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 let rec aux test_eq_only metasenv = function
169 | NCic.Prod (n,so,ta) ->
170 let metasenv,so = aux true metasenv so in
171 let metasenv,ta = aux test_eq_only metasenv ta in
172 metasenv,NCic.Prod (n,so,ta)
173 | NCic.Sort (NCic.Type [(`CProp|`Type),_]) as orig when test_eq_only ->
175 | NCic.Sort (NCic.Type _) when test_eq_only -> raise exc
176 | NCic.Sort (NCic.Type u) when is_sup ->
177 metasenv, NCic.Sort (NCic.Type (unopt exc (NCicEnvironment.sup u)))
178 | NCic.Sort (NCic.Type u) ->
179 metasenv, NCic.Sort (NCic.Type
180 (unopt exc (NCicEnvironment.inf ~strict:false u)))
181 | NCic.Meta (n,_) as orig ->
183 let _,_,_,_ = NCicUtils.lookup_subst n subst in metasenv,orig
184 with NCicUtils.Subst_not_found _ ->
185 let metasenv, _ = NCicMetaSubst.extend_meta metasenv n in
188 NCicUntrusted.map_term_fold_a (fun _ x -> x) test_eq_only aux metasenv t
190 aux test_eq_only metasenv t
193 let rec sortfy exc metasenv subst = function
194 | NCic.Sort _ as orig -> metasenv, orig
195 | NCic.Meta (n,lc) ->
196 let attrs, context, ty = NCicUtils.lookup_meta n metasenv in
197 let kind = NCicUntrusted.kind_of_meta attrs in
198 kindfy exc metasenv subst context n lc ty kind `IsSort
199 | NCic.Implicit _ -> assert false
202 and kindfy exc metasenv subst context n lc ty kind kind2 =
203 match kind, ty, kind2 with
204 | `IsSort, _, _ -> assert(snd lc = NCic.Irl 0); metasenv, NCic.Meta(n,lc)
205 | k1, NCic.Implicit (`Typeof _), (`IsType|`IsTerm as k2) ->
206 let k = NCicUntrusted.max_kind k1 k2 in
208 NCicUntrusted.replace_in_metasenv n
209 (fun attrs,cc,ty -> NCicUntrusted.set_kind k attrs, cc, ty) metasenv
211 metasenv, NCic.Meta(n,lc)
212 | _, NCic.Implicit (`Typeof _), `IsSort ->
214 NCicUntrusted.replace_in_metasenv n
215 (fun attrs,_,ty-> NCicUntrusted.set_kind `IsSort attrs,[],ty) metasenv
217 metasenv, NCic.Meta (n,(0,NCic.Irl 0))
220 sortfy exc metasenv subst (NCicReduction.whd ~subst context ty)
223 NCicUntrusted.replace_in_metasenv n
224 (fun attrs,_,_-> NCicUntrusted.set_kind `IsSort attrs,[],ty) metasenv
226 metasenv, NCic.Meta (n,(0,NCic.Irl 0))
227 | k1, _, k2 when NCicUntrusted.max_kind k1 k2 = k1-> metasenv, NCic.Meta(n,lc)
228 | `IsTerm, ty, `IsType ->
230 sortfy exc metasenv subst (NCicReduction.whd ~subst context ty)
233 NCicUntrusted.replace_in_metasenv n
234 (fun attrs,cc,_-> NCicUntrusted.set_kind `IsType attrs,cc,ty) metasenv
236 metasenv, NCic.Meta (n,lc)
237 | _ -> assert false (* XXX *)
239 and instantiate rdb test_eq_only metasenv subst context n lc t swap =
240 (*D*) inside 'I'; try let rc =
241 pp (lazy(string_of_int n^" :=?= "^ppterm ~metasenv ~subst ~context t));
243 UnificationFailure (mk_msg metasenv subst context (NCic.Meta (n,lc)) t) in
244 let move_to_subst i attrs cc t ty metasenv subst =
245 let metasenv = List.remove_assoc i metasenv in
246 pp (lazy(string_of_int n ^ " :==> "^
247 ppterm ~metasenv ~subst ~context:cc t));
248 metasenv, (i,(attrs, cc, t, ty)) :: subst
250 let delift_to_subst test_eq_only n lc attrs cc t ty context metasenv subst =
251 pp (lazy(string_of_int n ^ " := 111 = "^
252 ppterm ~metasenv ~subst ~context t));
253 let (metasenv, subst), t =
256 ~unify:(fun m s c t1 t2 ->
259 try Some (unify rdb test_eq_only m s c t1 t2 )
260 with UnificationFailure _ | Uncertain _ -> None
263 metasenv subst context n lc t
264 with NCicMetaSubst.Uncertain msg ->
265 pp (lazy ("delift is uncertain: " ^ Lazy.force msg));
266 raise (Uncertain msg)
267 | NCicMetaSubst.MetaSubstFailure msg ->
268 pp (lazy ("delift fails: " ^ Lazy.force msg));
269 raise (UnificationFailure msg)
271 pp (lazy(string_of_int n ^ " := 222 = "^
272 ppterm ~metasenv ~subst ~context:cc t^ppmetasenv ~subst metasenv));
273 (* Unifying the types may have already instantiated n. *)
275 let _, _,oldt,_ = NCicUtils.lookup_subst n subst in
276 let oldt = NCicSubstitution.subst_meta lc oldt in
277 let t = NCicSubstitution.subst_meta lc t in
278 (* conjecture: always fail --> occur check *)
279 unify rdb test_eq_only metasenv subst context t oldt
280 with NCicUtils.Subst_not_found _ ->
281 move_to_subst n attrs cc t ty metasenv subst
283 let attrs, cc, ty = NCicUtils.lookup_meta n metasenv in
284 match NCicUntrusted.kind_of_meta attrs, ty, t, swap with
285 | `IsSort, (NCic.Implicit (`Typeof _) as bot), NCic.Sort (NCic.Type u),false->
287 let u = NCicEnvironment.inf ~strict:false u in
288 let t = NCic.Sort (NCic.Type (unopt exc u)) in
289 move_to_subst n attrs cc t bot metasenv subst
290 | `IsSort, (NCic.Implicit (`Typeof _) as bot), NCic.Sort (NCic.Type u),true ->
292 let u = NCicEnvironment.sup u in
293 let t = NCic.Sort (NCic.Type (unopt exc u)) in
294 move_to_subst n attrs cc t bot metasenv subst
295 | `IsSort, (NCic.Sort(NCic.Type u1) as ty), NCic.Sort (NCic.Type u2), false ->
298 NCicEnvironment.inf ~strict:false (u1 @
299 unopt exc (NCicEnvironment.inf ~strict:true u2))
301 let t = NCic.Sort (NCic.Type (unopt exc u)) in
302 move_to_subst n attrs cc t ty metasenv subst
303 | `IsSort, (NCic.Sort(NCic.Type u1) as ty), NCic.Sort (NCic.Type u2), true ->
305 let u = unopt exc (NCicEnvironment.sup u2) in
306 if NCicEnvironment.universe_lt u u1 then
307 let t = NCic.Sort (NCic.Type u) in
308 move_to_subst n attrs cc t ty metasenv subst
310 | _, _, NCic.Meta(m,lcm), _ when List.mem_assoc m subst ->
311 (* deref needed for locked metas, maybe should be done outside *)
312 let _,_,bo,_ = NCicUtils.lookup_subst m subst in
313 let bo = NCicSubstitution.subst_meta lcm bo in
314 instantiate rdb test_eq_only metasenv subst context n lc bo swap
315 | kind, (NCic.Implicit (`Typeof _) as bot), NCic.Meta(m,lcm), _ ->
317 let attrsm, ccm, tym = NCicUtils.lookup_meta m metasenv in
318 let kindm = NCicUntrusted.kind_of_meta attrsm in
319 let metasenv, t = kindfy exc metasenv subst ccm m lcm tym kindm kind in
320 move_to_subst n attrs cc t bot metasenv subst
321 | kind, ty, (NCic.Meta(m,_) as t), _ when
322 let _, _, tym = NCicUtils.lookup_meta m metasenv in
323 (match tym with NCic.Implicit (`Typeof _) -> true | _ -> false) ->
325 let attrsm, _, _ = NCicUtils.lookup_meta m metasenv in
326 let kindm = NCicUntrusted.kind_of_meta attrsm in
327 let metasenv, _ = kindfy exc metasenv subst cc n lc ty kind kindm in
328 let attrs, cc, ty = NCicUtils.lookup_meta n metasenv in
329 let metasenv = NCicUntrusted.replace_in_metasenv m
330 (fun _,_,_ -> attrs,cc,ty) metasenv
332 (* XXX *)move_to_subst n attrs cc t ty metasenv subst
333 | kind, ty, NCic.Meta(m,lcm), _ ->
335 let ty_t, ccm, kindm =
336 let at, ccm, tym = NCicUtils.lookup_meta m metasenv in
337 NCicSubstitution.subst_meta lcm tym, ccm, NCicUntrusted.kind_of_meta at
339 let lty = NCicSubstitution.subst_meta lc ty in
340 pp (lazy ("On the types: " ^
341 ppterm ~metasenv ~subst ~context lty ^
342 (if test_eq_only then " === " else "=<=") ^
343 ppterm ~metasenv ~subst ~context ty_t));
344 let metasenv, subst =
345 unify rdb test_eq_only metasenv subst context ty_t lty
347 let metasenv, t = kindfy exc metasenv subst ccm m lcm ty_t kindm kind in
348 delift_to_subst test_eq_only n lc attrs cc t ty context metasenv subst
349 | _, (NCic.Implicit (`Typeof _) as bot), t, swap ->
351 let metasenv, t = fix metasenv subst swap test_eq_only exc t in
352 (* let ty_t = NCicTypeChecker.typeof ~metasenv ~subst context t in *)
353 (* ty andrebbe deliftato *)
354 delift_to_subst test_eq_only n lc attrs cc t bot context metasenv subst
357 let lty = NCicSubstitution.subst_meta lc ty in
358 let metasenv, t = fix metasenv subst swap test_eq_only exc t in
359 let ty_t = NCicTypeChecker.typeof ~metasenv ~subst context t in
360 pp (lazy ("On the types: " ^
361 ppterm ~metasenv ~subst ~context lty ^
362 (if test_eq_only then " === " else "=<=") ^
363 ppterm ~metasenv ~subst ~context ty_t));
364 let metasenv, subst =
365 unify rdb test_eq_only metasenv subst context ty_t lty
367 delift_to_subst test_eq_only n lc attrs cc t ty context metasenv subst
368 (*D*) in outside None; rc with exn -> outside (Some exn); raise exn
370 and unify rdb test_eq_only metasenv subst context t1 t2 =
371 (*D*) inside 'U'; try let rc =
372 let fo_unif test_eq_only metasenv subst (norm1,t1) (norm2,t2) =
373 (*D*) inside 'F'; try let rc =
374 pp (lazy(" " ^ ppterm ~metasenv ~subst ~context t1 ^ " ==?== " ^
375 ppterm ~metasenv ~subst ~context t2 ^ ppmetasenv
377 pp (lazy(" " ^ ppterm ~metasenv ~subst:[] ~context t1 ^ " ==??== " ^
378 ppterm ~metasenv ~subst:[] ~context t2 ^ ppmetasenv
384 | C.Appl [_], _ | _, C.Appl [_] | C.Appl [], _ | _, C.Appl []
385 | C.Appl (C.Appl _::_), _ | _, C.Appl (C.Appl _::_) ->
386 prerr_endline "Appl [Appl _;_] or Appl [] or Appl [_] invariant";
388 | (C.Sort (C.Type a), C.Sort (C.Type b)) when not test_eq_only ->
389 if NCicEnvironment.universe_leq a b then metasenv, subst
390 else raise (UnificationFailure (mk_msg metasenv subst context t1 t2))
391 | (C.Sort (C.Type a), C.Sort (C.Type b)) ->
392 if NCicEnvironment.universe_eq a b then metasenv, subst
393 else raise (UnificationFailure (mk_msg metasenv subst context t1 t2))
394 | (C.Sort C.Prop,C.Sort (C.Type _)) ->
395 if (not test_eq_only) then metasenv, subst
396 else raise (UnificationFailure (mk_msg metasenv subst context t1 t2))
398 | (C.Lambda (name1,s1,t1), C.Lambda(_,s2,t2))
399 | (C.Prod (name1,s1,t1), C.Prod(_,s2,t2)) ->
400 let metasenv, subst = unify rdb true metasenv subst context s1 s2 in
401 unify rdb test_eq_only metasenv subst ((name1, C.Decl s1)::context) t1 t2
402 | (C.LetIn (name1,ty1,s1,t1), C.LetIn(_,ty2,s2,t2)) ->
403 let metasenv,subst=unify rdb test_eq_only metasenv subst context ty1 ty2 in
404 let metasenv,subst=unify rdb test_eq_only metasenv subst context s1 s2 in
405 let context = (name1, C.Def (s1,ty1))::context in
406 unify rdb test_eq_only metasenv subst context t1 t2
408 | (C.Meta (n1,(s1,l1 as lc1)),C.Meta (n2,(s2,l2 as lc2))) when n1 = n2 ->
410 let l1 = NCicUtils.expand_local_context l1 in
411 let l2 = NCicUtils.expand_local_context l2 in
412 let metasenv, subst, to_restrict, _ =
414 (fun t1 t2 (metasenv, subst, to_restrict, i) ->
416 let metasenv, subst =
417 unify rdb test_eq_only metasenv subst context
418 (NCicSubstitution.lift s1 t1) (NCicSubstitution.lift s2 t2)
420 metasenv, subst, to_restrict, i-1
421 with UnificationFailure _ | Uncertain _ ->
422 metasenv, subst, i::to_restrict, i-1)
423 l1 l2 (metasenv, subst, [], List.length l1)
425 if to_restrict <> [] then
426 let metasenv, subst, _ =
427 NCicMetaSubst.restrict metasenv subst n1 to_restrict
432 | Invalid_argument _ -> assert false
433 | NCicMetaSubst.MetaSubstFailure msg ->
435 let _,_,term,_ = NCicUtils.lookup_subst n1 subst in
436 let term1 = NCicSubstitution.subst_meta lc1 term in
437 let term2 = NCicSubstitution.subst_meta lc2 term in
438 unify rdb test_eq_only metasenv subst context term1 term2
439 with NCicUtils.Subst_not_found _-> raise (UnificationFailure msg))
441 | NCic.Appl (NCic.Meta (i,_)::_ as l1),
442 NCic.Appl (NCic.Meta (j,_)::_ as l2) when i=j ->
445 (fun (metasenv, subst) t1 t2 ->
446 unify rdb test_eq_only metasenv subst context t1 t2)
447 (metasenv,subst) l1 l2
448 with Invalid_argument _ ->
449 raise (UnificationFailure (mk_msg metasenv subst context t1 t2)))
451 | _, NCic.Meta (n, _) when is_locked n subst ->
452 (let (metasenv, subst), i =
453 match NCicReduction.whd ~subst context t1 with
454 | NCic.Appl (NCic.Meta (i,l) as meta :: args) ->
455 let metasenv, lambda_Mj =
456 lambda_intros rdb metasenv subst context (List.length args)
457 (NCicTypeChecker.typeof ~metasenv ~subst context meta)
459 unify rdb test_eq_only metasenv subst context
460 (C.Meta (i,l)) lambda_Mj,
462 | NCic.Meta (i,_) -> (metasenv, subst), i
464 raise (UnificationFailure (lazy "Locked term vs non
465 flexible term; probably not saturated enough yet!"))
467 let t1 = NCicReduction.whd ~subst context t1 in
469 match t1 with NCic.Meta (j,l) -> j, l | _ -> assert false
471 let metasenv, subst =
472 instantiate rdb test_eq_only metasenv subst context j lj t2 true
474 (* We need to remove the out_scope_tags to avoid propagation of
475 them that triggers again the ad-hoc case *)
477 List.map (fun (i,(tag,ctx,bo,ty)) ->
480 (function `InScope | `OutScope _ -> false | _ -> true) tag
486 let name, ctx, term, ty = NCicUtils.lookup_subst i subst in
487 let term = eta_reduce subst term in
488 let subst = List.filter (fun (j,_) -> j <> i) subst in
489 metasenv, ((i, (name, ctx, term, ty)) :: subst)
490 with Not_found -> assert false))
492 | C.Meta (n,lc), t when List.mem_assoc n subst ->
493 let _,_,term,_ = NCicUtils.lookup_subst n subst in
494 let term = NCicSubstitution.subst_meta lc term in
495 unify rdb test_eq_only metasenv subst context term t
497 | t, C.Meta (n,lc) when List.mem_assoc n subst ->
498 let _,_,term,_ = NCicUtils.lookup_subst n subst in
499 let term = NCicSubstitution.subst_meta lc term in
500 unify rdb test_eq_only metasenv subst context t term
502 | NCic.Appl (NCic.Meta (i,l)::args), _ when List.mem_assoc i subst ->
503 let _,_,term,_ = NCicUtils.lookup_subst i subst in
504 let term = NCicSubstitution.subst_meta l term in
505 unify rdb test_eq_only metasenv subst context
506 (mk_appl ~upto:(List.length args) term args) t2
508 | _, NCic.Appl (NCic.Meta (i,l)::args) when List.mem_assoc i subst ->
509 let _,_,term,_ = NCicUtils.lookup_subst i subst in
510 let term = NCicSubstitution.subst_meta l term in
511 unify rdb test_eq_only metasenv subst context t1
512 (mk_appl ~upto:(List.length args) term args)
514 | C.Meta (n,lc), t ->
515 instantiate rdb test_eq_only metasenv subst context n lc
516 (NCicReduction.head_beta_reduce ~subst t) false
518 | t, C.Meta (n,lc) ->
519 instantiate rdb test_eq_only metasenv subst context n lc
520 (NCicReduction.head_beta_reduce ~subst t) true
522 | NCic.Appl (NCic.Meta (i,l) as meta :: args), _ ->
523 let metasenv, lambda_Mj =
524 lambda_intros rdb metasenv subst context (List.length args)
525 (NCicTypeChecker.typeof ~metasenv ~subst context meta)
527 let metasenv, subst =
529 unify rdb test_eq_only metasenv subst context
530 (C.Meta (i,l)) lambda_Mj
531 with UnificationFailure msg | Uncertain msg when not norm2->
532 (* failure: let's try again argument vs argument *)
533 raise (KeepReducing msg)
535 let metasenv, subst =
536 unify rdb test_eq_only metasenv subst context t1 t2
539 let name, ctx, term, ty = NCicUtils.lookup_subst i subst in
540 let term = eta_reduce subst term in
541 let subst = List.filter (fun (j,_) -> j <> i) subst in
542 metasenv, ((i, (name, ctx, term, ty)) :: subst)
543 with Not_found -> assert false)
545 | _, NCic.Appl (NCic.Meta (i,l) as meta :: args) ->
546 let metasenv, lambda_Mj =
547 lambda_intros rdb metasenv subst context (List.length args)
548 (NCicTypeChecker.typeof ~metasenv ~subst context meta)
550 let metasenv, subst =
552 unify rdb test_eq_only metasenv subst context
553 lambda_Mj (C.Meta (i,l))
554 with UnificationFailure msg | Uncertain msg when not norm1 ->
555 (* failure: let's try again argument vs argument *)
556 raise (KeepReducing msg)
558 let metasenv, subst =
559 unify rdb test_eq_only metasenv subst context t1 t2
562 let name, ctx, term, ty = NCicUtils.lookup_subst i subst in
563 let term = eta_reduce subst term in
564 let subst = List.filter (fun (j,_) -> j <> i) subst in
565 metasenv, ((i, (name, ctx, term, ty)) :: subst)
566 with Not_found -> assert false)
568 (* processing this case here we avoid a useless small delta step *)
569 | (C.Appl ((C.Const r1) as _hd1::tl1), C.Appl (C.Const r2::tl2))
571 let relevance = NCicEnvironment.get_relevance r1 in
572 let metasenv, subst, _ =
575 (fun (metasenv, subst, relevance) t1 t2 ->
577 match relevance with b::tl -> b,tl | _ -> true, [] in
578 let metasenv, subst =
579 try unify rdb test_eq_only metasenv subst context t1 t2
580 with UnificationFailure _ | Uncertain _ when not b ->
583 metasenv, subst, relevance)
584 (metasenv, subst, relevance) tl1 tl2
586 Invalid_argument _ ->
587 raise (Uncertain (mk_msg metasenv subst context t1 t2))
588 | UnificationFailure _ | Uncertain _ when not (norm1 && norm2) ->
589 raise (KeepReducing (mk_msg metasenv subst context t1 t2))
590 | KeepReducing _ | KeepReducingThis _ -> assert false
594 | (C.Match (Ref.Ref (_,Ref.Ind (_,tyno,_)) as ref1,outtype1,term1,pl1),
595 C.Match (ref2,outtype2,term2,pl2)) ->
596 let _,_,itl,_,_ = NCicEnvironment.get_checked_indtys ref1 in
597 let _,_,ty,_ = List.nth itl tyno in
598 let rec remove_prods ~subst context ty =
599 let ty = NCicReduction.whd ~subst context ty in
602 | C.Prod (name,so,ta) ->
603 remove_prods ~subst ((name,(C.Decl so))::context) ta
607 match remove_prods ~subst [] ty with
608 | C.Sort C.Prop -> true
611 if not (Ref.eq ref1 ref2) then
612 raise (Uncertain (mk_msg metasenv subst context t1 t2))
614 let metasenv, subst =
615 unify rdb test_eq_only metasenv subst context outtype1 outtype2 in
616 let metasenv, subst =
617 try unify rdb test_eq_only metasenv subst context term1 term2
618 with UnificationFailure _ | Uncertain _ when is_prop ->
623 (fun (metasenv,subst) ->
624 unify rdb test_eq_only metasenv subst context)
625 (metasenv, subst) pl1 pl2
626 with Invalid_argument _ -> assert false)
627 | (C.Implicit _, _) | (_, C.Implicit _) -> assert false
628 | _ when norm1 && norm2 ->
629 if (could_reduce t1 || could_reduce t2) then
630 raise (Uncertain (mk_msg metasenv subst context t1 t2))
632 raise (UnificationFailure (mk_msg metasenv subst context t1 t2))
633 | _ -> raise (KeepReducing (mk_msg metasenv subst context t1 t2))
634 (*D*) in outside None; rc with exn -> outside (Some exn); raise exn
636 let try_hints metasenv subst (_,t1 as mt1) (_,t2 as mt2) (* exc*) =
637 (*D*) inside 'H'; try let rc =
638 pp(lazy ("\nProblema:\n" ^
639 ppterm ~metasenv ~subst ~context t1 ^ " =?= " ^
640 ppterm ~metasenv ~subst ~context t2));
642 NCicUnifHint.look_for_hint rdb metasenv subst context t1 t2
644 let rec cand_iter = function
645 | [] -> None (* raise exc *)
646 | (metasenv,(c1,c2),premises)::tl ->
647 pp (lazy ("\nProvo il candidato:\n" ^
651 ppterm ~metasenv ~subst ~context a ^ " =?= " ^
652 ppterm ~metasenv ~subst ~context b) premises) ^
653 "\n-------------------------------------------\n"^
654 ppterm ~metasenv ~subst ~context c1 ^ " = " ^
655 ppterm ~metasenv ~subst ~context c2));
657 (*D*) inside 'K'; try let rc =
659 fo_unif test_eq_only metasenv subst mt1 (false,c1) in
661 fo_unif test_eq_only metasenv subst (false,c2) mt2 in
664 (fun (metasenv, subst) (x,y) ->
665 unify rdb test_eq_only metasenv subst context x y)
666 (metasenv, subst) premises
668 pp(lazy("FUNZIONA!"));
669 Some (metasenv, subst)
670 (*D*) in outside None; rc with exn -> outside (Some exn); raise exn
672 KeepReducing _ | UnificationFailure _ | Uncertain _ -> cand_iter tl
673 | KeepReducingThis _ -> assert false
676 (*D*) in outside None; rc with exn -> outside (Some exn); raise exn
678 let put_in_whd m1 m2 =
679 NCicReduction.reduce_machine ~delta:max_int ~subst context m1,
680 NCicReduction.reduce_machine ~delta:max_int ~subst context m2
682 let fo_unif_w_hints test_eq_only metasenv subst (_,t1 as m1) (_,t2 as m2) =
683 try fo_unif test_eq_only metasenv subst m1 m2
685 | UnificationFailure _ as exn -> raise exn
686 | KeepReducing _ | Uncertain _ as exn ->
687 let (t1,norm1 as tm1),(t2,norm2 as tm2) =
688 put_in_whd (0,[],t1,[]) (0,[],t2,[])
691 try_hints metasenv subst
692 (norm1,NCicReduction.unwind t1) (norm2,NCicReduction.unwind t2)
697 | KeepReducing msg -> raise (KeepReducingThis (msg,tm1,tm2))
698 | Uncertain _ as exn -> raise exn
701 let height_of = function
702 | NCic.Const (Ref.Ref (_,Ref.Def h))
703 | NCic.Const (Ref.Ref (_,Ref.Fix (_,_,h)))
704 | NCic.Appl(NCic.Const(Ref.Ref(_,Ref.Def h))::_)
705 | NCic.Appl(NCic.Const(Ref.Ref(_,Ref.Fix (_,_,h)))::_) -> h
708 let small_delta_step ~subst
709 ((_,_,t1,_ as m1, norm1) as x1) ((_,_,t2,_ as m2, norm2) as x2)
711 assert (not (norm1 && norm2));
713 x1,NCicReduction.reduce_machine ~delta:0 ~subst context m2
715 NCicReduction.reduce_machine ~delta:0 ~subst context m1,x2
717 let h1 = height_of t1 in
718 let h2 = height_of t2 in
719 let delta = if h1 = h2 then max 0 (h1 -1) else min h1 h2 in
720 NCicReduction.reduce_machine ~delta ~subst context m1,
721 NCicReduction.reduce_machine ~delta ~subst context m2
723 let rec unif_machines metasenv subst =
725 | ((k1,e1,t1,s1),norm1 as m1),((k2,e2,t2,s2),norm2 as m2) ->
726 (*D*) inside 'M'; try let rc =
728 ppterm ~metasenv ~subst ~context
729 (NCicReduction.unwind (k1,e1,t1,s1)) ^
731 ppterm ~metasenv ~subst ~context
732 (NCicReduction.unwind (k2,e2,t2,s2))));
733 pp (lazy (string_of_bool norm1 ^ " ?? " ^ string_of_bool norm2));
734 let relevance = [] (* TO BE UNDERSTOOD
736 | C.Const r -> NCicEnvironment.get_relevance r
738 let unif_from_stack t1 t2 b metasenv subst =
740 let t1 = NCicReduction.from_stack ~delta:max_int t1 in
741 let t2 = NCicReduction.from_stack ~delta:max_int t2 in
742 unif_machines metasenv subst (put_in_whd t1 t2)
743 with UnificationFailure _ | Uncertain _ when not b ->
746 let rec check_stack l1 l2 r todo =
748 | x1::tl1, x2::tl2, r::tr-> check_stack tl1 tl2 tr ((x1,x2,r)::todo)
749 | x1::tl1, x2::tl2, []-> check_stack tl1 tl2 [] ((x1,x2,true)::todo)
751 NCicReduction.unwind (k1,e1,t1,List.rev l1),
752 NCicReduction.unwind (k2,e2,t2,List.rev l2),
755 let hh1,hh2,todo=check_stack (List.rev s1) (List.rev s2) relevance [] in
758 fo_unif_w_hints test_eq_only metasenv subst (norm1,hh1) (norm2,hh2) in
760 (fun (metasenv,subst) (x1,x2,r) ->
761 unif_from_stack x1 x2 r metasenv subst
762 ) (metasenv,subst) todo
764 | KeepReducing _ -> assert false
765 | KeepReducingThis _ ->
766 assert (not (norm1 && norm2));
767 unif_machines metasenv subst (small_delta_step ~subst m1 m2)
768 | UnificationFailure _ | Uncertain _ when (not (norm1 && norm2))
769 -> unif_machines metasenv subst (small_delta_step ~subst m1 m2)
770 | UnificationFailure msg
771 when could_reduce (NCicReduction.unwind (fst m1))
772 || could_reduce (NCicReduction.unwind (fst m2))
773 -> raise (Uncertain msg)
774 (*D*) in outside None; rc with exn -> outside (Some exn); raise exn
776 try fo_unif_w_hints test_eq_only metasenv subst (false,t1) (false,t2)
778 | KeepReducingThis (msg,tm1,tm2) ->
780 unif_machines metasenv subst (tm1,tm2)
782 | UnificationFailure _ -> raise (UnificationFailure msg)
783 | Uncertain _ -> raise (Uncertain msg)
784 | KeepReducing _ -> assert false)
785 | KeepReducing _ -> assert false
787 (*D*) in outside None; rc with KeepReducing _ -> assert false | exn -> outside (Some exn); raise exn
789 and delift_type_wrt_terms rdb metasenv subst context t args =
790 let lc = List.rev args @ mk_irl (List.length context) (List.length args+1) in
791 let (metasenv, subst), t =
794 ~unify:(fun m s c t1 t2 ->
797 try Some (unify rdb false m s c t1 t2 )
798 with UnificationFailure _ | Uncertain _ -> None
801 metasenv subst context 0 (0,NCic.Ctx lc) t
803 NCicMetaSubst.MetaSubstFailure _
804 | NCicMetaSubst.Uncertain _ -> (metasenv, subst), t
810 let unify rdb ?(test_eq_only=false) =
812 unify rdb test_eq_only;;
815 fix m s true false (UnificationFailure (lazy "no sup"))