+++ /dev/null
-(* Copyright (C) 2000, HELM Team.
- *
- * This file is part of HELM, an Hypertextual, Electronic
- * Library of Mathematics, developed at the Computer Science
- * Department, University of Bologna, Italy.
- *
- * HELM is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version 2
- * of the License, or (at your option) any later version.
- *
- * HELM is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with HELM; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston,
- * MA 02111-1307, USA.
- *
- * For details, see the HELM World-Wide-Web page,
- * http://cs.unibo.it/helm/.
- *)
-
-exception CicReductionInternalError;;
-exception WrongUriToInductiveDefinition;;
-
-let fdebug = ref 1;;
-let debug t env s =
- let rec debug_aux t i =
- let module C = Cic in
- let module U = UriManager in
- CicPp.ppobj (C.Variable ("DEBUG", None, t)) ^ "\n" ^ i
- in
- if !fdebug = 0 then
- begin
- print_endline (s ^ "\n" ^ List.fold_right debug_aux (t::env) "") ;
- flush stdout
- end
-;;
-
-exception Impossible of int;;
-exception ReferenceToDefinition;;
-exception ReferenceToAxiom;;
-exception ReferenceToVariable;;
-exception ReferenceToCurrentProof;;
-exception ReferenceToInductiveDefinition;;
-
-(* takes a well-typed term *)
-let whd =
- let rec whdaux l =
- let module C = Cic in
- let module S = CicSubstitution in
- function
- C.Rel _ as t -> if l = [] then t else C.Appl (t::l)
- | C.Var uri as t ->
- (match CicEnvironment.get_cooked_obj uri 0 with
- C.Definition _ -> raise ReferenceToDefinition
- | C.Axiom _ -> raise ReferenceToAxiom
- | C.CurrentProof _ -> raise ReferenceToCurrentProof
- | C.InductiveDefinition _ -> raise ReferenceToInductiveDefinition
- | C.Variable (_,None,_) -> if l = [] then t else C.Appl (t::l)
- | C.Variable (_,Some body,_) -> whdaux l body
- )
- | C.Meta _ as t -> if l = [] then t else C.Appl (t::l)
- | C.Sort _ as t -> t (* l should be empty *)
- | C.Implicit as t -> t
- | C.Cast (te,ty) -> whdaux l te (*CSC E' GIUSTO BUTTARE IL CAST? *)
- | C.Prod _ as t -> t (* l should be empty *)
- | C.Lambda (name,s,t) as t' ->
- (match l with
- [] -> t'
- | he::tl -> whdaux tl (S.subst he t)
- (* when name is Anonimous the substitution should be superfluous *)
- )
- | C.LetIn (n,s,t) -> whdaux l (S.subst (whdaux [] s) t)
- | C.Appl (he::tl) -> whdaux (tl@l) he
- | C.Appl [] -> raise (Impossible 1)
- | C.Const (uri,cookingsno) as t ->
- (match CicEnvironment.get_cooked_obj uri cookingsno with
- C.Definition (_,body,_,_) -> whdaux l body
- | C.Axiom _ -> if l = [] then t else C.Appl (t::l)
- | C.Variable _ -> raise ReferenceToVariable
- | C.CurrentProof (_,_,body,_) -> whdaux l body
- | C.InductiveDefinition _ -> raise ReferenceToInductiveDefinition
- )
- | C.Abst _ as t -> t (*CSC l should be empty ????? *)
- | C.MutInd (uri,_,_) as t -> if l = [] then t else C.Appl (t::l)
- | C.MutConstruct (uri,_,_,_) as t -> if l = [] then t else C.Appl (t::l)
- | C.MutCase (mutind,cookingsno,i,_,term,pl) as t ->
- let decofix =
- function
- C.CoFix (i,fl) as t ->
- let (_,_,body) = List.nth fl i in
- let body' =
- let counter = ref (List.length fl) in
- List.fold_right
- (fun _ -> decr counter ; S.subst (C.CoFix (!counter,fl)))
- fl
- body
- in
- whdaux [] body'
- | C.Appl (C.CoFix (i,fl) :: tl) ->
- let (_,_,body) = List.nth fl i in
- let body' =
- let counter = ref (List.length fl) in
- List.fold_right
- (fun _ -> decr counter ; S.subst (C.CoFix (!counter,fl)))
- fl
- body
- in
- whdaux tl body'
- | t -> t
- in
- (match decofix (whdaux [] term) with
- C.MutConstruct (_,_,_,j) -> whdaux l (List.nth pl (j-1))
- | C.Appl (C.MutConstruct (_,_,_,j) :: tl) ->
- let (arity, r, num_ingredients) =
- match CicEnvironment.get_obj mutind with
- C.InductiveDefinition (tl,ingredients,r) ->
- let (_,_,arity,_) = List.nth tl i
- and num_ingredients =
- List.fold_right
- (fun (k,l) i ->
- if k < cookingsno then i + List.length l else i
- ) ingredients 0
- in
- (arity,r,num_ingredients)
- | _ -> raise WrongUriToInductiveDefinition
- in
- let ts =
- let num_to_eat = r + num_ingredients in
- let rec eat_first =
- function
- (0,l) -> l
- | (n,he::tl) when n > 0 -> eat_first (n - 1, tl)
- | _ -> raise (Impossible 5)
- in
- eat_first (num_to_eat,tl)
- in
- whdaux (ts@l) (List.nth pl (j-1))
- | C.Abst _| C.Cast _ | C.Implicit ->
- raise (Impossible 2) (* we don't trust our whd ;-) *)
- | _ -> t
- )
- | C.Fix (i,fl) as t ->
- let (_,recindex,_,body) = List.nth fl i in
- let recparam =
- try
- Some (List.nth l recindex)
- with
- _ -> None
- in
- (match recparam with
- Some recparam ->
- (match whdaux [] recparam with
- C.MutConstruct _
- | C.Appl ((C.MutConstruct _)::_) ->
- let body' =
- let counter = ref (List.length fl) in
- List.fold_right
- (fun _ -> decr counter ; S.subst (C.Fix (!counter,fl)))
- fl
- body
- in
- (* Possible optimization: substituting whd recparam in l *)
- whdaux l body'
- | _ -> if l = [] then t else C.Appl (t::l)
- )
- | None -> if l = [] then t else C.Appl (t::l)
- )
- | C.CoFix (i,fl) as t ->
- (*CSC vecchio codice
- let (_,_,body) = List.nth fl i in
- let body' =
- let counter = ref (List.length fl) in
- List.fold_right
- (fun _ -> decr counter ; S.subst (C.CoFix (!counter,fl)))
- fl
- body
- in
- whdaux l body'
- *)
- if l = [] then t else C.Appl (t::l)
- in
- whdaux []
-;;
-
-(* t1, t2 must be well-typed *)
-let are_convertible t1 t2 =
- let module U = UriManager in
- let rec aux t1 t2 =
- debug t1 [t2] "PREWHD";
- (* this trivial euristic cuts down the total time of about five times ;-) *)
- (* this because most of the time t1 and t2 are "sintactically" the same *)
- if t1 = t2 then
- true
- else
- begin
- let module C = Cic in
- let t1' = whd t1
- and t2' = whd t2 in
- debug t1' [t2'] "POSTWHD";
- match (t1',t2') with
- (C.Rel n1, C.Rel n2) -> n1 = n2
- | (C.Var uri1, C.Var uri2) -> U.eq uri1 uri2
- | (C.Meta n1, C.Meta n2) -> n1 = n2
- | (C.Sort s1, C.Sort s2) -> true (*CSC da finire con gli universi *)
- | (C.Prod (_,s1,t1), C.Prod(_,s2,t2)) ->
- aux s1 s2 && aux t1 t2
- | (C.Lambda (_,s1,t1), C.Lambda(_,s2,t2)) ->
- aux s1 s2 && aux t1 t2
- | (C.Appl l1, C.Appl l2) ->
- (try
- List.fold_right2 (fun x y b -> aux x y && b) l1 l2 true
- with
- Invalid_argument _ -> false
- )
- | (C.Const (uri1,_), C.Const (uri2,_)) ->
- (*CSC: questo commento e' chiaro o delirante? Io lo sto scrivendo *)
- (*CSC: mentre sono delirante, quindi ... *)
- (* WARNING: it is really important that the two cookingsno are not *)
- (* checked for equality. This allows not to cook an object with no *)
- (* ingredients only to update the cookingsno. E.g: if a term t has *)
- (* a reference to a term t1 which does not depend on any variable *)
- (* and t1 depends on a term t2 (that can't depend on any variable *)
- (* because of t1), then t1 cooked at every level could be the same *)
- (* as t1 cooked at level 0. Doing so, t2 will be extended in t *)
- (* with cookingsno 0 and not 2. But this will not cause any trouble*)
- (* if here we don't check that the two cookingsno are equal. *)
- U.eq uri1 uri2
- | (C.MutInd (uri1,k1,i1), C.MutInd (uri2,k2,i2)) ->
- (* WARNIG: see the previous warning *)
- U.eq uri1 uri2 && i1 = i2
- | (C.MutConstruct (uri1,_,i1,j1), C.MutConstruct (uri2,_,i2,j2)) ->
- (* WARNIG: see the previous warning *)
- U.eq uri1 uri2 && i1 = i2 && j1 = j2
- | (C.MutCase (uri1,_,i1,outtype1,term1,pl1),
- C.MutCase (uri2,_,i2,outtype2,term2,pl2)) ->
- (* WARNIG: see the previous warning *)
- (* aux outtype1 outtype2 should be true if aux pl1 pl2 *)
- U.eq uri1 uri2 && i1 = i2 && aux outtype1 outtype2 &&
- aux term1 term2 &&
- List.fold_right2 (fun x y b -> b && aux x y) pl1 pl2 true
- | (C.Fix (i1,fl1), C.Fix (i2,fl2)) ->
- i1 = i2 &&
- List.fold_right2
- (fun (_,recindex1,ty1,bo1) (_,recindex2,ty2,bo2) b ->
- b && recindex1 = recindex2 && aux ty1 ty2 && aux bo1 bo2)
- fl1 fl2 true
- | (C.CoFix (i1,fl1), C.CoFix (i2,fl2)) ->
- i1 = i2 &&
- List.fold_right2
- (fun (_,ty1,bo1) (_,ty2,bo2) b ->
- b && aux ty1 ty2 && aux bo1 bo2)
- fl1 fl2 true
- | (C.Abst _, _) | (_, C.Abst _) | (C.Cast _, _) | (_, C.Cast _)
- | (C.Implicit, _) | (_, C.Implicit) ->
- raise (Impossible 3) (* we don't trust our whd ;-) *)
- | (_,_) -> false
- end
- in
- aux t1 t2
-;;
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