diff --git a/ChangeLog b/ChangeLog
index 049d61ab5..04980bbcc 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,9 @@
 2003-07-10  Alexandre Duret-Lutz  <aduret@src.lip6.fr>
 
+	* src/tgbaalgos/ltl2tgba.cc (ltl_trad_visitor::visit(multop)): 
+	Forward root_ to children of And.
+	(ltl_trad_visitor::recurse): Take a root argument.
+
 	* src/tgba/tgbabddconcretefactory.hh
 	(tgba_bdd_concrete_factory::add_relation): Rename as ...
 	(tgba_bdd_concrete_factory::constrain_relation): ... this.
diff --git a/src/tgbaalgos/ltl2tgba.cc b/src/tgbaalgos/ltl2tgba.cc
index 3b8986682..00c1383c6 100644
--- a/src/tgbaalgos/ltl2tgba.cc
+++ b/src/tgbaalgos/ltl2tgba.cc
@@ -191,11 +191,17 @@ namespace spot
     visit(const multop* node)
     {
       int op = -1;
+      bool root = false;
       switch (node->op())
 	{
 	case multop::And:
 	  op = bddop_and;
 	  res_ = bddtrue;
+	  // When the root formula is a conjunction it's ok to
+	  // consider all children as root formulae.  This allows the
+	  // root-G trick to save many more variable.  (See the
+	  // translation of G.)
+	  root = root_;
 	  break;
 	case multop::Or:
 	  op = bddop_or;
@@ -206,14 +212,14 @@ namespace spot
       unsigned s = node->size();
       for (unsigned n = 0; n < s; ++n)
 	{
-	  res_ = bdd_apply(res_, recurse(node->nth(n)), op);
+	  res_ = bdd_apply(res_, recurse(node->nth(n), root), op);
 	}
     }
 
     bdd
-    recurse(const formula* f)
+    recurse(const formula* f, bool root = false)
     {
-      ltl_trad_visitor v(fact_);
+      ltl_trad_visitor v(fact_, root);
       f->accept(v);
       return v.result();
     }