My question is how these two are different...according to my both will generate (a+b)*
The second string is ((a+b)3)* which can be expanded as ((a+b)(a+b)(a+b))*=((aa+ab+ba+bb)(a+b))* =(aaa+aab+aba+abb+baa+bab+bba+bbb)*
Can this generate any string of length 1 or 2?
L= [(a+b)3]* is language genrating strings multiple of 3. not mod 3.
Ok p= (a+b)3 , now [p3]* will not generate string with length 1,2.