anchor.diff:  ;;;; TRE environment
  -;;;; Copyright (C) 2005-2006,2008-2009 Sven Klose <pixel@copei.de>
  -;;;;
  -;;;; Character functions
  -
  -(defun lower-case-p (c)
  -  "Return T if character is lower case."
  -  (range-p c #\a #\z))
  -
  -(defun upper-case-p (c)
  -  "Return T if character is upper case."
  -  (range-p c #\A #\Z))
  -
  -(defun alpha-char-p (c)
  -  "Return T if argument is an alphabetic character."
  -  (or (lower-case-p c)
  -      (upper-case-p c)))
  +;;;; Copyright (C) 2005-2006,2008-2010 Sven Klose <pixel@copei.de>
   
   (defun char-upcase (c)
     "Return upper case equivalent of lower case character."
  
positive.code:     			 (character+ c (character- #\a #\A))
      			 c)))
  
  ;XXX error on c-transpiler call if base has no init.
  (defun digit-char-p (c &optional (base 10))
    "Return T if character is a digit."
    (labels ((digit-p ()
               (range-p c #\0 #\9))
             (digit-alpha-p (start)
  
negative.code:         	      (or (digit-alpha-p #\a)
  				      (digit-alpha-p #\A)))))))
  
  (def-rest-predicate alphanumericp c ()
    (or (alpha-char-p c)
        (digit-char-p c)))
  