diff --git a/cw/cw.tex b/cw/cw.tex
index d109e71..e5bf0dc 100644
--- a/cw/cw.tex
+++ b/cw/cw.tex
@@ -6,7 +6,7 @@
 \usepackage{tabularx}
 \usepackage{pdfpages}
 \usepackage{float}
-\usepackage{amsmath}
+\usepackage{amsmath, amssymb}
 \usepackage{systeme}
 
 \usepackage{graphicx}
@@ -135,7 +135,7 @@
 	This q pairs work because when the oracle selects b=0:
 
 	There will be no colisions:
-	$$\exists i,k : i \ne j \land P_{0i} \ne p E_{0i} \implies E_{0i} \ne E_{0j}$$
+	$$\nexists i,k : i \ne j \land P_{0i} \ne p E_{0i} \implies E_{0i} \ne E_{0j}$$
 	there if you don't find any colissions you can assume that the the oracle selected b=0
 
 	if the oracle selects b=1: