diff --git a/tests/python/stutter-inv.ipynb b/tests/python/stutter-inv.ipynb
index 4229be2f4..69068fca7 100644
--- a/tests/python/stutter-inv.ipynb
+++ b/tests/python/stutter-inv.ipynb
@@ -302,7 +302,7 @@
        "</svg>\n"
       ],
       "text/plain": [
-       "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7f6b5c32c720> >"
+       "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7fa2444ce810> >"
       ]
      },
      "metadata": {},
@@ -595,7 +595,7 @@
        "</svg>\n"
       ],
       "text/plain": [
-       "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7f6b5c358f90> >"
+       "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7fa24445d270> >"
       ]
      },
      "metadata": {},
@@ -804,7 +804,7 @@
        "</svg>\n"
       ],
       "text/plain": [
-       "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7f6b5c358f90> >"
+       "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7fa24445d270> >"
       ]
      },
      "metadata": {},
@@ -963,7 +963,7 @@
        "</svg>\n"
       ],
       "text/plain": [
-       "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7f6b5c358ea0> >"
+       "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7fa2444ce8a0> >"
       ]
      },
      "metadata": {},
@@ -1062,7 +1062,7 @@
        "</svg>\n"
       ],
       "text/plain": [
-       "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7f6b5c32c750> >"
+       "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7fa24446e5d0> >"
       ]
      },
      "metadata": {},
@@ -1279,47 +1279,11 @@
        "</svg>\n"
       ],
       "text/plain": [
-       "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7f6b5c2cb360> >"
+       "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7fa24446e660> >"
       ]
      },
      "metadata": {},
      "output_type": "display_data"
-    },
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "HOA: v1\n",
-      "States: 6\n",
-      "Start: 5\n",
-      "AP: 1 \"a\"\n",
-      "Acceptance: 3 (Inf(0)&Inf(1)) | Inf(2)\n",
-      "properties: trans-labels explicit-labels trans-acc stutter-invariant\n",
-      "--BODY--\n",
-      "State: 0\n",
-      "[!0] 0 {1}\n",
-      "[0] 0\n",
-      "[0] 1 {0}\n",
-      "State: 1\n",
-      "[0] 0\n",
-      "[0] 1 {0}\n",
-      "State: 2\n",
-      "[t] 2\n",
-      "[!0] 3\n",
-      "[0] 4\n",
-      "State: 3\n",
-      "[!0] 3 {2}\n",
-      "[0] 4 {2}\n",
-      "State: 4\n",
-      "[!0] 3 {2}\n",
-      "State: 5\n",
-      "[!0] 3\n",
-      "[0] 1\n",
-      "[0] 4\n",
-      "[t] 0\n",
-      "[t] 2\n",
-      "--END--\n"
-     ]
     }
    ],
    "source": [
@@ -1330,9 +1294,7 @@
     "display(aut)\n",
     "# The stutter_invariant property is set on AUT as a side effect\n",
     "# of calling sutter_invariant_states() or any variant of it.\n",
-    "assert(aut.prop_stutter_invariant().is_true())\n",
-    "\n",
-    "print(aut.to_str())"
+    "assert(aut.prop_stutter_invariant().is_true())"
    ]
   },
   {
@@ -1446,7 +1408,7 @@
        "</svg>\n"
       ],
       "text/plain": [
-       "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7f6b5c2cb480> >"
+       "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7fa244d50270> >"
       ]
      },
      "metadata": {},
@@ -1577,7 +1539,7 @@
        "</svg>\n"
       ],
       "text/plain": [
-       "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7f6b5c2cbd50> >"
+       "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7fa24446eb70> >"
       ]
      },
      "metadata": {},
@@ -1837,7 +1799,7 @@
        "</svg>\n"
       ],
       "text/plain": [
-       "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7f6b5c2dd570> >"
+       "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7fa244480540> >"
       ]
      },
      "metadata": {},
@@ -2151,7 +2113,7 @@
        "</svg>\n"
       ],
       "text/plain": [
-       "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7f6b5c2dd570> >"
+       "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7fa244480540> >"
       ]
      },
      "metadata": {},