tests if a set of values are identical to the first
(eq form form+) (!eq form form+)
Will return #f (false) as soon as it encounters a form that is not identical to the first. Otherwise, will return #t (true).
(define h "hello") (eq "hello" h)
Like most predicates, this function can also be negated by prepending the
! character. In this case, #t (true) will be returned if not all forms are equal.