diff --git a/ChangeLog b/ChangeLog
index 41a799d84..632b0eb81 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,13 @@
+2003-06-30  Alexandre Duret-Lutz  <aduret@src.lip6.fr>
+
+	* src/tgba/tgbabddconcretefactory.cc: 
+	(tgba_bdd_concrete_factory::tgba_bdd_concrete_factory): New.
+	(tgba_bdd_concrete_factory::create_state): Update now_to_next_.
+	(tgba_bdd_concrete_factory::finish): Constraint Next variables
+	in the relation.
+	* src/tgba/tgbabddconcretefactory.hh 
+	(tgba_bdd_concrete_factory::now_to_next_): New variable.
+
 2003-06-28  Alexandre Duret-Lutz  <aduret@src.lip6.fr>
 
 	Fix errors reported by ICC.
diff --git a/src/tgba/tgbabddconcretefactory.hh b/src/tgba/tgbabddconcretefactory.hh
index c827d496a..83ac08e39 100644
--- a/src/tgba/tgbabddconcretefactory.hh
+++ b/src/tgba/tgbabddconcretefactory.hh
@@ -12,6 +12,8 @@ namespace spot
   class tgba_bdd_concrete_factory: public bdd_factory, public tgba_bdd_factory
   {
   public:
+    tgba_bdd_concrete_factory();
+
     virtual ~tgba_bdd_concrete_factory();
 
     /// Create a state variable for formula \a f.
@@ -66,6 +68,8 @@ namespace spot
 
     typedef std::map<const ltl::formula*, bdd> acc_map_;
     acc_map_ acc_;		///< BDD associated to each accepting condition
+    bddPair *now_to_next_;	///< \brief Rewriting pairs to transform
+                                ///  Now variables into Next variables.
   };
 
 }