anchor.diff:             "LISP-IMPLEMENTATION-TYPE-KEYWORD"
              "VERSION"
              "MACHINE-TYPE-KEYWORD"
  -           "DISTRIBUTION" 
  +           "DISTRIBUTION"
              "EXECUTABLE-NAME"
              "EXECUTABLE-FILENAME"
              "PRINT-MANIFEST"
  
positive.code: 
  (defun system-depends-on/recursive (system)
    (delete-duplicates
     (transitive-closure 
      (function system-depends-on)
      (list (string-downcase system)))
     :test 'string=))
  
negative.code: 
             ;; Checked with Linux RedHat 6.1, 6.2, 7.0
             ;; Checked with Linux Immunix 6.2.
             ;; 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)
  