All code must be done in Beginner Student Language in racket$/$Dr racket.

Unless otherwise stated, for all function design problems you must provide $($i$)$ a signature, $($ii$)$ a purpose statement, $($iii$)$ check$-$expects, and $($iv$)$ the actual code, in the language specified at the top of this page.

Unless otherwise stated, for all data design problems you must provide $($i$)$ a definition, $($ii$)$ an interpretation, $($iii$)$ examples, and $($iv$)$ a template.

You can use list functions for the exercises.

functions to avoid:

equal?

equal~$?$

eq$?$

eqv?

assq

assoc

assv

member

member?

memq

remove

remove$-$all

Exercise $3$ Design the data necessary to represent a book, which can either be physical or electronic. All books have a title and author. Physical books are either paperback or hardcover, and have some number of pages. Electronic $($e$-$books$)$ have a format $($pdf$,$ epub, txt$)$ and a source URL. All books have an author and a title.