diff --git a/book_equations.ipynb b/book_equations.ipynb
index ad8a8e9..c06b03a 100644
--- a/book_equations.ipynb
+++ b/book_equations.ipynb
@@ -974,7 +974,7 @@
     "**Equation 16-6: Q-Learning using an exploration function**\n",
     "\n",
     "$\n",
-    "Q(s, a) \\gets (1-\\alpha)Q(s,a) + \\alpha\\left(r + \\gamma . \\underset{\\alpha'}{\\max}f(Q(s', a'), N(s', a'))\\right)\n",
+    "Q(s, a) \\gets (1-\\alpha)Q(s,a) + \\alpha\\left(r + \\gamma \\, \\underset{a'}{\\max}f(Q(s', a'), N(s', a'))\\right)\n",
     "$\n",
     "\n",
     "**Equation 16-7: Target Q-Value**\n",