# Theory Of Computation Test – Question 15

Consider the following languages.

$&space;1)&space;L1&space;=&space;\left&space;\{&space;ww&space;|&space;w&space;\in&space;\left&space;\{&space;a\right&space;\}^*&space;\right&space;\}$

$&space;2)&space;L2&space;=&space;\left&space;\{&space;w_1w_2&space;|&space;\,\,&space;w_1,w_2&space;\in&space;\Sigma^*&space;\,\,where\,\,&space;w_1&space;\neq&space;w_2\right&space;\}$

$&space;3)&space;L3&space;=&space;\left&space;\{&space;b^nc^n&space;\,|\,n&space;\geq&space;0\right&space;\}&space;\cup&space;\left&space;\{&space;a^kb^mc^p\,|\,k,m,p&space;\geq&space;0&space;\right&space;\}$

Which of the above is Not a Regular language?

• 1.
• 2.
• 3.
• 4.