Skip to content
Related Articles

Related Articles

Save Article
Improve Article
Save Article
Like Article

GATE | GATE CS 2013 | Question 41

  • Last Updated : 11 Oct, 2021

Which of the following is/are undecidable?

gatecs2013.15
(A) 3 only
(B) 3 and 4 only
(C) 1, 2 and 3 only
(D) 2 and 3 only


Answer: (D)

Explanation:

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.

  • First is Emptiness for CFG; whether a CFG is empty or not, this problem is decidable.
  • Second is everything for CFG; whether a CFG will generate all possible strings (completeness of CFG), this problem is undecidable.
  • Third is Regularity for REC; whether language generated by TM is regular is undecidable.
  • Fourth is equivalence for regular; whether language generated by DFA and NFA are same is decidable.

Second and third will be undecidable. Hence, option (D) is Correct.



Quiz of this Question

My Personal Notes arrow_drop_up
Recommended Articles
Page :