L1 is a recursively enumerable language over Σ. An algorithm A effectively…

GATE · 2004 · CS

L1 is a recursively enumerable language over Σ. An algorithm A effectively enumerates its words as w1, w2, w3, ... Define another language L2 over Σ Union {#} as {wi # wj : wi, wj ∈ L1, i < j}. Here # is a new symbol. Consider the following assertions.

S1 :  L1 is recursive implies L2 is recursive
S2 : L2 is recursive implies L1 is recursive 

Which of the following statements is true ?

  1. A.

    Both S1 and S2 are true

  2. B.

    S1 is true but S2 is not necessarily true

  3. C.

    S2 is true but S1 is not necessarily true

  4. D.

    Neither is necessarily true

Attempted by 52 students.

Sign up free to check your answer

Sign up free

Explore the full course: Gate Guidance By Sanchit Sir

Loading lesson…