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_______________________________________________________________ *)
12 (* $Id: nCicReduction.ml 8250 2008-03-25 17:56:20Z tassi $ *)
14 (* web interface stuff *)
17 ref (function (`Start_type_checking _|`Type_checking_completed _) -> ())
20 let set_logger f = logger := f;;
22 exception TypeCheckerFailure of string Lazy.t
23 exception AssertFailure of string Lazy.t
25 let shift_k e (c,rf,x,safes) =
26 e::c,List.map (fun (k,v) -> k+1,v) rf,x+1,List.map ((+)1) safes
29 (* $Id: cicTypeChecker.ml 8213 2008-03-13 18:48:26Z sacerdot $ *)
34 (* the boolean h means already protected *)
35 (* args is the list of arguments the type of the constructor that may be *)
36 (* found in head position must be applied to. *)
37 and guarded_by_constructors ~subst context n nn h te args coInductiveTypeURI =
39 (*CSC: There is a lot of code replication between the cases X and *)
40 (*CSC: (C.Appl X tl). Maybe it will be better to define a function *)
41 (*CSC: that maps X into (C.Appl X []) when X is not already a C.Appl *)
42 match CicReduction.whd ~subst context te with
43 C.Rel m when m > n && m <= nn -> h
51 (* the term has just been type-checked *)
52 raise (AssertFailure (lazy "17"))
53 | C.Lambda (name,so,de) ->
54 does_not_occur ~subst context n nn so &&
55 guarded_by_constructors ~subst ((Some (name,(C.Decl so)))::context)
56 (n + 1) (nn + 1) h de args coInductiveTypeURI
57 | C.Appl ((C.Rel m)::tl) when m > n && m <= nn ->
59 List.fold_right (fun x i -> i && does_not_occur ~subst context n nn x) tl true
60 | C.Appl ((C.MutConstruct (uri,i,j,exp_named_subst))::tl) ->
64 CicEnvironment.get_cooked_obj ~trust:false CicUniv.empty_ugraph uri
65 with Not_found -> assert false
68 C.InductiveDefinition (itl,_,_,_) ->
69 let (_,_,_,cl) = List.nth itl i in
70 let (_,cons) = List.nth cl (j - 1) in
71 CicSubstitution.subst_vars exp_named_subst cons
73 raise (TypeCheckerFailure
74 (lazy ("Unknown mutual inductive definition:" ^ UriManager.string_of_uri uri)))
76 let rec analyse_branch context ty te =
77 match CicReduction.whd ~subst context ty with
78 C.Meta _ -> raise (AssertFailure (lazy "34"))
82 does_not_occur ~subst context n nn te
85 raise (AssertFailure (lazy "24"))(* due to type-checking *)
86 | C.Prod (name,so,de) ->
87 analyse_branch ((Some (name,(C.Decl so)))::context) de te
90 raise (AssertFailure (lazy "25"))(* due to type-checking *)
91 | C.Appl ((C.MutInd (uri,_,_))::_) when uri == coInductiveTypeURI ->
92 guarded_by_constructors ~subst context n nn true te []
94 | C.Appl ((C.MutInd (uri,_,_))::_) ->
95 guarded_by_constructors ~subst context n nn true te tl
98 does_not_occur ~subst context n nn te
99 | C.Const _ -> raise (AssertFailure (lazy "26"))
100 | C.MutInd (uri,_,_) when uri == coInductiveTypeURI ->
101 guarded_by_constructors ~subst context n nn true te []
104 does_not_occur ~subst context n nn te
105 | C.MutConstruct _ -> raise (AssertFailure (lazy "27"))
106 (*CSC: we do not consider backbones with a MutCase, Fix, Cofix *)
107 (*CSC: in head position. *)
111 raise (AssertFailure (lazy "28"))(* due to type-checking *)
113 let rec analyse_instantiated_type context ty l =
114 match CicReduction.whd ~subst context ty with
120 | C.Cast _ -> raise (AssertFailure (lazy "29"))(* due to type-checking *)
121 | C.Prod (name,so,de) ->
126 analyse_branch context so he &&
127 analyse_instantiated_type
128 ((Some (name,(C.Decl so)))::context) de tl
132 raise (AssertFailure (lazy "30"))(* due to type-checking *)
135 (fun i x -> i && does_not_occur ~subst context n nn x) true l
136 | C.Const _ -> raise (AssertFailure (lazy "31"))
139 (fun i x -> i && does_not_occur ~subst context n nn x) true l
140 | C.MutConstruct _ -> raise (AssertFailure (lazy "32"))
141 (*CSC: we do not consider backbones with a MutCase, Fix, Cofix *)
142 (*CSC: in head position. *)
146 raise (AssertFailure (lazy "33"))(* due to type-checking *)
148 let rec instantiate_type args consty =
152 let consty' = CicReduction.whd ~subst context consty in
158 let instantiated_de = CicSubstitution.subst he de in
159 (*CSC: siamo sicuri che non sia troppo forte? *)
160 does_not_occur ~subst context n nn tlhe &
161 instantiate_type tl instantiated_de tltl
163 (*CSC:We do not consider backbones with a MutCase, a *)
164 (*CSC:FixPoint, a CoFixPoint and so on in head position.*)
165 raise (AssertFailure (lazy "23"))
167 | [] -> analyse_instantiated_type context consty' l
168 (* These are all the other cases *)
170 instantiate_type args consty tl
171 | C.Appl ((C.CoFix (_,fl))::tl) ->
172 List.fold_left (fun i x -> i && does_not_occur ~subst context n nn x) true tl &&
173 let len = List.length fl in
174 let n_plus_len = n + len
175 and nn_plus_len = nn + len
176 (*CSC: Is a Decl of the ty ok or should I use Def of a Fix? *)
179 (fun (types,len) (n,ty,_) ->
180 (Some (C.Name n,(C.Decl (CicSubstitution.lift len ty)))::types,
186 i && does_not_occur ~subst context n nn ty &&
187 guarded_by_constructors ~subst (tys@context) n_plus_len nn_plus_len
188 h bo args coInductiveTypeURI
190 | C.Appl ((C.MutCase (_,_,out,te,pl))::tl) ->
191 List.fold_left (fun i x -> i && does_not_occur ~subst context n nn x) true tl &&
192 does_not_occur ~subst context n nn out &&
193 does_not_occur ~subst context n nn te &&
197 guarded_by_constructors ~subst context n nn h x args
201 List.fold_right (fun x i -> i && does_not_occur ~subst context n nn x) l true
202 | C.Var (_,exp_named_subst)
203 | C.Const (_,exp_named_subst) ->
205 (fun (_,x) i -> i && does_not_occur ~subst context n nn x) exp_named_subst true
206 | C.MutInd _ -> assert false
207 | C.MutConstruct (_,_,_,exp_named_subst) ->
209 (fun (_,x) i -> i && does_not_occur ~subst context n nn x) exp_named_subst true
210 | C.MutCase (_,_,out,te,pl) ->
211 does_not_occur ~subst context n nn out &&
212 does_not_occur ~subst context n nn te &&
216 guarded_by_constructors ~subst context n nn h x args
220 let len = List.length fl in
221 let n_plus_len = n + len
222 and nn_plus_len = nn + len
223 (*CSC: Is a Decl of the ty ok or should I use Def of a Fix? *)
226 (fun (types,len) (n,_,ty,_) ->
227 (Some (C.Name n,(C.Decl (CicSubstitution.lift len ty)))::types,
232 (fun (_,_,ty,bo) i ->
233 i && does_not_occur ~subst context n nn ty &&
234 does_not_occur ~subst (tys@context) n_plus_len nn_plus_len bo
237 let len = List.length fl in
238 let n_plus_len = n + len
239 and nn_plus_len = nn + len
240 (*CSC: Is a Decl of the ty ok or should I use Def of a Fix? *)
243 (fun (types,len) (n,ty,_) ->
244 (Some (C.Name n,(C.Decl (CicSubstitution.lift len ty)))::types,
250 i && does_not_occur ~subst context n nn ty &&
251 guarded_by_constructors ~subst (tys@context) n_plus_len nn_plus_len
253 args coInductiveTypeURI
257 type_of_aux ~logger context t ugraph
261 (** wrappers which instantiate fresh loggers *)
263 (* check_allowed_sort_elimination uri i s1 s2
264 This function is used outside the kernel to determine in advance whether
265 a MutCase will be allowed or not.
266 [uri,i] is the type of the term to match
267 [s1] is the sort of the term to eliminate (i.e. the head of the arity
268 of the inductive type [uri,i])
269 [s2] is the sort of the goal (i.e. the head of the type of the outtype
271 let check_allowed_sort_elimination uri i s1 s2 =
272 fst (check_allowed_sort_elimination ~subst:[] ~metasenv:[]
273 ~logger:(new CicLogger.logger) [] uri i true
274 (Cic.Implicit None) (* never used *) (Cic.Sort s1) (Cic.Sort s2)
275 CicUniv.empty_ugraph)
278 Deannotate.type_of_aux' := fun context t -> fst (type_of_aux' [] context t CicUniv.oblivion_ugraph);;
283 module R = NCicReduction
284 module Ref = NReference
285 module S = NCicSubstitution
287 module E = NCicEnvironment
289 let rec split_prods ~subst context n te =
290 match (n, R.whd ~subst context te) with
291 | (0, _) -> context,te
292 | (n, C.Prod (name,so,ta)) when n > 0 ->
293 split_prods ~subst ((name,(C.Decl so))::context) (n - 1) ta
294 | (_, _) -> raise (AssertFailure (lazy "split_prods"))
297 let debruijn ?(cb=fun _ _ -> ()) uri number_of_types =
301 | C.Meta (i,(s,C.Ctx l)) ->
302 let l1 = NCicUtils.sharing_map (aux (k-s)) l in
303 if l1 == l then t else C.Meta (i,(s,C.Ctx l1))
305 | C.Const (Ref.Ref (_,uri1,(Ref.Fix (no,_) | Ref.CoFix no)))
306 | C.Const (Ref.Ref (_,uri1,Ref.Ind no)) when NUri.eq uri uri1 ->
307 C.Rel (k + number_of_types - no)
308 | t -> NCicUtils.map (fun _ k -> k+1) k aux t
315 let sort_of_prod ~metasenv ~subst context (name,s) (t1, t2) =
316 let t1 = R.whd ~subst context t1 in
317 let t2 = R.whd ~subst ((name,C.Decl s)::context) t2 in
319 | C.Sort s1, C.Sort C.Prop -> t2
320 | C.Sort (C.Type u1), C.Sort (C.Type u2) -> C.Sort (C.Type (max u1 u2))
321 | C.Sort _,C.Sort (C.Type _) -> t2
322 | C.Sort (C.Type _) , C.Sort C.CProp -> t1
323 | C.Sort _, C.Sort C.CProp -> t2
326 | C.Sort _, C.Meta _ when U.is_closed t2 -> t2
328 raise (TypeCheckerFailure (lazy (Printf.sprintf
329 "Prod: expected two sorts, found = %s, %s"
330 (NCicPp.ppterm ~subst ~metasenv ~context t1)
331 (NCicPp.ppterm ~subst ~metasenv ~context t2))))
334 let eat_prods ~subst ~metasenv context he ty_he args_with_ty =
335 let rec aux ty_he = function
337 | (arg, ty_arg)::tl ->
338 match R.whd ~subst context ty_he with
341 prerr_endline (NCicPp.ppterm ~subst ~metasenv ~context s ^ " - Vs - "
342 ^ NCicPp.ppterm ~subst ~metasenv
344 prerr_endline (NCicPp.ppterm ~subst ~metasenv ~context (S.subst ~avoid_beta_redexes:true arg t));
346 if R.are_convertible ~subst ~metasenv context ty_arg s then
347 aux (S.subst ~avoid_beta_redexes:true arg t) tl
351 (lazy (Printf.sprintf
352 ("Appl: wrong application of %s: the parameter %s has type"^^
353 "\n%s\nbut it should have type \n%s\n")
354 (NCicPp.ppterm ~subst ~metasenv ~context he)
355 (NCicPp.ppterm ~subst ~metasenv ~context arg)
356 (NCicPp.ppterm ~subst ~metasenv ~context ty_arg)
357 (NCicPp.ppterm ~subst ~metasenv ~context s))))
361 (lazy (Printf.sprintf
362 "Appl: %s is not a function, it cannot be applied"
363 (NCicPp.ppterm ~subst ~metasenv ~context
364 (let res = List.length tl in
365 let eaten = List.length args_with_ty - res in
368 (fst (HExtlib.split_nth eaten args_with_ty)))))))))
370 aux ty_he args_with_ty
373 let fix_lefts_in_constrs ~subst uri paramsno tyl i =
374 let len = List.length tyl in
375 let _,_,arity,cl = List.nth tyl i in
376 let tys = List.map (fun (_,n,ty,_) -> n,C.Decl ty) tyl in
380 let debruijnedty = debruijn uri len ty in
381 id, snd (split_prods ~subst tys paramsno ty),
382 snd (split_prods ~subst tys paramsno debruijnedty))
385 let lefts = fst (split_prods ~subst [] paramsno arity) in
389 exception DoesOccur;;
391 let does_not_occur ~subst context n nn t =
392 let rec aux (context,n,nn as k) _ = function
393 | C.Rel m when m > n && m <= nn -> raise DoesOccur
395 (try (match List.nth context (m-1) with
396 | _,C.Def (bo,_) -> aux k () (S.lift m bo)
398 with Failure _ -> assert false)
399 | C.Meta (_,(_,(C.Irl 0 | C.Ctx []))) -> (* closed meta *) ()
400 | C.Meta (mno,(s,l)) ->
402 let _,_,term,_ = U.lookup_subst mno subst in
403 aux (context,n+s,nn+s) () (S.subst_meta (0,l) term)
404 with CicUtil.Subst_not_found _ -> match l with
405 | C.Irl len -> if not (n >= s+len || s > nn) then raise DoesOccur
406 | C.Ctx lc -> List.iter (aux (context,n+s,nn+s) ()) lc)
407 | t -> U.fold (fun e (ctx,n,nn) -> (e::ctx,n+1,nn+1)) k aux () t
409 try aux (context,n,nn) () t; true
410 with DoesOccur -> false
413 (*CSC l'indice x dei tipi induttivi e' t.c. n < x <= nn *)
414 (*CSC questa funzione e' simile alla are_all_occurrences_positive, ma fa *)
415 (*CSC dei controlli leggermente diversi. Viene invocata solamente dalla *)
416 (*CSC strictly_positive *)
417 (*CSC definizione (giusta???) tratta dalla mail di Hugo ;-) *)
418 let rec weakly_positive ~subst context n nn uri te =
419 (*CSC: Che schifo! Bisogna capire meglio e trovare una soluzione ragionevole!*)
420 let dummy_mutind = C.Implicit `Hole in
421 (*CSC: mettere in cicSubstitution *)
422 let rec subst_inductive_type_with_dummy_mutind _ = function
423 | C.Const (Ref.Ref (_,uri',Ref.Ind 0)) when NUri.eq uri' uri -> dummy_mutind
424 | C.Appl ((C.Const (Ref.Ref (_,uri',Ref.Ind 0)))::tl) when NUri.eq uri' uri ->
426 | t -> U.map (fun _ x->x) () subst_inductive_type_with_dummy_mutind t
428 match R.whd context te with
429 | C.Const (Ref.Ref (_,uri',Ref.Ind _))
430 | C.Appl ((C.Const (Ref.Ref (_,uri',Ref.Ind _)))::_) when NUri.eq uri' uri -> true
431 | C.Prod (name,source,dest) when
432 does_not_occur ~subst ((name,C.Decl source)::context) 0 n dest ->
433 (* dummy abstraction, so we behave as in the anonimous case *)
434 strictly_positive ~subst context n nn
435 (subst_inductive_type_with_dummy_mutind () source) &&
436 weakly_positive ~subst ((name,C.Decl source)::context)
437 (n + 1) (nn + 1) uri dest
438 | C.Prod (name,source,dest) ->
439 does_not_occur ~subst context n nn
440 (subst_inductive_type_with_dummy_mutind () source)&&
441 weakly_positive ~subst ((name,C.Decl source)::context)
442 (n + 1) (nn + 1) uri dest
444 raise (TypeCheckerFailure (lazy "Malformed inductive constructor type"))
446 (* instantiate_parameters ps (x1:T1)...(xn:Tn)C *)
447 (* returns ((x_|ps|:T_|ps|)...(xn:Tn)C){ps_1 / x1 ; ... ; ps_|ps| / x_|ps|} *)
448 and instantiate_parameters params c =
451 | C.Prod (_,_,ta), he::tl -> instantiate_parameters tl (S.subst he ta)
452 | t,l -> raise (AssertFailure (lazy "1"))
454 and strictly_positive ~subst context n nn te =
455 match R.whd context te with
456 | t when does_not_occur ~subst context n nn t -> true
458 | C.Prod (name,so,ta) ->
459 does_not_occur ~subst context n nn so &&
460 strictly_positive ~subst ((name,C.Decl so)::context) (n+1) (nn+1) ta
461 | C.Appl ((C.Rel m)::tl) when m > n && m <= nn ->
462 List.for_all (does_not_occur ~subst context n nn) tl
463 | C.Appl (C.Const (Ref.Ref (_,uri,Ref.Ind i) as r)::tl) ->
464 let _,paramsno,tyl,_,i = E.get_checked_indtys r in
465 let _,name,ity,cl = List.nth tyl i in
466 let ok = List.length tyl = 1 in
467 let params, arguments = HExtlib.split_nth paramsno tl in
468 let lifted_params = List.map (S.lift 1) params in
470 List.map (fun (_,_,te) -> instantiate_parameters lifted_params te) cl
473 List.for_all (does_not_occur ~subst context n nn) arguments &&
475 (weakly_positive ~subst ((name,C.Decl ity)::context) (n+1) (nn+1) uri) cl
478 (* the inductive type indexes are s.t. n < x <= nn *)
479 and are_all_occurrences_positive ~subst context uri indparamsno i n nn te =
480 match R.whd context te with
481 | C.Appl ((C.Rel m)::tl) when m = i ->
487 match R.whd context x with
488 | C.Rel m when m = n - (indparamsno - k) -> k - 1
489 | _ -> raise (TypeCheckerFailure (lazy
490 ("Non-positive occurence in mutual inductive definition(s) [1]" ^
491 NUri.string_of_uri uri))))
495 List.for_all (does_not_occur ~subst context n nn) tl
497 raise (TypeCheckerFailure
498 (lazy ("Non-positive occurence in mutual inductive definition(s) [2]"^
499 NUri.string_of_uri uri)))
500 | C.Rel m when m = i ->
501 if indparamsno = 0 then
504 raise (TypeCheckerFailure
505 (lazy ("Non-positive occurence in mutual inductive definition(s) [3]"^
506 NUri.string_of_uri uri)))
507 | C.Prod (name,source,dest) when
508 does_not_occur ~subst ((name,C.Decl source)::context) 0 n dest ->
509 strictly_positive ~subst context n nn source &&
510 are_all_occurrences_positive ~subst
511 ((name,C.Decl source)::context) uri indparamsno
512 (i+1) (n + 1) (nn + 1) dest
513 | C.Prod (name,source,dest) ->
514 does_not_occur ~subst context n nn source &&
515 are_all_occurrences_positive ~subst ((name,C.Decl source)::context)
516 uri indparamsno (i+1) (n + 1) (nn + 1) dest
519 (TypeCheckerFailure (lazy ("Malformed inductive constructor type " ^
520 (NUri.string_of_uri uri))))
523 exception NotGuarded of string Lazy.t;;
525 let rec typeof ~subst ~metasenv context term =
526 let rec typeof_aux context =
527 fun t -> (*prerr_endline (NCicPp.ppterm ~context t); *)
531 match List.nth context (n - 1) with
532 | (_,C.Decl ty) -> S.lift n ty
533 | (_,C.Def (_,ty)) -> S.lift n ty
534 with Failure _ -> raise (TypeCheckerFailure (lazy "unbound variable")))
535 | C.Sort (C.Type i) -> C.Sort (C.Type (i+1))
536 | C.Sort s -> C.Sort (C.Type 0)
537 | C.Implicit _ -> raise (AssertFailure (lazy "Implicit found"))
538 | C.Meta (n,l) as t ->
539 let canonical_ctx,ty =
541 let _,c,_,ty = U.lookup_subst n subst in c,ty
542 with U.Subst_not_found _ -> try
543 let _,_,c,ty = U.lookup_meta n metasenv in c,ty
544 with U.Meta_not_found _ ->
545 raise (AssertFailure (lazy (Printf.sprintf
546 "%s not found" (NCicPp.ppterm ~subst ~metasenv ~context t))))
548 check_metasenv_consistency t ~subst ~metasenv context canonical_ctx l;
550 | C.Const ref -> type_of_constant ref
551 | C.Prod (name,s,t) ->
552 let sort1 = typeof_aux context s in
553 let sort2 = typeof_aux ((name,(C.Decl s))::context) t in
554 sort_of_prod ~metasenv ~subst context (name,s) (sort1,sort2)
555 | C.Lambda (n,s,t) ->
556 let sort = typeof_aux context s in
557 (match R.whd ~subst context sort with
558 | C.Meta _ | C.Sort _ -> ()
561 (TypeCheckerFailure (lazy (Printf.sprintf
562 ("Not well-typed lambda-abstraction: " ^^
563 "the source %s should be a type; instead it is a term " ^^
564 "of type %s") (NCicPp.ppterm ~subst ~metasenv ~context s)
565 (NCicPp.ppterm ~subst ~metasenv ~context sort)))));
566 let ty = typeof_aux ((n,(C.Decl s))::context) t in
568 | C.LetIn (n,ty,t,bo) ->
569 let ty_t = typeof_aux context t in
570 let _ = typeof_aux context ty in
571 if not (R.are_convertible ~subst ~metasenv context ty ty_t) then
574 (lazy (Printf.sprintf
575 "The type of %s is %s but it is expected to be %s"
576 (NCicPp.ppterm ~subst ~metasenv ~context t)
577 (NCicPp.ppterm ~subst ~metasenv ~context ty_t)
578 (NCicPp.ppterm ~subst ~metasenv ~context ty))))
580 let ty_bo = typeof_aux ((n,C.Def (t,ty))::context) bo in
581 S.subst ~avoid_beta_redexes:true t ty_bo
582 | C.Appl (he::(_::_ as args)) ->
583 let ty_he = typeof_aux context he in
584 let args_with_ty = List.map (fun t -> t, typeof_aux context t) args in
586 prerr_endline ("HEAD: " ^ NCicPp.ppterm ~subst ~metasenv ~context ty_he);
587 prerr_endline ("TARGS: " ^ String.concat " | " (List.map (NCicPp.ppterm
588 ~subst ~metasenv ~context) (List.map snd args_with_ty)));
589 prerr_endline ("ARGS: " ^ String.concat " | " (List.map (NCicPp.ppterm
590 ~subst ~metasenv ~context) (List.map fst args_with_ty)));
592 eat_prods ~subst ~metasenv context he ty_he args_with_ty
593 | C.Appl _ -> raise (AssertFailure (lazy "Appl of length < 2"))
594 | C.Match (Ref.Ref (_,_,Ref.Ind tyno) as r,outtype,term,pl) ->
595 let outsort = typeof_aux context outtype in
596 let inductive,leftno,itl,_,_ = E.get_checked_indtys r in
598 let _,_,_,cl = List.nth itl tyno in List.length cl
600 let parameters, arguments =
601 let ty = R.whd ~subst context (typeof_aux context term) in
604 C.Const (Ref.Ref (_,_,Ref.Ind _) as r') -> r',[]
605 | C.Appl (C.Const (Ref.Ref (_,_,Ref.Ind _) as r') :: tl) -> r',tl
608 (TypeCheckerFailure (lazy (Printf.sprintf
609 "Case analysis: analysed term %s is not an inductive one"
610 (NCicPp.ppterm ~subst ~metasenv ~context term)))) in
611 if not (Ref.eq r r') then
613 (TypeCheckerFailure (lazy (Printf.sprintf
614 ("Case analysys: analysed term type is %s, but is expected " ^^
615 "to be (an application of) %s")
616 (NCicPp.ppterm ~subst ~metasenv ~context ty)
617 (NCicPp.ppterm ~subst ~metasenv ~context (C.Const r')))))
619 try HExtlib.split_nth leftno tl
622 raise (TypeCheckerFailure (lazy (Printf.sprintf
623 "%s is partially applied"
624 (NCicPp.ppterm ~subst ~metasenv ~context ty)))) in
625 (* let's control if the sort elimination is allowed: [(I q1 ... qr)|B] *)
626 let sort_of_ind_type =
627 if parameters = [] then C.Const r
628 else C.Appl ((C.Const r)::parameters) in
629 let type_of_sort_of_ind_ty = typeof_aux context sort_of_ind_type in
630 check_allowed_sort_elimination ~subst ~metasenv r context
631 sort_of_ind_type type_of_sort_of_ind_ty outsort;
632 (* let's check if the type of branches are right *)
633 if List.length pl <> constructorsno then
634 raise (TypeCheckerFailure (lazy ("Wrong number of cases in a match")));
635 let j,branches_ok,p_ty, exp_p_ty =
637 (fun (j,b,old_p_ty,old_exp_p_ty) p ->
640 let cons = Ref.mk_constructor j r in
641 if parameters = [] then C.Const cons
642 else C.Appl (C.Const cons::parameters)
644 let ty_p = typeof_aux context p in
645 let ty_cons = typeof_aux context cons in
647 type_of_branch ~subst context leftno outtype cons ty_cons 0
649 j+1, R.are_convertible ~subst ~metasenv context ty_p ty_branch,
652 j,false,old_p_ty,old_exp_p_ty
653 ) (1,true,C.Sort C.Prop,C.Sort C.Prop) pl
655 if not branches_ok then
658 (lazy (Printf.sprintf ("Branch for constructor %s :=\n%s\n"^^
659 "has type %s\nnot convertible with %s")
660 (NCicPp.ppterm ~subst ~metasenv ~context
661 (C.Const (Ref.mk_constructor (j-1) r)))
662 (NCicPp.ppterm ~metasenv ~subst ~context (List.nth pl (j-2)))
663 (NCicPp.ppterm ~metasenv ~subst ~context p_ty)
664 (NCicPp.ppterm ~metasenv ~subst ~context exp_p_ty))));
665 let res = outtype::arguments@[term] in
666 R.head_beta_reduce (C.Appl res)
667 | C.Match _ -> assert false
669 and type_of_branch ~subst context leftno outty cons tycons liftno =
670 match R.whd ~subst context tycons with
671 | C.Const (Ref.Ref (_,_,Ref.Ind _)) -> C.Appl [S.lift liftno outty ; cons]
672 | C.Appl (C.Const (Ref.Ref (_,_,Ref.Ind _))::tl) ->
673 let _,arguments = HExtlib.split_nth leftno tl in
674 C.Appl (S.lift liftno outty::arguments@[cons])
675 | C.Prod (name,so,de) ->
677 match S.lift 1 cons with
678 | C.Appl l -> C.Appl (l@[C.Rel 1])
679 | t -> C.Appl [t ; C.Rel 1]
682 type_of_branch ~subst ((name,(C.Decl so))::context)
683 leftno outty cons de (liftno+1))
684 | _ -> raise (AssertFailure (lazy "type_of_branch"))
686 (* check_metasenv_consistency checks that the "canonical" context of a
687 metavariable is consitent - up to relocation via the relocation list l -
688 with the actual context *)
689 and check_metasenv_consistency
690 ~subst ~metasenv term context canonical_context l
693 | shift, NCic.Irl n ->
694 let context = snd (HExtlib.split_nth shift context) in
695 let rec compare = function
699 raise (AssertFailure (lazy (Printf.sprintf
700 "Local and canonical context %s have different lengths"
701 (NCicPp.ppterm ~subst ~context ~metasenv term))))
703 raise (TypeCheckerFailure (lazy (Printf.sprintf
704 "Unbound variable -%d in %s" m
705 (NCicPp.ppterm ~subst ~metasenv ~context term))))
708 (_,C.Decl t1), (_,C.Decl t2)
709 | (_,C.Def (t1,_)), (_,C.Def (t2,_))
710 | (_,C.Def (_,t1)), (_,C.Decl t2) ->
711 if not (R.are_convertible ~subst ~metasenv tl t1 t2) then
714 (lazy (Printf.sprintf
715 ("Not well typed metavariable local context for %s: " ^^
716 "%s expected, which is not convertible with %s")
717 (NCicPp.ppterm ~subst ~metasenv ~context term)
718 (NCicPp.ppterm ~subst ~metasenv ~context t2)
719 (NCicPp.ppterm ~subst ~metasenv ~context t1))))
722 (TypeCheckerFailure (lazy (Printf.sprintf
723 ("Not well typed metavariable local context for %s: " ^^
724 "a definition expected, but a declaration found")
725 (NCicPp.ppterm ~subst ~metasenv ~context term)))));
726 compare (m - 1,tl,ctl)
728 compare (n,context,canonical_context)
730 (* we avoid useless lifting by shortening the context*)
731 let l,context = (0,lc_kind), snd (HExtlib.split_nth shift context) in
732 let lifted_canonical_context =
733 let rec lift_metas i = function
735 | (n,C.Decl t)::tl ->
736 (n,C.Decl (S.subst_meta l (S.lift i t)))::(lift_metas (i+1) tl)
737 | (n,C.Def (t,ty))::tl ->
738 (n,C.Def ((S.subst_meta l (S.lift i t)),
739 S.subst_meta l (S.lift i ty)))::(lift_metas (i+1) tl)
741 lift_metas 1 canonical_context in
742 let l = U.expand_local_context lc_kind in
747 | t, (_,C.Def (ct,_)) ->
748 (*CSC: the following optimization is to avoid a possibly expensive
749 reduction that can be easily avoided and that is quite
750 frequent. However, this is better handled using levels to
756 match List.nth context (n - 1) with
757 | (_,C.Def (te,_)) -> S.lift n te
762 if not (R.are_convertible ~subst ~metasenv context optimized_t ct)
766 (lazy (Printf.sprintf
767 ("Not well typed metavariable local context: " ^^
768 "expected a term convertible with %s, found %s")
769 (NCicPp.ppterm ~subst ~metasenv ~context ct)
770 (NCicPp.ppterm ~subst ~metasenv ~context t))))
771 | t, (_,C.Decl ct) ->
772 let type_t = typeof_aux context t in
773 if not (R.are_convertible ~subst ~metasenv context type_t ct) then
774 raise (TypeCheckerFailure
775 (lazy (Printf.sprintf
776 ("Not well typed metavariable local context: "^^
777 "expected a term of type %s, found %s of type %s")
778 (NCicPp.ppterm ~subst ~metasenv ~context ct)
779 (NCicPp.ppterm ~subst ~metasenv ~context t)
780 (NCicPp.ppterm ~subst ~metasenv ~context type_t))))
781 ) l lifted_canonical_context
783 Invalid_argument _ ->
784 raise (AssertFailure (lazy (Printf.sprintf
785 "Local and canonical context %s have different lengths"
786 (NCicPp.ppterm ~subst ~metasenv ~context term))))
788 and is_non_informative context paramsno c =
789 let rec aux context c =
790 match R.whd context c with
791 | C.Prod (n,so,de) ->
792 let s = typeof_aux context so in
793 s = C.Sort C.Prop && aux ((n,(C.Decl so))::context) de
795 let context',dx = split_prods ~subst:[] context paramsno c in
798 and check_allowed_sort_elimination ~subst ~metasenv r =
801 | C.Appl l -> C.Appl (l @ [arg])
802 | t -> C.Appl [t;arg] in
803 let rec aux context ind arity1 arity2 =
804 let arity1 = R.whd ~subst context arity1 in
805 let arity2 = R.whd ~subst context arity2 in
806 match arity1,arity2 with
807 | C.Prod (name,so1,de1), C.Prod (_,so2,de2) ->
808 if not (R.are_convertible ~subst ~metasenv context so1 so2) then
809 raise (TypeCheckerFailure (lazy (Printf.sprintf
810 "In outtype: expected %s, found %s"
811 (NCicPp.ppterm ~subst ~metasenv ~context so1)
812 (NCicPp.ppterm ~subst ~metasenv ~context so2)
814 aux ((name, C.Decl so1)::context)
815 (mkapp (S.lift 1 ind) (C.Rel 1)) de1 de2
816 | C.Sort _, C.Prod (name,so,ta) ->
817 if not (R.are_convertible ~subst ~metasenv context so ind) then
818 raise (TypeCheckerFailure (lazy (Printf.sprintf
819 "In outtype: expected %s, found %s"
820 (NCicPp.ppterm ~subst ~metasenv ~context ind)
821 (NCicPp.ppterm ~subst ~metasenv ~context so)
823 (match arity1,ta with
824 | (C.Sort (C.CProp | C.Type _), C.Sort _)
825 | (C.Sort C.Prop, C.Sort C.Prop) -> ()
826 | (C.Sort C.Prop, C.Sort (C.CProp | C.Type _)) ->
827 (* TODO: we should pass all these parameters since we
828 * have them already *)
829 let inductive,leftno,itl,_,i = E.get_checked_indtys r in
830 let itl_len = List.length itl in
831 let _,name,ty,cl = List.nth itl i in
832 let cl_len = List.length cl in
833 (* is it a singleton or empty non recursive and non informative
837 (itl_len = 1 && cl_len = 1 &&
838 is_non_informative [name,C.Decl ty] leftno
839 (let _,_,x = List.nth cl 0 in x)))
841 raise (TypeCheckerFailure (lazy
842 ("Sort elimination not allowed")));
849 typeof_aux context term
851 and check_mutual_inductive_defs uri ~metasenv ~subst is_ind leftno tyl =
852 (* let's check if the arity of the inductive types are well formed *)
853 List.iter (fun (_,_,x,_) -> ignore (typeof ~subst ~metasenv [] x)) tyl;
854 (* let's check if the types of the inductive constructors are well formed. *)
855 let len = List.length tyl in
856 let tys = List.rev (List.map (fun (_,n,ty,_) -> (n,(C.Decl ty))) tyl) in
862 let debruijnedte = debruijn uri len te in
863 ignore (typeof ~subst ~metasenv tys debruijnedte);
864 (* let's check also the positivity conditions *)
867 (are_all_occurrences_positive ~subst tys uri leftno i 0 len
872 (lazy ("Non positive occurence in "^NUri.string_of_uri uri))))
877 and eat_lambdas ~subst ~metasenv context n te =
878 match (n, R.whd ~subst context te) with
879 | (0, _) -> (te, context)
880 | (n, C.Lambda (name,so,ta)) when n > 0 ->
881 eat_lambdas ~subst ~metasenv ((name,(C.Decl so))::context) (n - 1) ta
883 raise (AssertFailure (lazy (Printf.sprintf "9 (%d, %s)" n
884 (NCicPp.ppterm ~subst ~metasenv ~context te))))
886 and guarded_by_destructors ~subst ~metasenv context recfuns t =
887 let recursor f k t = NCicUtils.fold shift_k k (fun k () -> f k) () t in
888 let rec aux (context, recfuns, x, safes as k) = function
889 | C.Rel m as t when List.mem_assoc m recfuns ->
890 raise (NotGuarded (lazy
891 (NCicPp.ppterm ~subst ~metasenv ~context t ^ " passed around")))
893 (match List.nth context (m-1) with
895 | _,C.Def (bo,_) -> aux (context, recfuns, x, safes) (S.lift m bo))
897 | C.Appl ((C.Rel m)::tl) as t when List.mem_assoc m recfuns ->
898 let rec_no = List.assoc m recfuns in
899 if not (List.length tl > rec_no) then
900 raise (NotGuarded (lazy
901 (NCicPp.ppterm ~context ~subst ~metasenv t ^
902 " is a partial application of a fix")))
904 let rec_arg = List.nth tl rec_no in
905 if not (is_really_smaller ~subst ~metasenv k rec_arg) then
906 raise (NotGuarded (lazy
907 (NCicPp.ppterm ~context ~subst ~metasenv rec_arg ^ " not smaller")));
909 | C.Match (Ref.Ref (_,uri,_) as ref,outtype,term,pl) as t ->
910 (match R.whd ~subst context term with
911 | C.Rel m | C.Appl (C.Rel m :: _ ) as t when List.mem m safes || m = x ->
912 let isinductive, paramsno, tl, _, i = E.get_checked_indtys ref in
913 if not isinductive then recursor aux k t
915 let c_ctx,len,cl = fix_lefts_in_constrs ~subst uri paramsno tl i in
916 let args = match t with C.Appl (_::tl) -> tl | _ -> [] in
918 List.iter (aux k) args;
920 (fun p (_,_,bruijnedc) ->
921 let rl = recursive_args ~subst ~metasenv c_ctx 0 len bruijnedc in
922 let p, k = get_new_safes ~subst k p rl in
925 | _ -> recursor aux k t)
926 | t -> recursor aux k t
928 try aux (context, recfuns, 1, []) t
929 with NotGuarded s -> raise (TypeCheckerFailure s)
933 let len = List.length fl in
934 let n_plus_len = n + len
935 and nn_plus_len = nn + len
936 and x_plus_len = x + len
939 (fun (types,len) (n,_,ty,_) ->
940 (Some (C.Name n,(C.Decl (CicSubstitution.lift len ty)))::types,
943 and safes' = List.map (fun x -> x + len) safes in
945 (fun (_,_,ty,bo) i ->
946 i && guarded_by_destructors ~subst context n nn kl x_plus_len safes' ty &&
947 guarded_by_destructors ~subst (tys@context) n_plus_len nn_plus_len kl
951 let len = List.length fl in
952 let n_plus_len = n + len
953 and nn_plus_len = nn + len
954 and x_plus_len = x + len
957 (fun (types,len) (n,ty,_) ->
958 (Some (C.Name n,(C.Decl (CicSubstitution.lift len ty)))::types,
961 and safes' = List.map (fun x -> x + len) safes in
965 guarded_by_destructors ~subst context n nn kl x_plus_len safes' ty &&
966 guarded_by_destructors ~subst (tys@context) n_plus_len nn_plus_len kl
971 and guarded_by_constructors ~subst ~metasenv _ _ _ _ _ _ _ = true
973 and recursive_args ~subst ~metasenv context n nn te =
974 match R.whd context te with
975 | C.Rel _ | C.Appl _ -> []
976 | C.Prod (name,so,de) ->
977 (not (does_not_occur ~subst context n nn so)) ::
978 (recursive_args ~subst ~metasenv
979 ((name,(C.Decl so))::context) (n+1) (nn + 1) de)
981 raise (AssertFailure (lazy ("recursive_args:" ^ NCicPp.ppterm ~subst
982 ~metasenv ~context:[] t)))
984 and get_new_safes ~subst (context, recfuns, x, safes as k) p rl =
985 match R.whd ~subst context p, rl with
986 | C.Lambda (name,so,ta), b::tl ->
987 let safes = (if b then [0] else []) @ safes in
989 (shift_k (name,(C.Decl so)) (context, recfuns, x, safes)) ta tl
990 | C.Meta _ as e, _ | e, [] -> e, k
991 | _ -> raise (AssertFailure (lazy "Ill formed pattern"))
993 and split_prods ~subst context n te =
994 match n, R.whd ~subst context te with
996 | n, C.Prod (name,so,ta) when n > 0 ->
997 split_prods ~subst ((name,(C.Decl so))::context) (n - 1) ta
998 | _ -> raise (AssertFailure (lazy "split_prods"))
1000 and is_really_smaller ~subst ~metasenv (context, recfuns, x, safes as k) te =
1001 match R.whd ~subst context te with
1002 | C.Rel m when List.mem m safes -> true
1004 | C.LetIn _ -> raise (AssertFailure (lazy "letin after whd"))
1005 | C.Sort _ | C.Implicit _ | C.Prod _ | C.Lambda _
1006 | C.Const (Ref.Ref (_,_,(Ref.Decl | Ref.Def | Ref.Ind _ | Ref.CoFix _))) ->
1007 raise (AssertFailure (lazy "not a constructor"))
1008 | C.Appl ([]|[_]) -> raise (AssertFailure (lazy "empty/unary appl"))
1010 (*CSC: sulla coda ci vogliono dei controlli? secondo noi no, ma *)
1011 (*CSC: solo perche' non abbiamo trovato controesempi *)
1012 (*TASSI: da capire soprattutto se he รจ un altro fix che non ha ridotto...*)
1013 is_really_smaller ~subst ~metasenv k he
1014 | C.Const (Ref.Ref (_,_,Ref.Con _)) -> false
1015 | C.Const (Ref.Ref (_,_,Ref.Fix _)) -> assert false
1016 (*| C.Fix (_, fl) ->
1017 let len = List.length fl in
1018 let n_plus_len = n + len
1019 and nn_plus_len = nn + len
1020 and x_plus_len = x + len
1023 (fun (types,len) (n,_,ty,_) ->
1024 (Some (C.Name n,(C.Decl (CicSubstitution.lift len ty)))::types,
1027 and safes' = List.map (fun x -> x + len) safes in
1029 (fun (_,_,ty,bo) i ->
1031 is_really_smaller ~subst (tys@context) n_plus_len nn_plus_len kl
1032 x_plus_len safes' bo
1035 true (* XXX if this check is repeated when the user completes the
1037 | C.Match (Ref.Ref (_,uri,_) as ref,outtype,term,pl) ->
1039 | C.Rel m | C.Appl (C.Rel m :: _ ) when List.mem m safes || m = x ->
1040 let isinductive, paramsno, tl, _, i = E.get_checked_indtys ref in
1041 if not isinductive then
1042 List.for_all (is_really_smaller ~subst ~metasenv k) pl
1044 let c_ctx,len,cl = fix_lefts_in_constrs ~subst uri paramsno tl i in
1046 (fun p (_,_,debruijnedte) ->
1047 let rl'=recursive_args ~subst ~metasenv c_ctx 0 len debruijnedte in
1048 let e, k = get_new_safes ~subst k p rl' in
1049 is_really_smaller ~subst ~metasenv k e)
1051 | _ -> List.for_all (is_really_smaller ~subst ~metasenv k) pl)
1053 and returns_a_coinductive ~subst context ty =
1054 match R.whd ~subst context ty with
1055 | C.Const (Ref.Ref (_,uri,Ref.Ind _) as ref)
1056 | C.Appl (C.Const (Ref.Ref (_,uri,Ref.Ind _) as ref)::_) ->
1057 let isinductive, _, _, _, _ = E.get_checked_indtys ref in
1058 if isinductive then None else (Some uri)
1059 | C.Prod (n,so,de) ->
1060 returns_a_coinductive ~subst ((n,C.Decl so)::context) de
1063 and type_of_constant ((Ref.Ref (_,uri,_)) as ref) =
1065 match E.get_obj uri with
1066 | true, cobj -> cobj
1068 !logger (`Start_type_checking uri);
1069 check_obj_well_typed uobj;
1071 !logger (`Type_checking_completed uri);
1074 match cobj, ref with
1075 | (_,_,_,_,C.Inductive (_,_,tl,_)), Ref.Ref (_,_,Ref.Ind i) ->
1076 let _,_,arity,_ = List.nth tl i in arity
1077 | (_,_,_,_,C.Inductive (_,_,tl,_)), Ref.Ref (_,_,Ref.Con (i,j)) ->
1078 let _,_,_,cl = List.nth tl i in
1079 let _,_,arity = List.nth cl (j-1) in
1081 | (_,_,_,_,C.Fixpoint (_,fl,_)), Ref.Ref (_,_,(Ref.Fix (i,_)|Ref.CoFix i)) ->
1082 let _,_,_,arity,_ = List.nth fl i in
1084 | (_,_,_,_,C.Constant (_,_,_,ty,_)), Ref.Ref (_,_,(Ref.Def |Ref.Decl)) -> ty
1085 | _ -> raise (AssertFailure (lazy "type_of_constant: environment/reference"))
1087 and check_obj_well_typed (uri,height,metasenv,subst,kind) =
1088 (* CSC: here we should typecheck the metasenv and the subst *)
1089 assert (metasenv = [] && subst = []);
1091 | C.Constant (_,_,Some te,ty,_) ->
1093 prerr_endline ("TY: " ^ NCicPp.ppterm ~subst ~metasenv ~context:[] ty);
1094 prerr_endline ("BO: " ^ NCicPp.ppterm ~subst ~metasenv ~context:[] te);
1096 let _ = typeof ~subst ~metasenv [] ty in
1097 let ty_te = typeof ~subst ~metasenv [] te in
1098 (* prerr_endline "XXXX"; *)
1099 if not (R.are_convertible ~subst ~metasenv [] ty_te ty) then
1100 raise (TypeCheckerFailure (lazy (Printf.sprintf
1101 "the type of the body is not the one expected:\n%s\nvs\n%s"
1102 (NCicPp.ppterm ~subst ~metasenv ~context:[] ty_te)
1103 (NCicPp.ppterm ~subst ~metasenv ~context:[] ty))))
1104 | C.Constant (_,_,None,ty,_) -> ignore (typeof ~subst ~metasenv [] ty)
1105 | C.Inductive (is_ind, leftno, tyl, _) ->
1106 check_mutual_inductive_defs uri ~metasenv ~subst is_ind leftno tyl
1107 | C.Fixpoint (inductive,fl,_) ->
1110 (fun (types,kl,len) (_,name,k,ty,_) ->
1111 let _ = typeof ~subst ~metasenv [] ty in
1112 ((name,(C.Decl (S.lift len ty)))::types, k::kl,len+1)
1115 List.iter (fun (_,name,x,ty,bo) ->
1116 let bo = debruijn uri len bo in
1117 let ty_bo = typeof ~subst ~metasenv types bo in
1118 if not (R.are_convertible ~subst ~metasenv types ty_bo (S.lift len ty))
1119 then raise (TypeCheckerFailure (lazy ("(Co)Fix: ill-typed bodies")))
1121 if inductive then begin
1122 let m, context = eat_lambdas ~subst ~metasenv types (x + 1) bo in
1123 (* guarded by destructors conditions D{f,k,x,M} *)
1124 let rec enum_from k =
1125 function [] -> [] | v::tl -> (k,v)::enum_from (k+1) tl
1127 guarded_by_destructors
1128 ~subst ~metasenv context (enum_from (x+2) kl) m
1130 match returns_a_coinductive ~subst [] ty with
1132 raise (TypeCheckerFailure
1133 (lazy "CoFix: does not return a coinductive type"))
1135 (* guarded by constructors conditions C{f,M} *)
1136 if not (guarded_by_constructors ~subst ~metasenv
1137 types 0 len false bo [] uri)
1139 raise (TypeCheckerFailure
1140 (lazy "CoFix: not guarded by constructors"))
1143 let typecheck_obj = check_obj_well_typed;;