This is LaTeX code:

[latex]
L(\tau) = \begin{cases}
\left( \frac{1}{2} \right)^n, & (\forall \, i \in \{1, \ldots, n\}) \ \tau \leq x_i \leq \tau + 2 \\
0 & {\sf inace}
\end{cases}
[/latex]