* src/tgbaalgos/magic.hh: Fix a comment and remove se05 interface.

* src/tgbaalgos/magic.cc: Fix a comment.
* src/tgbaalgos/se05.hh: New file.
* src/tgbaalgos/se05.cc: Fix a comment.
* src/tgbaalgos/tau03.hh: New file.
* src/tgbaalgos/tau03.cc: New file.
* src/tgbaalgos/Makefile.am: Add it.
* src/tgbatest/ltl2tgba.cc: Add tau03 new emptiness check.
* src/tgbatest/randtgba.cc: Add tau03 new emptiness check.
* src/tgbatest/emptchkr: Fix a comment.
* src/tgbatest/tba_samples_from_spin/explicit1_1.tba,
src/tgbatest/tba_samples_from_spin/explicit1_2.tba,
src/tgbatest/tba_samples_from_spin/explicit1_3.tba,
src/tgbatest/tba_samples_from_spin/explicit1_4.tba,
src/tgbatest/tba_samples_from_spin/explicit1_5.tba,
src/tgbatest/tba_samples_from_spin/explicit1_6.tba,
src/tgbatest/tba_samples_from_spin/explicit1_7.tba,
src/tgbatest/tba_samples_from_spin/explicit1_8.tba,
src/tgbatest/tba_samples_from_spin/explicit1_9.tba,
src/tgbatest/tba_samples_from_spin/explicit2_1.tba,
src/tgbatest/tba_samples_from_spin/explicit2_2.tba,
src/tgbatest/tba_samples_from_spin/explicit2_3.tba,
src/tgbatest/tba_samples_from_spin/explicit2_4.tba,
src/tgbatest/tba_samples_from_spin/explicit2_5.tba,
src/tgbatest/tba_samples_from_spin/explicit2_6.tba,
src/tgbatest/tba_samples_from_spin/explicit2_7.tba,
src/tgbatest/tba_samples_from_spin/explicit2_8.tba,
src/tgbatest/tba_samples_from_spin/explicit2_9.tba: New files
* src/tgbatest/tba_samples_from_spin.test : New test.
* src/tgbatest/Makefile.am: Add it.

ChangeLog

@@ -1,3 +1,36 @@
+2004-11-17  Poitrenaud Denis  <denis@src.lip6.fr>
+
+	* src/tgbaalgos/magic.hh: Fix a comment and remove se05 interface.
+	* src/tgbaalgos/magic.cc: Fix a comment.
+	* src/tgbaalgos/se05.hh: New file.
+	* src/tgbaalgos/se05.cc: Fix a comment.
+	* src/tgbaalgos/tau03.hh: New file.
+	* src/tgbaalgos/tau03.cc: New file.
+	* src/tgbaalgos/Makefile.am: Add it.
+	* src/tgbatest/ltl2tgba.cc: Add tau03 new emptiness check.
+	* src/tgbatest/randtgba.cc: Add tau03 new emptiness check.
+	* src/tgbatest/emptchkr: Fix a comment.
+	* src/tgbatest/tba_samples_from_spin/explicit1_1.tba,
+	src/tgbatest/tba_samples_from_spin/explicit1_2.tba,
+	src/tgbatest/tba_samples_from_spin/explicit1_3.tba,
+	src/tgbatest/tba_samples_from_spin/explicit1_4.tba,
+	src/tgbatest/tba_samples_from_spin/explicit1_5.tba,
+	src/tgbatest/tba_samples_from_spin/explicit1_6.tba,
+	src/tgbatest/tba_samples_from_spin/explicit1_7.tba,
+	src/tgbatest/tba_samples_from_spin/explicit1_8.tba,
+	src/tgbatest/tba_samples_from_spin/explicit1_9.tba,
+	src/tgbatest/tba_samples_from_spin/explicit2_1.tba,
+	src/tgbatest/tba_samples_from_spin/explicit2_2.tba,
+	src/tgbatest/tba_samples_from_spin/explicit2_3.tba,
+	src/tgbatest/tba_samples_from_spin/explicit2_4.tba,
+	src/tgbatest/tba_samples_from_spin/explicit2_5.tba,
+	src/tgbatest/tba_samples_from_spin/explicit2_6.tba,
+	src/tgbatest/tba_samples_from_spin/explicit2_7.tba,
+	src/tgbatest/tba_samples_from_spin/explicit2_8.tba,
+	src/tgbatest/tba_samples_from_spin/explicit2_9.tba: New files
+	* src/tgbatest/tba_samples_from_spin.test : New test.
+	* src/tgbatest/Makefile.am: Add it.
+
 2004-11-17  Alexandre Duret-Lutz  <adl@src.lip6.fr>
 
 	* src/tgba/tgba.hh, src/tgbaalgos/dotty.hh,

src/tgbaalgos/Makefile.am

@@ -43,7 +43,9 @@ tgbaalgos_HEADERS = \
   replayrun.hh \
   rundotdec.hh \
   save.hh \
+  se05.hh \
   stats.hh \
+  tau03.hh \
   reductgba_sim.hh
 
 noinst_LTLIBRARIES = libtgbaalgos.la
@@ -66,6 +68,7 @@ libtgbaalgos_la_SOURCES = \
   save.cc \
   se05.cc \
   stats.cc \
+  tau03.cc \
   reductgba_sim.cc \
   reductgba_sim_del.cc
 

src/tgbaalgos/magic.cc

@@ -19,12 +19,12 @@
 // Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
 // 02111-1307, USA.
 
-#include <cstring>
+#include <cassert>
-#include <iostream>
-#include "misc/hash.hh"
 #include <list>
 #include <iterator>
-#include <cassert>
+#include "misc/hash.hh"
+#include "tgba/tgba.hh"
+#include "emptiness.hh"
 #include "magic.hh"
 
 namespace spot
@@ -68,7 +68,7 @@ namespace spot
 
       /// \brief Perform a Magic Search.
       ///
-      /// \return non null pointer iff the algorithm has found a 
+      /// \return non null pointer iff the algorithm has found a
       /// new accepting path.
       ///
       /// check() can be called several times (until it returns a null
@@ -129,10 +129,10 @@ namespace spot
         const state* s;
         /// Design the next successor of \a s which has to be visited.
         tgba_succ_iterator* it;
-        /// The label of the transition followed to reach \a s
+        /// The label of the transition traversed to reach \a s
         /// (false for the first one).
         bdd label;
-        /// The acc set of the transition followed to reach \a s
+        /// The acceptance set of the transition traversed to reach \a s
         /// (false for the first one).
         bdd acc;
       };
@@ -255,9 +255,6 @@ namespace spot
                 f.it->next();
                 typename heap::color_ref c = h.get_color_ref(s_prime);
                 if (c.is_white())
-                // Notice that this case is taken into account only to  
-                // support successive calls to the check method. Without
-                // this functionnality, one can check assert(c.is_white()).
                 // Go down the edge (f.s, <label, acc>, s_prime)
                   {
                     ++nbn;

src/tgbaalgos/magic.hh

@@ -22,25 +22,26 @@
 #ifndef SPOT_TGBAALGOS_MAGIC_HH
 # define SPOT_TGBAALGOS_MAGIC_HH
 
-#include "tgba/tgba.hh"
+#include <cstddef>
-#include "emptiness.hh"
 
 namespace spot
 {
+  class tgba;
+  class emptiness_check;
 
   /// \addtogroup emptiness_check_algorithms
   /// @{
 
   /// \brief Returns an emptiness checker on the spot::tgba automaton \a a.
-  /// During the visit of \a a, the returned checker stores explicitely all
-  /// the traversed states.
   ///
   /// \pre The automaton \a a must have at most one accepting condition (i.e.
   /// it is a TBA).
   ///
-  /// The method \a check() of the returned checker can be called several times
+  /// During the visit of \a a, the returned checker stores explicitely all
+  /// the traversed states.
+  /// The method \a check() of the checker can be called several times
   /// (until it returns a null pointer) to enumerate all the visited accepting
-  /// paths. The implemented algorithm is the following.
+  /// paths. The implemented algorithm is the following:
   ///
   /// \verbatim
   /// procedure check ()
@@ -95,111 +96,31 @@ namespace spot
   emptiness_check* explicit_magic_search(const tgba *a);
 
   /// \brief Returns an emptiness checker on the spot::tgba automaton \a a.
-  /// During the visit of \a a, the returned checker does not store explicitely
-  /// the traversed states but uses the bit state hashing technic. However, the
-  /// implemented algorithm is the same as the one of
-  /// spot::explicit_magic_search.
   ///
   /// \pre The automaton \a a must have at most one accepting condition (i.e.
   /// it is a TBA).
   ///
+  /// During the visit of \a a, the returned checker does not store explicitely
+  /// the traversed states but uses the bit-state hashing technic presented in:
+  ///
+  /// \verbatim
+  /// @book{Holzmann91,
+  ///    author = {G.J. Holzmann},
+  ///    title = {Design and Validation of Computer Protocols},
+  ///    publisher = {Prentice-Hall},
+  ///    address = {Englewood Cliffs, New Jersey},
+  ///    year = {1991}
+  /// }
+  /// \endverbatim
+  ///
+  /// Consequently, the detection of an acceptence cycle is not ensured. The
+  /// implemented algorithm is the same as the one of
+  /// spot::explicit_magic_search.
+  ///
   /// \sa spot::explicit_magic_search
   ///
   emptiness_check* bit_state_hashing_magic_search(const tgba *a, size_t size);
 
-  /// \brief Returns an emptiness check on the spot::tgba automaton \a a.
-  /// During the visit of \a a, the returned checker stores explicitely all
-  /// the traversed states.
-  ///
-  /// \pre The automaton \a a must have at most one accepting condition (i.e.
-  /// it is a TBA).
-  ///
-  /// The method \a check() of the returned checker can be called several times
-  /// (until it returns a null pointer) to enumerate all the visited accepting
-  /// paths. The implemented algorithm is the following:
-  ///
-  /// \verbatim
-  /// procedure check ()
-  /// begin
-  ///   weight = 0;
-  ///   call dfs_blue(s0);
-  /// end;
-  ///
-  /// procedure dfs_blue (s)
-  /// begin
-  ///   s.color = cyan;
-  ///   s.weight = weight;
-  ///   for all t in post(s) do
-  ///     if t.color == white then
-  ///       if the edge (s,t) is accepting then
-  ///         weight = weight + 1;
-  ///       end if;
-  ///       call dfs_blue(t);
-  ///       if the edge (s,t) is accepting then
-  ///         weight = weight - 1;
-  ///       end if;
-  ///     else if t.color == cyan and
-  ///             (the edge (s,t) is accepting or
-  ///              weight > t.weight) then
-  ///       report cycle;
-  ///     end if;
-  ///     if the edge (s,t) is accepting then
-  ///       call dfs_red(t);
-  ///     end if;
-  ///   end for;
-  ///   s.color = blue;
-  /// end;
-  ///
-  /// procedure dfs_red(s)
-  /// begin
-  ///   if s.color == cyan then
-  ///     report cycle;
-  ///   end if;
-  ///   s.color = red;
-  ///   for all t in post(s) do
-  ///     if t.color != red then
-  ///       call dfs_red(t);
-  ///     end if;
-  ///   end for;
-  /// end;
-  /// \endverbatim
-  ///
-  /// It is an adaptation to TBA (and a slight extension) of the one
-  /// presented in
-  /// \verbatim
-  ///  InProceedings{   schwoon.05.tacas,
-  ///    author        = {Stephan Schwoon and Javier Esparza},
-  ///    title         = {A Note on On-The-Fly Verification Algorithms},
-  ///    booktitle     = {TACAS'05},
-  ///    pages         = {},
-  ///    year          = {2005},
-  ///    volume        = {},
-  ///    series        = {LNCS},
-  ///    publisher     = {Springer-Verlag}
-  ///  }
-  /// \endverbatim
-  ///
-  /// The extention consists in the introduction of a weight associated
-  /// to each state in the blue stack (the cyan states). The weight of a
-  /// cyan state corresponds to the number of accepting arcs traversed to reach
-  /// it from the initial state. Weights are used to detect accepting cycle in
-  /// the blue dfs.
-  ///
-  emptiness_check* explicit_se05_search(const tgba *a);
-
-  /// \brief Returns an emptiness checker on the spot::tgba automaton \a a.
-  /// During the visit of \a a, the returned checker does not store explicitely
-  /// the traversed states but uses the bit state hashing technic. However, the
-  /// implemented algorithm is the same as the one of
-  /// spot::explicit_se05_search.
-  ///
-  /// \pre The automaton \a a must have at most one accepting condition (i.e.
-  /// it is a TBA).
-  ///
-  /// \sa spot::explicit_se05_search
-  ///
-  emptiness_check* bit_state_hashing_se05_search(const tgba *a, size_t size);
-
   /// @}
 }
 

src/tgbaalgos/se05.cc

@@ -24,11 +24,14 @@
 #ifdef TRACE
 #include <iostream>
 #endif
-#include "misc/hash.hh"
+
+#include <cassert>
 #include <list>
 #include <iterator>
-#include <cassert>
+#include "misc/hash.hh"
-#include "magic.hh"
+#include "tgba/tgba.hh"
+#include "emptiness.hh"
+#include "se05.hh"
 
 namespace spot
 {
@@ -133,10 +136,10 @@ namespace spot
         const state* s;
         /// Design the next successor of \a s which has to be visited.
         tgba_succ_iterator* it;
-        /// The label of the transition followed to reach \a s
+        /// The label of the transition traversed to reach \a s
         /// (false for the first one).
         bdd label;
-        /// The acc set of the transition followed to reach \a s
+        /// The acceptance set of the transition traversed to reach \a s
         /// (false for the first one).
         bdd acc;
       };
@@ -181,7 +184,7 @@ namespace spot
             stack_item& f = st_blue.front();
 #ifdef TRACE
             std::cout << "DFS_BLUE treats: "
-            << a->format_state(f.s) << std::endl;
+                      << a->format_state(f.s) << std::endl;
 #endif
             if (!f.it->done())
               {
@@ -299,7 +302,7 @@ namespace spot
             stack_item& f = st_red.front();
 #ifdef TRACE
             std::cout << "DFS_RED treats: "
-            << a->format_state(f.s) << std::endl;
+                      << a->format_state(f.s) << std::endl;
 #endif
             if (!f.it->done())
               {
@@ -314,9 +317,6 @@ namespace spot
                 f.it->next();
                 typename heap::color_ref c = h.get_color_ref(s_prime);
                 if (c.is_white())
-                // Notice that this case is taken into account only to
-                // support successive calls to the check method. Without
-                // this functionnality => assert(c.is_white())
                 // Go down the edge (f.s, <label, acc>, s_prime)
                   {
 #ifdef TRACE

src/tgbaalgos/se05.hh

@@ -0,0 +1,148 @@
+// Copyright (C) 2003, 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_TGBAALGOS_SE05_HH
+# define SPOT_TGBAALGOS_SE05_HH
+
+#include <cstddef>
+
+namespace spot
+{
+  class tgba;
+  class emptiness_check;
+
+  /// \addtogroup emptiness_check_algorithms
+  /// @{
+
+  /// \brief Returns an emptiness check on the spot::tgba automaton \a a.
+  ///
+  /// \pre The automaton \a a must have at most one accepting condition (i.e.
+  /// it is a TBA).
+  ///
+  /// During the visit of \a a, the returned checker stores explicitely all
+  /// the traversed states.
+  /// The method \a check() of the checker can be called several times
+  /// (until it returns a null pointer) to enumerate all the visited accepting
+  /// paths. The implemented algorithm is an optimization of
+  /// spot::explicit_magic_search and is the following:
+  ///
+  /// \verbatim
+  /// procedure check ()
+  /// begin
+  ///   weight = 0;
+  ///   call dfs_blue(s0);
+  /// end;
+  ///
+  /// procedure dfs_blue (s)
+  /// begin
+  ///   s.color = cyan;
+  ///   s.weight = weight;
+  ///   for all t in post(s) do
+  ///     if t.color == white then
+  ///       if the edge (s,t) is accepting then
+  ///         weight = weight + 1;
+  ///       end if;
+  ///       call dfs_blue(t);
+  ///       if the edge (s,t) is accepting then
+  ///         weight = weight - 1;
+  ///       end if;
+  ///     else if t.color == cyan and
+  ///             (the edge (s,t) is accepting or
+  ///              weight > t.weight) then
+  ///       report cycle;
+  ///     end if;
+  ///     if the edge (s,t) is accepting then
+  ///       call dfs_red(t);
+  ///     end if;
+  ///   end for;
+  ///   s.color = blue;
+  /// end;
+  ///
+  /// procedure dfs_red(s)
+  /// begin
+  ///   if s.color == cyan then
+  ///     report cycle;
+  ///   end if;
+  ///   s.color = red;
+  ///   for all t in post(s) do
+  ///     if t.color != red then
+  ///       call dfs_red(t);
+  ///     end if;
+  ///   end for;
+  /// end;
+  /// \endverbatim
+  ///
+  /// It is an adaptation to TBA (and a slight extension) of the one
+  /// presented in
+  /// \verbatim
+  ///  @techreport{SE04,
+  ///    author = {Stefan Schwoon and Javier Esparza},
+  ///    institution = {Universit{\"a}t Stuttgart, Fakult\"at Informatik,
+  ///    Elektrotechnik und Informationstechnik},
+  ///    month = {November},
+  ///    number = {2004/06},
+  ///    title = {A Note on On-The-Fly Verification Algorithms},
+  ///    year = {2004},
+  ///    url =
+  ///{http://www.fmi.uni-stuttgart.de/szs/publications/info/schwoosn.SE04.shtml}
+  ///  }
+  /// \endverbatim
+  ///
+  /// The extention consists in the introduction of a weight associated
+  /// to each state in the blue stack (the cyan states). The weight of a
+  /// cyan state corresponds to the number of accepting arcs traversed to reach
+  /// it from the initial state. Weights are used to detect accepting cycle in
+  /// the blue dfs.
+  ///
+  /// \sa spot::explicit_magic_search
+  ///
+  emptiness_check* explicit_se05_search(const tgba *a);
+
+  /// \brief Returns an emptiness checker on the spot::tgba automaton \a a.
+  ///
+  /// \pre The automaton \a a must have at most one accepting condition (i.e.
+  /// it is a TBA).
+  ///
+  /// During the visit of \a a, the returned checker does not store explicitely
+  /// the traversed states but uses the bit-state hashing technicpresented in:
+  ///
+  /// \verbatim
+  /// @book{Holzmann91,
+  ///    author = {G.J. Holzmann},
+  ///    title = {Design and Validation of Computer Protocols},
+  ///    publisher = {Prentice-Hall},
+  ///    address = {Englewood Cliffs, New Jersey},
+  ///    year = {1991}
+  /// }
+  /// \endverbatim
+  ///
+  /// Consequently, the detection of an acceptence cycle is not ensured. The
+  /// implemented algorithm is the same as the one of
+  /// spot::explicit_se05_search.
+  ///
+  /// \sa spot::explicit_se05_search
+  ///
+  emptiness_check* bit_state_hashing_se05_search(const tgba *a, size_t size);
+
+  /// @}
+}
+
+#endif // SPOT_TGBAALGOS_MAGIC_HH

src/tgbaalgos/tau03.cc

@@ -0,0 +1,423 @@
+// Copyright (C) 2003, 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.
+
+//#define TRACE
+
+#ifdef TRACE
+#include <iostream>
+#include "tgba/bddprint.hh"
+#endif
+
+#include <cassert>
+#include <list>
+#include <iterator>
+#include "misc/hash.hh"
+#include "tgba/tgba.hh"
+#include "emptiness.hh"
+#include "magic.hh"
+#include "tau03.hh"
+
+namespace spot
+{
+  namespace
+  {
+    enum color {WHITE, CYAN, BLUE};
+
+    /// \brief Emptiness checker on spot::tgba automata having at most one
+    /// accepting condition (i.e. a TBA).
+    template <typename heap>
+    class tau03_search : public emptiness_check
+    {
+    public:
+      /// \brief Initialize the search algorithm on the automaton \a a
+      tau03_search(const tgba *a, size_t size)
+        : h(size), a(a), all_cond(a->all_acceptance_conditions())
+      {
+        assert(a->number_of_acceptance_conditions() > 0);
+      }
+
+      virtual ~tau03_search()
+      {
+        // Release all iterators on the stacks.
+        while (!st_blue.empty())
+          {
+            h.pop_notify(st_blue.front().s);
+            delete st_blue.front().it;
+            st_blue.pop_front();
+          }
+        while (!st_red.empty())
+          {
+            h.pop_notify(st_red.front().s);
+            delete st_red.front().it;
+            st_red.pop_front();
+          }
+      }
+
+      /// \brief Perform a Magic Search.
+      ///
+      /// \return non null pointer iff the algorithm has found an
+      /// accepting path.
+      virtual emptiness_check_result* check()
+      {
+        if (!st_red.empty())
+          {
+            assert(!st_blue.empty());
+            return 0;
+          }
+        assert(st_blue.empty());
+        nbn = nbt = 0;
+        sts = mdp = 0;
+        const state* s0 = a->get_init_state();
+        ++nbn;
+        h.add_new_state(s0, CYAN);
+        push(st_blue, s0, bddfalse, bddfalse);
+        if (dfs_blue())
+          return new emptiness_check_result;
+        return 0;
+      }
+
+      virtual std::ostream& print_stats(std::ostream &os) const
+      {
+        os << nbn << " distinct nodes visited" << std::endl;
+        os << nbt << " transitions explored" << std::endl;
+        os << mdp << " nodes for the maximal stack depth" << std::endl;
+        return os;
+      }
+
+    private:
+      /// \brief counters for statistics (number of distinct nodes, of
+      /// transitions and maximal stacks size.
+      int nbn, nbt, mdp, sts;
+
+      struct stack_item
+      {
+        stack_item(const state* n, tgba_succ_iterator* i, bdd l, bdd a)
+          : s(n), it(i), label(l), acc(a) {};
+        /// The visited state.
+        const state* s;
+        /// Design the next successor of \a s which has to be visited.
+        tgba_succ_iterator* it;
+        /// The label of the transition traversed to reach \a s
+        /// (false for the first one).
+        bdd label;
+        /// The acceptance set of the transition traversed to reach \a s
+        /// (false for the first one).
+        bdd acc;
+      };
+
+      typedef std::list<stack_item> stack_type;
+
+      void push(stack_type& st, const state* s,
+                        const bdd& label, const bdd& acc)
+      {
+        ++sts;
+        if (sts>mdp)
+          mdp = sts;
+        tgba_succ_iterator* i = a->succ_iter(s);
+        i->first();
+        st.push_front(stack_item(s, i, label, acc));
+      }
+
+      /// \brief Stack of the blue dfs.
+      stack_type st_blue;
+
+      /// \brief Stack of the red dfs.
+      stack_type st_red;
+
+      /// \brief Map where each visited state is colored
+      /// by the last dfs visiting it.
+      heap h;
+
+      /// State targeted by the red dfs.
+      const state* target;
+
+      /// The automata to check.
+      const tgba* a;
+
+      /// The unique accepting condition of the automaton \a a.
+      bdd all_cond;
+
+      bool dfs_blue()
+      {
+        while (!st_blue.empty())
+          {
+            stack_item& f = st_blue.front();
+#ifdef TRACE
+            std::cout << "DFS_BLUE treats: "
+                      << a->format_state(f.s) << std::endl;
+#endif
+            if (!f.it->done())
+              {
+                ++nbt;
+                const state *s_prime = f.it->current_state();
+                bdd label = f.it->current_condition();
+                bdd acc = f.it->current_acceptance_conditions();
+#ifdef TRACE
+                std::cout << "  Visit the successor: "
+                          << a->format_state(s_prime) << std::endl;
+#endif
+                f.it->next();
+                typename heap::color_ref c = h.get_color_ref(s_prime);
+                if (c.is_white())
+                // Go down the edge (f.s, <label, acc>, s_prime)
+                  {
+                    ++nbn;
+#ifdef TRACE
+                    std::cout << "  It is white, go down" << std::endl;
+#endif
+                    h.add_new_state(s_prime, CYAN);
+                    push(st_blue, s_prime, label, acc);
+                  }
+                else // Backtrack the edge (f.s, <label, acc>, s_prime)
+                  {
+#ifdef TRACE
+                      std::cout << "  It is cyan or blue, pop it"
+                                << std::endl;
+#endif
+                      h.pop_notify(s_prime);
+                  }
+              }
+            else
+            // Backtrack the edge
+            //        (predecessor of f.s in st_blue, <f.label, f.acc>, f.s)
+              {
+#ifdef TRACE
+                std::cout << "  All the successors have been visited"
+                          << ", rescan this successors"
+                          << std::endl;
+#endif
+                typename heap::color_ref c = h.get_color_ref(f.s);
+                assert(!c.is_white());
+                tgba_succ_iterator* i = a->succ_iter(f.s);
+                for (i->first(); !i->done(); i->next())
+                  {
+                    ++nbt;
+                    const state *s_prime = i->current_state();
+                    bdd label = i->current_condition();
+                    bdd acc = i->current_acceptance_conditions();
+                    typename heap::color_ref c_prime = h.get_color_ref(s_prime);
+                    assert(!c_prime.is_white());
+                    bdd acu = acc | c.get_acc();
+#ifdef TRACE
+                    std::cout << "DFS_BLUE rescanning from: "
+                              << a->format_state(f.s) << std::endl;
+                    std::cout << "  tests "
+                              << a->format_state(s_prime) << std::endl;
+                    std::cout << "  if ";
+                    bdd_print_acc(std::cout, a->get_dict(), acu);
+                    std::cout << std::endl;
+                    std::cout << "  is not included in ";
+                    bdd_print_acc(std::cout, a->get_dict(), c_prime.get_acc());
+                    std::cout << std::endl;
+#endif
+                    if ((c_prime.get_acc() & acu) != acu)
+                      {
+#ifdef TRACE
+                        std::cout << "  that is true, starts a red dfs with "
+                                  << a->format_state(s_prime)
+                                  << "  propagating: ";
+                        bdd_print_acc(std::cout, a->get_dict(), acu);
+                        std::cout << std::endl;
+#endif
+                        target = f.s;
+                        c_prime.cumulate_acc(acu);
+                        push(st_red, s_prime, label, acc);
+                        if (target->compare(s_prime) == 0 &&
+                            c_prime.get_acc() == all_cond)
+                          {
+                            delete i;
+                            return true;
+                          }
+                        if (dfs_red(acu) || c.get_acc() == all_cond)
+                          {
+                            delete i;
+                            return true;
+                          }
+                     }
+                  }
+                delete i;
+                c.set_color(BLUE);
+                delete f.it;
+                --sts;
+                h.pop_notify(f.s);
+                st_blue.pop_front();
+              }
+          }
+        return false;
+      }
+
+      bool dfs_red(const bdd& acu)
+      {
+        assert(!st_red.empty());
+
+        while (!st_red.empty())
+          {
+            stack_item& f = st_red.front();
+#ifdef TRACE
+            std::cout << "DFS_RED treats: "
+                      << a->format_state(f.s) << std::endl;
+#endif
+            if (!f.it->done()) // Go down
+              {
+                ++nbt;
+                const state *s_prime = f.it->current_state();
+                bdd label = f.it->current_condition();
+                bdd acc = f.it->current_acceptance_conditions();
+#ifdef TRACE
+                std::cout << "  Visit the successor: "
+                          << a->format_state(s_prime) << std::endl;
+#endif
+                f.it->next();
+                typename heap::color_ref c_prime = h.get_color_ref(s_prime);
+                if (!c_prime.is_white() &&
+                    (c_prime.get_acc() & acu) != acu)
+                  {
+#ifdef TRACE
+                        std::cout << "  It is cyan or blue and propagation "
+                                  << "is nedded, go down"
+                                  << std::endl;
+#endif
+                    c_prime.cumulate_acc(acu);
+                    push(st_red, s_prime, label, acc);
+                    if (target->compare(s_prime) == 0  &&
+                            c_prime.get_acc() == all_cond)
+                      return true;
+                  }
+                  else
+                    {
+#ifdef TRACE
+                      std::cout << "  It is white or no propagation is needed "
+                                << ", pop it"
+                                << std::endl;
+#endif
+                      if (c_prime.is_white())
+                        delete s_prime;
+                      h.pop_notify(s_prime);
+                    }
+              }
+            else // Backtrack
+              {
+#ifdef TRACE
+                std::cout << "  All the successors have been visited"
+                          << ", pop it" << std::endl;
+#endif
+                --sts;
+                h.pop_notify(f.s);
+                delete f.it;
+                st_red.pop_front();
+              }
+          }
+        return false;
+      }
+
+    };
+
+    class explicit_tau03_search_heap
+    {
+    public:
+      class color_ref
+      {
+      public:
+        color_ref(color* c, bdd* a) :p(c), acc(a)
+          {
+          }
+        color get_color() const
+          {
+            return *p;
+          }
+        void set_color(color c)
+          {
+            assert(!is_white());
+            *p = c;
+          }
+        const bdd& get_acc() const
+          {
+            assert(!is_white());
+            return *acc;
+          }
+        void cumulate_acc(const bdd& a)
+          {
+            assert(!is_white());
+            *acc |= a;
+          }
+        bool is_white() const
+          {
+            return p == 0;
+          }
+      private:
+        color *p;
+        bdd* acc;
+      };
+
+      explicit_tau03_search_heap(size_t)
+        {
+        }
+
+      ~explicit_tau03_search_heap()
+        {
+          hash_type::const_iterator s = h.begin();
+          while (s != h.end())
+            {
+              // Advance the iterator before deleting the "key" pointer.
+              const state* ptr = s->first;
+              ++s;
+              delete ptr;
+            }
+        }
+
+      color_ref get_color_ref(const state*& s)
+        {
+          hash_type::iterator it = h.find(s);
+          if (it==h.end())
+            return color_ref(0, 0);
+          if (s!=it->first)
+            {
+              delete s;
+              s = it->first;
+            }
+          return color_ref(&(it->second.first), &(it->second.second));
+        }
+
+      void add_new_state(const state* s, color c)
+        {
+          assert(h.find(s)==h.end());
+          h.insert(std::make_pair(s, std::make_pair(c, bddfalse)));
+        }
+
+      void pop_notify(const state*)
+        {
+        }
+
+    private:
+
+      typedef Sgi::hash_map<const state*, std::pair<color, bdd>,
+                state_ptr_hash, state_ptr_equal> hash_type;
+      hash_type h;
+    };
+
+  } // anonymous
+
+  emptiness_check* explicit_tau03_search(const tgba *a)
+  {
+    return new tau03_search<explicit_tau03_search_heap>(a, 0);
+  }
+
+}

src/tgbaalgos/tau03.hh

@@ -0,0 +1,110 @@
+// Copyright (C) 2003, 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_TGBAALGOS_TAU03_HH
+# define SPOT_TGBAALGOS_TAU03_HH
+
+namespace spot
+{
+  class tgba;
+  class emptiness_check;
+
+  /// \addtogroup emptiness_check_algorithms
+  /// @{
+
+  /// \brief Returns an emptiness checker on the spot::tgba automaton \a a.
+  ///
+  /// \pre The automaton \a a must have at least one accepting condition.
+  ///
+  /// During the visit of \a a, the returned checker stores explicitely all
+  /// the traversed states. The implemented algorithm is the following:
+  ///
+  /// \verbatim
+  /// procedure check ()
+  /// begin
+  ///   call dfs_blue(s0);
+  /// end;
+  ///
+  /// procedure dfs_blue (s)
+  /// begin
+  ///   s.color = cyan;
+  ///   s.acc = emptyset;
+  ///   for all t in post(s) do
+  ///     if t.color == white then
+  ///       call dfs_blue(t);
+  ///     end if;
+  ///   end for;
+  ///   for all t in post(s) do
+  ///     let (s, l, a, t) be the edge from s to t;
+  ///     if a U s.acc not included in t.acc then
+  ///       target = s;
+  ///       call dfs_red(t, a U s.acc);
+  ///     end if;
+  ///   end for;
+  ///   if s.acc == all_acc then
+  ///     report a cycle;
+  ///   end if;
+  ///   s.color = blue;
+  /// end;
+  ///
+  /// procedure dfs_red(s, A)
+  /// begin
+  ///   s.acc = s.acc U A;
+  ///   // The following test has been added to the origiginal algorithm to
+  ///   // report a cycle as soon as possible (and to mimic the classic magic
+  ///   // search.
+  ///   if s == target and s.acc == all_acc then
+  ///     report a cycle;
+  ///   end if;
+  ///   for all t in post(s) do
+  ///     let (s, l, a, t) be the edge from s to t;
+  ///     if t.color != white and A not included in t.acc then
+  ///       call dfs_red(t, A);
+  ///     end if;
+  ///   end for;
+  /// end;
+  /// \endverbatim
+  ///
+  /// This algorithm is the one presented in
+  ///
+  /// \verbatim
+  /// @techreport{HUT-TCS-A83,
+  ///    address = {Espoo, Finland},
+  ///    author = {Heikki Tauriainen},
+  ///    institution = {Helsinki University of Technology, Laboratory for
+  ///    Theoretical Computer Science},
+  ///    month = {December},
+  ///    number = {A83},
+  ///    pages = {132},
+  ///    title = {On Translating Linear Temporal Logic into Alternating and
+  ///    Nondeterministic Automata},
+  ///    type = {Research Report},
+  ///    year = {2003},
+  ///    url = {http://www.tcs.hut.fi/Publications/info/bibdb.HUT-TCS-A83.shtml}
+  /// }
+  /// \endverbatim
+  ///
+  emptiness_check* explicit_tau03_search(const tgba *a);
+
+  /// @}
+}
+
+#endif // SPOT_TGBAALGOS_MAGIC_HH

src/tgbatest/Makefile.am

@@ -84,6 +84,7 @@ TESTS = \
   emptchke.test \
   dfs.test \
   emptchkr.test \
+  tba_samples_from_spin.test \
   spotlbtt.test
 
 EXTRA_DIST = $(TESTS) ltl2baw.pl

src/tgbatest/emptchkr.test

@@ -36,7 +36,7 @@ run 0 ./randtgba -e 100 -s  50 -r -a 1 0.1 -d 0.02
 run 0 ./randtgba -e 100 -s 100 -r -a 1 0.1 -d 0.04
 run 0 ./randtgba -e 100 -s 150 -r -a 1 0.1 -d 0.08
 
-# Two acceptance conditions
+# Four acceptance conditions
 run 0 ./randtgba -e 100 -s 200 -r -a 4 0.1 -d 0.01
 run 0 ./randtgba -e 100 -s 250 -r -a 4 0.1 -d 0.02
 run 0 ./randtgba -e 100 -s 300 -r -a 4 0.1 -d 0.04

src/tgbatest/ltl2tgba.cc

@@ -36,6 +36,8 @@
 #include "tgbaalgos/lbtt.hh"
 #include "tgba/tgbatba.hh"
 #include "tgbaalgos/magic.hh"
+#include "tgbaalgos/se05.hh"
+#include "tgbaalgos/tau03.hh"
 #include "tgbaalgos/gtec/gtec.hh"
 #include "tgbaalgos/gtec/ce.hh"
 #include "tgbaparse/public.hh"
@@ -125,7 +127,8 @@ syntax(char* prog)
 	    << "  bsh_se05_search[(heap size in MB - 10MB by default)]"
             << std::endl
 	    << "  bsh_se05_search_repeated[(heap size in MB - 10MB"
-            << " by default)]" << std::endl;
+            << " by default)]" << std::endl
+	    << "  tau03_search" << std::endl;
   exit(2);
 }
 
@@ -144,9 +147,10 @@ main(int argc, char** argv)
   int output = 0;
   int formula_index = 0;
   std::string echeck_algo;
-  enum { None, Couvreur, Couvreur2, MagicSearch, Se05Search } echeck = None;
+  enum { None, Couvreur, Couvreur2, MagicSearch, Se05Search, Tau03Search }
+                                                                 echeck = None;
   enum { NoneDup, BFS, DFS } dupexp = NoneDup;
-  bool magic_many = false;
+  bool search_many = false;
   bool bit_state_hashing = false;
   int heap_size = 10*1024*1024;
   bool expect_counter_example = false;
@@ -368,7 +372,7 @@ main(int argc, char** argv)
 	{
 	  echeck = MagicSearch;
 	  degeneralize_maybe = true;
-	  magic_many = true;
+	  search_many = true;
 	}
       else if (echeck_algo == "bsh_magic_search")
 	{
@@ -381,7 +385,7 @@ main(int argc, char** argv)
 	  echeck = MagicSearch;
 	  degeneralize_maybe = true;
           bit_state_hashing = true;
-	  magic_many = true;
+	  search_many = true;
 	}
       else if (echeck_algo == "se05_search")
 	{
@@ -392,7 +396,7 @@ main(int argc, char** argv)
 	{
 	  echeck = Se05Search;
 	  degeneralize_maybe = true;
-	  magic_many = true;
+	  search_many = true;
 	}
       else if (echeck_algo == "bsh_se05_search")
 	{
@@ -405,7 +409,11 @@ main(int argc, char** argv)
 	  echeck = Se05Search;
 	  degeneralize_maybe = true;
           bit_state_hashing = true;
-	  magic_many = true;
+	  search_many = true;
+	}
+      else if (echeck_algo == "tau03_search")
+	{
+	  echeck = Tau03Search;
 	}
       else
 	{
@@ -649,6 +657,19 @@ main(int argc, char** argv)
           else
             ec = spot::explicit_se05_search(a);
           break;
+
+	case Tau03Search:
+          if (a->number_of_acceptance_conditions() == 0)
+            {
+              std::cout << "To apply tau03_search, the automaton must have at "
+                        << "least on accepting condition. Try with another "
+                        << "algorithm." << std::endl;
+            }
+          else
+            {
+              ec = spot::explicit_tau03_search(a);
+            }
+	  break;
 	}
 
       if (ec)
@@ -702,7 +723,7 @@ main(int argc, char** argv)
 		}
 	      delete res;
 	    }
-	  while (magic_many);
+	  while (search_many);
 	  delete ec;
 	}
 

src/tgbatest/randtgba.cc

@@ -34,6 +34,8 @@
 #include "tgbaalgos/emptiness.hh"
 #include "tgbaalgos/gtec/gtec.hh"
 #include "tgbaalgos/magic.hh"
+#include "tgbaalgos/se05.hh"
+#include "tgbaalgos/tau03.hh"
 #include "tgbaalgos/replayrun.hh"
 
 void
@@ -42,7 +44,7 @@ syntax(char* prog)
   std::cerr << "Usage: "<< prog << " [OPTIONS...] PROPS..." << std::endl
 	    << std::endl
 	    << "Options:" << std::endl
-	    << "  -a N F  number of accepence conditions a propability that"
+	    << "  -a N F  number of acceptance conditions and probability that"
 	    << " one is true [0 0.0]" << std::endl
 	    << "  -d F    density of the graph [0.2]" << std::endl
 	    << "  -e N    compare result of all "
@@ -205,6 +207,13 @@ main(int argc, char** argv)
 	  ec_name.push_back("couvreur99_shy");
 	  ec_safe.push_back(true);
 
+	  if (opt_n_acc >= 1)
+	    {
+              ec_obj.push_back(spot::explicit_tau03_search(a));
+              ec_name.push_back("explicit_tau03_search");
+              ec_safe.push_back(true);
+            }
+
 	  if (opt_n_acc <= 1)
 	    {
 	      ec_obj.push_back(spot::explicit_magic_search(a));

src/tgbatest/tba_samples_from_spin.test

@@ -0,0 +1,76 @@
+#!/bin/sh
+# Copyright (C) 2003, 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.
+
+. ./defs
+
+light_run()
+{
+  expected_exitcode=$1
+  shift
+  exitcode=0
+  "$@" || exitcode=$?
+  test $exitcode = $expected_exitcode || exit 1
+}
+
+set -e
+
+expect_ce()
+{
+  light_run 0 ./ltl2tgba -X -e "$1"
+  light_run 0 ./ltl2tgba -X -ecouvreur99_shy "$1"
+  light_run 0 ./ltl2tgba -X -emagic_search "$1"
+  light_run 0 ./ltl2tgba -X -ebsh_magic_search "$1"
+  light_run 0 ./ltl2tgba -X -ese05_search "$1"
+  light_run 0 ./ltl2tgba -X -ebsh_se05_search "$1"
+  light_run 0 ./ltl2tgba -X -etau03_search "$1"
+}
+
+expect_no()
+{
+  light_run 0 ./ltl2tgba -X -E "$1"
+  light_run 0 ./ltl2tgba -X -Ecouvreur99_shy "$1"
+  light_run 0 ./ltl2tgba -X -Emagic_search "$1"
+  light_run 0 ./ltl2tgba -X -Ebsh_magic_search "$1"
+  light_run 0 ./ltl2tgba -X -Ese05_search "$1"
+  light_run 0 ./ltl2tgba -X -Ebsh_se05_search "$1"
+  light_run 0 ./ltl2tgba -X -Etau03_search "$1"
+}
+
+expect_no tba_samples_from_spin/explicit1_1.tba
+expect_ce tba_samples_from_spin/explicit1_2.tba
+expect_no tba_samples_from_spin/explicit1_3.tba
+expect_no tba_samples_from_spin/explicit1_4.tba
+expect_ce tba_samples_from_spin/explicit1_5.tba
+expect_no tba_samples_from_spin/explicit1_6.tba
+expect_no tba_samples_from_spin/explicit1_7.tba
+expect_ce tba_samples_from_spin/explicit1_8.tba
+expect_ce tba_samples_from_spin/explicit1_9.tba
+
+expect_ce tba_samples_from_spin/explicit2_1.tba
+expect_ce tba_samples_from_spin/explicit2_2.tba
+expect_no tba_samples_from_spin/explicit2_3.tba
+expect_no tba_samples_from_spin/explicit2_4.tba
+expect_ce tba_samples_from_spin/explicit2_5.tba
+expect_no tba_samples_from_spin/explicit2_6.tba
+expect_ce tba_samples_from_spin/explicit2_7.tba
+expect_ce tba_samples_from_spin/explicit2_8.tba
+expect_no tba_samples_from_spin/explicit2_9.tba