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 $ *)
15 module R = NCicReduction
16 module Ref = NReference
17 module S = NCicSubstitution
19 module E = NCicEnvironment
22 (* web interface stuff *)
25 ref (function (`Start_type_checking _|`Type_checking_completed _) -> ())
28 let set_logger f = logger := f;;
30 exception TypeCheckerFailure of string Lazy.t
31 exception AssertFailure of string Lazy.t
34 | Evil of int (* rno *)
35 | UnfFix of bool list (* fixed arguments *)
39 let is_dangerous i l =
40 List.exists (function (j,Evil _) when j=i -> true | _ -> false) l
44 List.exists (function (j,UnfFix _) when j=i -> true | _ -> false) l
48 List.exists (function (j,Safe) when j=i -> true | _ -> false) l
52 try match List.assoc i l with Evil rno -> rno | _ -> assert false
53 with Not_found -> assert false
56 let get_fixed_args i l =
57 try match List.assoc i l with UnfFix fa -> fa | _ -> assert false
58 with Not_found -> assert false
61 let shift_k e (c,rf,x) = e::c,List.map (fun (k,v) -> k+1,v) rf,x+1;;
63 let string_of_recfuns ~subst ~metasenv ~context l =
64 let pp = PP.ppterm ~subst ~metasenv ~context in
65 let safe, rest = List.partition (function (_,Safe) -> true | _ -> false) l in
66 let dang,unf = List.partition (function (_,UnfFix _)-> false | _->true)rest in
67 "\n\tsafes: "^String.concat "," (List.map (fun (i,_)->pp (C.Rel i)) safe) ^
68 "\n\tfix : "^String.concat ","
70 (function (i,UnfFix l)-> pp(C.Rel i)^"/"^String.concat "," (List.map
72 | _ ->assert false) unf) ^
73 "\n\trec : "^String.concat ","
75 (function (i,Evil rno)->pp(C.Rel i)^"/"^string_of_int rno
76 | _ -> assert false) dang)
79 let fixed_args bos j n nn =
80 let rec aux k acc = function
81 | C.Appl (C.Rel i::args) when i-k > n && i-k <= nn ->
82 let rec combine l1 l2 =
85 | he1::tl1, he2::tl2 -> (he1,he2)::combine tl1 tl2
86 | he::tl, [] -> (false,C.Rel ~-1)::combine tl [] (* dummy term *)
87 | [],_::_ -> assert false
89 let lefts, _ = HExtlib.split_nth (min j (List.length args)) args in
90 List.map (fun ((b,x),i) -> b && x = C.Rel (k-i))
91 (HExtlib.list_mapi (fun x i -> x,i) (combine acc lefts))
92 | t -> U.fold (fun _ k -> k+1) k aux acc t
94 List.fold_left (aux 0)
95 (let rec f = function 0 -> [] | n -> true :: f (n-1) in f j) bos
98 let rec list_iter_default2 f l1 def l2 =
101 | a::ta, b::tb -> f a b; list_iter_default2 f ta def tb
102 | a::ta, [] -> f a def; list_iter_default2 f ta def []
105 let rec split_prods ~subst context n te =
106 match (n, R.whd ~subst context te) with
107 | (0, _) -> context,te
108 | (n, C.Prod (name,so,ta)) when n > 0 ->
109 split_prods ~subst ((name,(C.Decl so))::context) (n - 1) ta
110 | (_, _) -> raise (AssertFailure (lazy "split_prods"))
113 let debruijn ?(cb=fun _ _ -> ()) uri number_of_types context =
117 | C.Meta (i,(s,C.Ctx l)) ->
118 let l1 = U.sharing_map (aux (k-s)) l in
119 if l1 == l then t else C.Meta (i,(s,C.Ctx l1))
121 | C.Const (Ref.Ref (_,uri1,(Ref.Fix (no,_) | Ref.CoFix no)))
122 | C.Const (Ref.Ref (_,uri1,Ref.Ind no)) when NUri.eq uri uri1 ->
123 C.Rel (k + number_of_types - no)
124 | t -> U.map (fun _ k -> k+1) k aux t
128 aux (List.length context)
131 let sort_of_prod ~metasenv ~subst context (name,s) (t1, t2) =
132 let t1 = R.whd ~subst context t1 in
133 let t2 = R.whd ~subst ((name,C.Decl s)::context) t2 in
135 | C.Sort s1, C.Sort C.Prop -> t2
136 | C.Sort (C.Type u1), C.Sort (C.Type u2) -> C.Sort (C.Type (max u1 u2))
137 | C.Sort _,C.Sort (C.Type _) -> t2
138 | C.Sort (C.Type _) , C.Sort C.CProp -> t1
139 | C.Sort _, C.Sort C.CProp -> t2
142 | C.Sort _, C.Meta _ when U.is_closed t2 -> t2
144 raise (TypeCheckerFailure (lazy (Printf.sprintf
145 "Prod: expected two sorts, found = %s, %s"
146 (PP.ppterm ~subst ~metasenv ~context t1)
147 (PP.ppterm ~subst ~metasenv ~context t2))))
150 let eat_prods ~subst ~metasenv context he ty_he args_with_ty =
151 let rec aux ty_he = function
153 | (arg, ty_arg)::tl ->
154 match R.whd ~subst context ty_he with
157 prerr_endline (PP.ppterm ~subst ~metasenv ~context s ^ " - Vs - "
158 ^ PP.ppterm ~subst ~metasenv ~context ty_arg);
159 prerr_endline (PP.ppterm ~subst ~metasenv ~context
160 (S.subst ~avoid_beta_redexes:true arg t));
162 if R.are_convertible ~subst ~metasenv context ty_arg s then
163 aux (S.subst ~avoid_beta_redexes:true arg t) tl
167 (lazy (Printf.sprintf
168 ("Appl: wrong application of %s: the parameter %s has type"^^
169 "\n%s\nbut it should have type \n%s\nContext:\n%s\n")
170 (PP.ppterm ~subst ~metasenv ~context he)
171 (PP.ppterm ~subst ~metasenv ~context arg)
172 (PP.ppterm ~subst ~metasenv ~context ty_arg)
173 (PP.ppterm ~subst ~metasenv ~context s)
174 (PP.ppcontext ~subst ~metasenv context))))
178 (lazy (Printf.sprintf
179 "Appl: %s is not a function, it cannot be applied"
180 (PP.ppterm ~subst ~metasenv ~context
181 (let res = List.length tl in
182 let eaten = List.length args_with_ty - res in
185 (fst (HExtlib.split_nth eaten args_with_ty)))))))))
187 aux ty_he args_with_ty
190 (* instantiate_parameters ps (x1:T1)...(xn:Tn)C *)
191 (* returns ((x_|ps|:T_|ps|)...(xn:Tn)C){ps_1 / x1 ; ... ; ps_|ps| / x_|ps|} *)
192 let rec instantiate_parameters params c =
195 | C.Prod (_,_,ta), he::tl -> instantiate_parameters tl (S.subst he ta)
196 | t,l -> raise (AssertFailure (lazy "1"))
199 (* specialized only constructors, arities are left untouched *)
200 let specialize_inductive_type_constrs ~subst context ty_term =
201 match R.whd ~subst context ty_term with
202 | C.Const (Ref.Ref (_,uri,Ref.Ind i) as ref)
203 | C.Appl (C.Const (Ref.Ref (_,uri,Ref.Ind i) as ref) :: _ ) as ty ->
204 let args = match ty with C.Appl (_::tl) -> tl | _ -> [] in
205 let is_ind, leftno, itl, attrs, i = E.get_checked_indtys ref in
206 let left_args,_ = HExtlib.split_nth leftno args in
208 List.map (fun (rel, name, arity, cl) ->
210 List.map (fun (rel, name, ty) ->
211 rel, name, instantiate_parameters left_args ty)
215 is_ind, leftno, itl, attrs, i
219 let fix_lefts_in_constrs ~subst r_uri r_len context ty_term =
220 let _,_,itl,_,i = specialize_inductive_type_constrs ~subst context ty_term in
221 let _,_,_,cl = List.nth itl i in
223 List.map (fun (_,id,ty) -> id, debruijn r_uri r_len context ty) cl
225 (* since arities are closed they are not lifted *)
226 List.map (fun (_,name,arity,_) -> name, C.Decl arity) itl, cl
229 exception DoesOccur;;
231 let does_not_occur ~subst context n nn t =
232 let rec aux (context,n,nn as k) _ = function
233 | C.Rel m when m > n && m <= nn -> raise DoesOccur
235 (try (match List.nth context (m-1) with
236 | _,C.Def (bo,_) -> aux k () (S.lift m bo)
238 with Failure _ -> assert false)
239 | C.Meta (_,(_,(C.Irl 0 | C.Ctx []))) -> (* closed meta *) ()
240 | C.Meta (mno,(s,l)) ->
242 let _,_,term,_ = U.lookup_subst mno subst in
243 aux (context,n+s,nn+s) () (S.subst_meta (0,l) term)
244 with CicUtil.Subst_not_found _ -> match l with
245 | C.Irl len -> if not (n >= s+len || s > nn) then raise DoesOccur
246 | C.Ctx lc -> List.iter (aux (context,n+s,nn+s) ()) lc)
247 | t -> U.fold (fun e (ctx,n,nn) -> (e::ctx,n+1,nn+1)) k aux () t
249 try aux (context,n,nn) () t; true
250 with DoesOccur -> false
253 (*CSC l'indice x dei tipi induttivi e' t.c. n < x <= nn *)
254 (*CSC questa funzione e' simile alla are_all_occurrences_positive, ma fa *)
255 (*CSC dei controlli leggermente diversi. Viene invocata solamente dalla *)
256 (*CSC strictly_positive *)
257 (*CSC definizione (giusta???) tratta dalla mail di Hugo ;-) *)
258 let rec weakly_positive ~subst context n nn uri te =
259 (*CSC: Che schifo! Bisogna capire meglio e trovare una soluzione ragionevole!*)
260 let dummy = C.Sort (C.Type ~-1) in
261 (*CSC: mettere in cicSubstitution *)
262 let rec subst_inductive_type_with_dummy _ = function
263 | C.Const (Ref.Ref (_,uri',Ref.Ind 0)) when NUri.eq uri' uri -> dummy
264 | C.Appl ((C.Const (Ref.Ref (_,uri',Ref.Ind 0)))::tl)
265 when NUri.eq uri' uri -> dummy
266 | t -> U.map (fun _ x->x) () subst_inductive_type_with_dummy t
268 match R.whd context te with
269 | C.Const (Ref.Ref (_,uri',Ref.Ind _))
270 | C.Appl ((C.Const (Ref.Ref (_,uri',Ref.Ind _)))::_)
271 when NUri.eq uri' uri -> true
272 | C.Prod (name,source,dest) when
273 does_not_occur ~subst ((name,C.Decl source)::context) 0 1 dest ->
274 (* dummy abstraction, so we behave as in the anonimous case *)
275 strictly_positive ~subst context n nn
276 (subst_inductive_type_with_dummy () source) &&
277 weakly_positive ~subst ((name,C.Decl source)::context)
278 (n + 1) (nn + 1) uri dest
279 | C.Prod (name,source,dest) ->
280 does_not_occur ~subst context n nn
281 (subst_inductive_type_with_dummy () source)&&
282 weakly_positive ~subst ((name,C.Decl source)::context)
283 (n + 1) (nn + 1) uri dest
285 raise (TypeCheckerFailure (lazy "Malformed inductive constructor type"))
287 and strictly_positive ~subst context n nn te =
288 match R.whd context te with
289 | t when does_not_occur ~subst context n nn t -> true
291 | C.Prod (name,so,ta) ->
292 does_not_occur ~subst context n nn so &&
293 strictly_positive ~subst ((name,C.Decl so)::context) (n+1) (nn+1) ta
294 | C.Appl ((C.Rel m)::tl) when m > n && m <= nn ->
295 List.for_all (does_not_occur ~subst context n nn) tl
296 | C.Appl (C.Const (Ref.Ref (_,uri,Ref.Ind i) as r)::tl) ->
297 let _,paramsno,tyl,_,i = E.get_checked_indtys r in
298 let _,name,ity,cl = List.nth tyl i in
299 let ok = List.length tyl = 1 in
300 let params, arguments = HExtlib.split_nth paramsno tl in
301 let lifted_params = List.map (S.lift 1) params in
303 List.map (fun (_,_,te) -> instantiate_parameters lifted_params te) cl
306 List.for_all (does_not_occur ~subst context n nn) arguments &&
308 (weakly_positive ~subst ((name,C.Decl ity)::context) (n+1) (nn+1) uri) cl
311 (* the inductive type indexes are s.t. n < x <= nn *)
312 and are_all_occurrences_positive ~subst context uri indparamsno i n nn te =
313 match R.whd context te with
314 | C.Appl ((C.Rel m)::tl) as reduct when m = i ->
320 match R.whd context x with
321 | C.Rel m when m = n - (indparamsno - k) -> k - 1
322 | y -> raise (TypeCheckerFailure (lazy
323 ("Argument "^string_of_int (indparamsno - k + 1) ^ " (of " ^
324 string_of_int indparamsno ^ " fixed) is not homogeneous in "^
325 "appl:\n"^ PP.ppterm ~context ~subst ~metasenv:[] reduct))))
329 List.for_all (does_not_occur ~subst context n nn) tl
331 raise (TypeCheckerFailure
332 (lazy ("Non-positive occurence in mutual inductive definition(s) [2]"^
333 NUri.string_of_uri uri)))
334 | C.Rel m when m = i ->
335 if indparamsno = 0 then
338 raise (TypeCheckerFailure
339 (lazy ("Non-positive occurence in mutual inductive definition(s) [3]"^
340 NUri.string_of_uri uri)))
341 | C.Prod (name,source,dest) when
342 does_not_occur ~subst ((name,C.Decl source)::context) 0 1 dest ->
343 strictly_positive ~subst context n nn source &&
344 are_all_occurrences_positive ~subst
345 ((name,C.Decl source)::context) uri indparamsno
346 (i+1) (n + 1) (nn + 1) dest
347 | C.Prod (name,source,dest) ->
348 if not (does_not_occur ~subst context n nn source) then
349 raise (TypeCheckerFailure (lazy ("Non-positive occurrence in "^
350 PP.ppterm ~context ~metasenv:[] ~subst te)));
351 are_all_occurrences_positive ~subst ((name,C.Decl source)::context)
352 uri indparamsno (i+1) (n + 1) (nn + 1) dest
355 (TypeCheckerFailure (lazy ("Malformed inductive constructor type " ^
356 (NUri.string_of_uri uri))))
359 exception NotGuarded of string Lazy.t;;
361 let rec typeof ~subst ~metasenv context term =
362 let rec typeof_aux context =
363 fun t -> (*prerr_endline (PP.ppterm ~metasenv ~subst ~context t);*)
367 match List.nth context (n - 1) with
368 | (_,C.Decl ty) -> S.lift n ty
369 | (_,C.Def (_,ty)) -> S.lift n ty
370 with Failure _ -> raise (TypeCheckerFailure (lazy "unbound variable")))
371 | C.Sort (C.Type i) -> C.Sort (C.Type (i+1))
372 | C.Sort s -> C.Sort (C.Type 0)
373 | C.Implicit _ -> raise (AssertFailure (lazy "Implicit found"))
374 | C.Meta (n,l) as t ->
375 let canonical_ctx,ty =
377 let _,c,_,ty = U.lookup_subst n subst in c,ty
378 with U.Subst_not_found _ -> try
379 let _,_,c,ty = U.lookup_meta n metasenv in c,ty
380 with U.Meta_not_found _ ->
381 raise (AssertFailure (lazy (Printf.sprintf
382 "%s not found" (PP.ppterm ~subst ~metasenv ~context t))))
384 check_metasenv_consistency t ~subst ~metasenv context canonical_ctx l;
386 | C.Const ref -> type_of_constant ref
387 | C.Prod (name,s,t) ->
388 let sort1 = typeof_aux context s in
389 let sort2 = typeof_aux ((name,(C.Decl s))::context) t in
390 sort_of_prod ~metasenv ~subst context (name,s) (sort1,sort2)
391 | C.Lambda (n,s,t) ->
392 let sort = typeof_aux context s in
393 (match R.whd ~subst context sort with
394 | C.Meta _ | C.Sort _ -> ()
397 (TypeCheckerFailure (lazy (Printf.sprintf
398 ("Not well-typed lambda-abstraction: " ^^
399 "the source %s should be a type; instead it is a term " ^^
400 "of type %s") (PP.ppterm ~subst ~metasenv ~context s)
401 (PP.ppterm ~subst ~metasenv ~context sort)))));
402 let ty = typeof_aux ((n,(C.Decl s))::context) t in
404 | C.LetIn (n,ty,t,bo) ->
405 let ty_t = typeof_aux context t in
406 let _ = typeof_aux context ty in
407 if not (R.are_convertible ~subst ~metasenv context ty ty_t) then
410 (lazy (Printf.sprintf
411 "The type of %s is %s but it is expected to be %s"
412 (PP.ppterm ~subst ~metasenv ~context t)
413 (PP.ppterm ~subst ~metasenv ~context ty_t)
414 (PP.ppterm ~subst ~metasenv ~context ty))))
416 let ty_bo = typeof_aux ((n,C.Def (t,ty))::context) bo in
417 S.subst ~avoid_beta_redexes:true t ty_bo
418 | C.Appl (he::(_::_ as args)) ->
419 let ty_he = typeof_aux context he in
420 let args_with_ty = List.map (fun t -> t, typeof_aux context t) args in
422 prerr_endline ("HEAD: " ^ PP.ppterm ~subst ~metasenv ~context ty_he);
423 prerr_endline ("TARGS: " ^ String.concat " | " (List.map (PP.ppterm
424 ~subst ~metasenv ~context) (List.map snd args_with_ty)));
425 prerr_endline ("ARGS: " ^ String.concat " | " (List.map (PP.ppterm
426 ~subst ~metasenv ~context) (List.map fst args_with_ty)));
428 eat_prods ~subst ~metasenv context he ty_he args_with_ty
429 | C.Appl _ -> raise (AssertFailure (lazy "Appl of length < 2"))
430 | C.Match (Ref.Ref (_,_,Ref.Ind tyno) as r,outtype,term,pl) ->
431 let outsort = typeof_aux context outtype in
432 let inductive,leftno,itl,_,_ = E.get_checked_indtys r in
434 let _,_,_,cl = List.nth itl tyno in List.length cl
436 let parameters, arguments =
437 let ty = R.whd ~subst context (typeof_aux context term) in
440 C.Const (Ref.Ref (_,_,Ref.Ind _) as r') -> r',[]
441 | C.Appl (C.Const (Ref.Ref (_,_,Ref.Ind _) as r') :: tl) -> r',tl
444 (TypeCheckerFailure (lazy (Printf.sprintf
445 "Case analysis: analysed term %s is not an inductive one"
446 (PP.ppterm ~subst ~metasenv ~context term)))) in
447 if not (Ref.eq r r') then
449 (TypeCheckerFailure (lazy (Printf.sprintf
450 ("Case analysys: analysed term type is %s, but is expected " ^^
451 "to be (an application of) %s")
452 (PP.ppterm ~subst ~metasenv ~context ty)
453 (PP.ppterm ~subst ~metasenv ~context (C.Const r')))))
455 try HExtlib.split_nth leftno tl
458 raise (TypeCheckerFailure (lazy (Printf.sprintf
459 "%s is partially applied"
460 (PP.ppterm ~subst ~metasenv ~context ty)))) in
461 (* let's control if the sort elimination is allowed: [(I q1 ... qr)|B] *)
462 let sort_of_ind_type =
463 if parameters = [] then C.Const r
464 else C.Appl ((C.Const r)::parameters) in
465 let type_of_sort_of_ind_ty = typeof_aux context sort_of_ind_type in
466 check_allowed_sort_elimination ~subst ~metasenv r context
467 sort_of_ind_type type_of_sort_of_ind_ty outsort;
468 (* let's check if the type of branches are right *)
469 if List.length pl <> constructorsno then
470 raise (TypeCheckerFailure (lazy ("Wrong number of cases in a match")));
471 let j,branches_ok,p_ty, exp_p_ty =
473 (fun (j,b,old_p_ty,old_exp_p_ty) p ->
476 let cons = Ref.mk_constructor j r in
477 if parameters = [] then C.Const cons
478 else C.Appl (C.Const cons::parameters)
480 let ty_p = typeof_aux context p in
481 let ty_cons = typeof_aux context cons in
483 type_of_branch ~subst context leftno outtype cons ty_cons 0
485 j+1, R.are_convertible ~subst ~metasenv context ty_p ty_branch,
488 j,false,old_p_ty,old_exp_p_ty
489 ) (1,true,C.Sort C.Prop,C.Sort C.Prop) pl
491 if not branches_ok then
494 (lazy (Printf.sprintf ("Branch for constructor %s :=\n%s\n"^^
495 "has type %s\nnot convertible with %s")
496 (PP.ppterm ~subst ~metasenv ~context
497 (C.Const (Ref.mk_constructor (j-1) r)))
498 (PP.ppterm ~metasenv ~subst ~context (List.nth pl (j-2)))
499 (PP.ppterm ~metasenv ~subst ~context p_ty)
500 (PP.ppterm ~metasenv ~subst ~context exp_p_ty))));
501 let res = outtype::arguments@[term] in
502 R.head_beta_reduce (C.Appl res)
503 | C.Match _ -> assert false
505 and type_of_branch ~subst context leftno outty cons tycons liftno =
506 match R.whd ~subst context tycons with
507 | C.Const (Ref.Ref (_,_,Ref.Ind _)) -> C.Appl [S.lift liftno outty ; cons]
508 | C.Appl (C.Const (Ref.Ref (_,_,Ref.Ind _))::tl) ->
509 let _,arguments = HExtlib.split_nth leftno tl in
510 C.Appl (S.lift liftno outty::arguments@[cons])
511 | C.Prod (name,so,de) ->
513 match S.lift 1 cons with
514 | C.Appl l -> C.Appl (l@[C.Rel 1])
515 | t -> C.Appl [t ; C.Rel 1]
518 type_of_branch ~subst ((name,(C.Decl so))::context)
519 leftno outty cons de (liftno+1))
520 | _ -> raise (AssertFailure (lazy "type_of_branch"))
522 (* check_metasenv_consistency checks that the "canonical" context of a
523 metavariable is consitent - up to relocation via the relocation list l -
524 with the actual context *)
525 and check_metasenv_consistency
526 ~subst ~metasenv term context canonical_context l
530 let context = snd (HExtlib.split_nth shift context) in
531 let rec compare = function
535 raise (AssertFailure (lazy (Printf.sprintf
536 "Local and canonical context %s have different lengths"
537 (PP.ppterm ~subst ~context ~metasenv term))))
539 raise (TypeCheckerFailure (lazy (Printf.sprintf
540 "Unbound variable -%d in %s" m
541 (PP.ppterm ~subst ~metasenv ~context term))))
544 (_,C.Decl t1), (_,C.Decl t2)
545 | (_,C.Def (t1,_)), (_,C.Def (t2,_))
546 | (_,C.Def (_,t1)), (_,C.Decl t2) ->
547 if not (R.are_convertible ~subst ~metasenv tl t1 t2) then
550 (lazy (Printf.sprintf
551 ("Not well typed metavariable local context for %s: " ^^
552 "%s expected, which is not convertible with %s")
553 (PP.ppterm ~subst ~metasenv ~context term)
554 (PP.ppterm ~subst ~metasenv ~context t2)
555 (PP.ppterm ~subst ~metasenv ~context t1))))
558 (TypeCheckerFailure (lazy (Printf.sprintf
559 ("Not well typed metavariable local context for %s: " ^^
560 "a definition expected, but a declaration found")
561 (PP.ppterm ~subst ~metasenv ~context term)))));
562 compare (m - 1,tl,ctl)
564 compare (n,context,canonical_context)
566 (* we avoid useless lifting by shortening the context*)
567 let l,context = (0,lc_kind), snd (HExtlib.split_nth shift context) in
568 let lifted_canonical_context =
569 let rec lift_metas i = function
571 | (n,C.Decl t)::tl ->
572 (n,C.Decl (S.subst_meta l (S.lift i t)))::(lift_metas (i+1) tl)
573 | (n,C.Def (t,ty))::tl ->
574 (n,C.Def ((S.subst_meta l (S.lift i t)),
575 S.subst_meta l (S.lift i ty)))::(lift_metas (i+1) tl)
577 lift_metas 1 canonical_context in
578 let l = U.expand_local_context lc_kind in
583 | t, (_,C.Def (ct,_)) ->
584 (*CSC: the following optimization is to avoid a possibly expensive
585 reduction that can be easily avoided and that is quite
586 frequent. However, this is better handled using levels to
592 match List.nth context (n - 1) with
593 | (_,C.Def (te,_)) -> S.lift n te
598 if not (R.are_convertible ~subst ~metasenv context optimized_t ct)
602 (lazy (Printf.sprintf
603 ("Not well typed metavariable local context: " ^^
604 "expected a term convertible with %s, found %s")
605 (PP.ppterm ~subst ~metasenv ~context ct)
606 (PP.ppterm ~subst ~metasenv ~context t))))
607 | t, (_,C.Decl ct) ->
608 let type_t = typeof_aux context t in
609 if not (R.are_convertible ~subst ~metasenv context type_t ct) then
610 raise (TypeCheckerFailure
611 (lazy (Printf.sprintf
612 ("Not well typed metavariable local context: "^^
613 "expected a term of type %s, found %s of type %s")
614 (PP.ppterm ~subst ~metasenv ~context ct)
615 (PP.ppterm ~subst ~metasenv ~context t)
616 (PP.ppterm ~subst ~metasenv ~context type_t))))
617 ) l lifted_canonical_context
619 Invalid_argument _ ->
620 raise (AssertFailure (lazy (Printf.sprintf
621 "Local and canonical context %s have different lengths"
622 (PP.ppterm ~subst ~metasenv ~context term))))
624 and is_non_informative context paramsno c =
625 let rec aux context c =
626 match R.whd context c with
627 | C.Prod (n,so,de) ->
628 let s = typeof_aux context so in
629 s = C.Sort C.Prop && aux ((n,(C.Decl so))::context) de
631 let context',dx = split_prods ~subst:[] context paramsno c in
634 and check_allowed_sort_elimination ~subst ~metasenv r =
637 | C.Appl l -> C.Appl (l @ [arg])
638 | t -> C.Appl [t;arg] in
639 let rec aux context ind arity1 arity2 =
640 let arity1 = R.whd ~subst context arity1 in
641 let arity2 = R.whd ~subst context arity2 in
642 match arity1,arity2 with
643 | C.Prod (name,so1,de1), C.Prod (_,so2,de2) ->
644 if not (R.are_convertible ~subst ~metasenv context so1 so2) then
645 raise (TypeCheckerFailure (lazy (Printf.sprintf
646 "In outtype: expected %s, found %s"
647 (PP.ppterm ~subst ~metasenv ~context so1)
648 (PP.ppterm ~subst ~metasenv ~context so2)
650 aux ((name, C.Decl so1)::context)
651 (mkapp (S.lift 1 ind) (C.Rel 1)) de1 de2
652 | C.Sort _, C.Prod (name,so,ta) ->
653 if not (R.are_convertible ~subst ~metasenv context so ind) then
654 raise (TypeCheckerFailure (lazy (Printf.sprintf
655 "In outtype: expected %s, found %s"
656 (PP.ppterm ~subst ~metasenv ~context ind)
657 (PP.ppterm ~subst ~metasenv ~context so)
659 (match arity1,ta with
660 | (C.Sort (C.CProp | C.Type _), C.Sort _)
661 | (C.Sort C.Prop, C.Sort C.Prop) -> ()
662 | (C.Sort C.Prop, C.Sort (C.CProp | C.Type _)) ->
663 (* TODO: we should pass all these parameters since we
664 * have them already *)
665 let inductive,leftno,itl,_,i = E.get_checked_indtys r in
666 let itl_len = List.length itl in
667 let _,name,ty,cl = List.nth itl i in
668 let cl_len = List.length cl in
669 (* is it a singleton or empty non recursive and non informative
673 (itl_len = 1 && cl_len = 1 &&
674 is_non_informative [name,C.Decl ty] leftno
675 (let _,_,x = List.nth cl 0 in x)))
677 raise (TypeCheckerFailure (lazy
678 ("Sort elimination not allowed")));
685 typeof_aux context term
687 and check_mutual_inductive_defs uri ~metasenv ~subst is_ind leftno tyl =
688 (* let's check if the arity of the inductive types are well formed *)
689 List.iter (fun (_,_,x,_) -> ignore (typeof ~subst ~metasenv [] x)) tyl;
690 (* let's check if the types of the inductive constructors are well formed. *)
691 let len = List.length tyl in
692 let tys = List.rev (List.map (fun (_,n,ty,_) -> (n,(C.Decl ty))) tyl) in
698 let debruijnedte = debruijn uri len [] te in
699 ignore (typeof ~subst ~metasenv tys debruijnedte);
700 (* let's check also the positivity conditions *)
703 (are_all_occurrences_positive ~subst tys uri leftno i 0 len
708 (lazy ("Non positive occurence in "^NUri.string_of_uri uri))))
713 and eat_lambdas ~subst ~metasenv context n te =
714 match (n, R.whd ~subst context te) with
715 | (0, _) -> (te, context)
716 | (n, C.Lambda (name,so,ta)) when n > 0 ->
717 eat_lambdas ~subst ~metasenv ((name,(C.Decl so))::context) (n - 1) ta
719 raise (AssertFailure (lazy (Printf.sprintf "eat_lambdas (%d, %s)" n
720 (PP.ppterm ~subst ~metasenv ~context te))))
722 and eat_or_subst_lambdas ~subst ~metasenv n te to_be_subst args
723 (context, recfuns, x as k)
725 match n, R.whd ~subst context te, to_be_subst, args with
726 | (n, C.Lambda (name,so,ta),true::to_be_subst,arg::args) when n > 0 ->
727 eat_or_subst_lambdas ~subst ~metasenv (n - 1) (S.subst arg ta)
729 | (n, C.Lambda (name,so,ta),false::to_be_subst,arg::args) when n > 0 ->
730 eat_or_subst_lambdas ~subst ~metasenv (n - 1) ta to_be_subst args
731 (shift_k (name,(C.Decl so)) k)
732 | (_, te, _, _) -> te, k
734 and guarded_by_destructors r_uri r_len ~subst ~metasenv context recfuns t =
735 let recursor f k t = U.fold shift_k k (fun k () -> f k) () t in
736 let rec aux (context, recfuns, x as k) t =
737 let t = R.whd ~delta:max_int ~subst context t in
739 prerr_endline ("GB:\n" ^
740 PP.ppcontext ~subst ~metasenv context^
741 PP.ppterm ~metasenv ~subst ~context t^
742 string_of_recfuns ~subst ~metasenv ~context recfuns);
746 | C.Rel m as t when is_dangerous m recfuns ->
747 raise (NotGuarded (lazy
748 (PP.ppterm ~subst ~metasenv ~context t ^
749 " is a partial application of a fix")))
750 | C.Appl ((C.Rel m)::tl) as t when is_dangerous m recfuns ->
751 let rec_no = get_recno m recfuns in
752 if not (List.length tl > rec_no) then
753 raise (NotGuarded (lazy
754 (PP.ppterm ~context ~subst ~metasenv t ^
755 " is a partial application of a fix")))
757 let rec_arg = List.nth tl rec_no in
758 if not (is_really_smaller r_uri r_len ~subst ~metasenv k rec_arg) then
759 raise (NotGuarded (lazy (Printf.sprintf ("Recursive call %s, %s is not"
760 ^^ " smaller.\ncontext:\n%s") (PP.ppterm ~context ~subst ~metasenv
761 t) (PP.ppterm ~context ~subst ~metasenv rec_arg)
762 (PP.ppcontext ~subst ~metasenv context))));
764 | C.Appl ((C.Rel m)::tl) when is_unfolded m recfuns ->
765 let fixed_args = get_fixed_args m recfuns in
766 list_iter_default2 (fun x b -> if not b then aux k x) tl false fixed_args
768 (match List.nth context (m-1) with
770 | _,C.Def (bo,_) -> aux k (S.lift m bo))
772 | C.Appl (C.Const ((Ref.Ref (_,uri,Ref.Fix (i,recno))) as r)::args) ->
773 if List.exists (fun t -> try aux k t;false with NotGuarded _ -> true) args
775 let fl,_,_ = E.get_checked_fixes r in
777 List.split (List.map (fun (_,name,_,ty,bo) -> (name, C.Decl ty), bo) fl)
779 let fl_len = List.length fl in
780 let bos = List.map (debruijn uri fl_len context) bos in
781 let j = List.fold_left min max_int (List.map (fun (_,_,i,_,_)->i) fl) in
782 let ctx_len = List.length context in
783 (* we may look for fixed params not only up to j ... *)
784 let fa = fixed_args bos j ctx_len (ctx_len + fl_len) in
785 list_iter_default2 (fun x b -> if not b then aux k x) args false fa;
786 let context = context@ctx_tys in
787 let ctx_len = List.length context in
789 HExtlib.list_mapi (fun _ i -> ctx_len - i, UnfFix fa) ctx_tys
791 let new_k = context, extra_recfuns@recfuns, x in
796 eat_or_subst_lambdas ~subst ~metasenv j bo fa args new_k
800 List.length args > recno &&
801 (*case where the recursive argument is already really_smaller *)
802 is_really_smaller r_uri r_len ~subst ~metasenv k
803 (List.nth args recno)
805 let bo,(context, _, _ as new_k) = bo_and_k in
807 eat_lambdas ~subst ~metasenv context (recno + 1 - j) bo in
808 let new_context_part,_ =
809 HExtlib.split_nth (List.length context' - List.length context)
811 let k = List.fold_right shift_k new_context_part new_k in
812 let context, recfuns, x = k in
813 let k = context, (1,Safe)::recfuns, x in
819 List.iter (fun (bo,k) -> aux k bo) bos_and_ks
820 | C.Match (Ref.Ref (_,uri,_) as ref,outtype,term,pl) as t ->
821 (match R.whd ~subst context term with
822 | C.Rel m | C.Appl (C.Rel m :: _ ) as t when is_safe m recfuns || m = x ->
823 (* TODO: add CoInd to references so that this call is useless *)
824 let isinductive, _, _, _, _ = E.get_checked_indtys ref in
825 if not isinductive then recursor aux k t
827 let ty = typeof ~subst ~metasenv context term in
828 let itl_ctx,dcl = fix_lefts_in_constrs ~subst r_uri r_len context ty in
829 let args = match t with C.Appl (_::tl) -> tl | _ -> [] in
830 let dc_ctx = context @ itl_ctx in
831 let start, stop = List.length context, List.length context + r_len in
833 List.iter (aux k) args;
836 let rl = recursive_args ~subst ~metasenv dc_ctx start stop dc in
837 let p, k = get_new_safes ~subst k p rl in
840 | _ -> recursor aux k t)
841 | t -> recursor aux k t
843 NotGuarded _ as exc ->
844 let t' = R.whd ~delta:0 ~subst context t in
845 if t = t' then raise exc
848 try aux (context, recfuns, 1) t
849 with NotGuarded s -> raise (TypeCheckerFailure s)
851 and guarded_by_constructors ~subst ~metasenv context t indURI indlen =
852 let rec aux context n nn h te =
853 match R.whd ~subst context te with
854 | C.Rel m when m > n && m <= nn -> h
855 | C.Rel _ | C.Meta _ -> true
859 | C.Const (Ref.Ref (_,_,Ref.Ind _))
860 | C.LetIn _ -> raise (AssertFailure (lazy "17"))
861 | C.Lambda (name,so,de) ->
862 does_not_occur ~subst context n nn so &&
863 aux ((name,C.Decl so)::context) (n + 1) (nn + 1) h de
864 | C.Appl ((C.Rel m)::tl) when m > n && m <= nn ->
865 h && List.for_all (does_not_occur ~subst context n nn) tl
866 | C.Const (Ref.Ref (_,_,Ref.Con _)) -> true
867 | C.Appl (C.Const (Ref.Ref (_,uri, Ref.Con (i,j)) as ref) :: tl) as t ->
868 let _, paramsno, _, _, _ = E.get_checked_indtys ref in
869 let ty_t = typeof ~subst ~metasenv context t in
870 let tys, cl = fix_lefts_in_constrs ~subst indURI indlen context ty_t in
871 let len_ctx = List.length context in
872 let len_tys = List.length tys in
873 let context_c = context @ tys in
874 let _,c = List.nth cl (j-1) in
876 recursive_args ~subst ~metasenv context_c len_ctx (len_ctx+len_tys) c in
877 let rec analyse_instantiated_type rec_spec args =
878 match rec_spec, args with
879 | h::rec_spec, he::args ->
880 aux context n nn h he && analyse_instantiated_type rec_spec args
882 | _ -> raise (AssertFailure (lazy
883 ("Too many args for constructor: " ^ String.concat " "
884 (List.map (fun x-> PP.ppterm ~subst ~metasenv ~context x) args))))
886 let left, args = HExtlib.split_nth paramsno tl in
887 List.for_all (does_not_occur ~subst context n nn) left &&
888 analyse_instantiated_type rec_params args
889 | C.Appl ((C.Match (_,out,te,pl))::_)
890 | C.Match (_,out,te,pl) as t ->
891 let tl = match t with C.Appl (_::tl) -> tl | _ -> [] in
892 List.for_all (does_not_occur ~subst context n nn) tl &&
893 does_not_occur ~subst context n nn out &&
894 does_not_occur ~subst context n nn te &&
895 List.for_all (aux context n nn h) pl
896 | C.Const (Ref.Ref (_,_,(Ref.Fix _| Ref.CoFix _)) as ref)
897 | C.Appl(C.Const (Ref.Ref(_,_,(Ref.Fix _| Ref.CoFix _)) as ref) :: _) as t ->
898 let tl = match t with C.Appl (_::tl) -> tl | _ -> [] in
899 let fl,_,_ = E.get_checked_fixes ref in
900 let tys = List.map (fun (_,n,_,ty,_) -> n, C.Decl ty) fl in
901 List.for_all (does_not_occur ~subst context n nn) tl &&
903 (fun (_,_,_,ty,bo) ->
904 aux (context@tys) n nn h (debruijn indURI indlen context bo))
907 | C.Appl _ as t -> does_not_occur ~subst context n nn t
909 aux context 0 indlen false t
911 and recursive_args ~subst ~metasenv context n nn te =
912 match R.whd context te with
913 | C.Rel _ | C.Appl _ | C.Const _ -> []
914 | C.Prod (name,so,de) ->
915 (not (does_not_occur ~subst context n nn so)) ::
916 (recursive_args ~subst ~metasenv
917 ((name,(C.Decl so))::context) (n+1) (nn + 1) de)
919 raise (AssertFailure (lazy ("recursive_args:" ^ PP.ppterm ~subst
920 ~metasenv ~context:[] t)))
922 and get_new_safes ~subst (context, recfuns, x as k) p rl =
923 match R.whd ~subst context p, rl with
924 | C.Lambda (name,so,ta), b::tl ->
925 let recfuns = (if b then [0,Safe] else []) @ recfuns in
927 (shift_k (name,(C.Decl so)) (context, recfuns, x)) ta tl
928 | C.Meta _ as e, _ | e, [] -> e, k
929 | _ -> raise (AssertFailure (lazy "Ill formed pattern"))
931 and is_really_smaller
932 r_uri r_len ~subst ~metasenv (context, recfuns, x as k) te
934 match R.whd ~subst context te with
935 | C.Rel m when is_safe m recfuns -> true
936 | C.Lambda (name, s, t) ->
937 is_really_smaller r_uri r_len ~subst ~metasenv (shift_k (name,C.Decl s) k) t
939 is_really_smaller r_uri r_len ~subst ~metasenv k he
942 | C.Const (Ref.Ref (_,_,Ref.Con _)) -> false
943 | C.Const (Ref.Ref (_,_,Ref.Fix _)) -> assert false
945 | C.Match (Ref.Ref (_,uri,_) as ref,outtype,term,pl) ->
947 | C.Rel m | C.Appl (C.Rel m :: _ ) when is_safe m recfuns || m = x ->
948 (* TODO: add CoInd to references so that this call is useless *)
949 let isinductive, _, _, _, _ = E.get_checked_indtys ref in
950 if not isinductive then
951 List.for_all (is_really_smaller r_uri r_len ~subst ~metasenv k) pl
953 let ty = typeof ~subst ~metasenv context term in
954 let itl_ctx,dcl= fix_lefts_in_constrs ~subst r_uri r_len context ty in
955 let start, stop = List.length context, List.length context + r_len in
956 let dc_ctx = context @ itl_ctx in
959 let rl = recursive_args ~subst ~metasenv dc_ctx start stop dc in
960 let e, k = get_new_safes ~subst k p rl in
961 is_really_smaller r_uri r_len ~subst ~metasenv k e)
963 | _ -> List.for_all (is_really_smaller r_uri r_len ~subst ~metasenv k) pl)
966 and returns_a_coinductive ~subst context ty =
967 match R.whd ~subst context ty with
968 | C.Const (Ref.Ref (_,uri,Ref.Ind _) as ref)
969 | C.Appl (C.Const (Ref.Ref (_,uri,Ref.Ind _) as ref)::_) ->
970 let isinductive, _, _, _, _ = E.get_checked_indtys ref in
971 if isinductive then None else (Some uri)
972 | C.Prod (n,so,de) ->
973 returns_a_coinductive ~subst ((n,C.Decl so)::context) de
976 and type_of_constant ((Ref.Ref (_,uri,_)) as ref) =
978 match E.get_obj uri with
981 !logger (`Start_type_checking uri);
982 check_obj_well_typed uobj;
984 !logger (`Type_checking_completed uri);
988 | (_,_,_,_,C.Inductive (_,_,tl,_)), Ref.Ref (_,_,Ref.Ind i) ->
989 let _,_,arity,_ = List.nth tl i in arity
990 | (_,_,_,_,C.Inductive (_,_,tl,_)), Ref.Ref (_,_,Ref.Con (i,j)) ->
991 let _,_,_,cl = List.nth tl i in
992 let _,_,arity = List.nth cl (j-1) in
994 | (_,_,_,_,C.Fixpoint (_,fl,_)), Ref.Ref (_,_,(Ref.Fix (i,_)|Ref.CoFix i)) ->
995 let _,_,_,arity,_ = List.nth fl i in
997 | (_,_,_,_,C.Constant (_,_,_,ty,_)), Ref.Ref (_,_,(Ref.Def |Ref.Decl)) -> ty
998 | _ -> raise (AssertFailure (lazy "type_of_constant: environment/reference"))
1000 and check_obj_well_typed (uri,height,metasenv,subst,kind) =
1001 (* CSC: here we should typecheck the metasenv and the subst *)
1002 assert (metasenv = [] && subst = []);
1004 | C.Constant (_,_,Some te,ty,_) ->
1005 let _ = typeof ~subst ~metasenv [] ty in
1006 let ty_te = typeof ~subst ~metasenv [] te in
1007 if not (R.are_convertible ~subst ~metasenv [] ty_te ty) then
1008 raise (TypeCheckerFailure (lazy (Printf.sprintf (
1009 "the type of the body is not convertible with the declared one.\n"^^
1010 "inferred type:\n%s\nexpected type:\n%s")
1011 (PP.ppterm ~subst ~metasenv ~context:[] ty_te)
1012 (PP.ppterm ~subst ~metasenv ~context:[] ty))))
1013 | C.Constant (_,_,None,ty,_) -> ignore (typeof ~subst ~metasenv [] ty)
1014 | C.Inductive (is_ind, leftno, tyl, _) ->
1015 check_mutual_inductive_defs uri ~metasenv ~subst is_ind leftno tyl
1016 | C.Fixpoint (inductive,fl,_) ->
1017 let types, kl, len =
1019 (fun (types,kl,len) (_,name,k,ty,_) ->
1020 let _ = typeof ~subst ~metasenv [] ty in
1021 ((name,(C.Decl (S.lift len ty)))::types, k::kl,len+1)
1025 List.split (List.map2
1026 (fun (_,_,_,_,bo) rno ->
1027 let dbo = debruijn uri len [] bo in
1031 List.iter2 (fun (_,name,x,ty,_) bo ->
1032 let ty_bo = typeof ~subst ~metasenv types bo in
1033 if not (R.are_convertible ~subst ~metasenv types ty_bo (S.lift len ty))
1034 then raise (TypeCheckerFailure (lazy ("(Co)Fix: ill-typed bodies")))
1036 if inductive then begin
1037 let m, context = eat_lambdas ~subst ~metasenv types (x + 1) bo in
1040 match List.hd context with _,C.Decl t -> t | _ -> assert false
1042 match R.whd ~subst (List.tl context) he with
1043 | C.Const (Ref.Ref (_,uri,Ref.Ind _) as ref)
1044 | C.Appl (C.Const (Ref.Ref (_,uri,Ref.Ind _) as ref) :: _) ->
1045 let _,_,itl,_,_ = E.get_checked_indtys ref in
1046 uri, List.length itl
1049 (* guarded by destructors conditions D{f,k,x,M} *)
1050 let rec enum_from k =
1051 function [] -> [] | v::tl -> (k,v)::enum_from (k+1) tl
1053 guarded_by_destructors r_uri r_len
1054 ~subst ~metasenv context (enum_from (x+2) kl) m
1056 match returns_a_coinductive ~subst [] ty with
1058 raise (TypeCheckerFailure
1059 (lazy "CoFix: does not return a coinductive type"))
1061 (* guarded by constructors conditions C{f,M} *)
1063 (guarded_by_constructors ~subst ~metasenv types bo uri len)
1065 raise (TypeCheckerFailure
1066 (lazy "CoFix: not guarded by constructors"))
1069 let typecheck_obj = check_obj_well_typed;;