$1.$ Write regular expressions to capture the following. You may use the regular expressions meta$-$symbols

covered in Chapter $2,$ such as vertical bar and asterisk. Use single quotes $($like Antlr$4)$ or double quotes

$($like Flex$)$ around single or multiple characters in the alphabet $($character literals$)$ in the regular

expression to get an exact match. For example, use $$abc$$ or "abc" to match the string abc. Be

consistent. You will need to escape a single quote or double quote $(\backslash$ or $\backslash "$ to represent these

characters $($whichever you use$)$ when needed in C string literals. The backslash can also precede any

printable ASCII character. Some have a special meaning, such as

and $\backslash$t for a newline character or

tab non$-$printable character when the respective string is used to generate a newline or tab when the

translated program is run. You may also need to escape the slash when a slash character is needed in

C string literal: $\backslash \backslash .$

$($a$)$ String literals in C$.$ These are delimited by double quotes $("),$ and may not contain actual newline

characters. If you find it necessary you can let nl represent the actual newline character when

typing in a string. Note that this is different than

$.$ In C$,$ you cannot split string literals across

lines. You may find it helpful to introduce shorthand notation to represent any character that

is not a member of a small specified set. For notational convenience, let the regular expression

extension not$($a$1,$ a$2,,$ an$)=($b$1|$b$2|...|$bm$),$ where the bis are all the characters in the alphabet other than the aj s$.$