In case LISP programmers would like to implement && and || operators, the way they exist in C, the way to do that is as follows:
(defmacro && (head &rest tail)
`(if ,head
,(if (null tail)
T
`(&& ,@tail) ) ) )
(defmacro || (head &rest tail)
`(if ,head
T
,(if (null tail)
NIL
`(|| ,@tail) ) ) )
Bear In Mind, within LISP, Not every successful function-call returns non-NIL. Therefore, I would use a slightly fancier approach, if any…