1
GATE CSE 2021 Set 2
MCQ (More than One Correct Answer)
+1
-0
Let L1 be a regular language and L2 be a context-free language. Which of the following languages is/are context-free?
A
L1 ∩ L̅2
B
L1 ∪ (L2 ∪ L̅2)
C
$$\overline {{{\bar L}_1} \cup {{\bar L}_2}} $$
D
(L∩ L2) ∪ (L̅1 ∩ L2)
2
GATE CSE 2021 Set 1
MCQ (Single Correct Answer)
+1
-0.33
Suppose that L1 is a regular and L2 is a context-free language, Which one of the following languages is NOT necessarily context-free?
A
L1 ⋅ L2
B
L1 ∪ L2
C
L1 ∩ L2
D
L1 - L2
3
GATE CSE 2021 Set 1
MCQ (Single Correct Answer)
+1
-0
Let $$\left\langle M \right\rangle $$ denote an encoding of an automation M. Suppose that ∑ = {0, 1}. Which of the following languages is/are NOT recursive?
A
L = { $$\left\langle M \right\rangle $$ | M is a PDA such that L(M) = ∑*}
B
L = { $$\left\langle M \right\rangle $$ | M is a DFA such that L(M) = Φ}
C
L = { $$\left\langle M \right\rangle $$ | M is a PDA such that L(M) = Φ}
D
L = { $$\left\langle M \right\rangle $$ | M is a DFA such that L(M) = ∑*}
4
GATE CSE 2016 Set 1
MCQ (Single Correct Answer)
+1
-0.3
Which of the following languages is generated by the given grammar? $$$S \to aS|bS|\varepsilon $$$
A
$$\left\{ {{a^n}{b^m}|n,m \ge 0} \right\}$$
B
$$\left\{ {w \in \left\{ {a,b} \right\}{}^ * |w} \right.$$ has equal number of $$a’s$$ and $$\left. {b's} \right\}$$
C
$$\left\{ {{a^n}|n \ge 0} \right\} \cup \left\{ {{b^n}|n \ge 0} \right\} \cup \left\{ {{a^n}{b^n}|n \ge 0} \right\}$$
D
$${\left\{ {a,b} \right\}^ * }$$
GATE CSE Subjects
Software Engineering
Web Technologies
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