diff --git a/paper.md b/paper.md
index 5638c49..a0f6587 100644
--- a/paper.md
+++ b/paper.md
@@ -124,7 +124,7 @@ We can then reorganize the fraction:
 \end{equation}
 
 \begin{equation}\label{eq:15}
-\Bigl\{\Bigl(\frac{W_1}{a_1}\Bigr)^{W_1}*\Bigl(\frac{W_2}{a_2}\Bigr)^{W_2}*...*\Bigl(\frac{W_n}{a_n}\Bigr)^{W_n}\Bigr\}
+\Bigl( \Bigl( \frac{W_1}{a_1} \Bigr)^{W_1}*\Bigl(\frac{W_2}{a_2}\Bigr)^{W_2}*...*\Bigl(\frac{W_n}{a_n}\Bigr)^{W_n}\Bigr)
 \end{equation}