anchor.diff:                           (list prev curr)
                          (list "" ""))))
                     (dialect-pair
  -                   (if (and (null? (find "--dialect" prev))
  -                            (zero? (find "--dialect" curr)))
  -                       ;; The "--dialect" string is at the end of the arg list
  +                   (if (and (not (matches-opt? "-dialect" prev))
  +                            (matches-opt? "-dialect" curr))
  +                       ;; The "-dialect" string is at the end of the arg list
                          (list curr "")
  -                     (if (zero? (find "--dialect" prev))
  +                     (if (matches-opt? "-dialect" prev)
                            (list prev curr)
                          (list "" "")))))
                 (when (not (empty? (indent-pair 0)) (empty? (indent-pair 1)))
  
positive.code:              (bool? (lst [warning]))
               (bool? (lst [modify])))))
           (options (list (real-path) 1 "" '() nil nil true true true true nil))
           (zero-or-one? (lambda (num) (or (zero? num) (= num 1))))
           (matches-opt? (lambda (opt var) (zero-or-one? (find opt var))))
           (arguments
            (if (string? arguments)
                (parse arguments)
  
negative.code:          (option-arg?
            (lambda (arg)
              (or
               (matches-opt? "-dialect" arg)
               (matches-opt? "-bd" arg)
               (matches-opt? "-backup-dir" arg)
               (matches-opt? "-nb" arg)
               (matches-opt? "-no-backup" arg)
               (matches-opt? "-nc" arg)
               (matches-opt? "-no-compact" arg)
               (matches-opt? "-no" arg)
               (matches-opt? "-no-output" arg)
               (matches-opt? "-nm" arg)
               (matches-opt? "-no-modify" arg)
               (matches-opt? "-uni" arg)
               (matches-opt? "-uniform" arg)
               (matches-opt? "-ic" arg)
               (matches-opt? "-indent-comments" arg))))
           (option-list?
            (lambda (lst)
              (and
  