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]