# define isGRAPH(c) (isALNUM(c) || isPUNCT(c))
# define isPRINT(c) (((c) > 32 && (c) < 127) || (c) == ' ')
# define isPUNCT(c) (((c) >= 33 && (c) <= 47) || ((c) >= 58 && (c) <= 64) || ((c) >= 91 && (c) <= 96) || ((c) >= 123 && (c) <= 126))
-# define isXDIGIT(c) (isdigit(c) || ((c) >= 'a' && (c) <= 'f') || ((c) >= 'A' && (c) <= 'F'))
+# define isXDIGIT(c) (isDIGIT(c) || ((c) >= 'a' && (c) <= 'f') || ((c) >= 'A' && (c) <= 'F'))
# define toUPPER(c) (isLOWER(c) ? (c) - ('a' - 'A') : (c))
# define toLOWER(c) (isUPPER(c) ? (c) + ('a' - 'A') : (c))
#endif