$2.$ One particular language that is not context$-$free is L $=\{$ww $|$ w in $\{$A$,$ B$\}$

$\}$ which means

that a word x is in the language L if and only if $($i$)$ it only consists of As and Bs$,($ii$)$ it is

of even length, and $($iii$)$ if we split x in half the first and second half are the same.

$($a$)$ If a language is not context$-$free it is also not regular. Give a proof that L is not regular.

Note: you cannot use that L is not context$-$free $($unless you prove that$).$