anchor.diff:                       (ensure-class d-d-name
                                      :domain d
                                      :direct-superclasses 
  -                                   (list dm-mc lm-mc domain)
  +                                   (list dm-mc domain lm-mc)
                                      :metaclass md-mc
                                      #+SBCL :definition-source #+SBCL src))
   
  
positive.code: ;; (find-measurement-class :|cd|)
  
  
  #+TO-DO?
  (defclass gram (kilogram)
    ;; Kilogram is the base unit of measurement for mass, under the
    ;; Systeme International.
  
negative.code: 	    (base-f-e (measurement-base-factor-exponent %c)))
  	(unless (and (zerop base-f-e)
  		     (eql base-f 1))
  	  (let* (#+NIL (domain (class-of %c))
  		 (base-m (measurement-domain-base-measure c))
  		 (cf-to (make-conversion-factor  %c  base-m
  						 base-f base-f-e))
  		 (cf-from (make-conversion-factor base-m %c
  