Alpha-char-p is a Common Lisp function. See any Common Lisp
documentation for more information.
Major Section: PROGRAMMING
(Alpha-char-p x) is true if and only if x is a alphabetic
character, i.e., one of the characters #a, #b, ..., #z, #A, #B,
..., #Z.
The guard for alpha-char-p requires its argument to be a character.
Alpha-char-p is a Common Lisp function. See any Common Lisp
documentation for more information.