The language of non$-$empty strings where the final character appears at

most $3$ times in the string $($including the final character$).$

E$.$g$.,$ abccaba is in the language, while abcbcbab is not.

The language of strings of the form $a^n{b}^n{c}^n{a}^n$ for $n1.$

E$.$g$.,$ aabbccaa is in the language, while $abc$ is not.

The language of strings that can be turned into a palindrome by replacing

at most two characters by other characters.

E$.$g$.,$ aba is in the language because it is a palindrome, abb is in the lan$-$

guage because we can change one character to get a palindrome $($e$.$g$.,$ aba $),$

and aabc is in the language because we can change two characters to get a

palindrome $($e$.$g$.,$ aaaa$)$; however aabbccc is not in the language.

The language of strings for which the longest substring that matches $a^{*}$ is

longer than the longest substring that matches $b^{*}.$

E$.$g$.,$ caaaccbbaabaaac, baaacbbcaaabb and aaaa are in the language, while

aabbbcacacacaca is not.