1 (* Copyright (C) 2000, 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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15 * GNU General Public License for more details.
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19 * Foundation, Inc., 59 Temple Place - Suite 330, Boston,
22 * For details, see the HELM World-Wide-Web page,
23 * http://cs.unibo.it/helm/.
26 exception CicReductionInternalError;;
27 exception WrongUriToInductiveDefinition;;
31 let rec debug_aux t i =
33 let module U = UriManager in
34 CicPp.ppobj (C.Variable ("DEBUG", None, t)) ^ "\n" ^ i
38 print_endline (s ^ "\n" ^ List.fold_right debug_aux (t::env) "") ;
43 exception Impossible of int;;
44 exception ReferenceToDefinition;;
45 exception ReferenceToAxiom;;
46 exception ReferenceToVariable;;
47 exception ReferenceToCurrentProof;;
48 exception ReferenceToInductiveDefinition;;
49 exception RelToHiddenHypothesis;;
51 (* takes a well-typed term *)
55 let module S = CicSubstitution in
58 (match List.nth context (n-1) with
59 Some (_, C.Decl _) -> if l = [] then t else C.Appl (t::l)
60 | Some (_, C.Def bo) -> whdaux l (S.lift n bo)
61 | None -> raise RelToHiddenHypothesis
64 (match CicEnvironment.get_cooked_obj uri 0 with
65 C.Definition _ -> raise ReferenceToDefinition
66 | C.Axiom _ -> raise ReferenceToAxiom
67 | C.CurrentProof _ -> raise ReferenceToCurrentProof
68 | C.InductiveDefinition _ -> raise ReferenceToInductiveDefinition
69 | C.Variable (_,None,_) -> if l = [] then t else C.Appl (t::l)
70 | C.Variable (_,Some body,_) -> whdaux l body
72 | C.Meta _ as t -> if l = [] then t else C.Appl (t::l)
73 | C.Sort _ as t -> t (* l should be empty *)
74 | C.Implicit as t -> t
75 | C.Cast (te,ty) -> whdaux l te (*CSC E' GIUSTO BUTTARE IL CAST? *)
76 | C.Prod _ as t -> t (* l should be empty *)
77 | C.Lambda (name,s,t) as t' ->
80 | he::tl -> whdaux tl (S.subst he t)
81 (* when name is Anonimous the substitution should be superfluous *)
83 | C.LetIn (n,s,t) -> whdaux l (S.subst (whdaux [] s) t)
84 | C.Appl (he::tl) -> whdaux (tl@l) he
85 | C.Appl [] -> raise (Impossible 1)
86 | C.Const (uri,cookingsno) as t ->
87 (match CicEnvironment.get_cooked_obj uri cookingsno with
88 C.Definition (_,body,_,_) -> whdaux l body
89 | C.Axiom _ -> if l = [] then t else C.Appl (t::l)
90 | C.Variable _ -> raise ReferenceToVariable
91 | C.CurrentProof (_,_,body,_) -> whdaux l body
92 | C.InductiveDefinition _ -> raise ReferenceToInductiveDefinition
94 | C.Abst _ as t -> t (*CSC l should be empty ????? *)
95 | C.MutInd (uri,_,_) as t -> if l = [] then t else C.Appl (t::l)
96 | C.MutConstruct (uri,_,_,_) as t -> if l = [] then t else C.Appl (t::l)
97 | C.MutCase (mutind,cookingsno,i,_,term,pl) as t->
100 C.CoFix (i,fl) as t ->
101 let (_,_,body) = List.nth fl i in
103 let counter = ref (List.length fl) in
105 (fun _ -> decr counter ; S.subst (C.CoFix (!counter,fl)))
110 | C.Appl (C.CoFix (i,fl) :: tl) ->
111 let (_,_,body) = List.nth fl i in
113 let counter = ref (List.length fl) in
115 (fun _ -> decr counter ; S.subst (C.CoFix (!counter,fl)))
122 (match decofix (whdaux [] term) with
123 C.MutConstruct (_,_,_,j) -> whdaux l (List.nth pl (j-1))
124 | C.Appl (C.MutConstruct (_,_,_,j) :: tl) ->
125 let (arity, r, num_ingredients) =
126 match CicEnvironment.get_obj mutind with
127 C.InductiveDefinition (tl,ingredients,r) ->
128 let (_,_,arity,_) = List.nth tl i
129 and num_ingredients =
132 if k < cookingsno then i + List.length l else i
135 (arity,r,num_ingredients)
136 | _ -> raise WrongUriToInductiveDefinition
139 let num_to_eat = r + num_ingredients in
143 | (n,he::tl) when n > 0 -> eat_first (n - 1, tl)
144 | _ -> raise (Impossible 5)
146 eat_first (num_to_eat,tl)
148 whdaux (ts@l) (List.nth pl (j-1))
149 | C.Abst _| C.Cast _ | C.Implicit ->
150 raise (Impossible 2) (* we don't trust our whd ;-) *)
151 | _ -> if l = [] then t else C.Appl (t::l)
153 | C.Fix (i,fl) as t ->
154 let (_,recindex,_,body) = List.nth fl i in
157 Some (List.nth l recindex)
163 (match whdaux [] recparam with
165 | C.Appl ((C.MutConstruct _)::_) ->
167 let counter = ref (List.length fl) in
169 (fun _ -> decr counter ; S.subst (C.Fix (!counter,fl)))
173 (* Possible optimization: substituting whd recparam in l *)
175 | _ -> if l = [] then t else C.Appl (t::l)
177 | None -> if l = [] then t else C.Appl (t::l)
179 | C.CoFix (i,fl) as t ->
180 if l = [] then t else C.Appl (t::l)
184 prerr_endline ("PRIMA WHD" ^ CicPp.ppterm t) ; flush stderr ;
185 List.iter (function (Cic.Decl t) -> prerr_endline ("Context: " ^ CicPp.ppterm t) | (Cic.Def t) -> prerr_endline ("Context:= " ^ CicPp.ppterm t)) context ; flush stderr ; prerr_endline "<PRIMA WHD" ; flush stderr ;
190 t in prerr_endline "DOPO WHD" ; flush stderr ; res
194 (* t1, t2 must be well-typed *)
195 let are_convertible =
196 let module U = UriManager in
197 let rec aux context t1 t2 =
199 (* this trivial euristic cuts down the total time of about five times ;-) *)
200 (* this because most of the time t1 and t2 are "sintactically" the same *)
205 let module C = Cic in
207 (C.Rel n1, C.Rel n2) -> n1 = n2
208 | (C.Var uri1, C.Var uri2) -> U.eq uri1 uri2
209 | (C.Meta (n1,l1), C.Meta (n2,l2)) ->
217 | Some t1',Some t2' -> aux context t1' t2'
219 | (C.Sort s1, C.Sort s2) -> true (*CSC da finire con gli universi *)
220 | (C.Prod (name1,s1,t1), C.Prod(_,s2,t2)) ->
221 aux context s1 s2 && aux ((Some (name1, (C.Decl s1)))::context) t1 t2
222 | (C.Lambda (name1,s1,t1), C.Lambda(_,s2,t2)) ->
223 aux context s1 s2 && aux ((Some (name1, (C.Decl s1)))::context) t1 t2
224 | (C.LetIn (name1,s1,t1), C.LetIn(_,s2,t2)) ->
225 aux context s1 s2 && aux ((Some (name1, (C.Def s1)))::context) t1 t2
226 | (C.Appl l1, C.Appl l2) ->
228 List.fold_right2 (fun x y b -> aux context x y && b) l1 l2 true
230 Invalid_argument _ -> false
232 | (C.Const (uri1,_), C.Const (uri2,_)) ->
233 (*CSC: questo commento e' chiaro o delirante? Io lo sto scrivendo *)
234 (*CSC: mentre sono delirante, quindi ... *)
235 (* WARNING: it is really important that the two cookingsno are not*)
236 (* checked for equality. This allows not to cook an object with no*)
237 (* ingredients only to update the cookingsno. E.g: if a term t has*)
238 (* a reference to a term t1 which does not depend on any variable *)
239 (* and t1 depends on a term t2 (that can't depend on any variable *)
240 (* because of t1), then t1 cooked at every level could be the same*)
241 (* as t1 cooked at level 0. Doing so, t2 will be extended in t *)
242 (* with cookingsno 0 and not 2. But this will not cause any *)
243 (* trouble if here we don't check that the two cookingsno are *)
246 | (C.MutInd (uri1,k1,i1), C.MutInd (uri2,k2,i2)) ->
247 (* WARNIG: see the previous warning *)
248 U.eq uri1 uri2 && i1 = i2
249 | (C.MutConstruct (uri1,_,i1,j1), C.MutConstruct (uri2,_,i2,j2)) ->
250 (* WARNIG: see the previous warning *)
251 U.eq uri1 uri2 && i1 = i2 && j1 = j2
252 | (C.MutCase (uri1,_,i1,outtype1,term1,pl1),
253 C.MutCase (uri2,_,i2,outtype2,term2,pl2)) ->
254 (* WARNIG: see the previous warning *)
255 (* aux context outtype1 outtype2 should be true if *)
256 (* aux context pl1 pl2 *)
257 U.eq uri1 uri2 && i1 = i2 && aux context outtype1 outtype2 &&
258 aux context term1 term2 &&
259 List.fold_right2 (fun x y b -> b && aux context x y) pl1 pl2 true
260 | (C.Fix (i1,fl1), C.Fix (i2,fl2)) ->
262 List.map (function (n,_,ty,_) -> Some (C.Name n,(C.Decl ty))) fl1
266 (fun (_,recindex1,ty1,bo1) (_,recindex2,ty2,bo2) b ->
267 b && recindex1 = recindex2 && aux context ty1 ty2 &&
268 aux (tys@context) bo1 bo2)
270 | (C.CoFix (i1,fl1), C.CoFix (i2,fl2)) ->
272 List.map (function (n,ty,_) -> Some (C.Name n,(C.Decl ty))) fl1
276 (fun (_,ty1,bo1) (_,ty2,bo2) b ->
277 b && aux context ty1 ty2 && aux (tys@context) bo1 bo2)
279 | (C.Abst _, _) | (_, C.Abst _) | (C.Cast _, _) | (_, C.Cast _)
280 | (C.Implicit, _) | (_, C.Implicit) ->
281 raise (Impossible 3) (* we don't trust our whd ;-) *)
285 if aux2 t1 t2 then true
288 debug t1 [t2] "PREWHD";
289 let t1' = whd context t1
290 and t2' = whd context t2 in
291 debug t1' [t2'] "POSTWHD";