diff --git a/10_introduction_to_artificial_neural_networks.ipynb b/10_introduction_to_artificial_neural_networks.ipynb
index 6df82f8..26808ef 100644
--- a/10_introduction_to_artificial_neural_networks.ipynb
+++ b/10_introduction_to_artificial_neural_networks.ipynb
@@ -160,7 +160,7 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "def logit(z):\n",
+    "def sigmoid(z):\n",
     "    return 1 / (1 + np.exp(-z))\n",
     "\n",
     "def relu(z):\n",
@@ -181,8 +181,8 @@
     "plt.figure(figsize=(11,4))\n",
     "\n",
     "plt.subplot(121)\n",
-    "plt.plot(z, np.sign(z), \"r-\", linewidth=2, label=\"Step\")\n",
-    "plt.plot(z, logit(z), \"g--\", linewidth=2, label=\"Logit\")\n",
+    "plt.plot(z, np.sign(z), \"r-\", linewidth=1, label=\"Step\")\n",
+    "plt.plot(z, sigmoid(z), \"g--\", linewidth=2, label=\"Sigmoid\")\n",
     "plt.plot(z, np.tanh(z), \"b-\", linewidth=2, label=\"Tanh\")\n",
     "plt.plot(z, relu(z), \"m-.\", linewidth=2, label=\"ReLU\")\n",
     "plt.grid(True)\n",
@@ -191,10 +191,10 @@
     "plt.axis([-5, 5, -1.2, 1.2])\n",
     "\n",
     "plt.subplot(122)\n",
-    "plt.plot(z, derivative(np.sign, z), \"r-\", linewidth=2, label=\"Step\")\n",
+    "plt.plot(z, derivative(np.sign, z), \"r-\", linewidth=1, label=\"Step\")\n",
     "plt.plot(0, 0, \"ro\", markersize=5)\n",
     "plt.plot(0, 0, \"rx\", markersize=10)\n",
-    "plt.plot(z, derivative(logit, z), \"g--\", linewidth=2, label=\"Logit\")\n",
+    "plt.plot(z, derivative(sigmoid, z), \"g--\", linewidth=2, label=\"Sigmoid\")\n",
     "plt.plot(z, derivative(np.tanh, z), \"b-\", linewidth=2, label=\"Tanh\")\n",
     "plt.plot(z, derivative(relu, z), \"m-.\", linewidth=2, label=\"ReLU\")\n",
     "plt.grid(True)\n",
@@ -215,9 +215,6 @@
     "def heaviside(z):\n",
     "    return (z >= 0).astype(z.dtype)\n",
     "\n",
-    "def sigmoid(z):\n",
-    "    return 1/(1+np.exp(-z))\n",
-    "\n",
     "def mlp_xor(x1, x2, activation=heaviside):\n",
     "    return activation(-activation(x1 + x2 - 1.5) + activation(x1 + x2 - 0.5) - 0.5)"
    ]