anchor.diff:                                  (matches-opt? "-backup-dir" curr))
                              (and (not (matches-opt? "-bd" prev))
                                   (matches-opt? "-bd" curr)))
  -                       ;; The "--backup-dir" string is at the end of the arg list
  +                       ;; The "-backup-dir" string is at the end of the arg list
                          (list curr "")
                        (if (or (matches-opt? "-bd" prev)
                                (matches-opt? "-backup-dir" prev))
  
positive.code:          (option-arg?
            (lambda (arg)
              (or
               (matches-opt? "-dialect" arg)
               (matches-opt? "-bd" arg)
               (matches-opt? "-backup-dir" arg)
  
negative.code:              (bool? (lst [compact]))
               (bool? (lst [warning]))
               (bool? (lst [modify])))))
           (options (list (real-path) 1 "" '() nil nil true true true true nil ""))
           (matches-opt? (lambda (opt var)
                           (letn ((dashes (find "^-+" opt 0)))
                             (and (if dashes
  