Q$4(8$ points$)$

Question $4-$Regular Expressions

Let $n_1,n_2,$dots,$n_9$ denote the $9$ digits of you Student ID$.$ We let $=\{a,b,c\}$ be the

alphabet we work with in this question. For each of the languages listed in the parts

below, provide description in words or set notation of the language, if the question

defines it by a regular expression and provide a regular expression if the question

defines the language by a description in words or set notation. For each of the four

languages also determine whether the language contains the empty word $lon$ and give an

example of one word over $$ that is in the language and one such word that is not in

the language. Recall that, for a word $w,$ we let $|w|$ denote the length of the word $($that

is$,$ the number of symbols in w$).$

$($a$)(ab{)}^{+}c(ab{)}^{+}c.$

$($b$)a\frac{O}{}$

$($c$)\{win{}^{**}||w|n\},$ where $n=n_1+n_2.$

$($d$)|)$:$\}$ is divisible by $\{$:$n_5\}.$

$2+2+2+2$ points

PLEASE PROVIDE ME THE DESCRIPTION WITH SET NOTATION