Introduce mealy_prod

Product between mealy machines
with propagation of synthesis outputs
and additional assertions.
Currently it only supports input complete machines

* spot/twaalgos/mealy_machine.cc,
  spot/twaalgos/mealy_machine.hh: Here
* bin/ltlsynt.cc: Use
* tests/python/except.py,
  tests/python/synthesis.ipynb: Test

bin/ltlsynt.cc

@@ -545,7 +545,8 @@ namespace
                && "ltlsynt: Cannot handle TGBA as strategy.");
         tot_strat = mealy_machines.front().mealy_like;
         for (size_t i = 1; i < mealy_machines.size(); ++i)
-          tot_strat = spot::product(tot_strat, mealy_machines[i].mealy_like);
+          tot_strat = spot::mealy_product(tot_strat,
+                                          mealy_machines[i].mealy_like);
         printer.print(tot_strat, timer_printer_dummy);
       }
 

spot/twaalgos/mealy_machine.cc

@@ -34,6 +34,7 @@
 #include <spot/misc/minato.hh>
 #include <spot/twaalgos/game.hh>
 #include <spot/twaalgos/hoa.hh>
+#include <spot/twaalgos/product.hh>
 #include <spot/twaalgos/synthesis.hh>
 
 #include <picosat/picosat.h>
@@ -55,6 +56,7 @@
 
 namespace
 {
+  using namespace spot;
   bool is_deterministic_(const std::vector<bdd>& ins)
   {
     const unsigned n_ins = ins.size();
@@ -64,6 +66,24 @@ namespace
           return false;
     return true;
   }
+
+  bool is_complete_(const const_twa_graph_ptr& m,
+                    const bdd& outs)
+  {
+    auto* sp = m->get_named_prop<region_t>("state-player");
+    const auto N = m->num_states();
+    for (auto s = 0u; s < N; ++s)
+      {
+        if (sp && sp->at(s))
+          continue; // No need tpo check player states
+        bdd all_cond = bddfalse;
+        for (const auto& e : m->out(s))
+          all_cond |= bdd_exist(e.cond, outs);
+        if (all_cond != bddtrue)
+          return false;
+      }
+    return true;
+  }
 }
 
 
@@ -3843,4 +3863,38 @@ namespace spot
     return true;
   }
 
+  twa_graph_ptr
+  mealy_product(const const_twa_graph_ptr& left,
+                const const_twa_graph_ptr& right)
+  {
+    bdd outs[] = {get_synthesis_outputs(left),
+                  get_synthesis_outputs(right)};
+
+#ifndef NDEBUG
+    for (const auto& [m, n, o] : {std::tuple{left, "left", outs[0]},
+                                            {right, "right", outs[1]}})
+      {
+        if (!is_mealy(m))
+          throw std::runtime_error(std::string("mealy_prod(): ") + n
+                                  + " is not a mealy machine");
+        if (!is_complete_(m, o))
+          throw std::runtime_error(std::string("mealy_prod(): ") + n
+                                   + " is not input complete");
+      }
+#endif
+
+    auto p = product(left, right);
+    bdd pouts = outs[0] & outs[1];
+    set_synthesis_outputs(p, pouts);
+
+#ifndef NDEBUG
+    if (!is_mealy(p))
+      throw std::runtime_error("mealy_prod(): Prooduct is not mealy");
+    if (!is_complete_(p, pouts))
+      throw std::runtime_error("mealy_prod(): Prooduct is not input complete. "
+                               "Incompatible machines?");
+#endif
+
+    return p;
+  }
 }

spot/twaalgos/mealy_machine.hh

@@ -128,4 +128,14 @@ namespace spot
   is_split_mealy_specialization(const_twa_graph_ptr left,
                                 const_twa_graph_ptr right,
                                 bool verbose = false);
+
+  /// \brief Product between two mealy machines \a left and \a right.
+  /// \pre The machines have to be both either split or unsplit,
+  /// input complete and compatible. All of this is check by assertion
+  /// \result The mealy machine representing the shared behaviour.
+  /// The resulting machine has the same class (mealy/separated/split)
+  /// as the input machines
+  SPOT_API twa_graph_ptr
+  mealy_product(const const_twa_graph_ptr& left,
+                const const_twa_graph_ptr& right);
 }

tests/python/except.py

@@ -331,3 +331,20 @@ except RuntimeError as e:
     tc.assertIn("already registered", se)
 else:
     report_missing_exception()
+
+
+si = spot.synthesis_info()
+si.s = spot.synthesis_info.algo_LAR
+g1 = spot.ltl_to_game("G((i0 xor i1) <-> o0)", ["o0"], si)
+g2 = spot.ltl_to_game("G((i0 xor i1) <-> (!o0 & !o1))", ["o0", "o1"], si)
+spot.solve_game(g1)
+spot.solve_game(g2)
+strat1 = spot.solved_game_to_separated_mealy(g1)
+strat2 = spot.solved_game_to_separated_mealy(g2)
+try:
+    stratcomp = spot.mealy_product(strat1, strat2)
+except RuntimeError as e:
+    se = str(e)
+    tc.assertIn("Incompatible", se)
+else:
+    report_missing_exception()

tests/python/synthesis.ipynb

@@ -696,7 +696,7 @@
        "</svg>\n"
       ],
       "text/plain": [
-       "<spot.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7fc5ec2bf930> >"
+       "<spot.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7f05083f22a0> >"
       ]
      },
      "metadata": {},
@@ -2714,7 +2714,7 @@
        "</svg>\n"
       ],
       "text/plain": [
-       "<spot.aig; proxy of <Swig Object of type 'spot::aig_ptr *' at 0x7fc5ec2bfc00> >"
+       "<spot.aig; proxy of <Swig Object of type 'spot::aig_ptr *' at 0x7f05083a6900> >"
       ]
      },
      "metadata": {},
@@ -3027,7 +3027,7 @@
        "</svg>\n"
       ],
       "text/plain": [
-       "<spot.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7fc5dc8463f0> >"
+       "<spot.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7f05082c7a20> >"
       ]
      },
      "metadata": {},
@@ -3102,7 +3102,7 @@
        "</svg>\n"
       ],
       "text/plain": [
-       "<spot.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7fc5ec2bf990> >"
+       "<spot.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7f05083f2300> >"
       ]
      },
      "metadata": {},
@@ -3179,7 +3179,7 @@
        "</svg>\n"
       ],
       "text/plain": [
-       "<spot.aig; proxy of <Swig Object of type 'spot::aig_ptr *' at 0x7fc5ec2bffc0> >"
+       "<spot.aig; proxy of <Swig Object of type 'spot::aig_ptr *' at 0x7f05083f28d0> >"
       ]
      },
      "metadata": {},
@@ -3306,7 +3306,7 @@
        "</svg>\n"
       ],
       "text/plain": [
-       "<spot.aig; proxy of <Swig Object of type 'spot::aig_ptr *' at 0x7fc5dc846f30> >"
+       "<spot.aig; proxy of <Swig Object of type 'spot::aig_ptr *' at 0x7f05083a64b0> >"
       ]
      },
      "metadata": {},
@@ -3327,8 +3327,13 @@
     "It can happen that the complete specification of the controller can be separated into sub-specifications with DISJOINT output propositions, see Finkbeiner et al. Specification Decomposition for Reactive Synthesis.\n",
     "This results in multiple Mealy machines which have to be converted into one single AIG circuit.\n",
     "\n",
-    "This can be done using the function `mealy_machines_to_aig()`, which takes a vector of separated Mealy machines as argument.\n",
+    "This can be done in two ways:\n",
-    "In order for this to work, all Mealy machines need to share the same `bdd_dict`. This can be ensured by passing a common options strucuture."
+    "\n",
+    "1. Using the function `mealy_machines_to_aig()`, which takes a vector of separated mealy machines as argument.\n",
+    "2. Combine the mealy machines into one before passing it to `mealy_machine_to aig(). This currently only supports input complete machines of the same type (mealy/separated mealy/split mealy)\n",
+    "\n",
+    "Note that the method version is usually preferable as it is faster.\n",
+    "Also note that in order for this to work, all mealy machines need to share the same `bdd_dict`. This can be ensured by passing a common options strucuture."
    ]
   },
   {
@@ -3623,7 +3628,7 @@
      "name": "stdout",
      "output_type": "stream",
      "text": [
-      "Circuit implementing both machines:\n"
+      "Circuit implementing both machines from a vector of machines:\n"
      ]
     },
     {
@@ -3733,7 +3738,185 @@
        "</svg>\n"
       ],
       "text/plain": [
-       "<spot.aig; proxy of <Swig Object of type 'spot::aig_ptr *' at 0x7fc5ec237ed0> >"
+       "<spot.aig; proxy of <Swig Object of type 'spot::aig_ptr *' at 0x7f05083f2fc0> >"
+      ]
+     },
+     "metadata": {},
+     "output_type": "display_data"
+    },
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Combining the two machines into one.\n"
+     ]
+    },
+    {
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+       "</svg>\n"
+      ],
+      "text/plain": [
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+     "output_type": "display_data"
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+    {
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+      ],
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       ]
      },
      "metadata": {},
@@ -3753,9 +3936,16 @@
     "strat2 = spot.solved_game_to_separated_mealy(g2)\n",
     "print(\"Reduced strategies:\")\n",
     "display_inline(strat1, strat2)\n",
-    "print(\"Circuit implementing both machines:\")\n",
+    "#Method 1\n",
+    "print(\"Circuit implementing both machines from a vector of machines:\")\n",
     "aig = spot.mealy_machines_to_aig([strat1, strat2], \"isop\")\n",
-    "display(aig)"
+    "display(aig)\n",
+    "#Method 2\n",
+    "strat_comb = spot.mealy_product(strat1, strat2)\n",
+    "print(\"Combining the two machines into one.\")\n",
+    "display(strat_comb)\n",
+    "aig_comb = spot.mealy_machine_to_aig(strat_comb, \"isop\")\n",
+    "display(aig_comb)"
    ]
   },
   {
@@ -3906,7 +4096,7 @@
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       ],
       "text/plain": [
-       "<spot.aig; proxy of <Swig Object of type 'spot::aig_ptr *' at 0x7fc5ec2bf390> >"
+       "<spot.aig; proxy of <Swig Object of type 'spot::aig_ptr *' at 0x7f05082c7660> >"
       ]
      },
      "metadata": {},
@@ -4030,7 +4220,7 @@
        "</svg>\n"
       ],
       "text/plain": [
-       "<spot.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7fc5dc846690> >"
+       "<spot.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7f05082c7690> >"
       ]
      },
      "execution_count": 16,
@@ -4419,7 +4609,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.9.2"
+   "version": "3.8.10"
   }
  },
  "nbformat": 4,