diff --git a/Notebooks/Chap07/7_1_Backpropagation_in_Toy_Model.ipynb b/Notebooks/Chap07/7_1_Backpropagation_in_Toy_Model.ipynb
index 9f3e7bd..c184ffd 100644
--- a/Notebooks/Chap07/7_1_Backpropagation_in_Toy_Model.ipynb
+++ b/Notebooks/Chap07/7_1_Backpropagation_in_Toy_Model.ipynb
@@ -4,7 +4,7 @@
   "metadata": {
     "colab": {
       "provenance": [],
-      "authorship_tag": "ABX9TyPmaYT+KLPAmZxse087Eisa",
+      "authorship_tag": "ABX9TyMMmg6voEOOY2uS6iFsD42d",
       "include_colab_link": true
     },
     "kernelspec": {
@@ -262,7 +262,7 @@
     {
       "cell_type": "markdown",
       "source": [
-        "**Step 2:** Compute the derivatives of $y$ with respect to the intermediate quantities that we just calculated, but in reverse order:\n",
+        "**Step 2:** Compute the derivatives of $\\ell_i$ with respect to the intermediate quantities that we just calculated, but in reverse order:\n",
         "\n",
         "\\begin{eqnarray}\n",
         "\\quad \\frac{\\partial \\ell_i}{\\partial f_3}, \\quad \\frac{\\partial \\ell_i}{\\partial h_3}, \\quad \\frac{\\partial \\ell_i}{\\partial f_2}, \\quad\n",