# Recent questions tagged regular

1
Suppose $h$ is the homomorphism from the alphabet $\{0,1,2\}$ to the alphabet $\{a,b\}$ de fined by$:$ $h(0)=a;h(1)=ab,$ and $h(2)=ba.$ What is $h(0120)?$ What is $h(21120)?$ If $L$ is the language $L(01^{*}2),$ what is $h(L)?$ If $L$ ... the language consisting of only the one string $ababa.$ What is $h^{-1}(L)?$ If $L$ is the language $L(a(ba)^{*}),$what is $h^{-1}(L)?$
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difference between a*(ba)* and (a+ba)* and how to represent both in finite automata?
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Consider the following statements:- I) Type-0 grammar generate exactly all language that can be accepted by a total Turing machine. II) Type-1 grammar generate exactly all languages that can be recognized by a linear bounded automata. III) Type-3 grammar have one to one correspondence ... G2) A -> Aa/a both are type 3 grammar but both represent same regular expression as a+ what is wrong in this??
1 vote
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Consider these statements: S1: If a language is infinite, it has to be non-Regular. S2: Let L be any language. $(\overline{L})^{*} \neq (\overline{L^{*}})$ (a) Both are True (c) S1 → True, S2 → False (b) Both are False (d) S1 → False, S2 → True
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a*b*b (a+ (ab)*)* b* shortest string generated by this RE?
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The equality of two regular expression is computed in? Give reasons also.. Constant Time polynomial time logarithmic Polynomial time Exponential time
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1) (L/a)a=L(the left side represents the concatenation of the languages L/a and {a}) 2) a(a/L)=L(again concatenation with {a},this time on the left,is intended) 3) (La)/a=L 4) a/(aL)=L
1 vote
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1 vote
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If r1 and r2 are 2 Regular Expression Such that r1 = (a+b)* r2 = (a*+b*+a*b*+b*a*) What are the different case's in which r1 = r2 ? Please Explain with an example
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Regular grammars can only describe regular languages, why reverse is not true .What should be the most appropriate Reason ? Explain with in few Lines .If possible give an exp too.
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Problem 1 : what is the Language associated with this regular expression ? a*b* write it down. Problem 2: Does either a subset or Super-set of a regular language is always a regular ? Problem 3 : What is the difference between a^n b^n and a*b* Explain with a example .
1 vote