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.
7 * HELM is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version 2
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13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with HELM; if not, write to the Free Software
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 let debug_print = fun _ -> ()
28 let rec injection_tac ~term =
29 let injection_tac ~term status =
30 let (proof, goal) = status in
32 let module U = UriManager in
33 let module P = PrimitiveTactics in
34 let module T = Tacticals in
35 let _,metasenv,_,_ = proof in
36 let _,context,_ = CicUtil.lookup_meta goal metasenv in
37 let termty,_ = (* TASSI: FIXME *)
38 CicTypeChecker.type_of_aux' metasenv context term CicUniv.empty_ugraph in
39 ProofEngineTypes.apply_tactic
41 (C.Appl [(C.MutInd (equri, 0, [])) ; tty ; t1 ; t2])
42 when LibraryObjects.is_eq_URI equri -> (
44 (C.MutInd (turi,typeno,exp_named_subst))
45 | (C.Appl (C.MutInd (turi,typeno,exp_named_subst)::_)) -> (
47 ((C.MutConstruct (uri1,typeno1,consno1,exp_named_subst1)),
48 (C.MutConstruct (uri2,typeno2,consno2,exp_named_subst2)))
49 when (uri1 = uri2) && (typeno1 = typeno2) &&
50 (consno1 = consno2) && (exp_named_subst1 = exp_named_subst2) ->
51 (* raise (ProofEngineTypes.Fail "Injection: nothing to do") ; *) T.id_tac
52 | ((C.Appl ((C.MutConstruct (uri1,typeno1,consno1,exp_named_subst1))::applist1)),
53 (C.Appl ((C.MutConstruct (uri2,typeno2,consno2,exp_named_subst2))::applist2)))
54 when (uri1 = uri2) && (typeno1 = typeno2) && (consno1 = consno2) && (exp_named_subst1 = exp_named_subst2) ->
55 let rec traverse_list i l1 l2 =
58 | hd1::tl1,hd2::tl2 ->
60 ~start:(injection1_tac ~i ~term)
61 ~continuation:(traverse_list (i+1) tl1 tl2)
62 | _ -> raise (ProofEngineTypes.Fail (lazy "Discriminate: i 2 termini hanno in testa lo stesso costruttore, ma applicato a un numero diverso di termini. possibile???"))
63 in traverse_list 1 applist1 applist2
64 | ((C.MutConstruct (uri1,typeno1,consno1,exp_named_subst1)),
65 (C.MutConstruct (uri2,typeno2,consno2,exp_named_subst2)))
66 | ((C.MutConstruct (uri1,typeno1,consno1,exp_named_subst1)),
67 (C.Appl ((C.MutConstruct (uri2,typeno2,consno2,exp_named_subst2))::_)))
68 | ((C.Appl ((C.MutConstruct (uri1,typeno1,consno1,exp_named_subst1))::_)),
69 (C.MutConstruct (uri2,typeno2,consno2,exp_named_subst2)))
70 | ((C.Appl ((C.MutConstruct (uri1,typeno1,consno1,exp_named_subst1))::_)),
71 (C.Appl ((C.MutConstruct (uri2,typeno2,consno2,exp_named_subst2))::_)))
72 when (consno1 <> consno2) || (exp_named_subst1 <> exp_named_subst2) ->
73 (* raise (ProofEngineTypes.Fail "Injection: not a projectable equality but a discriminable one") ; *) T.id_tac
74 | _ -> (* raise (ProofEngineTypes.Fail "Injection: not a projectable equality") ; *) T.id_tac
76 | _ -> raise (ProofEngineTypes.Fail (lazy "Injection: not a projectable equality"))
78 | _ -> raise (ProofEngineTypes.Fail (lazy "Injection: not an equation"))
81 ProofEngineTypes.mk_tactic (injection_tac ~term)
83 and injection1_tac ~term ~i =
84 let injection1_tac ~term ~i status =
85 let (proof, goal) = status in
86 (* precondizione: t1 e t2 hanno in testa lo stesso costruttore ma differiscono (o potrebbero differire?) nell'i-esimo parametro del costruttore *)
88 let module S = CicSubstitution in
89 let module U = UriManager in
90 let module P = PrimitiveTactics in
91 let module T = Tacticals in
92 let _,metasenv,_,_ = proof in
93 let _,context,_ = CicUtil.lookup_meta goal metasenv in
94 let termty,_ = (* TASSI: FIXME *)
95 CicTypeChecker.type_of_aux' metasenv context term CicUniv.empty_ugraph in
96 match termty with (* an equality *)
97 (C.Appl [(C.MutInd (equri, 0, [])) ; tty ; t1 ; t2])
98 when LibraryObjects.is_eq_URI equri -> (
99 match tty with (* some inductive type *)
100 (C.MutInd (turi,typeno,exp_named_subst))
101 | (C.Appl (C.MutInd (turi,typeno,exp_named_subst)::_)) ->
102 let t1',t2',consno = (* sono i due sottotermini che differiscono *)
104 ((C.Appl ((C.MutConstruct (uri1,typeno1,consno1,exp_named_subst1))::applist1)),
105 (C.Appl ((C.MutConstruct (uri2,typeno2,consno2,exp_named_subst2))::applist2)))
106 when (uri1 = uri2) && (typeno1 = typeno2) && (consno1 = consno2) && (exp_named_subst1 = exp_named_subst2) -> (* controllo ridondante *)
107 (List.nth applist1 (i-1)),(List.nth applist2 (i-1)),consno2
111 CicTypeChecker.type_of_aux' metasenv context t1'
112 CicUniv.empty_ugraph in
114 match fst(CicEnvironment.get_obj
115 CicUniv.empty_ugraph turi ) with
116 C.InductiveDefinition (ind_type_list,_,nr_ind_params_dx,_) ->
117 let _,_,_,constructor_list = (List.nth ind_type_list typeno) in
118 let i_constr_id,_ = List.nth constructor_list (consno - 1) in
120 (function (id,cty) ->
121 let reduced_cty = CicReduction.whd context cty in
124 C.Prod (_,_,target) when (k <= nr_ind_params_dx) ->
126 | C.Prod (binder,source,target) when (k > nr_ind_params_dx) ->
130 | C.Anonymous -> C.Name "y"
132 C.Lambda (binder',source,(aux target (k+1)))
134 let nr_param_constr = k - 1 - nr_ind_params_dx in
135 if (id = i_constr_id)
136 then C.Rel (nr_param_constr - i + 1)
137 else S.lift (nr_param_constr + 1) t1' (* + 1 per liftare anche il lambda agguinto esternamente al case *)
141 | _ -> raise (ProofEngineTypes.Fail (lazy "Discriminate: object is not an Inductive Definition: it's imposible"))
143 ProofEngineTypes.apply_tactic
145 ~start:(P.cut_tac (C.Appl [(C.MutInd (equri,0,[])) ; tty' ; t1' ; t2']))
148 ~start:(injection_tac ~term:(C.Rel 1))
149 ~continuation:T.id_tac (* !!! qui devo anche fare clear di term tranne al primo passaggio *)
152 ~start:(ProofEngineTypes.mk_tactic
154 let (proof, goal) = status in
155 let _,metasenv,_,_ = proof in
156 let _,context,gty = CicUtil.lookup_meta goal metasenv in
159 (C.Appl (C.MutInd (_,_,_)::arglist)) ->
161 | _ -> raise (ProofEngineTypes.Fail (lazy "Injection: goal after cut is not correct"))
163 ProofEngineTypes.apply_tactic
164 (ReductionTactics.change_tac
165 ~pattern:(ProofEngineTypes.conclusion_pattern
168 C.Appl [ C.Lambda (C.Name "x", tty,
169 C.MutCase (turi, typeno,
170 (C.Lambda ((C.Name "x"),
182 (EqualityTactics.rewrite_simpl_tac
183 ~direction:`LeftToRight
184 ~pattern:(ProofEngineTypes.conclusion_pattern None)
186 ~continuation:EqualityTactics.reflexivity_tac
190 | _ -> raise (ProofEngineTypes.Fail (lazy "Discriminate: not a discriminable equality"))
192 | _ -> raise (ProofEngineTypes.Fail (lazy "Discriminate: not an equality"))
194 ProofEngineTypes.mk_tactic (injection1_tac ~term ~i)
197 exception TwoDifferentSubtermsFound of int
199 (* term ha tipo t1=t2; funziona solo se t1 e t2 hanno in testa costruttori
202 let discriminate'_tac ~term =
203 let module C = Cic in
204 let module U = UriManager in
205 let module P = PrimitiveTactics in
206 let module T = Tacticals in
207 let fail msg = raise (ProofEngineTypes.Fail (lazy ("Discriminate: " ^ msg))) in
208 let find_discriminating_consno t1 t2 =
211 | C.MutConstruct _, C.MutConstruct _ when t1 = t2 -> None
212 | C.Appl ((C.MutConstruct _ as constr1) :: args1),
213 C.Appl ((C.MutConstruct _ as constr2) :: args2)
214 when constr1 = constr2 ->
215 let rec aux_list l1 l2 =
218 | hd1 :: tl1, hd2 :: tl2 ->
219 (match aux hd1 hd2 with
220 | None -> aux_list tl1 tl2
221 | Some _ as res -> res)
222 | _ -> (* same constructor applied to a different number of args *)
226 | ((C.MutConstruct (_,_,consno1,subst1)),
227 (C.MutConstruct (_,_,consno2,subst2)))
228 | ((C.MutConstruct (_,_,consno1,subst1)),
229 (C.Appl ((C.MutConstruct (_,_,consno2,subst2)) :: _)))
230 | ((C.Appl ((C.MutConstruct (_,_,consno1,subst1)) :: _)),
231 (C.MutConstruct (_,_,consno2,subst2)))
232 | ((C.Appl ((C.MutConstruct (_,_,consno1,subst1)) :: _)),
233 (C.Appl ((C.MutConstruct (_,_,consno2,subst2)) :: _)))
234 when (consno1 <> consno2) || (subst1 <> subst2) ->
236 | _ -> fail "not a discriminable equality"
240 let mk_pattern turi typeno consno context left_args =
241 (* a list of "True" except for the element in position consno which
243 match fst (CicEnvironment.get_obj CicUniv.empty_ugraph turi) with
244 | C.InductiveDefinition (ind_type_list,_,nr_ind_params,_) ->
245 let _,_,_,constructor_list = List.nth ind_type_list typeno in
246 let false_constr_id,_ = List.nth constructor_list (consno - 1) in
249 (* dubbio: e' corretto ridurre in questo context ??? *)
250 let red_ty = CicReduction.whd context cty in
253 | C.Prod (_,_,target) when (k <= nr_ind_params) ->
254 CicSubstitution.subst (List.nth left_args (k-1))
256 | C.Prod (binder,source,target) when (k > nr_ind_params) ->
257 C.Lambda (binder, source, (aux target (k+1)))
259 if (id = false_constr_id)
260 then (C.MutInd(LibraryObjects.false_URI (),0,[]))
261 else (C.MutInd(LibraryObjects.true_URI (),0,[]))
263 (CicSubstitution.lift 1 (aux red_ty 1)))
265 | _ -> (* object is not an inductive definition *)
268 let discriminate'_tac ~term status =
269 let (proof, goal) = status in
270 let _,metasenv,_,_ = proof in
271 let _,context,_ = CicUtil.lookup_meta goal metasenv in
273 CicTypeChecker.type_of_aux' metasenv context term CicUniv.empty_ugraph
276 | (C.Appl [(C.MutInd (equri, 0, [])) ; tty ; t1 ; t2])
277 when LibraryObjects.is_eq_URI equri ->
278 let turi,typeno,exp_named_subst,left_args =
280 | (C.MutInd (turi,typeno,exp_named_subst)) ->
281 turi,typeno,exp_named_subst,[]
282 | (C.Appl (C.MutInd (turi,typeno,exp_named_subst)::left_args)) ->
283 turi,typeno,exp_named_subst,left_args
284 | _ -> fail "not a discriminable equality"
287 match find_discriminating_consno t1 t2 with
288 | Some consno -> consno
289 | None -> fail "discriminating terms are structurally equal"
291 let pattern = mk_pattern turi typeno consno context left_args in
292 let (proof',goals') =
293 ProofEngineTypes.apply_tactic
294 (EliminationTactics.elim_type_tac
295 (C.MutInd (LibraryObjects.false_URI (), 0, [])))
300 let _,metasenv',_,_ = proof' in
301 let _,context',gty' = CicUtil.lookup_meta goal' metasenv' in
302 ProofEngineTypes.apply_tactic
305 (ReductionTactics.change_tac
306 ~pattern:(ProofEngineTypes.conclusion_pattern (Some gty'))
309 C.Lambda ( C.Name "x", tty,
310 C.MutCase (turi, typeno,
311 (C.Lambda ((C.Name "x"),
312 (CicSubstitution.lift 1 tty),
314 (C.Rel 1), pattern));
319 (EqualityTactics.rewrite_simpl_tac
320 ~direction:`RightToLeft
321 ~pattern:(ProofEngineTypes.conclusion_pattern None)
324 (IntroductionTactics.constructor_tac ~n:1)))
326 | [] -> fail "ElimType False left no goals"
327 | _ -> fail "ElimType False left more than one goal")
328 | _ -> fail "not an equality"
330 ProofEngineTypes.mk_tactic (discriminate'_tac ~term)
332 let discriminate_tac ~term =
333 let discriminate_tac ~term status =
334 ProofEngineTypes.apply_tactic
336 ~start:(* (injection_tac ~term) *) Tacticals.id_tac
337 ~continuation:(discriminate'_tac ~term)) (* NOOO!!! non term ma una (qualunque) delle nuove hyp introdotte da inject *)
340 ProofEngineTypes.mk_tactic (discriminate_tac ~term)
342 let decide_equality_tac =
343 (* il goal e' un termine della forma t1=t2\/~t1=t2; la tattica decide se l'uguaglianza
344 e' vera o no e lo risolve *)
347 let compare_tac ~term = Tacticals.id_tac
349 (* term is in the form t1=t2; the tactic leaves two goals: in the first you have to *)
350 (* demonstrate the goal with the additional hyp that t1=t2, in the second the hyp is ~t1=t2 *)
351 let module C = Cic in
352 let module U = UriManager in
353 let module P = PrimitiveTactics in
354 let module T = Tacticals in
355 let _,metasenv,_,_ = proof in
356 let _,context,gty = CicUtil.lookup_meta goal metasenv in
357 let termty = (CicTypeChecker.type_of_aux' metasenv context term) in
359 (C.Appl [(C.MutInd (uri, 0, [])); _; t1; t2]) when (uri = (U.uri_of_string "cic:/Coq/Init/Logic/eq.ind")) ->
361 let term' = (* (t1=t2)\/~(t1=t2) *)
363 (C.MutInd ((U.uri_of_string "cic:/Coq/Init/Logic/or.ind"), 0, [])) ;
366 (C.MutInd ((U.uri_of_string "cic:/Coq/Init/Logic/eq.ind"), 1, [])) ;
368 C.Appl [C.Const ((U.uri_of_string "cic:/Coq/Init/Logic/not.con"), []) ; t2]
373 ~start:(P.cut_tac ~term:term')
375 T.then_ ~start:(P.intros_tac) ~continuation:(P.elim_intros_simpl_tac ~term:(C.Rel 1)) ;
378 | (C.Appl [(C.MutInd (uri, 0, [])); _; t1; t2]) when (uri = (U.uri_of_string "cic:/Coq/Init/Logic_Type/eqT.ind")) ->
379 let term' = (* (t1=t2) \/ ~(t1=t2) *)
381 (C.MutInd ((U.uri_of_string "cic:/Coq/Init/Logic/or.ind"), 0, [])) ;
384 (C.MutInd ((U.uri_of_string "cic:/Coq/Init/Logic_Type/eqT.ind"), 1, [])) ;
386 C.Appl [C.Const ((U.uri_of_string "cic:/Coq/Init/Logic/not.con"), []) ; t2]
391 ~start:(P.cut_tac ~term:term')
393 T.then_ ~start:(P.intros_tac) ~continuation:(P.elim_intros_simpl_tac ~term:(C.Rel 1)) ;
396 | _ -> raise (ProofEngineTypes.Fail "Compare: Not an equality")
402 (* DISCRIMINTATE SENZA INJECTION
404 exception TwoDifferentSubtermsFound of (Cic.term * Cic.term * int)
406 let discriminate_tac ~term status =
407 let module C = Cic in
408 let module U = UriManager in
409 let module P = PrimitiveTactics in
410 let module T = Tacticals in
411 let (proof, goal) = status in
412 let _,metasenv,_,_ = proof in
413 let _,context,_ = CicUtil.lookup_meta goal metasenv in
414 let termty = (CicTypeChecker.type_of_aux' metasenv context term) in
416 (C.Appl [(C.MutInd (equri, 0, [])) ; tty ; t1 ; t2])
417 when (U.eq equri (U.uri_of_string "cic:/Coq/Init/Logic/eq.ind"))
418 or (U.eq equri (U.uri_of_string "cic:/Coq/Init/Logic_Type/eqT.ind")) -> (
420 (C.MutInd (turi,typeno,exp_named_subst))
421 | (C.Appl (C.MutInd (turi,typeno,exp_named_subst)::_)) ->
423 let (t1',t2',consno2') = (* bruuutto: uso un eccezione per terminare con successo! buuu!! :-/ *)
425 let rec traverse t1 t2 =
426 debug_print (lazy ("XXXX t1 " ^ CicPp.ppterm t1)) ;
427 debug_print (lazy ("XXXX t2 " ^ CicPp.ppterm t2)) ;
429 ((C.MutConstruct (uri1,typeno1,consno1,exp_named_subst1)),
430 (C.MutConstruct (uri2,typeno2,consno2,exp_named_subst2)))
431 when (uri1 = uri2) && (typeno1 = typeno2) && (consno1 = consno2) && (exp_named_subst1 = exp_named_subst2) ->
433 | ((C.Appl ((C.MutConstruct (uri1,typeno1,consno1,exp_named_subst1))::applist1)),
434 (C.Appl ((C.MutConstruct (uri2,typeno2,consno2,exp_named_subst2))::applist2)))
435 when (uri1 = uri2) && (typeno1 = typeno2) && (consno1 = consno2) && (exp_named_subst1 = exp_named_subst2) ->
436 let rec traverse_list l1 l2 =
439 | hd1::tl1,hd2::tl2 -> traverse hd1 hd2; traverse_list tl1 tl2
440 | _ -> raise (ProofEngineTypes.Fail "Discriminate: i 2 termini hanno in testa lo stesso costruttore, ma applicato a un numero diverso di termini. possibile???")
441 in traverse_list applist1 applist2
443 | ((C.MutConstruct (uri1,typeno1,consno1,exp_named_subst1)),
444 (C.MutConstruct (uri2,typeno2,consno2,exp_named_subst2)))
445 | ((C.MutConstruct (uri1,typeno1,consno1,exp_named_subst1)),
446 (C.Appl ((C.MutConstruct (uri2,typeno2,consno2,exp_named_subst2))::_)))
447 | ((C.Appl ((C.MutConstruct (uri1,typeno1,consno1,exp_named_subst1))::_)),
448 (C.MutConstruct (uri2,typeno2,consno2,exp_named_subst2)))
449 | ((C.Appl ((C.MutConstruct (uri1,typeno1,consno1,exp_named_subst1))::_)),
450 (C.Appl ((C.MutConstruct (uri2,typeno2,consno2,exp_named_subst2))::_)))
451 when (consno1 <> consno2) || (exp_named_subst1 <> exp_named_subst2) ->
452 raise (TwoDifferentSubtermsFound (t1,t2,consno2))
453 | _ -> raise (ProofEngineTypes.Fail "Discriminate: not a discriminable equality")
455 with (TwoDifferentSubtermsFound (t1,t2,consno2)) -> (t1,t2,consno2)
457 debug_print (lazy ("XXXX consno2' " ^ (string_of_int consno2'))) ;
459 then raise (ProofEngineTypes.Fail "Discriminate: Discriminating terms are structurally equal")
463 (* a list of "True" except for the element in position consno2' which is "False" *)
464 match fst(CicEnvironment.get_obj turi
465 CicUniv.empty_ugraph) with
466 C.InductiveDefinition (ind_type_list,_,nr_ind_params) ->
467 debug_print (lazy ("XXXX nth " ^ (string_of_int (List.length ind_type_list)) ^ " " ^ (string_of_int typeno))) ;
468 let _,_,_,constructor_list = (List.nth ind_type_list typeno) in
469 debug_print (lazy ("XXXX nth " ^ (string_of_int (List.length constructor_list)) ^ " " ^ (string_of_int consno2'))) ;
470 let false_constr_id,_ = List.nth constructor_list (consno2' - 1) in
471 debug_print (lazy "XXXX nth funzionano ") ;
473 (function (id,cty) ->
474 let red_ty = CicReduction.whd context cty in (* dubbio: e' corretto ridurre in questo context ??? *)
477 C.Prod (_,_,target) when (k <= nr_ind_params) ->
479 | C.Prod (binder,source,target) when (k > nr_ind_params) ->
480 C.Lambda (binder,source,(aux target (k+1)))
482 if (id = false_constr_id)
483 then (C.MutInd (U.uri_of_string "cic:/Coq/Init/Logic/False.ind") 0 [])
484 else (C.MutInd (U.uri_of_string "cic:/Coq/Init/Logic/True.ind") 0 [])
488 | _ -> raise (ProofEngineTypes.Fail "Discriminate: object is not an Inductive Definition: it's imposible")
491 let (proof',goals') =
492 EliminationTactics.elim_type_tac
493 ~term:(C.MutInd (U.uri_of_string "cic:/Coq/Init/Logic/False.ind") 0 [] )
498 let _,metasenv',_,_ = proof' in
499 let _,context',gty' =
500 CicUtil.lookup_meta goal' metasenv'
512 (C.Lambda ((C.Name "x"),tty,(C.Sort C.Prop))),
521 debug_print (lazy ("XXXX rewrite<-: " ^ CicPp.ppterm (CicTypeChecker.type_of_aux' metasenv' context' (C.Appl [(C.MutInd (equri,0,[])) ; tty ; t1' ; t2']))));
522 debug_print (lazy ("XXXX rewrite<-: " ^ CicPp.ppterm (C.Appl [(C.MutInd (equri,0,[])) ; tty ; t1' ; t2']))) ;
523 debug_print (lazy ("XXXX equri: " ^ U.string_of_uri equri)) ;
524 debug_print (lazy ("XXXX tty : " ^ CicPp.ppterm tty)) ;
525 debug_print (lazy ("XXXX tt1': " ^ CicPp.ppterm (CicTypeChecker.type_of_aux' metasenv' context' t1'))) ;
526 debug_print (lazy ("XXXX tt2': " ^ CicPp.ppterm (CicTypeChecker.type_of_aux' metasenv' context' t2'))) ;
527 if (CicTypeChecker.type_of_aux' metasenv' context' t1') <> tty then debug_print (lazy ("XXXX tt1': " ^ CicPp.ppterm (CicTypeChecker.type_of_aux' metasenv' context' t1'))) ;
528 if (CicTypeChecker.type_of_aux' metasenv' context' t2') <> tty then debug_print (lazy ("XXXX tt2': " ^ CicPp.ppterm (CicTypeChecker.type_of_aux' metasenv' context' t2'))) ;
529 if (CicTypeChecker.type_of_aux' metasenv' context' t1') <> (CicTypeChecker.type_of_aux' metasenv' context' t2')
530 then debug_print (lazy ("XXXX tt1': " ^ CicPp.ppterm (CicTypeChecker.type_of_aux'
531 metasenv' context' t1'))) ; debug_print (lazy ("XXXX tt2': " ^ CicPp.ppterm (CicTypeChecker.type_of_aux' metasenv' context' t2'))) ;
533 let termty' = ProofEngineReduction.replace_lifting ~equality:(==) ~what:t1 ~with_what:t1' ~where:termty in
534 let termty'' = ProofEngineReduction.replace_lifting ~equality:(==) ~what:t2 ~with_what:t2' ~where:termty' in
536 debug_print (lazy ("XXXX rewrite<- " ^ CicPp.ppterm term ^ " : " ^ CicPp.ppterm (CicTypeChecker.type_of_aux' metasenv' context' term)));
538 ~start:(EqualityTactics.rewrite_back_simpl_tac ~term:term)
539 ~continuation:(IntroductionTactics.constructor_tac ~n:1)
542 | _ -> raise (ProofEngineTypes.Fail "Discriminate: ElimType False left more (or less) than one goal")
544 | _ -> raise (ProofEngineTypes.Fail "Discriminate: not a discriminable equality")
546 | _ -> raise (ProofEngineTypes.Fail "Discriminate: not an equality")