Let R1 and R2 be regular sets defined over the alphabet, then
2015
Let R1 and R2 be regular sets defined over the alphabet, then
- A.
R1 ∩ R2 is not regular
- B.
R1 ∪ R2is not regular
- C.
Σ * - R1 is regular
- D.
R1 * is not regular
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Correct answer: C
Regular languages are closed under complementation. Therefore, if R1 is regular, Σ* - R1 (the complement of R1) must also be regular. While union, intersection, and Kleene star operations also preserve regularity, the correct option identifies closure under complementation.