* src/ltlvisit/formlength.cc: Rename as ...

* src/ltlvisit/length.cc: ... this.
* src/ltlvisit/length.hh: New file, extracted from ...
* src/ltlvisit/reducform.hh: ... here.
* src/ltlvisit/Makefile.am (ltlvisit_HEADERS): Add length.hh.
(libltlvisit_la_SOURCES): Rename formlength.cc as length.cc.
* src/ltltest/reduc.cc: Include length.hh.

src/ltlvisit/length.hh

@@ -0,0 +1,40 @@
+// Copyright (C) 2004  Laboratoire d'Informatique de Paris 6 (LIP6),
+// département Systèmes Répartis Coopératifs (SRC), Université Pierre
+// et Marie Curie.
+//
+// This file is part of Spot, a model checking library.
+//
+// Spot 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.
+//
+// Spot 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 Spot; see the file COPYING.  If not, write to the Free
+// Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+// 02111-1307, USA.
+
+#ifndef SPOT_LTLVISIT_LENGTH_HH
+# define SPOT_LTLVISIT_LENGTH_HH
+
+#include "ltlast/formula.hh"
+
+namespace spot
+{
+  namespace ltl
+  {
+    /// \brief Compute the length of a formula.
+    ///
+    /// The length of a formula is the number of atomic properties,
+    /// constants, and operators (logical and temporal) occurring in
+    /// the formula.
+    int length(const formula* f);
+  }
+}
+
+#endif // SPOT_LTLVISIT_LENGTH_HH