diff --git a/Wettersysteme-ZF.tex b/Wettersysteme-ZF.tex
index fff4fa0..40409e4 100644
--- a/Wettersysteme-ZF.tex
+++ b/Wettersysteme-ZF.tex
@@ -146,7 +146,14 @@
 	\rule{\linewidth}{0.25pt}
 \end{center}
 
-\section{Thermodynamik}
+\section{Operators}
+$$\mathrm{rot} \ u = \nabla \times \vec{u}$$
+
+$$\nabla = \begin{pmatrix}
+    \frac{\partial}{\partial x},
+    \frac{\partial}{\partial y},
+    \frac{\partial}{\partial z}
+\end{pmatrix}$$
 
 \scriptsize