GATE CSE 2000 | Question: 1.4

Question

Let $S$ and $T$ be languages over $\Sigma=\{a,b\}$ represented by the regular expressions $(a+b^*)^*$ and $(a+b)^*$, respectively. Which of the following is true?

• A. $S \subset T$
• B. $T \subset S$
• C. $S = T$
• D. $S \cap T = \phi$

Comments

Typo. Comma {a,b}

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Where?

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edited

Answer 1

Option C,

S = T,

All the below forms of REX are equivalent,

(a*b*)* = (b*a*)* = (a* + b)* = (a + b*)* = (a* + b*)* = (a + b)*