anchor.diff:                 (error "~s does not match any log levels" arg))))
           ((and (numberp arg)
                 (>= arg +min-log-level+)
  -              (<= arg +max-log-level+))
  +              (<= arg +log-level-unset+))
            arg)
           (t (error "~s does not match any log levels" arg))))
   
  
positive.code:   character: (o)ff (f)atal (e)rror (w)arn (i)nfo (d)ebug (t)race (u)nset,
  
    1 character digit 1 through 9 identyfing user1 through user9 levels." 
    (cond ((symbolp arg)
           (make-log-level (symbol-name arg)))
          ((stringp arg)
           (let ((len (length arg))
  
negative.code: (defparameter +log-level-from-string+ 
    '("OFF" "FATAL" "ERROR" "WARN" "INFO"
      "DEBUG" "USER1" "USER2" "USER3" "USER4" "TRACE"
      "USER5" "USER6" "USER7" "USER8" "USER9" "UNSET"))
  
  
  (defun make-log-level (arg)
  