Skip to content
Related Articles

Related Articles

Improve Article

GATE | Gate IT 2008 | Question 31

  • Last Updated : 28 Jun, 2021

Consider the following languages.

L1 = {ai bj ck | i = j, k ≥ 1}

L1 = {ai bj | j = 2i, i ≥ 0}

Which of the following is true?
(A) L1 is not a CFL but L2 is
(B) L1 ∩ L2 = ∅ and L1 is non-regular
(C) L1 ∪ L2 is not a CFL but L2 is
(D) There is a 4-state PDA that accepts L1, but there is no DPDA that accepts L2

Answer: (B)

Explanation: A: Both L1 and L2 are CFL

B: L1 ∩ L2 = ∅ is true

L1is not regular => true

=> B is true

C: L1 ∪ L2 is not a CFL nut L2 is CFL is closed under Union

=> False

D: Both L1 and L2 accepted by DPDA

Quiz of this Question

Attention reader! Don’t stop learning now.  Practice GATE exam well before the actual exam with the subject-wise and overall quizzes available in GATE Test Series Course.

Learn all GATE CS concepts with Free Live Classes on our youtube channel.

My Personal Notes arrow_drop_up
Recommended Articles
Page :