Register

DECIDABILITY DOUBT

468 views
2 votes
2 votes
1. If L1 is a decidable language and L2 is an undecidable language, then (L1 U L2) , is
(A) possibly finite
(B) possibly infinite
(C) possibly decidable
(D) possibly undecidable
(E) possibly semi-decidable

Which of the above A,B,C, D and E is/are TRUE?

2. If L1 is a decidable language and L2 is an undecidable language, then (L1 ∩ L2) , is
(A) possibly finite
(B) possibly infinite
(C) possibly decidable
(D) possibly undecidable
(E) possibly semi-decidable

Which of the above A,B,C, D and E is/are TRUE?

3. If L1 is a decidable language and L2 is an undecidable language, then (L1 - L2) , is
(A) possibly finite
(B) possibly infinite
(C) possibly decidable
(D) possibly undecidable
(E) possibly semi-decidable

Which of the above A,B,C, D and E is/are TRUE?

4. If L1 is a decidable language and L2 is an semi-decidable language, then (L1 U L2) , is
(A) possibly finite
(B) possibly infinite
(C) possibly decidable
(D) possibly undecidable
(E) possibly semi-decidable

Which of the above A,B,C, D and E is/are TRUE?

5. If L1 is a decidable language and L2 is an semi-decidable language, then (L1 ∩ L2) , is
(A) possibly finite
(B) possibly infinite
(C) possibly decidable
(D) possibly undecidable
(E) possibly semi-decidable

Which of the above A,B,C, D and E is/are TRUE?

6. If L1 is a decidable language and L2 is an semi-decidable language, then (L1 - L2) , is
(A) possibly finite
(B) possibly infinite
(C) possibly decidable
(D) possibly undecidable
(E) possibly semi-decidable

Which of the above A,B,C, D and E is/are TRUE?
User Avatar

Please log in or register to answer this question.

Voting & Accepting an answer helps improve the community
← PreviousNext →
← Previous in categoryNext in category →

Related questions

0 votes
0 votes
0 answers
3
Mk Utkarsh asked Nov 23, 2018
436 views
Self doubt decidability
$\text{L}_1 = \{\text{<M>}|\text{M is a TM and L(M) is infinite} \}$ Not RE $\text{L}_2 = \{ \text{<M>} | \text{M is a TM and L(M) is countable} \}$ and $\text{L}_3 = \{ \text{<M>} | \text{M is a TM and L(M) is uncountable}\}$ both are Recursive how?
$\text{L}_1 = \{\text{<M>}|\text{M is a TM and L(M) is infinite} \}$Not RE$\text{L}_2 = \{ \text{<M>} | \text{M is a TM and L(M) is countable} \}$and $\text{L}_3 = \{ \t...
User Avatar
0 votes
0 votes
0 answers
4
aditi19 asked Oct 29, 2018
251 views
Decidability Doubt
A recursive language is empty or a recursive language contains all strings over sigma*. Why this problem is undecidable?
A recursive language is empty or a recursive language contains all strings over sigma*. Why this problem is undecidable?
User Avatar
Link Copied!