483 views

2 Answers

3 votes
3 votes

Answer : Option A

language $L1$ : $L1$ is not Regular, Not even DCFL.. Why?

 In $L1$, All strings are of even length And We are required to find the Middle of the String..because In the First half part we can't have $c$ and in the next half part we can't have $a$. But Finite automaton do not have the power to find the Middle. 

language $L2$ : $L2$ is regular.

language $L3$ :  $L3$ is CSL. 

language $L4$ : $L4$ is Non-regular because there could come(occur) any number of $ac$ without any $abc$ occurrence. And So, After that we would need to remember how many $ac$ have occurred etc. Such things are not possible for $FA$ So, Non-regular.

1 votes
1 votes

Option b

  • L1 is regular .

Regular exp= (aa+bb+ab+ba)*.(bb+cc+bc+ca)*
  • L2 is also regular.

  • In L3  comparison between a ,b and c .so it is non regular

  • In L4 also there is comparison .so it is also non regular.

edited by

Related questions

0 votes
0 votes
2 answers
1
anupamsworld asked Aug 29, 2022
553 views
Which of the following is/are Regular?A] $\left \{ XWYW^{R} \space\ | \space\ W,X,Y \in \left \{ a,b \right \}^{+} \right \}$B] $\left \{ WXW^{R}Y \space\ | \space\ W,X,Y...
0 votes
0 votes
1 answer
2
0 votes
0 votes
2 answers
3
sanju77767 asked May 1, 2018
386 views
L={a^n b^n :n>=1} and R = (a+b)^* L union R is going to be regular or not regular plzz give reason L is not regular if N leads to infinity then how it can be regular .......
1 votes
1 votes
0 answers
4