|  | ANSI Common Lisp  13 Characters  13.1 Character Concepts 13.1.4   Character CategoriesThere are several (overlapping) categories of characters that have no formally
associated type but that are nevertheless useful to name. 
They include
     graphic characters, 
     alphabetic1 characters,
     characters with case 
       (uppercase and lowercase characters),
     numeric characters,
     alphanumeric characters,
 and digits (in a given radix).
For each implementation-defined attribute of a character,
the documentation for that implementation must specify whether 
characters that differ only in that attribute are permitted to differ
in whether are not they are members of one of the aforementioned categories.
 
Note that these terms are defined independently of any special syntax 
which might have been enabled in the current readtable.
 13.1.4.1  Graphic Characters
13.1.4.2  Alphabetic Characters
 13.1.4.3  Characters With Case
 13.1.4.4  Numeric Characters
 13.1.4.5  Alphanumeric Characters
 13.1.4.6  Digits in a Radix
 |