(reduce (lambda (list el) (remove el list :test test))
(cons list1 list2)))
-(defun flatten (x &optional acc)
- (cond ((null x) acc)
- ((atom x) (cons x acc))
- (t (flatten (car x) (flatten (cdr x) acc)))))
-
(defmacro aif (test-form then-form &optional else-form)
`(let ((it ,test-form))
(if it ,then-form ,else-form)))