ^
551 NCicPp.ppterm ~metasenv ~subst ~context b) premises) ^
552 "\n-------------------------------------------\n"^
553 NCicPp.ppterm ~metasenv ~subst ~context c1 ^ " = " ^
554 NCicPp.ppterm ~metasenv ~subst ~context c2);
558 fo_unif test_eq_only metasenv subst t1 c1 in
560 fo_unif test_eq_only metasenv subst c2 t2 in
563 (fun (metasenv, subst) (x,y) ->
564 unify rdb test_eq_only metasenv subst context x y)
565 (metasenv, subst) premises
567 Some (metasenv, subst)
569 UnificationFailure _ | Uncertain _ ->
574 let height_of = function
575 | NCic.Const (Ref.Ref (_,Ref.Def h))
576 | NCic.Const (Ref.Ref (_,Ref.Fix (_,_,h)))
577 | NCic.Appl(NCic.Const(Ref.Ref(_,Ref.Def h))::_)
578 | NCic.Appl(NCic.Const(Ref.Ref(_,Ref.Fix (_,_,h)))::_) -> h
581 let put_in_whd m1 m2 =
582 NCicReduction.reduce_machine ~delta:max_int ~subst context m1,
583 NCicReduction.reduce_machine ~delta:max_int ~subst context m2
585 let small_delta_step ~subst
586 ((_,_,t1,_ as m1, norm1) as x1) ((_,_,t2,_ as m2, norm2) as x2)
588 assert (not (norm1 && norm2));
590 x1,NCicReduction.reduce_machine ~delta:(height_of t2 -1) ~subst context m2
592 NCicReduction.reduce_machine ~delta:(height_of t1 -1) ~subst context m1,x2
594 let h1 = height_of t1 in
595 let h2 = height_of t2 in
596 let delta = if h1 = h2 then max 0 (h1 -1) else min h1 h2 in
597 NCicReduction.reduce_machine ~delta ~subst context m1,
598 NCicReduction.reduce_machine ~delta ~subst context m2
600 let rec unif_machines metasenv subst =
602 | ((k1,e1,t1,s1),norm1 as m1),((k2,e2,t2,s2),norm2 as m2) ->
603 (*D*) inside 'M'; try let rc =
605 NCicPp.ppterm ~metasenv ~subst ~context
606 (NCicReduction.unwind (k1,e1,t1,s1)) ^
608 NCicPp.ppterm ~metasenv ~subst ~context
609 (NCicReduction.unwind (k2,e2,t2,s2))));
610 pp (lazy (string_of_bool norm1 ^ " ?? " ^ string_of_bool norm2));
611 let relevance = [] (* TO BE UNDERSTOOD
613 | C.Const r -> NCicEnvironment.get_relevance r
615 let unif_from_stack t1 t2 b metasenv subst =
617 let t1 = NCicReduction.from_stack ~delta:max_int t1 in
618 let t2 = NCicReduction.from_stack ~delta:max_int t2 in
619 unif_machines metasenv subst (put_in_whd t1 t2)
620 with UnificationFailure _ | Uncertain _ when not b ->
623 let rec check_stack l1 l2 r todo =
625 | x1::tl1, x2::tl2, r::tr-> check_stack tl1 tl2 tr ((x1,x2,r)::todo)
626 | x1::tl1, x2::tl2, []-> check_stack tl1 tl2 [] ((x1,x2,true)::todo)
628 NCicReduction.unwind (k1,e1,t1,List.rev l1),
629 NCicReduction.unwind (k2,e2,t2,List.rev l2),
632 let hh1,hh2,todo=check_stack (List.rev s1) (List.rev s2) relevance [] in
634 let metasenv,subst = fo_unif test_eq_only metasenv subst hh1 hh2 in
636 (fun (metasenv,subst) (x1,x2,r) ->
637 unif_from_stack x1 x2 r metasenv subst
638 ) (metasenv,subst) todo
639 with UnificationFailure _ | Uncertain _ when not (norm1 && norm2) ->
640 unif_machines metasenv subst (small_delta_step ~subst m1 m2)
641 (*D*) in outside(); rc with exn -> outside (); raise exn
643 try fo_unif test_eq_only metasenv subst t1 t2
645 | UnificationFailure msg as exn ->
647 unif_machines metasenv subst
648 (put_in_whd (0,[],t1,[]) (0,[],t2,[]))
650 | UnificationFailure _ -> raise (UnificationFailure msg)
651 | Uncertain _ -> raise exn)
652 | Uncertain msg as exn ->
653 match try_hints metasenv subst t1 t2 with
657 unif_machines metasenv subst
658 (put_in_whd (0,[],t1,[]) (0,[],t2,[]))
660 | UnificationFailure _ -> raise (UnificationFailure msg)
661 | Uncertain _ -> raise exn
662 (*D*) in outside(); rc with exn -> outside (); raise exn
664 and delift_term_wrt_terms rdb metasenv subst context t args =
665 let metasenv, _, instance, _ =
666 NCicMetaSubst.mk_meta metasenv context `Term in
667 let meta_applied = NCicUntrusted.mk_appl instance args in
668 let metasenv,subst,meta_applied,_ =
669 !refiner_typeof ((rdb:> NRstatus.status)#set_coerc_db NCicCoercion.empty_db)
670 metasenv subst context meta_applied None
672 let metasenv, subst =
673 unify rdb true metasenv subst context meta_applied t in
674 let t = NCicSubstitution.lift (List.length args) instance in
675 let t = NCicUntrusted.mk_appl t (mk_irl (List.length args)) in
680 let unify rdb ?(test_eq_only=false) =
682 unify rdb test_eq_only;;
684 let fix_sorts = fix_sorts false (UnificationFailure (lazy "no sup"));;