(defun alpha-char-p (x)
(or (<= (char-code #\a) (char-code x) (char-code #\z))
- (<= (char-code #\Z) (char-code x) (char-code #\Z))))
+ (<= (char-code #\A) (char-code x) (char-code #\Z))))
(defun digit-char-p (x)
(if (and (<= (char-code #\0) (char-code x) (char-code #\9)))