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Results tagged with regular-languages
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user 121549
Questions about properties of the class of regular languages and individual languages.
3
votes
1
answer
480
views
If $A$ is context-free then $A^*$ is regular
I am currently studying for my exam and I am having trouble to solve this question:
Right or wrong: If $A$ is context-free then $A^*$ is regular.
I think it's wrong because if $A$ is context-free it …
- 147
3
votes
Accepted
If $A$ is context-free then $A^*$ is regular
Let $A=\{a^nb^n \mid n \in \mathbb{N}\}$. Then we know that $A$ is non-regular and context-free. Also we can see that $A^*\cap a^*b^*=A$. Since $a^*b^*$ is a regular expression, we do know that it is …
- 147
2
votes
Accepted
Proof that $L=\{a^ncb^n| n \in \mathbb{N}\}$ is not regular
Proof:
Lets assume L is regular. Then we know that L must meet the requirements of the pumping lemma.
So let p the pumping number.
Let $w=a^pcb^p$. $w$ is obviously of the length p and is in L. Theref …
- 147
0
votes
2
answers
626
views
Proof that $L=\{a^ncb^n| n \in \mathbb{N}\}$ is not regular
Prove that $L=\{a^ncb^n| n \in \mathbb{N}\}$ is not regular.
Here is my try, I would really appreciate if someone could tell me if this is a correct proof.
Proof:
Lets assume L is regular. Then we k …
- 147