anchor.diff:  
              ;; Checked with Linux RedHat 6.1, 6.2, 7.0
              ;; Checked with Linux Immunix 6.2.
  -           ;; There seems to be no way to differenciate 
  +           ;; There seems to be no way to differenciate
              ;; a RedHat 6.2 from an Immunix 6.2.
              ((with-open-file (inp "/etc/redhat-release"
                                    :if-does-not-exist nil)
  
positive.code: ;;;;SYSTEM:             Common-Lisp
  ;;;;USER-INTERFACE:     NONE
  ;;;;DESCRIPTION
  ;;;;    
  ;;;;    Check the licenses of the dependencies, write a manifest.
  ;;;;    
  ;;;;AUTHORS
  ;;;;    <PJB> Pascal J. Bourguignon <pjb@informatimago.com>
  ;;;;MODIFICATIONS
  
negative.code: 
  (defun system-depends-on/recursive (system)
    (delete-duplicates
     (transitive-closure
      (function system-depends-on)
      (list (string-downcase system)))
     :test 'string=))
  