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Recent questions tagged regular-expressions

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2
There are two sources on YouTube giving different answers for the same expression.I am confused. Is the given expressions wxwr | w,x $\in$(0,1)+ I think this is regular because this can be reduced to ending with 00 or 01 or 10 or 11 wwrx | w,x $\in$(0,1)+ I think this is regular because it can reduced to starting with 0 or 1
asked Oct 16, 2018 in Theory of Computation sripo 239 views
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Let l={ (ap )* | p is a prime number} and $\sum$={a}.The minimum number of states in NFA which can accept this language. This is a question from a test series,I just want to know if the question is valid as I feel raised to prime number will not be regular,correct me if I am wrong.Not asking for solution to the question but if the question is valid.
asked Oct 16, 2018 in Theory of Computation sripo 1.2k views
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Which is the equivalent Regular Expression for the following: "Strings in which every group of 3 symbols should contain atleast 1 a." a)[(a+b) (a+b)a]* b) [(a+b) (a+b)a]* [(a+b)(a+b)a]* c)[(ϵ + b + bb)a]* [ ϵ+ b + bb] d) (abb)* (bab)b* (bba)*
asked Oct 14, 2018 in Theory of Computation Sambhrant Maurya 139 views
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For $\sum$={a,b} Re given is b*ab*(aa)*b* this is non minimized dfa but when the dfa is minimized we get RE as b*a(a+b)*. How to show that are they equivalent or is it just worked for this case?
asked Oct 10, 2018 in Theory of Computation sripo 268 views
1 vote
1 answer
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what is the equivalent nfa for the given regular expression? a*b*(ba)*a*
asked Oct 9, 2018 in Theory of Computation suneetha 195 views
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2 answers
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difference between a*(ba)* and (a+ba)* and how to represent both in finite automata?
asked Oct 6, 2018 in Theory of Computation suneetha 124 views
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2 answers
10
how can we represent (ab)*ba*(b+a)*aab* in finite automata?
asked Oct 6, 2018 in Theory of Computation suneetha 128 views
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Let L be a regular language over $\{0,1\}$. Define the reverse of the language $L$ to be the language $L^R = \{ w \in \{0,1\}^* \: \: : \: \: \text{ reverse }(w) \in L\}$, where $\text{reverse}(w)$ denotes the string $w$ ... $x$ contains an odd number of $1's$ and $00$ as a substring$\}.$ Construct a regular expression for the language $L$.
asked Sep 18, 2018 in Theory of Computation jothee 98 views
1 vote
1 answer
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Consider the following regular expression R=(a+b)* (a+b+ε)a which of the following is equivalent to the above a)(a*+b*)+ (aa+ba) b)(ε+a+b*)+ a c)(a+b)+ (a+b+ε)a d)None of these
asked Sep 15, 2018 in Theory of Computation Kshitij Hansda 510 views
2 votes
2 answers
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Consider the regular expression R = a*b* + b*a*. The number of equivalence classes of Σ* to represent a language which is equivalent to R is ____________.
asked Sep 12, 2018 in Theory of Computation goluabhinan 208 views
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1 answer
21
can i get all the formulas of expression (a+b)*.
asked Sep 9, 2018 in Theory of Computation Prathap Ñsvr 162 views
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Consider this regular expression: r = (a*b)* + (b*a)* This is equivalent to (a) (a + b)* (b) (a + b)* · (ab)+ + (a + b)* (ba)+ (c) (a + b)*a + (a + b)* b (d) None of above
asked Sep 3, 2018 in Theory of Computation navya n 199 views
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2 answers
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How to construct a finite automata equivalent to the regular expression: ( 0 + 1 )* ( 00 + 11 ) ( 0 + 1 )*
asked Sep 1, 2018 in Theory of Computation iarnav 3.4k views
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1 answer
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Which of the following CFG’s can’t be simulated by an FSM ? a. S->Sa/b b. S->aSb/ab c. S->abX, X->cY, Y->d/aX d. None of these
asked Aug 31, 2018 in Theory of Computation Rackson 939 views
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1 answer
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Which of the regular expressions given below represent the following DFA? A) 0*1(1+00*1)* B) 0*1*1+11*0*1 C) (0+1)*1
asked Aug 31, 2018 in Theory of Computation aditi19 538 views
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2 answers
29
Give regular expression for all strings not ending with '01' on Σ={0, 1}. is this expression correct? (ɛ+1*0*+(0+1)*1*0)*
asked Aug 30, 2018 in Theory of Computation aditi19 133 views
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