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Which of the following is/are Regular?

A] $\left \{ XWYW^{R} \space\ | \space\ W,X,Y \in \left \{ a,b \right \}^{+} \right \}$

B] $\left \{ WXW^{R}Y \space\ | \space\ W,X,Y \in \left \{ a,b \right \}^{+} \right \}$

C] $\left \{ WXYW^{R} \space\ | \space\ W,X,Y \in \left \{ a,b \right \}^{+} \right \}$

D] None

R => Reverse

@Kabir5454

I have also replied the supporting expressions for my answer(all are regular).

Seems correct to me bro.

C is the regular

we don’t know about XY, but it belongs to Σ. So we can consider whatever as XY,

let's take a string abbababbaba. We can consider bbababbab as XYZ and string w = “a”  and w reverse also “a”

so we can take this grammar as regular a(a+b)*a or b(a+b)*b

### 1 comment

What about options A and B?
i think we can try this problem by applying pumping lemma . So that we can check the above options easily
by

### 1 comment

Pumping lemma for checking irregularity of a language. If a language satisfies pumping lemma then it may or may not be regular.

you are getting confused.

1 vote