1 (* Copyright (C) 2002, HELM Team.
3 * This file is part of HELM, an Hypertextual, Electronic
4 * Library of Mathematics, developed at the Computer Science
5 * Department, University of Bologna, Italy.
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23 * http://cs.unibo.it/helm/.
26 (******************************************************************************)
30 (* Claudio Sacerdoti Coen <sacerdot@cs.unibo.it> *)
34 (******************************************************************************)
38 (* The code of this module is derived from the code of CicReduction *)
40 exception Impossible of int;;
41 exception ReferenceToConstant;;
42 exception ReferenceToVariable;;
43 exception ReferenceToCurrentProof;;
44 exception ReferenceToInductiveDefinition;;
45 exception WrongUriToInductiveDefinition;;
46 exception WrongUriToConstant;;
47 exception RelToHiddenHypothesis;;
50 module S = CicSubstitution
52 let alpha_equivalence =
57 C.Var (uri1,exp_named_subst1), C.Var (uri2,exp_named_subst2) ->
58 UriManager.eq uri1 uri2 &&
59 aux_exp_named_subst exp_named_subst1 exp_named_subst2
60 | C.Cast (te,ty), C.Cast (te',ty') ->
61 aux te te' && aux ty ty'
62 | C.Prod (_,s,t), C.Prod (_,s',t') ->
64 | C.Lambda (_,s,t), C.Lambda (_,s',t') ->
66 | C.LetIn (_,s,t), C.LetIn(_,s',t') ->
68 | C.Appl l, C.Appl l' ->
71 (fun b t1 t2 -> b && aux t1 t2) true l l'
73 Invalid_argument _ -> false)
74 | C.Const (uri,exp_named_subst1), C.Const (uri',exp_named_subst2) ->
75 UriManager.eq uri uri' &&
76 aux_exp_named_subst exp_named_subst1 exp_named_subst2
77 | C.MutInd (uri,i,exp_named_subst1), C.MutInd (uri',i',exp_named_subst2) ->
78 UriManager.eq uri uri' && i = i' &&
79 aux_exp_named_subst exp_named_subst1 exp_named_subst2
80 | C.MutConstruct (uri,i,j,exp_named_subst1),
81 C.MutConstruct (uri',i',j',exp_named_subst2) ->
82 UriManager.eq uri uri' && i = i' && j = j' &&
83 aux_exp_named_subst exp_named_subst1 exp_named_subst2
84 | C.MutCase (sp,i,outt,t,pl), C.MutCase (sp',i',outt',t',pl') ->
85 UriManager.eq sp sp' && i = i' &&
86 aux outt outt' && aux t t' &&
89 (fun b t1 t2 -> b && aux t1 t2) true pl pl'
91 Invalid_argument _ -> false)
92 | C.Fix (i,fl), C.Fix (i',fl') ->
96 (fun b (_,i,ty,bo) (_,i',ty',bo') ->
97 b && i = i' && aux ty ty' && aux bo bo'
100 Invalid_argument _ -> false)
101 | C.CoFix (i,fl), C.CoFix (i',fl') ->
105 (fun b (_,ty,bo) (_,ty',bo') ->
106 b && aux ty ty' && aux bo bo'
109 Invalid_argument _ -> false)
110 | _,_ -> false (* we already know that t != t' *)
111 and aux_exp_named_subst exp_named_subst1 exp_named_subst2 =
114 (fun b (uri1,t1) (uri2,t2) ->
115 b && UriManager.eq uri1 uri2 && aux t1 t2
116 ) true exp_named_subst1 exp_named_subst2
118 Invalid_argument _ -> false
123 exception WhatAndWithWhatDoNotHaveTheSameLength;;
125 (* Replaces "textually" in "where" every term in "what" with the corresponding
126 term in "with_what". The terms in "what" ARE NOT lifted when binders are
127 crossed. The terms in "with_what" ARE NOT lifted when binders are crossed.
128 Every free variable in "where" IS NOT lifted by nnn.
130 let replace ~equality ~what ~with_what ~where =
132 let rec find_image_aux =
134 [],[] -> raise Not_found
135 | what::tl1,with_what::tl2 ->
136 if equality what t then with_what else find_image_aux (tl1,tl2)
137 | _,_ -> raise WhatAndWithWhatDoNotHaveTheSameLength
139 find_image_aux (what,with_what)
147 | C.Var (uri,exp_named_subst) ->
148 C.Var (uri,List.map (function (uri,t) -> uri, aux t) exp_named_subst)
151 | C.Implicit _ as t -> t
152 | C.Cast (te,ty) -> C.Cast (aux te, aux ty)
153 | C.Prod (n,s,t) -> C.Prod (n, aux s, aux t)
154 | C.Lambda (n,s,t) -> C.Lambda (n, aux s, aux t)
155 | C.LetIn (n,s,t) -> C.LetIn (n, aux s, aux t)
157 (* Invariant enforced: no application of an application *)
158 (match List.map aux l with
159 (C.Appl l')::tl -> C.Appl (l'@tl)
161 | C.Const (uri,exp_named_subst) ->
162 C.Const (uri,List.map (function (uri,t) -> uri, aux t) exp_named_subst)
163 | C.MutInd (uri,i,exp_named_subst) ->
165 (uri,i,List.map (function (uri,t) -> uri, aux t) exp_named_subst)
166 | C.MutConstruct (uri,i,j,exp_named_subst) ->
168 (uri,i,j,List.map (function (uri,t) -> uri, aux t) exp_named_subst)
169 | C.MutCase (sp,i,outt,t,pl) ->
170 C.MutCase (sp,i,aux outt, aux t,List.map aux pl)
174 (fun (name,i,ty,bo) -> (name, i, aux ty, aux bo))
177 C.Fix (i, substitutedfl)
181 (fun (name,ty,bo) -> (name, aux ty, aux bo))
184 C.CoFix (i, substitutedfl)
189 (* Replaces in "where" every term in "what" with the corresponding
190 term in "with_what". The terms in "what" ARE lifted when binders are
191 crossed. The terms in "with_what" ARE lifted when binders are crossed.
192 Every free variable in "where" IS NOT lifted by nnn.
193 Thus "replace_lifting_csc 1 ~with_what:[Rel 1; ... ; Rel 1]" is the
194 inverse of subst up to the fact that free variables in "where" are NOT
196 let replace_lifting ~equality ~what ~with_what ~where =
197 let find_image what t =
198 let rec find_image_aux =
200 [],[] -> raise Not_found
201 | what::tl1,with_what::tl2 ->
202 if equality what t then with_what else find_image_aux (tl1,tl2)
203 | _,_ -> raise WhatAndWithWhatDoNotHaveTheSameLength
205 find_image_aux (what,with_what)
207 let rec substaux k what t =
209 S.lift (k-1) (find_image what t)
213 | C.Var (uri,exp_named_subst) ->
214 let exp_named_subst' =
215 List.map (function (uri,t) -> uri,substaux k what t) exp_named_subst
217 C.Var (uri,exp_named_subst')
223 | Some t -> Some (substaux k what t)
228 | C.Implicit _ as t -> t
229 | C.Cast (te,ty) -> C.Cast (substaux k what te, substaux k what ty)
232 (n, substaux k what s, substaux (k + 1) (List.map (S.lift 1) what) t)
233 | C.Lambda (n,s,t) ->
235 (n, substaux k what s, substaux (k + 1) (List.map (S.lift 1) what) t)
238 (n, substaux k what s, substaux (k + 1) (List.map (S.lift 1) what) t)
240 (* Invariant: no Appl applied to another Appl *)
241 let tl' = List.map (substaux k what) tl in
243 match substaux k what he with
244 C.Appl l -> C.Appl (l@tl')
245 | _ as he' -> C.Appl (he'::tl')
247 | C.Appl _ -> assert false
248 | C.Const (uri,exp_named_subst) ->
249 let exp_named_subst' =
250 List.map (function (uri,t) -> uri,substaux k what t) exp_named_subst
252 C.Const (uri,exp_named_subst')
253 | C.MutInd (uri,i,exp_named_subst) ->
254 let exp_named_subst' =
255 List.map (function (uri,t) -> uri,substaux k what t) exp_named_subst
257 C.MutInd (uri,i,exp_named_subst')
258 | C.MutConstruct (uri,i,j,exp_named_subst) ->
259 let exp_named_subst' =
260 List.map (function (uri,t) -> uri,substaux k what t) exp_named_subst
262 C.MutConstruct (uri,i,j,exp_named_subst')
263 | C.MutCase (sp,i,outt,t,pl) ->
264 C.MutCase (sp,i,substaux k what outt, substaux k what t,
265 List.map (substaux k what) pl)
267 let len = List.length fl in
270 (fun (name,i,ty,bo) ->
271 (name, i, substaux k what ty,
272 substaux (k+len) (List.map (S.lift len) what) bo)
275 C.Fix (i, substitutedfl)
277 let len = List.length fl in
281 (name, substaux k what ty,
282 substaux (k+len) (List.map (S.lift len) what) bo)
285 C.CoFix (i, substitutedfl)
287 substaux 1 what where
290 (* Replaces in "where" every term in "what" with the corresponding
291 term in "with_what". The terms in "what" ARE NOT lifted when binders are
292 crossed. The terms in "with_what" ARE lifted when binders are crossed.
293 Every free variable in "where" IS lifted by nnn.
294 Thus "replace_lifting_csc 1 ~with_what:[Rel 1; ... ; Rel 1]" is the
295 inverse of subst up to the fact that "what" terms are NOT lifted. *)
296 let replace_lifting_csc nnn ~equality ~what ~with_what ~where =
298 let rec find_image_aux =
300 [],[] -> raise Not_found
301 | what::tl1,with_what::tl2 ->
302 if equality what t then with_what else find_image_aux (tl1,tl2)
303 | _,_ -> raise WhatAndWithWhatDoNotHaveTheSameLength
305 find_image_aux (what,with_what)
307 let rec substaux k t =
309 S.lift (k-1) (find_image t)
313 if n < k then C.Rel n else C.Rel (n + nnn)
314 | C.Var (uri,exp_named_subst) ->
315 let exp_named_subst' =
316 List.map (function (uri,t) -> uri,substaux k t) exp_named_subst
318 C.Var (uri,exp_named_subst')
324 | Some t -> Some (substaux k t)
329 | C.Implicit _ as t -> t
330 | C.Cast (te,ty) -> C.Cast (substaux k te, substaux k ty)
332 C.Prod (n, substaux k s, substaux (k + 1) t)
333 | C.Lambda (n,s,t) ->
334 C.Lambda (n, substaux k s, substaux (k + 1) t)
336 C.LetIn (n, substaux k s, substaux (k + 1) t)
338 (* Invariant: no Appl applied to another Appl *)
339 let tl' = List.map (substaux k) tl in
341 match substaux k he with
342 C.Appl l -> C.Appl (l@tl')
343 | _ as he' -> C.Appl (he'::tl')
345 | C.Appl _ -> assert false
346 | C.Const (uri,exp_named_subst) ->
347 let exp_named_subst' =
348 List.map (function (uri,t) -> uri,substaux k t) exp_named_subst
350 C.Const (uri,exp_named_subst')
351 | C.MutInd (uri,i,exp_named_subst) ->
352 let exp_named_subst' =
353 List.map (function (uri,t) -> uri,substaux k t) exp_named_subst
355 C.MutInd (uri,i,exp_named_subst')
356 | C.MutConstruct (uri,i,j,exp_named_subst) ->
357 let exp_named_subst' =
358 List.map (function (uri,t) -> uri,substaux k t) exp_named_subst
360 C.MutConstruct (uri,i,j,exp_named_subst')
361 | C.MutCase (sp,i,outt,t,pl) ->
362 C.MutCase (sp,i,substaux k outt, substaux k t,
363 List.map (substaux k) pl)
365 let len = List.length fl in
368 (fun (name,i,ty,bo) ->
369 (name, i, substaux k ty, substaux (k+len) bo))
372 C.Fix (i, substitutedfl)
374 let len = List.length fl in
378 (name, substaux k ty, substaux (k+len) bo))
381 C.CoFix (i, substitutedfl)
386 (* This is the inverse of the subst function. *)
387 let subst_inv ~equality ~what =
388 let rec find_image t = function
390 | hd :: tl -> equality t hd || find_image t tl
392 let rec subst_term k t =
393 if find_image t what then C.Rel k else inspect_term k t
394 and inspect_term k = function
395 | C.Rel n -> if n < k then C.Rel n else C.Rel (succ n)
397 | C.Implicit _ as t -> t
398 | C.Var (uri, enss) ->
399 let enss = List.map (subst_ens k) enss in
401 | C.Const (uri ,enss) ->
402 let enss = List.map (subst_ens k) enss in
404 | C.MutInd (uri, tyno, enss) ->
405 let enss = List.map (subst_ens k) enss in
406 C.MutInd (uri, tyno, enss)
407 | C.MutConstruct (uri, tyno, consno, enss) ->
408 let enss = List.map (subst_ens k) enss in
409 C.MutConstruct (uri, tyno, consno, enss)
411 let mss = List.map (subst_ms k) mss in
413 | C.Cast (t, v) -> C.Cast (subst_term k t, subst_term k v)
415 let ts = List.map (subst_term k) ts in
417 | C.MutCase (uri, tyno, outty, t, cases) ->
418 let cases = List.map (subst_term k) cases in
419 C.MutCase (uri, tyno, subst_term k outty, subst_term k t, cases)
420 | C.Prod (n, v, t) ->
421 C.Prod (n, subst_term k v, subst_term (succ k) t)
422 | C.Lambda (n, v, t) ->
423 C.Lambda (n, subst_term k v, subst_term (succ k) t)
424 | C.LetIn (n, v, t) ->
425 C.LetIn (n, subst_term k v, subst_term (succ k) t)
426 | C.Fix (i, fixes) ->
427 let fixesno = List.length fixes in
428 let fixes = List.map (subst_fix fixesno k) fixes in
430 | C.CoFix (i, cofixes) ->
431 let cofixesno = List.length cofixes in
432 let cofixes = List.map (subst_cofix cofixesno k) cofixes in
434 and subst_ens k (uri, t) = uri, subst_term k t
435 and subst_ms k = function
437 | Some t -> Some (subst_term k t)
438 and subst_fix fixesno k (n, ind, ty, bo) =
439 n, ind, subst_term k ty, subst_term (k + fixesno) bo
440 and subst_cofix cofixesno k (n, ty, bo) =
441 n, subst_term k ty, subst_term (k + cofixesno) bo
448 (* Takes a well-typed term and fully reduces it. *)
449 (*CSC: It does not perform reduction in a Case *)
451 let rec reduceaux context l =
454 (match List.nth context (n-1) with
455 Some (_,C.Decl _) -> if l = [] then t else C.Appl (t::l)
456 | Some (_,C.Def (bo,_)) -> reduceaux context l (S.lift n bo)
457 | None -> raise RelToHiddenHypothesis
459 | C.Var (uri,exp_named_subst) ->
460 let exp_named_subst' =
461 reduceaux_exp_named_subst context l exp_named_subst
463 (let o,_ = CicEnvironment.get_obj CicUniv.empty_ugraph uri in
465 C.Constant _ -> raise ReferenceToConstant
466 | C.CurrentProof _ -> raise ReferenceToCurrentProof
467 | C.InductiveDefinition _ -> raise ReferenceToInductiveDefinition
468 | C.Variable (_,None,_,_,_) ->
469 let t' = C.Var (uri,exp_named_subst') in
470 if l = [] then t' else C.Appl (t'::l)
471 | C.Variable (_,Some body,_,_,_) ->
473 (CicSubstitution.subst_vars exp_named_subst' body))
475 | C.Meta _ as t -> if l = [] then t else C.Appl (t::l)
476 | C.Sort _ as t -> t (* l should be empty *)
477 | C.Implicit _ as t -> t
479 C.Cast (reduceaux context l te, reduceaux context l ty)
480 | C.Prod (name,s,t) ->
483 reduceaux context [] s,
484 reduceaux ((Some (name,C.Decl s))::context) [] t)
485 | C.Lambda (name,s,t) ->
489 reduceaux context [] s,
490 reduceaux ((Some (name,C.Decl s))::context) [] t)
491 | he::tl -> reduceaux context tl (S.subst he t)
492 (* when name is Anonimous the substitution should be superfluous *)
495 reduceaux context l (S.subst (reduceaux context [] s) t)
497 let tl' = List.map (reduceaux context []) tl in
498 reduceaux context (tl'@l) he
499 | C.Appl [] -> raise (Impossible 1)
500 | C.Const (uri,exp_named_subst) ->
501 let exp_named_subst' =
502 reduceaux_exp_named_subst context l exp_named_subst
504 (let o,_ = CicEnvironment.get_obj CicUniv.empty_ugraph uri in
506 C.Constant (_,Some body,_,_,_) ->
508 (CicSubstitution.subst_vars exp_named_subst' body))
509 | C.Constant (_,None,_,_,_) ->
510 let t' = C.Const (uri,exp_named_subst') in
511 if l = [] then t' else C.Appl (t'::l)
512 | C.Variable _ -> raise ReferenceToVariable
513 | C.CurrentProof (_,_,body,_,_,_) ->
515 (CicSubstitution.subst_vars exp_named_subst' body))
516 | C.InductiveDefinition _ -> raise ReferenceToInductiveDefinition
518 | C.MutInd (uri,i,exp_named_subst) ->
519 let exp_named_subst' =
520 reduceaux_exp_named_subst context l exp_named_subst
522 let t' = C.MutInd (uri,i,exp_named_subst') in
523 if l = [] then t' else C.Appl (t'::l)
524 | C.MutConstruct (uri,i,j,exp_named_subst) ->
525 let exp_named_subst' =
526 reduceaux_exp_named_subst context l exp_named_subst
528 let t' = C.MutConstruct (uri,i,j,exp_named_subst') in
529 if l = [] then t' else C.Appl (t'::l)
530 | C.MutCase (mutind,i,outtype,term,pl) ->
534 let (_,_,body) = List.nth fl i in
536 let counter = ref (List.length fl) in
538 (fun _ -> decr counter ; S.subst (C.CoFix (!counter,fl)))
542 reduceaux context [] body'
543 | C.Appl (C.CoFix (i,fl) :: tl) ->
544 let (_,_,body) = List.nth fl i in
546 let counter = ref (List.length fl) in
548 (fun _ -> decr counter ; S.subst (C.CoFix (!counter,fl)))
552 let tl' = List.map (reduceaux context []) tl in
553 reduceaux context tl' body'
556 (match decofix (reduceaux context [] term) with
557 C.MutConstruct (_,_,j,_) -> reduceaux context l (List.nth pl (j-1))
558 | C.Appl (C.MutConstruct (_,_,j,_) :: tl) ->
560 let o,_ = CicEnvironment.get_obj CicUniv.empty_ugraph mutind in
562 C.InductiveDefinition (tl,_,r,_) ->
563 let (_,_,arity,_) = List.nth tl i in
565 | _ -> raise WrongUriToInductiveDefinition
571 | (n,he::tl) when n > 0 -> eat_first (n - 1, tl)
572 | _ -> raise (Impossible 5)
576 reduceaux context (ts@l) (List.nth pl (j-1))
577 | C.Cast _ | C.Implicit _ ->
578 raise (Impossible 2) (* we don't trust our whd ;-) *)
580 let outtype' = reduceaux context [] outtype in
581 let term' = reduceaux context [] term in
582 let pl' = List.map (reduceaux context []) pl in
584 C.MutCase (mutind,i,outtype',term',pl')
586 if l = [] then res else C.Appl (res::l)
590 List.map (function (name,_,ty,_) -> Some (C.Name name, C.Decl ty)) fl
595 (function (n,recindex,ty,bo) ->
596 (n,recindex,reduceaux context [] ty, reduceaux (tys@context) [] bo)
601 let (_,recindex,_,body) = List.nth fl i in
604 Some (List.nth l recindex)
610 (match reduceaux context [] recparam with
612 | C.Appl ((C.MutConstruct _)::_) ->
614 let counter = ref (List.length fl) in
616 (fun _ -> decr counter ; S.subst (C.Fix (!counter,fl)))
620 (* Possible optimization: substituting whd recparam in l*)
621 reduceaux context l body'
622 | _ -> if l = [] then t' () else C.Appl ((t' ())::l)
624 | None -> if l = [] then t' () else C.Appl ((t' ())::l)
628 List.map (function (name,ty,_) -> Some (C.Name name, C.Decl ty)) fl
633 (function (n,ty,bo) ->
634 (n,reduceaux context [] ty, reduceaux (tys@context) [] bo)
639 if l = [] then t' else C.Appl (t'::l)
640 and reduceaux_exp_named_subst context l =
641 List.map (function uri,t -> uri,reduceaux context [] t)
646 exception WrongShape;;
647 exception AlreadySimplified;;
649 (* Takes a well-typed term and *)
650 (* 1) Performs beta-iota-zeta reduction until delta reduction is needed *)
651 (* 2) Attempts delta-reduction. If the residual is a Fix lambda-abstracted *)
652 (* w.r.t. zero or more variables and if the Fix can be reductaed, than it*)
653 (* is reduced, the delta-reduction is succesfull and the whole algorithm *)
654 (* is applied again to the new redex; Step 3.1) is applied to the result *)
655 (* of the recursive simplification. Otherwise, if the Fix can not be *)
656 (* reduced, than the delta-reductions fails and the delta-redex is *)
657 (* not reduced. Otherwise, if the delta-residual is not the *)
658 (* lambda-abstraction of a Fix, then it performs step 3.2). *)
659 (* 3.1) Folds the application of the constant to the arguments that did not *)
660 (* change in every iteration, i.e. to the actual arguments for the *)
661 (* lambda-abstractions that precede the Fix. *)
662 (* 3.2) Computes the head beta-zeta normal form of the term. Then it tries *)
663 (* reductions. If the reduction cannot be performed, it returns the *)
664 (* original term (not the head beta-zeta normal form of the definiendum) *)
665 (*CSC: It does not perform simplification in a Case *)
668 (* a simplified term is active if it can create a redex when used as an *)
669 (* actual parameter *)
674 | C.Appl (C.MutConstruct _::_)
676 | C.Cast (bo,_) -> is_active bo
677 | C.LetIn _ -> assert false
680 (* reduceaux is equal to the reduceaux locally defined inside *)
681 (* reduce, but for the const case. *)
683 let rec reduceaux context l =
686 (* we never perform delta expansion automatically *)
687 if l = [] then t else C.Appl (t::l)
688 | C.Var (uri,exp_named_subst) ->
689 let exp_named_subst' =
690 reduceaux_exp_named_subst context l exp_named_subst
692 (let o,_ = CicEnvironment.get_obj CicUniv.empty_ugraph uri in
694 C.Constant _ -> raise ReferenceToConstant
695 | C.CurrentProof _ -> raise ReferenceToCurrentProof
696 | C.InductiveDefinition _ -> raise ReferenceToInductiveDefinition
697 | C.Variable (_,None,_,_,_) ->
698 let t' = C.Var (uri,exp_named_subst') in
699 if l = [] then t' else C.Appl (t'::l)
700 | C.Variable (_,Some body,_,_,_) ->
702 (CicSubstitution.subst_vars exp_named_subst' body)
704 | C.Meta _ as t -> if l = [] then t else C.Appl (t::l)
705 | C.Sort _ as t -> t (* l should be empty *)
706 | C.Implicit _ as t -> t
708 C.Cast (reduceaux context l te, reduceaux context [] ty)
709 | C.Prod (name,s,t) ->
712 reduceaux context [] s,
713 reduceaux ((Some (name,C.Decl s))::context) [] t)
714 | C.Lambda (name,s,t) ->
718 reduceaux context [] s,
719 reduceaux ((Some (name,C.Decl s))::context) [] t)
720 | he::tl -> reduceaux context tl (S.subst he t)
721 (* when name is Anonimous the substitution should be superfluous *)
724 reduceaux context l (S.subst (reduceaux context [] s) t)
726 let tl' = List.map (reduceaux context []) tl in
727 reduceaux context (tl'@l) he
728 | C.Appl [] -> raise (Impossible 1)
729 | C.Const (uri,exp_named_subst) ->
730 let exp_named_subst' =
731 reduceaux_exp_named_subst context l exp_named_subst
733 (let o,_ = CicEnvironment.get_obj CicUniv.empty_ugraph uri in
735 C.Constant (_,Some body,_,_,_) ->
736 if List.exists is_active l then
737 try_delta_expansion context l
738 (C.Const (uri,exp_named_subst'))
739 (CicSubstitution.subst_vars exp_named_subst' body)
741 let t' = C.Const (uri,exp_named_subst') in
742 if l = [] then t' else C.Appl (t'::l)
743 | C.Constant (_,None,_,_,_) ->
744 let t' = C.Const (uri,exp_named_subst') in
745 if l = [] then t' else C.Appl (t'::l)
746 | C.Variable _ -> raise ReferenceToVariable
747 | C.CurrentProof (_,_,body,_,_,_) -> reduceaux context l body
748 | C.InductiveDefinition _ -> raise ReferenceToInductiveDefinition
750 | C.MutInd (uri,i,exp_named_subst) ->
751 let exp_named_subst' =
752 reduceaux_exp_named_subst context l exp_named_subst
754 let t' = C.MutInd (uri,i,exp_named_subst') in
755 if l = [] then t' else C.Appl (t'::l)
756 | C.MutConstruct (uri,i,j,exp_named_subst) ->
757 let exp_named_subst' =
758 reduceaux_exp_named_subst context l exp_named_subst
760 let t' = C.MutConstruct(uri,i,j,exp_named_subst') in
761 if l = [] then t' else C.Appl (t'::l)
762 | C.MutCase (mutind,i,outtype,term,pl) ->
766 let (_,_,body) = List.nth fl i in
768 let counter = ref (List.length fl) in
770 (fun _ -> decr counter ; S.subst (C.CoFix (!counter,fl)))
774 reduceaux context [] body'
775 | C.Appl (C.CoFix (i,fl) :: tl) ->
776 let (_,_,body) = List.nth fl i in
778 let counter = ref (List.length fl) in
780 (fun _ -> decr counter ; S.subst (C.CoFix (!counter,fl)))
784 let tl' = List.map (reduceaux context []) tl in
785 reduceaux context tl' body'
788 (match decofix (reduceaux context [] term) (*(CicReduction.whd context term)*) with
789 C.MutConstruct (_,_,j,_) -> reduceaux context l (List.nth pl (j-1))
790 | C.Appl (C.MutConstruct (_,_,j,_) :: tl) ->
792 let o,_ = CicEnvironment.get_obj CicUniv.empty_ugraph mutind in
794 C.InductiveDefinition (tl,ingredients,r,_) ->
795 let (_,_,arity,_) = List.nth tl i in
797 | _ -> raise WrongUriToInductiveDefinition
803 | (n,he::tl) when n > 0 -> eat_first (n - 1, tl)
804 | _ -> raise (Impossible 5)
808 reduceaux context (ts@l) (List.nth pl (j-1))
809 | C.Cast _ | C.Implicit _ ->
810 raise (Impossible 2) (* we don't trust our whd ;-) *)
812 let outtype' = reduceaux context [] outtype in
813 let term' = reduceaux context [] term in
814 let pl' = List.map (reduceaux context []) pl in
816 C.MutCase (mutind,i,outtype',term',pl')
818 if l = [] then res else C.Appl (res::l)
822 List.map (function (name,_,ty,_) -> Some (C.Name name, C.Decl ty)) fl
827 (function (n,recindex,ty,bo) ->
828 (n,recindex,reduceaux context [] ty, reduceaux (tys@context) [] bo)
833 let (_,recindex,_,body) = List.nth fl i in
836 Some (List.nth l recindex)
842 (match reduceaux context [] recparam with
844 | C.Appl ((C.MutConstruct _)::_) ->
846 let counter = ref (List.length fl) in
848 (fun _ -> decr counter ; S.subst (C.Fix (!counter,fl)))
852 (* Possible optimization: substituting whd recparam in l*)
853 reduceaux context l body'
854 | _ -> if l = [] then t' () else C.Appl ((t' ())::l)
856 | None -> if l = [] then t' () else C.Appl ((t' ())::l)
860 List.map (function (name,ty,_) -> Some (C.Name name, C.Decl ty)) fl
865 (function (n,ty,bo) ->
866 (n,reduceaux context [] ty, reduceaux (tys@context) [] bo)
871 if l = [] then t' else C.Appl (t'::l)
872 and reduceaux_exp_named_subst context l =
873 List.map (function uri,t -> uri,reduceaux context [] t)
875 and try_delta_expansion context l term body =
877 let res,constant_args =
878 let rec aux rev_constant_args l =
880 C.Lambda (name,s,t) ->
883 [] -> raise WrongShape
885 (* when name is Anonimous the substitution should *)
887 aux (he::rev_constant_args) tl (S.subst he t)
890 aux rev_constant_args l (S.subst s t)
892 let (_,recindex,_,body) = List.nth fl i in
897 _ -> raise AlreadySimplified
899 (match reduceaux context [] recparam (*CicReduction.whd context recparam*) with
901 | C.Appl ((C.MutConstruct _)::_) ->
903 let counter = ref (List.length fl) in
906 decr counter ; S.subst (C.Fix (!counter,fl))
909 (* Possible optimization: substituting whd *)
911 reduceaux context l body',
912 List.rev rev_constant_args
913 | _ -> raise AlreadySimplified
915 | _ -> raise WrongShape
920 let term_to_fold, delta_expanded_term_to_fold =
921 match constant_args with
923 | _ -> C.Appl (term::constant_args), C.Appl (body::constant_args)
925 let simplified_term_to_fold =
926 reduceaux context [] delta_expanded_term_to_fold
928 replace_lifting (=) [simplified_term_to_fold] [term_to_fold] res
934 C.Lambda (name,s,t) ->
936 [] -> raise AlreadySimplified
938 (* when name is Anonimous the substitution should *)
940 aux tl (S.subst he t))
941 | C.LetIn (_,s,t) -> aux l (S.subst s t)
943 let simplified = reduceaux context l t in
944 let t' = if l = [] then t else C.Appl (t::l) in
945 if t' = simplified then
946 raise AlreadySimplified
953 if l = [] then term else C.Appl (term::l))
954 | AlreadySimplified ->
955 (* If we performed delta-reduction, we would find a Fix *)
956 (* not applied to a constructor. So, we refuse to perform *)
957 (* delta-reduction. *)
958 if l = [] then term else C.Appl (term::l)
963 let unfold ?what context where =
964 let contextlen = List.length context in
965 let first_is_the_expandable_head_of_second context' t1 t2 =
967 Cic.Const (uri,_), Cic.Const (uri',_)
968 | Cic.Var (uri,_), Cic.Var (uri',_)
969 | Cic.Const (uri,_), Cic.Appl (Cic.Const (uri',_)::_)
970 | Cic.Var (uri,_), Cic.Appl (Cic.Var (uri',_)::_) -> UriManager.eq uri uri'
972 | Cic.Var _, _ -> false
973 | Cic.Rel n, Cic.Rel m
974 | Cic.Rel n, Cic.Appl (Cic.Rel m::_) ->
975 n + (List.length context' - contextlen) = m
976 | Cic.Rel _, _ -> false
979 (ProofEngineTypes.Fail
980 (lazy "The term to unfold is not a constant, a variable or a bound variable "))
983 if tl = [] then he else Cic.Appl (he::tl) in
984 let cannot_delta_expand t =
986 (ProofEngineTypes.Fail
987 (lazy ("The term " ^ CicPp.ppterm t ^ " cannot be delta-expanded"))) in
988 let rec hd_delta_beta context tl =
992 match List.nth context (n-1) with
993 Some (_,Cic.Decl _) -> cannot_delta_expand t
994 | Some (_,Cic.Def (bo,_)) ->
995 CicReduction.head_beta_reduce
996 (appl (CicSubstitution.lift n bo) tl)
997 | None -> raise RelToHiddenHypothesis
999 Failure _ -> assert false)
1000 | Cic.Const (uri,exp_named_subst) as t ->
1001 let o,_ = CicEnvironment.get_obj CicUniv.empty_ugraph uri in
1003 Cic.Constant (_,Some body,_,_,_) ->
1004 CicReduction.head_beta_reduce
1005 (appl (CicSubstitution.subst_vars exp_named_subst body) tl)
1006 | Cic.Constant (_,None,_,_,_) -> cannot_delta_expand t
1007 | Cic.Variable _ -> raise ReferenceToVariable
1008 | Cic.CurrentProof _ -> raise ReferenceToCurrentProof
1009 | Cic.InductiveDefinition _ -> raise ReferenceToInductiveDefinition
1011 | Cic.Var (uri,exp_named_subst) as t ->
1012 let o,_ = CicEnvironment.get_obj CicUniv.empty_ugraph uri in
1014 Cic.Constant _ -> raise ReferenceToConstant
1015 | Cic.CurrentProof _ -> raise ReferenceToCurrentProof
1016 | Cic.InductiveDefinition _ -> raise ReferenceToInductiveDefinition
1017 | Cic.Variable (_,Some body,_,_,_) ->
1018 CicReduction.head_beta_reduce
1019 (appl (CicSubstitution.subst_vars exp_named_subst body) tl)
1020 | Cic.Variable (_,None,_,_,_) -> cannot_delta_expand t
1022 | Cic.Appl [] -> assert false
1023 | Cic.Appl (he::tl) -> hd_delta_beta context tl he
1024 | t -> cannot_delta_expand t
1026 let context_and_matched_term_list =
1028 None -> [context, where]
1031 ProofEngineHelpers.locate_in_term
1032 ~equality:first_is_the_expandable_head_of_second
1037 (ProofEngineTypes.Fail
1038 (lazy ("Term "^ CicPp.ppterm what ^ " not found in " ^ CicPp.ppterm where)))
1044 (function (context,where) -> hd_delta_beta context [] where)
1045 context_and_matched_term_list in
1046 let whats = List.map snd context_and_matched_term_list in
1047 replace ~equality:(==) ~what:whats ~with_what:reduced_terms ~where