diff --git a/Exercise sheet 6/exercise_sheet_06.ipynb b/Exercise sheet 6/exercise_sheet_06.ipynb
index ef61f3b..cbc1215 100644
--- a/Exercise sheet 6/exercise_sheet_06.ipynb	
+++ b/Exercise sheet 6/exercise_sheet_06.ipynb	
@@ -439,7 +439,7 @@
       "\tequilibrating took 1.5426356792449951  seconds\n",
       "\tmeasuring     took 3.485330104827881  seconds\n",
       "\n",
-      "T = 1.2000000000000002\n",
+      "T = 1.2\n",
       "\tequilibrating took 0.4475827217102051  seconds\n",
       "\tmeasuring     took 1.3380379676818848  seconds\n",
       "\n",
@@ -486,19 +486,19 @@
     "        \n",
     "        for idx, T in enumerate(temperatures):\n",
     "            toc()\n",
-    "            print(\"T =\", T)\n",
+    "            print(\"T = {:.1f}\".format(T))\n",
     "            beta = 1/T\n",
     "            \n",
     "            # Equilibrate\n",
     "            for _ in range(equilibration_moves):\n",
     "                xy_cluster_move(state,beta)\n",
-    "            print(\"\\tequilibrating took\", toc(), \" seconds\")\n",
+    "            print(\"\\tequilibrating took {:2.3f} seconds\".format(toc()))\n",
     "            \n",
     "            # Measure\n",
     "            for _ in range(measurement_moves):\n",
-    "                cluster_sizes[idx] += np.norm(xy_cluster_move(state,beta))\n",
+    "                cluster_sizes[idx] += xy_cluster_move(state,beta)\n",
     "            cluster_sizes[idx] /= measurement_moves\n",
-    "            print(\"\\tmeasuring     took\", toc(), \" seconds\")\n",
+    "            print(\"\\tmeasuring     took {:2.3f} seconds\".format(toc()))\n",
     "            print()\n",
     "            \n",
     "        f.create_dataset(\"cluster-size\",data=cluster_sizes)"
@@ -628,48 +628,48 @@
      "output_type": "stream",
      "text": [
       "T = 0.5\n",
-      "\tequilibrating took 2.6317245960235596  seconds\n",
-      "\tmeasuring     took 13.053837060928345  seconds\n",
+      "\tequilibrating took 2.632 seconds\n",
+      "\tmeasuring     took 13.054 seconds\n",
       "\n",
       "T = 0.6\n",
-      "\tequilibrating took 2.8574910163879395  seconds\n",
-      "\tmeasuring     took 12.967190027236938  seconds\n",
+      "\tequilibrating took 2.857 seconds\n",
+      "\tmeasuring     took 12.967 seconds\n",
       "\n",
       "T = 0.7\n",
-      "\tequilibrating took 3.4188122749328613  seconds\n",
-      "\tmeasuring     took 16.535584449768066  seconds\n",
+      "\tequilibrating took 3.419 seconds\n",
+      "\tmeasuring     took 16.536 seconds\n",
       "\n",
       "T = 0.8\n",
-      "\tequilibrating took 3.129852294921875  seconds\n",
-      "\tmeasuring     took 14.666396617889404  seconds\n",
+      "\tequilibrating took 3.130 seconds\n",
+      "\tmeasuring     took 14.666 seconds\n",
       "\n",
       "T = 0.9\n",
-      "\tequilibrating took 2.749675750732422  seconds\n",
-      "\tmeasuring     took 12.164067506790161  seconds\n",
+      "\tequilibrating took 2.750 seconds\n",
+      "\tmeasuring     took 12.164 seconds\n",
       "\n",
       "T = 1.0\n",
-      "\tequilibrating took 2.770905017852783  seconds\n",
-      "\tmeasuring     took 11.673817873001099  seconds\n",
+      "\tequilibrating took 2.771 seconds\n",
+      "\tmeasuring     took 11.674 seconds\n",
       "\n",
       "T = 1.1\n",
-      "\tequilibrating took 2.59846830368042  seconds\n",
-      "\tmeasuring     took 9.312909126281738  seconds\n",
+      "\tequilibrating took 2.598 seconds\n",
+      "\tmeasuring     took 9.313 seconds\n",
       "\n",
-      "T = 1.2000000000000002\n",
-      "\tequilibrating took 2.9586286544799805  seconds\n",
-      "\tmeasuring     took200] 10.83272385597229  seconds\n",
+      "T = 1.2\n",
+      "\tequilibrating took 2.959 seconds\n",
+      "\tmeasuring     took 10.833 seconds\n",
       "\n",
       "T = 1.3\n",
-      "\tequilibrating took 2.4720122814178467  seconds\n",
-      "\tmeasuring     took 9.212384223937988  seconds\n",
+      "\tequilibrating took 2.472 seconds\n",
+      "\tmeasuring     took 9.212 seconds\n",
       "\n",
       "T = 1.4\n",
-      "\tequilibrating took 3.3535523414611816  seconds\n",
-      "\tmeasuring     took 10.767858028411865  seconds\n",
+      "\tequilibrating took 3.354 seconds\n",
+      "\tmeasuring     took 10.768 seconds\n",
       "\n",
       "T = 1.5\n",
-      "\tequilibrating took 3.0648155212402344  seconds\n",
-      "\tmeasuring     took 9.897510051727295  seconds\n",
+      "\tequilibrating took 3.065 seconds\n",
+      "\tmeasuring     took 9.898 seconds\n",
       "\n"
      ]
     }
@@ -686,7 +686,7 @@
     "        \n",
     "        for idx, T in enumerate(temperatures):\n",
     "            toc()\n",
-    "            print(\"T =\", T)\n",
+    "            print(\"T = {:.1f}\".format(T))\n",
     "            beta = 1/T\n",
     "            # We let the sweep size depend on the width and the average cluster size\n",
     "            # from before:\n",
@@ -696,7 +696,7 @@
     "            for j in range(equil_sweeps*sweep_size):\n",
     "                xy_cluster_move(state,beta)\n",
     "                print(\"\\tequilibrating... [{}/{}]\".format(j, equil_sweeps*sweep_size), end='\\r')\n",
-    "            print(\"\\tequilibrating took\", toc(), \" seconds\")\n",
+    "            print(\"\\tequilibrating took {:2.3f} seconds\".format(toc()))\n",
     "            \n",
     "            # Measure\n",
     "            for j in range(measurements):\n",
@@ -708,7 +708,7 @@
     "                # TODO: Skip sweeps between measurements for last measurement in set.\n",
     "                for _ in range(measure_sweeps*sweep_size):\n",
     "                    xy_cluster_move(state,beta)\n",
-    "            print(\"\\tmeasuring     took\", toc(), \" seconds\")\n",
+    "            print(\"\\tmeasuring     took {:2.3f} seconds\".format(toc()))\n",
     "            print()\n",
     "            \n",
     "        f.create_dataset(\"square-magn\",data=square_magn)"
@@ -844,37 +844,37 @@
      "output_type": "stream",
      "text": [
       "T = 0.5\n",
-      "\tequilibrating took 5.539074659347534  seconds\n",
+      "\tequilibrating took 5.540 seconds\n",
       "\n",
       "T = 0.6\n",
-      "\tequilibrating took 5.275792598724365  seconds\n",
+      "\tequilibrating took 5.276 seconds\n",
       "\n",
       "T = 0.7\n",
-      "\tequilibrating took 6.957661867141724  seconds\n",
+      "\tequilibrating took 6.958 seconds\n",
       "\n",
       "T = 0.8\n",
-      "\tequilibrating took 6.382277250289917  seconds\n",
+      "\tequilibrating took 6.382 seconds\n",
       "\n",
       "T = 0.9\n",
-      "\tequilibrating took 5.454374074935913  seconds\n",
+      "\tequilibrating took 5.454 seconds\n",
       "\n",
       "T = 1.0\n",
-      "\tequilibrating took 5.399614572525024  seconds\n",
+      "\tequilibrating took 5.400 seconds\n",
       "\n",
       "T = 1.1\n",
-      "\tequilibrating took 4.563677787780762  seconds\n",
+      "\tequilibrating took 4.564 seconds\n",
       "\n",
-      "T = 1.2000000000000002\n",
-      "\tequilibrating took 5.712708473205566  seconds\n",
+      "T = 1.2\n",
+      "\tequilibrating took 5.713 seconds\n",
       "\n",
       "T = 1.3\n",
-      "\tequilibrating took 5.183827877044678  seconds\n",
+      "\tequilibrating took 5.184 seconds\n",
       "\n",
       "T = 1.4\n",
-      "\tequilibrating took 6.481664180755615  seconds\n",
+      "\tequilibrating took 6.482 seconds\n",
       "\n",
       "T = 1.5\n",
-      "\tequilibrating took 6.137166976928711  seconds\n",
+      "\tequilibrating took 6.137 seconds\n",
       "\n"
      ]
     }
@@ -889,7 +889,7 @@
     "        states = np.zeros(temperatures.shape + state.shape)\n",
     "        for idx, T in enumerate(temperatures):\n",
     "            toc()\n",
-    "            print(\"T =\", T)\n",
+    "            print(\"T = {:.1f}\".format(T))\n",
     "            beta = 1/T\n",
     "            sweep_size = np.ceil(width**2/f[\"cluster-size\"][idx]).astype(int)\n",
     "            \n",
@@ -897,7 +897,7 @@
     "            for j in range(equil_sweeps*sweep_size):\n",
     "                xy_cluster_move(state,beta)\n",
     "                print(\"\\tequilibrating... [{}/{}]\".format(j, equil_sweeps*sweep_size), end='\\r')\n",
-    "            print(\"\\tequilibrating took\", toc(), \" seconds\")\n",
+    "            print(\"\\tequilibrating took {:2.3f} seconds\".format(toc()))\n",
     "            states[idx] = state.copy()\n",
     "            print()\n",
     "        \n",
@@ -985,6 +985,14 @@
     "    plt.tight_layout()\n",
     "    plt.show()"
    ]
+  },
+  {
+   "cell_type": "markdown",
+   "id": "4b31ffe5",
+   "metadata": {},
+   "source": [
+    "The Kosterlitz-Thouless transition is vaguely visible. For $T = 1.0$ and lower, vortices and anti-vortices can be recognized. Above this temperature, this structure vanishes."
+   ]
   }
  ],
  "metadata": {