Merge pull request #13 from Kaiwen-S/patch-1

ib/markov/02_elementary_properties.tex

@@ -279,7 +279,7 @@ \subsection{Mean hitting times}
 \begin{theorem}
 	The vector \( (k_i^A)_{i \in I} \) is the minimal non-negative solution to the system of equations
 	\[
-		\begin{cases}
+		k_i^A = \begin{cases}
 			0                                   & \text{if } i \in A     \\
 			1 + \sum_{j \not\in A} P(i,j) k_j^A & \text{if } i \not\in A
 		\end{cases}