GATE | GATE MOCK 2017 | Question 54

Suppose M1 and M2 are two TM’s such that L(M1) = L(M2). Then

(A) On every input on which M1 doesn’t halt, M2 doesn’t halt too.

(B) On every i/p on which M1 halts, M2 halts too.



(C) On every i/p which M1 accepts, M2 halts.

(D) None of above.


Answer: (C)

Explanation:

M2 accepts strings in L(M1) so definitely it will halt. Other 2 are not guaranteed as Turing machine M does not accept w if it either rejects w by halting to a reject state or loops infinitely on w.


Quiz of this Question



My Personal Notes arrow_drop_up


Article Tags :

Be the First to upvote.


Please write to us at contribute@geeksforgeeks.org to report any issue with the above content.