Many improvements in tactics (and tactical) representation:

[helm.git] / helm / gTopLevel / proofEngine.mli

diff --git a/helm/gTopLevel/proofEngine.mli b/helm/gTopLevel/proofEngine.mli
index 1b110a66979d8d73104af0fe4cb198dc81e680f0..66bb4620e3dff4754b1d37be566c481c87ecbc6a 100644 (file)
--- a/helm/gTopLevel/proofEngine.mli
+++ b/helm/gTopLevel/proofEngine.mli
@@ -1,9 +1,33 @@
+(* 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/.
+ *)
 
 exception NotConvertible
 
   (* proof engine status *)
-val proof : ProofEngineTypes.proof ref
-val goal : ProofEngineTypes.goal ref
+val proof : ProofEngineTypes.proof option ref
+val goal : ProofEngineTypes.goal option ref
 
   (* start a new goal undoing part of the proof *)
 val perforate : Cic.context -> Cic.term -> Cic.term -> unit
@@ -35,4 +59,3 @@ val clear : Cic.hypothesis -> unit
   (* other tactics *)
 val elim_type : Cic.term -> unit
 val ring : unit -> unit
-