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 let shift_k_add_1_safe e (c,rf,x,safes) =
30 e::c,List.map (fun (k,v) -> k+1,v) rf,x+1,1::List.map ((+)1) safes
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 context =
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
312 aux (List.length context)
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\nContext:\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)
358 (NCicPp.ppcontext ~subst ~metasenv context))))
362 (lazy (Printf.sprintf
363 "Appl: %s is not a function, it cannot be applied"
364 (NCicPp.ppterm ~subst ~metasenv ~context
365 (let res = List.length tl in
366 let eaten = List.length args_with_ty - res in
369 (fst (HExtlib.split_nth eaten args_with_ty)))))))))
371 aux ty_he args_with_ty
374 (* instantiate_parameters ps (x1:T1)...(xn:Tn)C *)
375 (* returns ((x_|ps|:T_|ps|)...(xn:Tn)C){ps_1 / x1 ; ... ; ps_|ps| / x_|ps|} *)
376 let rec instantiate_parameters params c =
379 | C.Prod (_,_,ta), he::tl -> instantiate_parameters tl (S.subst he ta)
380 | t,l -> raise (AssertFailure (lazy "1"))
383 let specialize_inductive_type ~subst context ty_term =
384 match R.whd ~subst context ty_term with
385 | C.Const (Ref.Ref (_,uri,Ref.Ind i) as ref)
386 | C.Appl (C.Const (Ref.Ref (_,uri,Ref.Ind i) as ref) :: _ ) as ty ->
387 let args = match ty with C.Appl (_::tl) -> tl | _ -> [] in
388 let is_ind, leftno, itl, attrs, i = E.get_checked_indtys ref in
389 let left_args,_ = HExtlib.split_nth leftno args in
391 List.map (fun (rel, name, arity, cl) ->
392 let arity = instantiate_parameters left_args arity in
394 List.map (fun (rel, name, ty) ->
395 rel, name, instantiate_parameters left_args ty)
398 rel, name, arity, cl)
401 is_ind, leftno, itl, attrs, i
405 let fix_lefts_in_constrs ~subst r_uri r_len context ty_term =
406 let _,_,itl,_,i = specialize_inductive_type ~subst context ty_term in
407 let _,_,_,cl = List.nth itl i in
409 List.map (fun (_,id,ty) -> id, debruijn r_uri r_len context ty) cl
411 List.map (fun (_,name,arity,_) -> name, C.Decl arity) itl, cl
414 exception DoesOccur;;
416 let does_not_occur ~subst context n nn t =
417 let rec aux (context,n,nn as k) _ = function
418 | C.Rel m when m > n && m <= nn -> raise DoesOccur
420 (try (match List.nth context (m-1) with
421 | _,C.Def (bo,_) -> aux k () (S.lift m bo)
423 with Failure _ -> assert false)
424 | C.Meta (_,(_,(C.Irl 0 | C.Ctx []))) -> (* closed meta *) ()
425 | C.Meta (mno,(s,l)) ->
427 let _,_,term,_ = U.lookup_subst mno subst in
428 aux (context,n+s,nn+s) () (S.subst_meta (0,l) term)
429 with CicUtil.Subst_not_found _ -> match l with
430 | C.Irl len -> if not (n >= s+len || s > nn) then raise DoesOccur
431 | C.Ctx lc -> List.iter (aux (context,n+s,nn+s) ()) lc)
432 | t -> U.fold (fun e (ctx,n,nn) -> (e::ctx,n+1,nn+1)) k aux () t
434 try aux (context,n,nn) () t; true
435 with DoesOccur -> false
438 (*CSC l'indice x dei tipi induttivi e' t.c. n < x <= nn *)
439 (*CSC questa funzione e' simile alla are_all_occurrences_positive, ma fa *)
440 (*CSC dei controlli leggermente diversi. Viene invocata solamente dalla *)
441 (*CSC strictly_positive *)
442 (*CSC definizione (giusta???) tratta dalla mail di Hugo ;-) *)
443 let rec weakly_positive ~subst context n nn uri te =
444 (*CSC: Che schifo! Bisogna capire meglio e trovare una soluzione ragionevole!*)
445 let dummy = C.Sort (C.Type ~-1) in
446 (*CSC: mettere in cicSubstitution *)
447 let rec subst_inductive_type_with_dummy _ = function
448 | C.Const (Ref.Ref (_,uri',Ref.Ind 0)) when NUri.eq uri' uri -> dummy
449 | C.Appl ((C.Const (Ref.Ref (_,uri',Ref.Ind 0)))::tl)
450 when NUri.eq uri' uri -> dummy
451 | t -> U.map (fun _ x->x) () subst_inductive_type_with_dummy t
453 match R.whd context te with
454 | C.Const (Ref.Ref (_,uri',Ref.Ind _))
455 | C.Appl ((C.Const (Ref.Ref (_,uri',Ref.Ind _)))::_)
456 when NUri.eq uri' uri -> true
457 | C.Prod (name,source,dest) when
458 does_not_occur ~subst ((name,C.Decl source)::context) 0 1 dest ->
459 (* dummy abstraction, so we behave as in the anonimous case *)
460 strictly_positive ~subst context n nn
461 (subst_inductive_type_with_dummy () source) &&
462 weakly_positive ~subst ((name,C.Decl source)::context)
463 (n + 1) (nn + 1) uri dest
464 | C.Prod (name,source,dest) ->
465 does_not_occur ~subst context n nn
466 (subst_inductive_type_with_dummy () source)&&
467 weakly_positive ~subst ((name,C.Decl source)::context)
468 (n + 1) (nn + 1) uri dest
470 raise (TypeCheckerFailure (lazy "Malformed inductive constructor type"))
472 and strictly_positive ~subst context n nn te =
473 match R.whd context te with
474 | t when does_not_occur ~subst context n nn t -> true
476 | C.Prod (name,so,ta) ->
477 does_not_occur ~subst context n nn so &&
478 strictly_positive ~subst ((name,C.Decl so)::context) (n+1) (nn+1) ta
479 | C.Appl ((C.Rel m)::tl) when m > n && m <= nn ->
480 List.for_all (does_not_occur ~subst context n nn) tl
481 | C.Appl (C.Const (Ref.Ref (_,uri,Ref.Ind i) as r)::tl) ->
482 let _,paramsno,tyl,_,i = E.get_checked_indtys r in
483 let _,name,ity,cl = List.nth tyl i in
484 let ok = List.length tyl = 1 in
485 let params, arguments = HExtlib.split_nth paramsno tl in
486 let lifted_params = List.map (S.lift 1) params in
488 List.map (fun (_,_,te) -> instantiate_parameters lifted_params te) cl
491 List.for_all (does_not_occur ~subst context n nn) arguments &&
493 (weakly_positive ~subst ((name,C.Decl ity)::context) (n+1) (nn+1) uri) cl
496 (* the inductive type indexes are s.t. n < x <= nn *)
497 and are_all_occurrences_positive ~subst context uri indparamsno i n nn te =
498 match R.whd context te with
499 | C.Appl ((C.Rel m)::tl) as reduct when m = i ->
505 match R.whd context x with
506 | C.Rel m when m = n - (indparamsno - k) -> k - 1
507 | y -> raise (TypeCheckerFailure (lazy
508 ("Argument "^string_of_int (indparamsno - k + 1) ^ " (of " ^
509 string_of_int indparamsno ^ " fixed) is not homogeneous in "^
510 "appl:\n"^ NCicPp.ppterm ~context ~subst ~metasenv:[] reduct))))
514 List.for_all (does_not_occur ~subst context n nn) tl
516 raise (TypeCheckerFailure
517 (lazy ("Non-positive occurence in mutual inductive definition(s) [2]"^
518 NUri.string_of_uri uri)))
519 | C.Rel m when m = i ->
520 if indparamsno = 0 then
523 raise (TypeCheckerFailure
524 (lazy ("Non-positive occurence in mutual inductive definition(s) [3]"^
525 NUri.string_of_uri uri)))
526 | C.Prod (name,source,dest) when
527 does_not_occur ~subst ((name,C.Decl source)::context) 0 1 dest ->
528 strictly_positive ~subst context n nn source &&
529 are_all_occurrences_positive ~subst
530 ((name,C.Decl source)::context) uri indparamsno
531 (i+1) (n + 1) (nn + 1) dest
532 | C.Prod (name,source,dest) ->
533 if not (does_not_occur ~subst context n nn source) then
534 raise (TypeCheckerFailure (lazy ("Non-positive occurrence in "^
535 NCicPp.ppterm ~context ~metasenv:[] ~subst te)));
536 are_all_occurrences_positive ~subst ((name,C.Decl source)::context)
537 uri indparamsno (i+1) (n + 1) (nn + 1) dest
540 (TypeCheckerFailure (lazy ("Malformed inductive constructor type " ^
541 (NUri.string_of_uri uri))))
544 exception NotGuarded of string Lazy.t;;
546 let rec typeof ~subst ~metasenv context term =
547 let rec typeof_aux context =
548 fun t -> (*prerr_endline (NCicPp.ppterm ~context t); *)
552 match List.nth context (n - 1) with
553 | (_,C.Decl ty) -> S.lift n ty
554 | (_,C.Def (_,ty)) -> S.lift n ty
555 with Failure _ -> raise (TypeCheckerFailure (lazy "unbound variable")))
556 | C.Sort (C.Type i) -> C.Sort (C.Type (i+1))
557 | C.Sort s -> C.Sort (C.Type 0)
558 | C.Implicit _ -> raise (AssertFailure (lazy "Implicit found"))
559 | C.Meta (n,l) as t ->
560 let canonical_ctx,ty =
562 let _,c,_,ty = U.lookup_subst n subst in c,ty
563 with U.Subst_not_found _ -> try
564 let _,_,c,ty = U.lookup_meta n metasenv in c,ty
565 with U.Meta_not_found _ ->
566 raise (AssertFailure (lazy (Printf.sprintf
567 "%s not found" (NCicPp.ppterm ~subst ~metasenv ~context t))))
569 check_metasenv_consistency t ~subst ~metasenv context canonical_ctx l;
571 | C.Const ref -> type_of_constant ref
572 | C.Prod (name,s,t) ->
573 let sort1 = typeof_aux context s in
574 let sort2 = typeof_aux ((name,(C.Decl s))::context) t in
575 sort_of_prod ~metasenv ~subst context (name,s) (sort1,sort2)
576 | C.Lambda (n,s,t) ->
577 let sort = typeof_aux context s in
578 (match R.whd ~subst context sort with
579 | C.Meta _ | C.Sort _ -> ()
582 (TypeCheckerFailure (lazy (Printf.sprintf
583 ("Not well-typed lambda-abstraction: " ^^
584 "the source %s should be a type; instead it is a term " ^^
585 "of type %s") (NCicPp.ppterm ~subst ~metasenv ~context s)
586 (NCicPp.ppterm ~subst ~metasenv ~context sort)))));
587 let ty = typeof_aux ((n,(C.Decl s))::context) t in
589 | C.LetIn (n,ty,t,bo) ->
590 let ty_t = typeof_aux context t in
591 let _ = typeof_aux context ty in
592 if not (R.are_convertible ~subst ~metasenv context ty ty_t) then
595 (lazy (Printf.sprintf
596 "The type of %s is %s but it is expected to be %s"
597 (NCicPp.ppterm ~subst ~metasenv ~context t)
598 (NCicPp.ppterm ~subst ~metasenv ~context ty_t)
599 (NCicPp.ppterm ~subst ~metasenv ~context ty))))
601 let ty_bo = typeof_aux ((n,C.Def (t,ty))::context) bo in
602 S.subst ~avoid_beta_redexes:true t ty_bo
603 | C.Appl (he::(_::_ as args)) ->
604 let ty_he = typeof_aux context he in
605 let args_with_ty = List.map (fun t -> t, typeof_aux context t) args in
607 prerr_endline ("HEAD: " ^ NCicPp.ppterm ~subst ~metasenv ~context ty_he);
608 prerr_endline ("TARGS: " ^ String.concat " | " (List.map (NCicPp.ppterm
609 ~subst ~metasenv ~context) (List.map snd args_with_ty)));
610 prerr_endline ("ARGS: " ^ String.concat " | " (List.map (NCicPp.ppterm
611 ~subst ~metasenv ~context) (List.map fst args_with_ty)));
613 eat_prods ~subst ~metasenv context he ty_he args_with_ty
614 | C.Appl _ -> raise (AssertFailure (lazy "Appl of length < 2"))
615 | C.Match (Ref.Ref (_,_,Ref.Ind tyno) as r,outtype,term,pl) ->
616 let outsort = typeof_aux context outtype in
617 let inductive,leftno,itl,_,_ = E.get_checked_indtys r in
619 let _,_,_,cl = List.nth itl tyno in List.length cl
621 let parameters, arguments =
622 let ty = R.whd ~subst context (typeof_aux context term) in
625 C.Const (Ref.Ref (_,_,Ref.Ind _) as r') -> r',[]
626 | C.Appl (C.Const (Ref.Ref (_,_,Ref.Ind _) as r') :: tl) -> r',tl
629 (TypeCheckerFailure (lazy (Printf.sprintf
630 "Case analysis: analysed term %s is not an inductive one"
631 (NCicPp.ppterm ~subst ~metasenv ~context term)))) in
632 if not (Ref.eq r r') then
634 (TypeCheckerFailure (lazy (Printf.sprintf
635 ("Case analysys: analysed term type is %s, but is expected " ^^
636 "to be (an application of) %s")
637 (NCicPp.ppterm ~subst ~metasenv ~context ty)
638 (NCicPp.ppterm ~subst ~metasenv ~context (C.Const r')))))
640 try HExtlib.split_nth leftno tl
643 raise (TypeCheckerFailure (lazy (Printf.sprintf
644 "%s is partially applied"
645 (NCicPp.ppterm ~subst ~metasenv ~context ty)))) in
646 (* let's control if the sort elimination is allowed: [(I q1 ... qr)|B] *)
647 let sort_of_ind_type =
648 if parameters = [] then C.Const r
649 else C.Appl ((C.Const r)::parameters) in
650 let type_of_sort_of_ind_ty = typeof_aux context sort_of_ind_type in
651 check_allowed_sort_elimination ~subst ~metasenv r context
652 sort_of_ind_type type_of_sort_of_ind_ty outsort;
653 (* let's check if the type of branches are right *)
654 if List.length pl <> constructorsno then
655 raise (TypeCheckerFailure (lazy ("Wrong number of cases in a match")));
656 let j,branches_ok,p_ty, exp_p_ty =
658 (fun (j,b,old_p_ty,old_exp_p_ty) p ->
661 let cons = Ref.mk_constructor j r in
662 if parameters = [] then C.Const cons
663 else C.Appl (C.Const cons::parameters)
665 let ty_p = typeof_aux context p in
666 let ty_cons = typeof_aux context cons in
668 type_of_branch ~subst context leftno outtype cons ty_cons 0
670 j+1, R.are_convertible ~subst ~metasenv context ty_p ty_branch,
673 j,false,old_p_ty,old_exp_p_ty
674 ) (1,true,C.Sort C.Prop,C.Sort C.Prop) pl
676 if not branches_ok then
679 (lazy (Printf.sprintf ("Branch for constructor %s :=\n%s\n"^^
680 "has type %s\nnot convertible with %s")
681 (NCicPp.ppterm ~subst ~metasenv ~context
682 (C.Const (Ref.mk_constructor (j-1) r)))
683 (NCicPp.ppterm ~metasenv ~subst ~context (List.nth pl (j-2)))
684 (NCicPp.ppterm ~metasenv ~subst ~context p_ty)
685 (NCicPp.ppterm ~metasenv ~subst ~context exp_p_ty))));
686 let res = outtype::arguments@[term] in
687 R.head_beta_reduce (C.Appl res)
688 | C.Match _ -> assert false
690 and type_of_branch ~subst context leftno outty cons tycons liftno =
691 match R.whd ~subst context tycons with
692 | C.Const (Ref.Ref (_,_,Ref.Ind _)) -> C.Appl [S.lift liftno outty ; cons]
693 | C.Appl (C.Const (Ref.Ref (_,_,Ref.Ind _))::tl) ->
694 let _,arguments = HExtlib.split_nth leftno tl in
695 C.Appl (S.lift liftno outty::arguments@[cons])
696 | C.Prod (name,so,de) ->
698 match S.lift 1 cons with
699 | C.Appl l -> C.Appl (l@[C.Rel 1])
700 | t -> C.Appl [t ; C.Rel 1]
703 type_of_branch ~subst ((name,(C.Decl so))::context)
704 leftno outty cons de (liftno+1))
705 | _ -> raise (AssertFailure (lazy "type_of_branch"))
707 (* check_metasenv_consistency checks that the "canonical" context of a
708 metavariable is consitent - up to relocation via the relocation list l -
709 with the actual context *)
710 and check_metasenv_consistency
711 ~subst ~metasenv term context canonical_context l
714 | shift, NCic.Irl n ->
715 let context = snd (HExtlib.split_nth shift context) in
716 let rec compare = function
720 raise (AssertFailure (lazy (Printf.sprintf
721 "Local and canonical context %s have different lengths"
722 (NCicPp.ppterm ~subst ~context ~metasenv term))))
724 raise (TypeCheckerFailure (lazy (Printf.sprintf
725 "Unbound variable -%d in %s" m
726 (NCicPp.ppterm ~subst ~metasenv ~context term))))
729 (_,C.Decl t1), (_,C.Decl t2)
730 | (_,C.Def (t1,_)), (_,C.Def (t2,_))
731 | (_,C.Def (_,t1)), (_,C.Decl t2) ->
732 if not (R.are_convertible ~subst ~metasenv tl t1 t2) then
735 (lazy (Printf.sprintf
736 ("Not well typed metavariable local context for %s: " ^^
737 "%s expected, which is not convertible with %s")
738 (NCicPp.ppterm ~subst ~metasenv ~context term)
739 (NCicPp.ppterm ~subst ~metasenv ~context t2)
740 (NCicPp.ppterm ~subst ~metasenv ~context t1))))
743 (TypeCheckerFailure (lazy (Printf.sprintf
744 ("Not well typed metavariable local context for %s: " ^^
745 "a definition expected, but a declaration found")
746 (NCicPp.ppterm ~subst ~metasenv ~context term)))));
747 compare (m - 1,tl,ctl)
749 compare (n,context,canonical_context)
751 (* we avoid useless lifting by shortening the context*)
752 let l,context = (0,lc_kind), snd (HExtlib.split_nth shift context) in
753 let lifted_canonical_context =
754 let rec lift_metas i = function
756 | (n,C.Decl t)::tl ->
757 (n,C.Decl (S.subst_meta l (S.lift i t)))::(lift_metas (i+1) tl)
758 | (n,C.Def (t,ty))::tl ->
759 (n,C.Def ((S.subst_meta l (S.lift i t)),
760 S.subst_meta l (S.lift i ty)))::(lift_metas (i+1) tl)
762 lift_metas 1 canonical_context in
763 let l = U.expand_local_context lc_kind in
768 | t, (_,C.Def (ct,_)) ->
769 (*CSC: the following optimization is to avoid a possibly expensive
770 reduction that can be easily avoided and that is quite
771 frequent. However, this is better handled using levels to
777 match List.nth context (n - 1) with
778 | (_,C.Def (te,_)) -> S.lift n te
783 if not (R.are_convertible ~subst ~metasenv context optimized_t ct)
787 (lazy (Printf.sprintf
788 ("Not well typed metavariable local context: " ^^
789 "expected a term convertible with %s, found %s")
790 (NCicPp.ppterm ~subst ~metasenv ~context ct)
791 (NCicPp.ppterm ~subst ~metasenv ~context t))))
792 | t, (_,C.Decl ct) ->
793 let type_t = typeof_aux context t in
794 if not (R.are_convertible ~subst ~metasenv context type_t ct) then
795 raise (TypeCheckerFailure
796 (lazy (Printf.sprintf
797 ("Not well typed metavariable local context: "^^
798 "expected a term of type %s, found %s of type %s")
799 (NCicPp.ppterm ~subst ~metasenv ~context ct)
800 (NCicPp.ppterm ~subst ~metasenv ~context t)
801 (NCicPp.ppterm ~subst ~metasenv ~context type_t))))
802 ) l lifted_canonical_context
804 Invalid_argument _ ->
805 raise (AssertFailure (lazy (Printf.sprintf
806 "Local and canonical context %s have different lengths"
807 (NCicPp.ppterm ~subst ~metasenv ~context term))))
809 and is_non_informative context paramsno c =
810 let rec aux context c =
811 match R.whd context c with
812 | C.Prod (n,so,de) ->
813 let s = typeof_aux context so in
814 s = C.Sort C.Prop && aux ((n,(C.Decl so))::context) de
816 let context',dx = split_prods ~subst:[] context paramsno c in
819 and check_allowed_sort_elimination ~subst ~metasenv r =
822 | C.Appl l -> C.Appl (l @ [arg])
823 | t -> C.Appl [t;arg] in
824 let rec aux context ind arity1 arity2 =
825 let arity1 = R.whd ~subst context arity1 in
826 let arity2 = R.whd ~subst context arity2 in
827 match arity1,arity2 with
828 | C.Prod (name,so1,de1), C.Prod (_,so2,de2) ->
829 if not (R.are_convertible ~subst ~metasenv context so1 so2) then
830 raise (TypeCheckerFailure (lazy (Printf.sprintf
831 "In outtype: expected %s, found %s"
832 (NCicPp.ppterm ~subst ~metasenv ~context so1)
833 (NCicPp.ppterm ~subst ~metasenv ~context so2)
835 aux ((name, C.Decl so1)::context)
836 (mkapp (S.lift 1 ind) (C.Rel 1)) de1 de2
837 | C.Sort _, C.Prod (name,so,ta) ->
838 if not (R.are_convertible ~subst ~metasenv context so ind) then
839 raise (TypeCheckerFailure (lazy (Printf.sprintf
840 "In outtype: expected %s, found %s"
841 (NCicPp.ppterm ~subst ~metasenv ~context ind)
842 (NCicPp.ppterm ~subst ~metasenv ~context so)
844 (match arity1,ta with
845 | (C.Sort (C.CProp | C.Type _), C.Sort _)
846 | (C.Sort C.Prop, C.Sort C.Prop) -> ()
847 | (C.Sort C.Prop, C.Sort (C.CProp | C.Type _)) ->
848 (* TODO: we should pass all these parameters since we
849 * have them already *)
850 let inductive,leftno,itl,_,i = E.get_checked_indtys r in
851 let itl_len = List.length itl in
852 let _,name,ty,cl = List.nth itl i in
853 let cl_len = List.length cl in
854 (* is it a singleton or empty non recursive and non informative
858 (itl_len = 1 && cl_len = 1 &&
859 is_non_informative [name,C.Decl ty] leftno
860 (let _,_,x = List.nth cl 0 in x)))
862 raise (TypeCheckerFailure (lazy
863 ("Sort elimination not allowed")));
870 typeof_aux context term
872 and check_mutual_inductive_defs uri ~metasenv ~subst is_ind leftno tyl =
873 (* let's check if the arity of the inductive types are well formed *)
874 List.iter (fun (_,_,x,_) -> ignore (typeof ~subst ~metasenv [] x)) tyl;
875 (* let's check if the types of the inductive constructors are well formed. *)
876 let len = List.length tyl in
877 let tys = List.rev (List.map (fun (_,n,ty,_) -> (n,(C.Decl ty))) tyl) in
883 let debruijnedte = debruijn uri len [] te in
884 ignore (typeof ~subst ~metasenv tys debruijnedte);
885 (* let's check also the positivity conditions *)
888 (are_all_occurrences_positive ~subst tys uri leftno i 0 len
893 (lazy ("Non positive occurence in "^NUri.string_of_uri uri))))
898 and eat_lambdas ~subst ~metasenv context n te =
899 match (n, R.whd ~subst context te) with
900 | (0, _) -> (te, context)
901 | (n, C.Lambda (name,so,ta)) when n > 0 ->
902 eat_lambdas ~subst ~metasenv ((name,(C.Decl so))::context) (n - 1) ta
904 raise (AssertFailure (lazy (Printf.sprintf "9 (%d, %s)" n
905 (NCicPp.ppterm ~subst ~metasenv ~context te))))
907 and guarded_by_destructors r_uri r_len ~subst ~metasenv context recfuns t =
908 let recursor f k t = NCicUtils.fold shift_k k (fun k () -> f k) () t in
909 let rec aux (context, recfuns, x, safes as k) t =
911 prerr_endline ("GB: " ^ NCicPp.ppterm ~metasenv ~subst ~context t
912 ^ " " ^ String.concat "," (List.map (fun i -> NCicPp.ppterm ~metasenv ~subst ~context (C.Rel i)) safes));
914 let t = R.whd ~delta:max_int ~subst context t in
917 | C.Rel m as t when List.mem_assoc m recfuns ->
918 raise (NotGuarded (lazy
919 (NCicPp.ppterm ~subst ~metasenv ~context t ^ " passed around")))
921 (match List.nth context (m-1) with
923 | _,C.Def (bo,_) -> aux (context, recfuns, x, safes) (S.lift m bo))
925 | C.Appl ((C.Rel m)::tl) as t when List.mem_assoc m recfuns ->
926 let rec_no = List.assoc m recfuns in
927 if not (List.length tl > rec_no) then
928 raise (NotGuarded (lazy
929 (NCicPp.ppterm ~context ~subst ~metasenv t ^
930 " is a partial application of a fix")))
932 let rec_arg = List.nth tl rec_no in
933 if not (is_really_smaller r_uri r_len ~subst ~metasenv k rec_arg) then
934 raise (NotGuarded (lazy (Printf.sprintf ("Recursive call %s, %s is not"
935 ^^ " smaller.\ncontext:\n%s") (NCicPp.ppterm ~context ~subst ~metasenv
936 t) (NCicPp.ppterm ~context ~subst ~metasenv rec_arg)
937 (NCicPp.ppcontext ~subst ~metasenv context))));
939 | C.Appl (C.Const ((Ref.Ref (_,uri,Ref.Fix (i,j))) as r)::args)
940 when List.length args > j
941 (* TODO: extra check really usueful?? *)
942 && List.exists (fun (k,_) -> List.exists (fun t -> not (does_not_occur ~subst context k (k+1) t)) args) recfuns
943 && is_really_smaller r_uri r_len ~subst ~metasenv k (List.nth args j) ->
944 let fl,_,_ = E.get_checked_fixes r in
946 List.split (List.map (fun (_,name,_,ty,bo) -> (name, C.Decl ty), bo) fl)
948 let bo = List.nth bos i in
949 let bo = debruijn uri (List.length fl) context bo in
950 let args, rest = HExtlib.split_nth j args in
952 (* TODO: here we should check which args are passed around ... *)
953 if j > 0 then R.head_beta_reduce ~upto:j (C.Appl (bo::args)) else bo
955 let bo, context_rec = eat_lambdas ~subst ~metasenv context 1 bo in
957 if rest = [] then bo else
958 let rest = List.tl rest in if rest <> [] then C.Appl (bo::rest) else bo
960 let k = context@ctx_tys, recfuns, x, safes in
961 aux (shift_k_add_1_safe (List.hd context_rec) k) bo
962 | C.Match (Ref.Ref (_,uri,_) as ref,outtype,term,pl) as t ->
963 (match R.whd ~subst context term with
964 | C.Rel m | C.Appl (C.Rel m :: _ ) as t when List.mem m safes || m = x ->
965 (* TODO: add CoInd to references so that this call is useless *)
966 let isinductive, _, _, _, _ = E.get_checked_indtys ref in
967 if not isinductive then recursor aux k t
969 let ty = typeof ~subst ~metasenv context term in
970 let itl_ctx,cl = fix_lefts_in_constrs ~subst r_uri r_len context ty in
971 let args = match t with C.Appl (_::tl) -> tl | _ -> [] in
972 let dc_ctx = context @ itl_ctx in
973 let start, stop = List.length context, List.length context + r_len in
975 List.iter (aux k) args;
978 let rl = recursive_args ~subst ~metasenv dc_ctx start stop dc in
979 let p, k = get_new_safes ~subst k p rl in
982 | _ -> recursor aux k t)
983 | t -> recursor aux k t
985 NotGuarded _ as exc ->
986 let t' = R.whd ~delta:0 ~subst context t in
992 try aux (context, recfuns, 1, []) t
993 with NotGuarded s -> raise (TypeCheckerFailure s)
997 let len = List.length fl in
998 let n_plus_len = n + len
999 and nn_plus_len = nn + len
1000 and x_plus_len = x + len
1003 (fun (types,len) (n,_,ty,_) ->
1004 (Some (C.Name n,(C.Decl (CicSubstitution.lift len ty)))::types,
1007 and safes' = List.map (fun x -> x + len) safes in
1009 (fun (_,_,ty,bo) i ->
1010 i && guarded_by_destructors ~subst context n nn kl x_plus_len safes' ty &&
1011 guarded_by_destructors ~subst (tys@context) n_plus_len nn_plus_len kl
1012 x_plus_len safes' bo
1014 | C.CoFix (_, fl) ->
1015 let len = List.length fl in
1016 let n_plus_len = n + len
1017 and nn_plus_len = nn + len
1018 and x_plus_len = x + len
1021 (fun (types,len) (n,ty,_) ->
1022 (Some (C.Name n,(C.Decl (CicSubstitution.lift len ty)))::types,
1025 and safes' = List.map (fun x -> x + len) safes in
1029 guarded_by_destructors ~subst context n nn kl x_plus_len safes' ty &&
1030 guarded_by_destructors ~subst (tys@context) n_plus_len nn_plus_len kl
1031 x_plus_len safes' bo
1035 and guarded_by_constructors ~subst ~metasenv _ _ _ _ _ _ _ = true
1037 and recursive_args ~subst ~metasenv context n nn te =
1038 match R.whd context te with
1039 | C.Rel _ | C.Appl _ -> []
1040 | C.Prod (name,so,de) ->
1042 prerr_endline ("RA: " ^ NCicPp.ppterm ~subst ~metasenv ~context so
1043 ^ " == " ^ string_of_bool (not (does_not_occur ~subst context n nn so)));
1045 (not (does_not_occur ~subst context n nn so)) ::
1046 (recursive_args ~subst ~metasenv
1047 ((name,(C.Decl so))::context) (n+1) (nn + 1) de)
1049 raise (AssertFailure (lazy ("recursive_args:" ^ NCicPp.ppterm ~subst
1050 ~metasenv ~context:[] t)))
1052 and get_new_safes ~subst (context, recfuns, x, safes as k) p rl =
1053 match R.whd ~subst context p, rl with
1054 | C.Lambda (name,so,ta), b::tl ->
1055 let safes = (if b then [0] else []) @ safes in
1056 get_new_safes ~subst
1057 (shift_k (name,(C.Decl so)) (context, recfuns, x, safes)) ta tl
1058 | C.Meta _ as e, _ | e, [] ->
1060 prerr_endline ("GNS: " ^ String.concat ","
1062 NCicPp.ppterm ~subst ~metasenv:[] ~context (C.Rel i)) safes));
1065 | _ -> raise (AssertFailure (lazy "Ill formed pattern"))
1067 and split_prods ~subst context n te =
1068 match n, R.whd ~subst context te with
1069 | 0, _ -> context,te
1070 | n, C.Prod (name,so,ta) when n > 0 ->
1071 split_prods ~subst ((name,(C.Decl so))::context) (n - 1) ta
1072 | _ -> raise (AssertFailure (lazy "split_prods"))
1074 and is_really_smaller
1075 r_uri r_len ~subst ~metasenv (context, recfuns, x, safes as k) te
1077 match R.whd ~subst context te with
1078 | C.Rel m when List.mem m safes -> true
1079 | C.Lambda (name, s, t) ->
1080 is_really_smaller r_uri r_len ~subst ~metasenv (shift_k (name,C.Decl s) k) t
1082 is_really_smaller r_uri r_len ~subst ~metasenv k he
1085 | C.Const (Ref.Ref (_,_,Ref.Con _)) -> false
1086 | C.Const (Ref.Ref (_,_,Ref.Fix _)) -> assert false
1087 (*| C.Fix (_, fl) ->
1088 let len = List.length fl in
1089 let n_plus_len = n + len
1090 and nn_plus_len = nn + len
1091 and x_plus_len = x + len
1094 (fun (types,len) (n,_,ty,_) ->
1095 (Some (C.Name n,(C.Decl (CicSubstitution.lift len ty)))::types,
1098 and safes' = List.map (fun x -> x + len) safes in
1100 (fun (_,_,ty,bo) i ->
1102 is_really_smaller ~subst (tys@context) n_plus_len nn_plus_len kl
1103 x_plus_len safes' bo
1106 | C.Match (Ref.Ref (_,uri,_) as ref,outtype,term,pl) ->
1108 | C.Rel m | C.Appl (C.Rel m :: _ ) when List.mem m safes || m = x ->
1109 (* TODO: add CoInd to references so that this call is useless *)
1110 let isinductive, _, _, _, _ = E.get_checked_indtys ref in
1111 if not isinductive then
1112 List.for_all (is_really_smaller r_uri r_len ~subst ~metasenv k) pl
1114 let ty = typeof ~subst ~metasenv context term in
1115 let itl_ctx,dcl= fix_lefts_in_constrs ~subst r_uri r_len context ty in
1116 let start, stop = List.length context, List.length context + r_len in
1117 let dc_ctx = context @ itl_ctx in
1120 let rl = recursive_args ~subst ~metasenv dc_ctx start stop dc in
1121 let e, k = get_new_safes ~subst k p rl in
1122 is_really_smaller r_uri r_len ~subst ~metasenv k e)
1124 | _ -> List.for_all (is_really_smaller r_uri r_len ~subst ~metasenv k) pl)
1127 and returns_a_coinductive ~subst context ty =
1128 match R.whd ~subst context ty with
1129 | C.Const (Ref.Ref (_,uri,Ref.Ind _) as ref)
1130 | C.Appl (C.Const (Ref.Ref (_,uri,Ref.Ind _) as ref)::_) ->
1131 let isinductive, _, _, _, _ = E.get_checked_indtys ref in
1132 if isinductive then None else (Some uri)
1133 | C.Prod (n,so,de) ->
1134 returns_a_coinductive ~subst ((n,C.Decl so)::context) de
1137 and type_of_constant ((Ref.Ref (_,uri,_)) as ref) =
1139 match E.get_obj uri with
1140 | true, cobj -> cobj
1142 !logger (`Start_type_checking uri);
1143 check_obj_well_typed uobj;
1145 !logger (`Type_checking_completed uri);
1148 match cobj, ref with
1149 | (_,_,_,_,C.Inductive (_,_,tl,_)), Ref.Ref (_,_,Ref.Ind i) ->
1150 let _,_,arity,_ = List.nth tl i in arity
1151 | (_,_,_,_,C.Inductive (_,_,tl,_)), Ref.Ref (_,_,Ref.Con (i,j)) ->
1152 let _,_,_,cl = List.nth tl i in
1153 let _,_,arity = List.nth cl (j-1) in
1155 | (_,_,_,_,C.Fixpoint (_,fl,_)), Ref.Ref (_,_,(Ref.Fix (i,_)|Ref.CoFix i)) ->
1156 let _,_,_,arity,_ = List.nth fl i in
1158 | (_,_,_,_,C.Constant (_,_,_,ty,_)), Ref.Ref (_,_,(Ref.Def |Ref.Decl)) -> ty
1159 | _ -> raise (AssertFailure (lazy "type_of_constant: environment/reference"))
1161 and check_obj_well_typed (uri,height,metasenv,subst,kind) =
1162 (* CSC: here we should typecheck the metasenv and the subst *)
1163 assert (metasenv = [] && subst = []);
1165 | C.Constant (_,_,Some te,ty,_) ->
1166 let _ = typeof ~subst ~metasenv [] ty in
1167 let ty_te = typeof ~subst ~metasenv [] te in
1168 if not (R.are_convertible ~subst ~metasenv [] ty_te ty) then
1169 raise (TypeCheckerFailure (lazy (Printf.sprintf (
1170 "the type of the body is not convertible with the declared one.\n"^^
1171 "inferred type:\n%s\nexpected type:\n%s")
1172 (NCicPp.ppterm ~subst ~metasenv ~context:[] ty_te)
1173 (NCicPp.ppterm ~subst ~metasenv ~context:[] ty))))
1174 | C.Constant (_,_,None,ty,_) -> ignore (typeof ~subst ~metasenv [] ty)
1175 | C.Inductive (is_ind, leftno, tyl, _) ->
1176 check_mutual_inductive_defs uri ~metasenv ~subst is_ind leftno tyl
1177 | C.Fixpoint (inductive,fl,_) ->
1180 (fun (types,kl,len) (_,name,k,ty,_) ->
1181 let _ = typeof ~subst ~metasenv [] ty in
1182 ((name,(C.Decl (S.lift len ty)))::types, k::kl,len+1)
1185 List.iter (fun (_,name,x,ty,bo) ->
1186 let bo = debruijn uri len [] bo in
1187 let ty_bo = typeof ~subst ~metasenv types bo in
1188 if not (R.are_convertible ~subst ~metasenv types ty_bo (S.lift len ty))
1189 then raise (TypeCheckerFailure (lazy ("(Co)Fix: ill-typed bodies")))
1191 if inductive then begin
1192 let m, context = eat_lambdas ~subst ~metasenv types (x + 1) bo in
1195 match List.hd context with _,C.Decl t -> t | _ -> assert false
1197 match R.whd ~subst (List.tl context) he with
1198 | C.Const (Ref.Ref (_,uri,Ref.Ind _) as ref)
1199 | C.Appl (C.Const (Ref.Ref (_,uri,Ref.Ind _) as ref) :: _) ->
1200 let _,_,itl,_,_ = E.get_checked_indtys ref in
1201 uri, List.length itl
1204 (* guarded by destructors conditions D{f,k,x,M} *)
1205 let rec enum_from k =
1206 function [] -> [] | v::tl -> (k,v)::enum_from (k+1) tl
1208 guarded_by_destructors r_uri r_len
1209 ~subst ~metasenv context (enum_from (x+2) kl) m
1211 match returns_a_coinductive ~subst [] ty with
1213 raise (TypeCheckerFailure
1214 (lazy "CoFix: does not return a coinductive type"))
1216 (* guarded by constructors conditions C{f,M} *)
1217 if not (guarded_by_constructors ~subst ~metasenv
1218 types 0 len false bo [] uri)
1220 raise (TypeCheckerFailure
1221 (lazy "CoFix: not guarded by constructors"))
1224 let typecheck_obj = check_obj_well_typed;;