Common Data for Q14,15 &16 is given below: Ram takes two context-free languages $L_1$ and $L_2$
a). He concatenates $L_1 $ and $L_2$ to obtain a new set $L_3$.
b). He takes the complement of $L_3$ to obtain a set $L_4$
c). He forms a new language $L_5$ by taking the first half of each string in $L_4$ .
d). He obtains a new language $L_6$ by taking the second half of each string in $L_4$.
e). He concatenates $L_5$ and $L_6$ to obtain a new language $L_7$.
f). He takes the intersection of $L_7$ and $L_1$ to obtain a new language $L_8$.
Q14). The language $L_5$ is
a) finite
b).cfl but not regular
c).r.e. but not recursive
d).recursive set
Q15).The language $L_7$ is
a). cfl but not regular
b). csl
c). recursive but not a csl
d). r.e. set that is not recursive.
Q16). The language $L_8$ is
a). recursive
b). csl that is not finite
c). cfl that may regular
d). r.e. set that is never finite.
