I have following statements which I must prove or disprove :
1) Let $L$ be a CFL and $k \in N$ then $L^k$ is also a CFL.
2) $L_1 \subseteq L_2 \subseteq L_3$ are Languages, if $L_1$ and $L_3$ are DCFL, then $L_2$ is also a DCFL
The first one I have no idea how to start or whether it is also a CFL
For the second one I think that this is false, because the CF contains the REG and DCF which means $L_2$ can be a REG-Language or a CFL or DCFL?
Is this right? at least this is how I understand it