Recursive Language


Q11.

Let L1 be regular language, L2 be a deterministic context-free language and L3 a recursively enumerable, but not recursive, language. Which one of the following statements is false?
GateOverflow

Q12.

Let L1 be a recursive language. Let L2 and L3 be languages that are recursively enumerable but not recursive. Which of the following statements is not necessarily true?
GateOverflow

Q13.

Let L1 be a recursive language, and let L2 be a recursively enumerable but not a recursive language. Which one of the following is TRUE?
GateOverflow

Q14.

If L and \bar{L} are recursively enumerable then L is
GateOverflow

Q15.

L1 is a recursively enumerable language over \Sigma. An algorithm A effectively enumerates its words as w1, w2, w3, ... define another language L2 over \SigmaU{#} as {wi # wj : wi, wj \in L1, i \lt 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 ?
GateOverflow

Q16.

Which of the following is true ?
GateOverflow

Q17.

Choose the correct alternatives (More than one may be correct).Recursive languages are:
GateOverflow

Q18.

For S \in (0+1)^{*}, let d(s) denote the decimal value of s (e.g. d(101)=5). Let L={s \in (0+1)*| d(s) mod 5=2 and d(s) mod 7\neq4} Which one of the following statements is true?
GateOverflow