anchor.diff:  			g:direct-superclasses (list mc-mc)
   			:metaclass md-mc
   			#+SBCL :definition-source #+SBCL src))
  -                    
  -                    ;; FIXME: for B-D and D-D, use a class other than a
  -                    ;; MEASUREMENT-DOMAIN (?)
  -                    
                       (b-d ;; base measurement class for DOMAIN
                        ;; This class serves to allow for a base
                        ;; measurement class to be defined as an instance
  
positive.code:                                    :domain d
                                     :direct-superclasses 
                                     (list dm-mc lm-mc domain)
                                     :metaclass md-mc))
  
  		    (c  ;; measurement class denoted by 'class' name
  		     (ensure-class 
  
negative.code:                                    :domain d
                                     :direct-superclasses 
                                     (list bm-mc lm-mc domain)
                                     :metaclass md-mc
                                     #+SBCL :definition-source #+SBCL src))
                      (d-d ;; derived measurement class for DOMAIN (aux)
                       ;;
                       ;; FIXME: There may seem to be a certain
  