--- /dev/null
+(* Copyright (C) 2002, 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/.
+ *)
+
+(* $Id$ *)
+
+let absurd_tac ~term =
+ let absurd_tac ~term status =
+ let (proof, goal) = status in
+ let module C = Cic in
+ let module U = UriManager in
+ let module P = PrimitiveTactics in
+ let _,metasenv,_subst,_,_, _ = proof in
+ let _,context,ty = CicUtil.lookup_meta goal metasenv in
+ let absurd_URI =
+ match LibraryObjects.absurd_URI () with
+ Some uri -> uri
+ | None -> raise (ProofEngineTypes.Fail (lazy "You need to register the default \"absurd\" theorem first. Please use the \"default\" command"))
+ in
+ let ty_term,_ =
+ CicTypeChecker.type_of_aux' metasenv context term CicUniv.empty_ugraph in
+ if (ty_term = (C.Sort C.Prop)) (* ma questo controllo serve?? *)
+ then ProofEngineTypes.apply_tactic
+ (P.apply_tac
+ ~term:(
+ C.Appl [(C.Const (absurd_URI, [] )) ;
+ term ; ty])
+ )
+ status
+ else raise (ProofEngineTypes.Fail (lazy "Absurd: Not a Proposition"))
+ in
+ ProofEngineTypes.mk_tactic (absurd_tac ~term)
+;;
+
+(* FG: METTERE I NOMI ANCHE QUI? CSC: in teoria si', per la intros*)
+let contradiction_tac =
+ let contradiction_tac status =
+ let module C = Cic in
+ let module U = UriManager in
+ let module P = PrimitiveTactics in
+ let module T = Tacticals in
+ let false_URI =
+ match LibraryObjects.false_URI () with
+ Some uri -> uri
+ | None -> raise (ProofEngineTypes.Fail (lazy "You need to register the default \"false\" definition first. Please use the \"default\" command"))
+ in
+ try
+ ProofEngineTypes.apply_tactic (
+ T.then_
+ ~start:(P.intros_tac ())
+ ~continuation:(
+ T.then_
+ ~start:
+ (EliminationTactics.elim_type_tac (C.MutInd (false_URI, 0, [])))
+ ~continuation: VariousTactics.assumption_tac))
+ status
+ with
+ ProofEngineTypes.Fail msg when Lazy.force msg = "Assumption: No such assumption" -> raise (ProofEngineTypes.Fail (lazy "Contradiction: No such assumption"))
+ (* sarebbe piu' elegante se Assumtion sollevasse un'eccezione tutta sua che questa cattura, magari con l'aiuto di try_tactics *)
+ in
+ ProofEngineTypes.mk_tactic contradiction_tac
+;;
+
+(* Questa era in fourierR.ml
+(* !!!!! fix !!!!!!!!!! *)
+let contradiction_tac (proof,goal)=
+ Tacticals.then_
+ ~start:(PrimitiveTactics.intros_tac ~name:"bo?" ) (*inutile sia questo che quello prima della chiamata*)
+ ~continuation:(Tacticals.then_
+ ~start:(VariousTactics.elim_type_tac ~term:_False)
+ ~continuation:(assumption_tac))
+ (proof,goal)
+;;
+*)
+
+