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Question

L={xww |x,w$\epsilon${a,b}star} tell which machine

Comments

Above language is regular.

Trick : keep w as epsilon and use x for whatever string u want to generate.

Note : it is a complete language over a, b

Machine DFA.

Answer 1

L is regular. Since, w can be ϵ and x∈(a+b)∗ , making L=Σ∗   . i.e.; the set of strings generated by L  is {ϵ,a,b,aa,ab,ba,bb,aaa,…}=Σ∗