dtbasat: implement dba_sat_minimize()

* src/tgbaalgos/dtbasat.cc, src/tgbaalgos/dtbasat.hh: New files.
* src/tgbaalgos/Makefile.am: Add them.
* src/tgbatest/ltl2tgba.cc: Add option -RS.

src/tgbaalgos/dtbasat.hh

@@ -0,0 +1,46 @@
+// -*- coding: utf-8 -*-
+// Copyright (C) 2013 Laboratoire de Recherche et Développement
+// de l'Epita.
+//
+// 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 3 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 this program.  If not, see <http://www.gnu.org/licenses/>.
+
+#ifndef SPOT_TGBAALGOS_DTBASAT_HH
+# define SPOT_TGBAALGOS_DTBASAT_HH
+
+#include <iosfwd>
+#include "tgba/tgba.hh"
+#include "tgba/tgbaexplicit.hh"
+
+namespace spot
+{
+  /// \brief Attempt to reduce a deterministic TBA with a SAT solver.
+  ///
+  /// \param a the TGBA to reduce.  It should have only one acceptance
+  ///  set and be deterministic.  I.e., it should be a deterministic TBA.
+  ///
+  /// \param target_state_number the expected number of states wanted
+  /// in the resulting automaton.  If \a target_state_number is left
+  /// to its default value of -1, this function will attempt to build
+  /// the smallest possible deterministic TBA is can produce.
+  ///
+  /// If no automaton with \a target_state_number states is found, or
+  /// (in case <code>target_state_number == -1</code>) if no smaller
+  /// automaton is found, then a null pointer is returned.
+  SPOT_API tgba_explicit_number*
+  dba_sat_minimize(const tgba* a, int target_state_number = -1);
+}
+
+#endif // SPOT_TGBAALGOS_DTBASAT_HH