Test by Bikram | Mock GATE | Test 1 | Question: 21

Question

Consider the languages given below.

1. $L1 =$ {$a$^$n$ $b$^$m$ $c$^$m$ $d$^$n$ $|n >= 1$ and $m >= 1$}
2. $L2 =$ {$a$^$n$ $b$^$n$ $|n >= 1$}
3. $L3 =$ {$a$^$n$ $b$^$n$ $c$^$n$ $|n>=0$ }

Find the correct statement from the following:

• A.   $L1, L2$ and $L3$  are context Free languages
• B.   $L1, L2$ are but not $L3$, are context free Languages
• C.   $L2, L3$ are context free but not $L1$
• D.   Only $L2$  is context free

Answer 1

The equivalent context free grammar for L1 is, S -> aSd|aAd,  A -> bAc | bc