Which of the following identities of regular expression is NOT correct?
2023
Which of the following identities of regular expression is NOT correct?
- A.
ϕ + R = R
- B.
R* R* = R*
- C.
∧R = R
- D.
ϕR = R
Attempted by 82 students.
Show answer & explanation
Correct answer: D
For regular expressions, phi plus R equals R, R*R* equals R*, and lambda R equals R. But phi R equals phi, not R. Therefore, phi R = R is not correct.