diff --git a/notes.lyx b/notes.lyx
index 0608d7e..3729986 100644
--- a/notes.lyx
+++ b/notes.lyx
@@ -1148,6 +1148,13 @@ Dirichlet
 General definitions and properties
 \end_layout
 
+\begin_layout Itemize
+\begin_inset Formula $\Pr\left[A\mid B\right]>\Pr\left[A\right]\iff\Pr\left[B\mid A\right]>\Pr\left[B\right]$
+\end_inset
+
+
+\end_layout
+
 \begin_layout Itemize
 Linearity: 
 \begin_inset Formula $\E\left[aX+bY\right]=a\E\left[X\right]+b\E\left[Y\right]$