#!/usr/local/bin/sbcl --script

(defun remove-if-not-evenp (&optional) (remove-if-not #'evenp '()))

(format t "~a"(remove-if-not #'evenp '(1 2 3 4 5 6 7 8 9 10)))
(remove-if-not #'evenp '(1 2 3 4 5 6 7 8 9 10))

(remove-if-not-evenp(1 2 3 4))