# Which properties of context sensitive languages are decidable?

There are two context-sensitive languages, $L_1$ and $L_2$. Which of the following statements about them are decidable respectively undecidable?

1. $L_1 = \emptyset$
2. $L_1 = \Sigma^*$
3. $L_1 \cap L_2 = \emptyset$
4. $\overline{L_1}$ is also a context-sensitive language.
5. $L_1 = L_2$
• – vzn
Jun 8 '14 at 15:31