introduce containement checks functions

* spot/twaalgos/contains.hh, spot/twaalgos/contains.cc: New files.
* spot/twaalgos/Makefile.am, python/spot/impl.i: Add them.
* python/spot/__init__.py: Also attach these functions as methods,
and support string arguments.
* tests/python/contains.ipynb: New file.
* tests/Makefile.am, doc/org/tut.org: Add it.
* bin/autfilt.cc, tests/python/streett_totgba.py, tests/python/sum.py,
tests/python/toweak.py: Use the new function.

spot/twaalgos/Makefile.am

@@ -39,6 +39,7 @@ twaalgos_HEADERS = \
   complete.hh \
   complement.hh \
   compsusp.hh \
+  contains.hh \
   copy.hh \
   cycles.hh \
   degen.hh \
@@ -107,6 +108,7 @@ libtwaalgos_la_SOURCES = \
   complete.cc \
   complement.cc \
   compsusp.cc \
+  contains.cc \
   cycles.cc \
   degen.cc \
   determinize.cc \

spot/twaalgos/contains.cc

@@ -0,0 +1,101 @@
+// -*- coding: utf-8 -*-
+// Copyright (C) 2018 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/>.
+
+#include "config.h"
+#include <spot/twaalgos/contains.hh>
+#include <spot/twaalgos/postproc.hh>
+#include <spot/twaalgos/ltl2tgba_fm.hh>
+#include <spot/twaalgos/isdet.hh>
+#include <spot/twaalgos/dualize.hh>
+
+namespace spot
+{
+  namespace
+  {
+    static spot::const_twa_graph_ptr
+    ensure_deterministic(const spot::const_twa_graph_ptr& aut)
+    {
+      if (spot::is_deterministic(aut))
+        return aut;
+      spot::postprocessor p;
+      p.set_type(spot::postprocessor::Generic);
+      p.set_pref(spot::postprocessor::Deterministic);
+      p.set_level(spot::postprocessor::Low);
+      return p.run(std::const_pointer_cast<twa_graph>(aut));
+    }
+
+    static spot::const_twa_graph_ptr
+    translate(formula f, const bdd_dict_ptr& dict)
+    {
+      return ltl_to_tgba_fm(f, dict);
+    }
+  }
+
+  bool contains(const_twa_graph_ptr left, const_twa_graph_ptr right)
+  {
+    return !left->intersects(dualize(ensure_deterministic(right)));
+  }
+
+  bool contains(const_twa_graph_ptr left, formula right)
+  {
+    return !left->intersects(translate(formula::Not(right), left->get_dict()));
+  }
+
+  bool contains(formula left, const_twa_graph_ptr right)
+  {
+    auto left_aut = translate(left, right->get_dict());
+    return !left_aut->intersects(dualize(ensure_deterministic(right)));
+  }
+
+  bool contains(formula left, formula right)
+  {
+    auto dict = make_bdd_dict();
+    auto left_aut = translate(left, dict);
+    return !left_aut->intersects(translate(formula::Not(right), dict));
+  }
+
+  bool are_equivalent(const_twa_graph_ptr left, const_twa_graph_ptr right)
+  {
+    // Start with a deterministic automaton at right if possible to
+    // avoid a determinization (in case the first containment check
+    // fails).
+    if (!is_deterministic(right))
+      std::swap(left, right);
+    return contains(left, right) && contains(right, left);
+  }
+
+  bool are_equivalent(const_twa_graph_ptr left, formula right)
+  {
+    // The first containement check does not involve a
+    // complementation, the second might.
+    return contains(left, right) && contains(right, left);
+  }
+
+  bool are_equivalent(formula left, const_twa_graph_ptr right)
+  {
+    // The first containement check does not involve a
+    // complementation, the second might.
+    return contains(right, left) && contains(left, right);
+  }
+
+  bool are_equivalent(formula left, formula right)
+  {
+    return contains(right, left) && contains(left, right);
+  }
+}

spot/twaalgos/contains.hh

@@ -0,0 +1,60 @@
+// -*- coding: utf-8 -*-
+// Copyright (C) 2018 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/>.
+
+#pragma once
+
+#include <spot/twa/twagraph.hh>
+#include <spot/tl/formula.hh>
+
+/// \defgroup containment Language containment checks
+/// \ingroup twa_algorithms
+
+namespace spot
+{
+  /// \ingroup containment
+  /// \brief Test if the language of \a left is included in that of \a right.
+  ///
+  /// Both arguments can be either formulas or automata.  Formulas
+  /// will be converted into automata.
+  ///
+  /// The inclusion check if performed by ensuring that the automaton
+  /// associated to \a left does not intersect the automaton
+  /// associated to the complement of \a right.  It helps if \a right
+  /// is a deterministic automaton or a formula (because in both cases
+  /// complementation is easier).
+  /// @{
+  SPOT_API bool contains(const_twa_graph_ptr left, const_twa_graph_ptr right);
+  SPOT_API bool contains(const_twa_graph_ptr left, formula right);
+  SPOT_API bool contains(formula left, const_twa_graph_ptr right);
+  SPOT_API bool contains(formula left, formula right);
+  /// @}
+
+  /// \ingroup containment
+  /// \brief Test if the language of \a left is equivalent to that of \a right.
+  ///
+  /// Both arguments can be either formulas or automata.  Formulas
+  /// will be converted into automata.
+  /// @{
+  SPOT_API bool are_equivalent(const_twa_graph_ptr left,
+                               const_twa_graph_ptr right);
+  SPOT_API bool are_equivalent(const_twa_graph_ptr left, formula right);
+  SPOT_API bool are_equivalent(formula left, const_twa_graph_ptr right);
+  SPOT_API bool are_equivalent(formula left, formula right);
+  /// @}
+}