anchor.diff:    ()
     (:report
      (lambda (c s)
  -     (format s "No measureent class registered for name ~S"
  +     (format s "No measurement class registered for name ~S"
                (entity-not-found-name c)))))
   
      
  
positive.code:   ()
    (:report
     (lambda (c s)
       (format s "No measureent prefix registered for name ~S"
               (entity-not-found-name c)))))
  
  (define-condition prefix-degree-not-found (entity-not-found)
    ()
    (:report
     (lambda (c s)
       (format s "No measureent prefix registered for degree ~S"
               (entity-not-found-name c)))))
  
  
  
negative.code: 
  (deftype prefix-degree ()
    '(and (integer -24 24)
      ;; formally onto the SI standard for decimal prefixes
      (member 0 
       1 2 3 6 9 12 15 18 21 24
       -1 -2 -3 -6 -9 -12 -15 -18 -21 -24)))
  