Which of the following regular expression identities are true?
20122012
Which of the following regular expression identities are true?
Answer: C. (r + s)* = (r*s*)* — Option C is correct because (r + s)* represents all strings formed by r and s. This set equals (r* s*)* as any combination can be grouped into r blocks…
- A.
(r + s)* = r* s*
- B.
(r + s)* = r* + s*
- C.
(r + s)* = (r*s*)*
- D.
r* s* = r* + s*
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Correct answer: C
Option C is correct because (r + s)* represents all strings formed by r and s. This set equals (r* s*)* as any combination can be grouped into r blocks followed by s blocks. Options A, B, and D are false because they cannot generate mixed sequences like sr or rs.
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