fixed typo in temporal 0006 sol

temporal_logic/0006_sol.tex

@@ -6,7 +6,7 @@ We use the following Boolean variables:
 \end{itemize}
 
 \begin{itemize}
-    \item $\varphi_1 \coloneqq E(GF a \wedge GF c)$
-    \item $\varphi_2 \coloneqq A (GF a \wedge FG \neg c)$
-    \item $\varphi_3 \coloneqq A (GF a \rightarrow GF c)$
+    \item $\varphi_1 \coloneqq E(GF a \land GF c)$
+    \item $\varphi_2 \coloneqq A (GF a \land GF c)$
+    \item $\varphi_3 \coloneqq A (GF a \imp FG \neg c)$
 \end{itemize}