Fixed wrong theorem name.

src/op/banach/spectrum.tex

@@ -69,8 +69,8 @@
     which tends to $0$ as $|\lambda| \to \infty$, $R_x \in H(\complex; A) \cap C_0(\complex; A)$. By \hyperref[Liouville's Theorem]{theorem:liouville}, $R_x = 0$, which is impossible. 
 \end{proof}
 
-\begin{theorem}[Gelfand-Naimark]
-\label{theorem:gelfand-naimark}
+\begin{theorem}[Gelfand-Mazur]
+\label{theorem:gelfand-mazur}
     Let $A$ be a unital Banach algebra. If every non-zero element of $A$ is invertible, then $A$ is isometrically isomorphic to $\complex$. 
 \end{theorem}
 \begin{proof}