simulation: do not depend on bdd numbers for ordering classes

Fixes #262 again.  Reported by Maximilien Colange.

* spot/twaalgos/simulation.cc: Use state numbers to order classes, not
their signatures.  The problem was that even if two simulation of the
same automaton assign the same signature, the BDD identifier used for
that signature might be different, and therefore the ordering obtained
by using BDDs as keys in a map can be different.  A side-effect of
this change is that the order of states in automata produced by
simulation-based reduction may change; many tests had to be updated.
* tests/core/ltl2tgba.test: Add a new test case based on Maximilien's
report.
* tests/core/complement.test, tests/core/det.test,
tests/core/parseaut.test, tests/core/prodor.test,
tests/python/atva16-fig2a.ipynb, tests/python/automata.ipynb,
tests/python/decompose.ipynb, tests/python/highlighting.ipynb,
tests/python/piperead.ipynb, tests/python/testingaut.ipynb,
tests/python/word.ipynb: Update test cases for new order of states.

spot/twaalgos/simulation.cc

@@ -275,7 +275,7 @@ namespace spot
 
         // We run through the map bdd/list<state>, and we update
         // the previous_class_ with the new data.
-        for (auto& p: bdd_lstate_)
+        for (auto& p: sorted_classes_)
           {
             // If the signature of a state is bddfalse (no
             // edges) the class of this state is bddfalse
@@ -283,11 +283,11 @@ namespace spot
             // simplifications in the signature by removing a
             // edge which has as a destination a state with
             // no outgoing edge.
-            if (p.first == bddfalse)
-              for (auto s: p.second)
+            if (p->first == bddfalse)
+              for (unsigned s: p->second)
                 previous_class_[s] = bddfalse;
             else
-              for (auto s: p.second)
+              for (unsigned s: p->second)
                 previous_class_[s] = *it_bdd;
             ++it_bdd;
           }
@@ -302,10 +302,10 @@ namespace spot
           {
             update_previous_class();
             nb_partition_before = bdd_lstate_.size();
-            bdd_lstate_.clear();
             nb_po_before = po_size_;
             po_size_ = 0;
             update_sig();
+            // print_partition();
             go_to_next_it();
           }
 
@@ -347,8 +347,18 @@ namespace spot
 
       void update_sig()
       {
+        bdd_lstate_.clear();
+        sorted_classes_.clear();
         for (unsigned s = 0; s < size_a_; ++s)
-          bdd_lstate_[compute_sig(s)].emplace_back(s);
+          {
+            bdd sig = compute_sig(s);
+            auto p = bdd_lstate_.emplace(std::piecewise_construct,
+                                         std::make_tuple(sig),
+                                         std::make_tuple());
+            p.first->second.emplace_back(s);
+            if (p.second)
+              sorted_classes_.emplace_back(p.first);
+          }
       }
 
 
@@ -390,7 +400,7 @@ namespace spot
 
         std::list<bdd>::iterator it_bdd = used_var_.begin();
 
-        for (auto& p: bdd_lstate_)
+        for (auto& p: sorted_classes_)
           {
             // If the signature of a state is bddfalse (no edges) the
             // class of this state is bddfalse instead of an anonymous
@@ -398,9 +408,9 @@ namespace spot
             // removing an edge which has as a destination a state
             // with no outgoing edge.
             bdd acc = bddfalse;
-            if (p.first != bddfalse)
+            if (p->first != bddfalse)
               acc = *it_bdd;
-            now_to_next.emplace_back(p.first, acc);
+            now_to_next.emplace_back(p->first, acc);
             ++it_bdd;
           }
 
@@ -446,10 +456,10 @@ namespace spot
 
         if (implications)
           implications->resize(bdd_lstate_.size());
-        // Create one state per partition.
-        for (auto& p: bdd_lstate_)
+        // Create one state per class.
+        for (auto& p: sorted_classes_)
           {
-            bdd cl = previous_class_[p.second.front()];
+            bdd cl = previous_class_[p->second.front()];
             // A state may be referred to either by
             // its class, or by all the implied classes.
             auto s = gb->new_state(cl.id());
@@ -472,14 +482,14 @@ namespace spot
         auto all_inf = all_inf_;
         // For each class, we will create
         // all the edges between the states.
-        for (auto& p: bdd_lstate_)
+        for (auto& p: sorted_classes_)
           {
             // All states in p.second have the same class, so just
             // pick the class of the first one first one.
-            bdd src = previous_class_[p.second.front()];
+            bdd src = previous_class_[p->second.front()];
 
             // Get the signature to derive successors.
-            bdd sig = compute_sig(p.second.front());
+            bdd sig = compute_sig(p->second.front());
 
             if (Cosimulation)
               sig = bdd_compose(sig, bddfalse, bdd_var(bdd_initial));
@@ -613,12 +623,12 @@ namespace spot
       // where is the new class name.
       void print_partition()
       {
-        for (auto& p: bdd_lstate_)
+        for (auto& p: sorted_classes_)
           {
             std::cerr << "partition: "
-                      << bdd_format_isop(a_->get_dict(), p.first)
+                      << bdd_format_isop(a_->get_dict(), p->first)
                       << std::endl;
-            for (auto s: p.second)
+            for (auto s: p->second)
               std::cerr << "  - "
                         << a_->format_state(a_->state_from_number(s))
                         << '\n';
@@ -646,9 +656,13 @@ namespace spot
       // Represent the class of each state at the previous iteration.
       vector_state_bdd previous_class_;
 
-      // The list of state for each class at the current_iteration.
+      // The list of states for each class at the current_iteration.
       // Computed in `update_sig'.
       map_bdd_lstate bdd_lstate_;
+      // The above map, sorted by states number instead of BDD
+      // identifier to avoid non-determinism while iterating over all
+      // states.
+      std::vector<map_bdd_lstate::const_iterator> sorted_classes_;
 
       // The queue of free bdd. They will be used as the identifier
       // for the class.

tests/core/complement.test

@@ -118,11 +118,11 @@ properties: trans-labels explicit-labels trans-acc complete
 properties: deterministic stutter-invariant
 --BODY--
 State: 0
-[0] 1 {1}
 [!0] 0
-State: 1
 [0] 1 {1}
+State: 1
 [!0] 0 {0}
+[0] 1 {1}
 --END--
 EOF
 diff out expected

tests/core/det.test

 #!/bin/sh
 # -*- coding: utf-8 -*-
-# Copyright (C) 2013, 2014, 2015, 2016 Laboratoire de Recherche et
-# Développement de l'Epita (LRDE).
+# Copyright (C) 2013-2017 Laboratoire de Recherche et Développement de
+# l'Epita (LRDE).
 #
 # This file is part of Spot, a model checking library.
 #
@@ -148,20 +148,20 @@ cat >expected-nd.hoa <<EOF
 HOA: v1.1
 name: "XGa R (!a & Fa)"
 States: 2
-Start: 1
+Start: 0
 AP: 1 "a"
 acc-name: Buchi
 Acceptance: 1 Inf(0)
 properties: trans-labels explicit-labels state-acc !complete
 properties: !deterministic
-spot.highlight.states: 1 1
-spot.highlight.edges: 2 2 3 2
+spot.highlight.states: 0 1
+spot.highlight.edges: 1 2 2 2
 --BODY--
-State: 0 {0}
-[0] 0
-State: 1
+State: 0
 [!0] 0
 [!0] 1
+State: 1 {0}
+[0] 1
 --END--
 EOF
 diff expected-nd.hoa out-nd.hoa
@@ -173,19 +173,19 @@ cat >expected-rand.hoa <<EOF
 HOA: v1.1
 name: "XGa R (!a & Fa)"
 States: 2
-Start: 0
+Start: 1
 AP: 1 "a"
 acc-name: Buchi
 Acceptance: 1 Inf(0)
 properties: trans-labels explicit-labels state-acc !complete
 properties: !deterministic
-spot.highlight.states: 0 1
+spot.highlight.states: 1 1
 --BODY--
-State: 0
-[!0] 0
+State: 0 {0}
+[0] 0
+State: 1
 [!0] 1
-State: 1 {0}
-[0] 1
+[!0] 0
 --END--
 EOF
 diff expected-rand.hoa rand.hoa
@@ -197,20 +197,20 @@ cat >expected-rand2.hoa <<EOF
 HOA: v1.1
 name: "XGa R (!a & Fa)"
 States: 2
-Start: 0
+Start: 1
 AP: 1 "a"
 acc-name: Buchi
 Acceptance: 1 Inf(0)
 properties: trans-labels explicit-labels state-acc !complete
 properties: !deterministic
-spot.highlight.states: 0 5
-spot.highlight.edges: 1 5 2 5
+spot.highlight.states: 1 5
+spot.highlight.edges: 2 5 3 5
 --BODY--
-State: 0
-[!0] 0
+State: 0 {0}
+[0] 0
+State: 1
 [!0] 1
-State: 1 {0}
-[0] 1
+[!0] 0
 --END--
 EOF
 diff expected-rand2.hoa rand2.hoa

tests/core/ltl2tgba.test

@@ -255,3 +255,11 @@ ltl2tgba --low --any 'Xp1 xor (Fp1 M (!p1 M (Fp0 W p1)))' \
 ltl2tgba --low --any 'Xp1 xor (Fp1 M (!p1 M (Fp0 W p1)))' "$s" >res2
 ltl2tgba --low --any 'Fp0 -> XXG(1 U Gp1)' "$s" >>res2
 diff res1 res2
+
+# Another case where different but isomorphic automata
+# were output (issue #262 again).
+f1='F(Gp0 <-> Gp1)'
+f2='Gp1 | FGp0'
+(ltl2tgba -xsimul=1 --low "$f1"; ltl2tgba -xsimul=1 --low "$f2") > res1
+ltl2tgba -xsimul=1 --low "$f1" "$f2" > res2
+diff res1 res2

tests/core/parseaut.test

@@ -1692,7 +1692,7 @@ cat >expected <<EOF
 HOA: v1
 name: "(c U d) & G(Fa & Fb)"
 States: 3
-Start: 1
+Start: 0
 AP: 4 "c" "d" "a" "b"
 acc-name: generalized-Buchi 2
 Acceptance: 2 Inf(0)&Inf(1)
@@ -1700,39 +1700,39 @@ properties: implicit-labels trans-acc complete deterministic
 properties: stutter-invariant
 --BODY--
 State: 0
+2
 0
+1
+1
+2
 0
+1
+1
+2
 0
+1
+1
+2
 0
-0 {0}
-0 {0}
-0 {0}
-0 {0}
-0 {1}
-0 {1}
-0 {1}
-0 {1}
-0 {0 1}
-0 {0 1}
-0 {0 1}
-0 {0 1}
+1
+1
 State: 1
-2
 1
-0
-0
-2
 1
-0
-0
-2
 1
-0
-0
-2
 1
-0
-0
+1 {0}
+1 {0}
+1 {0}
+1 {0}
+1 {1}
+1 {1}
+1 {1}
+1 {1}
+1 {0 1}
+1 {0 1}
+1 {0 1}
+1 {0 1}
 State: 2
 2
 2

tests/core/prodor.test

 #!/bin/sh
 # -*- coding: utf-8 -*-
-# Copyright (C) 2015 Laboratoire de Recherche et Développement
+# Copyright (C) 2015, 2017 Laboratoire de Recherche et Développement
 # de l'Epita (LRDE).
 #
 # This file is part of Spot, a model checking library.
@@ -39,10 +39,10 @@ properties: trans-labels explicit-labels trans-acc complete
 properties: stutter-invariant
 --BODY--
 State: 0
-[0&1] 1 {1}
-[!0&1] 1
 [0] 0 {1}
 [!0] 0
+[0&1] 1 {1}
+[!0&1] 1
 State: 1
 [0&1] 1 {0 1}
 [!0&1] 1 {0}
@@ -70,10 +70,10 @@ Acceptance: 2 Inf(0)&Inf(1)
 properties: trans-labels explicit-labels trans-acc stutter-invariant
 --BODY--
 State: 0
-[0&1] 1 {1}
-[!0&1] 1
 [0] 0 {1}
 [!0] 0
+[0&1] 1 {1}
+[!0&1] 1
 State: 1
 [0&1] 1 {0 1}
 [!0&1] 1 {0}

tests/python/atva16-fig2a.ipynb

@@ -97,85 +97,85 @@
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+        "<!-- 0 -->\n",
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+        "<!-- I&#45;&gt;0 -->\n",
+        "<g id=\"edge1\" class=\"edge\"><title>I&#45;&gt;0</title>\n",
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-        "<path fill=\"none\" stroke=\"black\" d=\"M165.104,-35.5771C162.424,-56.718 163.723,-84 169,-84 173.7,-84 175.244,-62.3596 173.633,-42.6907\"/>\n",
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-        "<text text-anchor=\"start\" x=\"148.5\" y=\"-87.8\" font-family=\"Lato\" font-size=\"14.00\">!a &amp; !b</text>\n",
+        "<!-- 1&#45;&gt;1 -->\n",
+        "<g id=\"edge7\" class=\"edge\"><title>1&#45;&gt;1</title>\n",
+        "<path fill=\"none\" stroke=\"black\" d=\"M164.049,-135.467C158.901,-163.149 160.551,-202 169,-202 176.756,-202 178.783,-169.261 175.081,-142.477\"/>\n",
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+        "<text text-anchor=\"start\" x=\"153\" y=\"-205.8\" font-family=\"Lato\" font-size=\"14.00\" fill=\"#5da5da\">\u24ff</text>\n",
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-        "<text text-anchor=\"start\" x=\"169\" y=\"-105.8\" font-family=\"Lato\" font-size=\"14.00\" fill=\"#f17cb0\">\u2776</text>\n",
+        "<!-- 1&#45;&gt;1 -->\n",
+        "<g id=\"edge8\" class=\"edge\"><title>1&#45;&gt;1</title>\n",
+        "<path fill=\"none\" stroke=\"black\" d=\"M163.463,-135.36C155.342,-171.623 157.188,-230 169,-230 180.074,-230 182.389,-178.692 175.943,-142.399\"/>\n",
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+        "<text text-anchor=\"start\" x=\"150.5\" y=\"-248.8\" font-family=\"Lato\" font-size=\"14.00\">a &amp; !b</text>\n",
+        "<text text-anchor=\"start\" x=\"161\" y=\"-233.8\" font-family=\"Lato\" font-size=\"14.00\" fill=\"#5da5da\">\u24ff</text>\n",
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-        "<text text-anchor=\"start\" x=\"150.5\" y=\"-148.8\" font-family=\"Lato\" font-size=\"14.00\">a &amp; !b</text>\n",
-        "<text text-anchor=\"start\" x=\"161\" y=\"-133.8\" font-family=\"Lato\" font-size=\"14.00\" fill=\"#5da5da\">\u24ff</text>\n",
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+        "<text text-anchor=\"start\" x=\"148.5\" y=\"-71.8\" font-family=\"Lato\" font-size=\"14.00\">!a &amp; !b</text>\n",
+        "<text text-anchor=\"start\" x=\"153\" y=\"-57.8\" font-family=\"Lato\" font-size=\"14.00\" fill=\"#5da5da\">\u24ff</text>\n",
+        "<text text-anchor=\"start\" x=\"169\" y=\"-57.8\" font-family=\"Lato\" font-size=\"14.00\" fill=\"#f17cb0\">\u2776</text>\n",
         "</g>\n",
         "</g>\n",
         "</svg>\n"
        ],
        "text": [
-        "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7f79506d2900> >"
+        "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7f6b2060be40> >"
        ]
       }
      ],

tests/python/highlighting.ipynb

@@ -15,7 +15,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.5.3rc1"
+   "version": "3.5.3"
   },
   "name": ""
  },
@@ -254,7 +254,7 @@
         "</svg>\n"
        ],
        "text": [
-        "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7fd9b0b5ab70> >"
+        "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7f98b673b870> >"
        ]
       }
      ],
@@ -356,7 +356,7 @@
         "</svg>\n"
        ],
        "text": [
-        "<spot.twa; proxy of <Swig Object of type 'std::shared_ptr< spot::twa > *' at 0x7fd9b0aeb270> >"
+        "<spot.twa; proxy of <Swig Object of type 'std::shared_ptr< spot::twa > *' at 0x7f98b66ad630> >"
        ]
       }
      ],
@@ -571,7 +571,7 @@
         "</svg>\n"
        ],
        "text": [
-        "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7fd9b0aeb390> >"
+        "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7f98b66ad300> >"
        ]
       }
      ],
@@ -750,7 +750,7 @@
         "</svg>\n"
        ],
        "text": [
-        "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7fd9b0aeb390> >"
+        "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7f98b66ad300> >"
        ]
       }
      ],
@@ -830,7 +830,7 @@
         "</svg>\n"
        ],
        "text": [
-        "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7fd9b0aeb660> >"
+        "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7f98b66ad7b0> >"
        ]
       },
       {
@@ -876,7 +876,7 @@
         "</svg>\n"
        ],
        "text": [
-        "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7fd9b0aeb300> >"
+        "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7f98b66ad570> >"
        ]
       }
      ],
@@ -962,7 +962,7 @@
         "</svg>\n"
        ],
        "text": [
-        "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7fd9b0aeb150> >"
+        "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7f98b66ad750> >"
        ]
       }
      ],
@@ -1087,7 +1087,7 @@
         "</svg>\n"
        ],
        "text": [
-        "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7fd9b0aeb150> >"
+        "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7f98b66ad750> >"
        ]
       },
       {
@@ -1144,7 +1144,7 @@
         "</svg>\n"
        ],
        "text": [
-        "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7fd9b0aeb660> >"
+        "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7f98b66ad7b0> >"
        ]
       },
       {
@@ -1190,7 +1190,7 @@
         "</svg>\n"
        ],
        "text": [
-        "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7fd9b0aeb300> >"
+        "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7f98b66ad570> >"
        ]
       }
      ],
@@ -1397,7 +1397,7 @@
         "</svg>\n"
        ],
        "text": [
-        "<spot.impl.twa_product; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_product > *' at 0x7fd9b0aeb750> >"
+        "<spot.impl.twa_product; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_product > *' at 0x7f98b66ad510> >"
        ]
       },
       {
@@ -1471,7 +1471,7 @@
         "</svg>\n"
        ],
        "text": [
-        "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7fd9b0aeb630> >"
+        "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7f98b66adb70> >"
        ]
       },
       {
@@ -1555,7 +1555,7 @@
         "</svg>\n"
        ],
        "text": [