anchor.diff:            :parent-bandwidth (memory-parent-bandwidth memory)))
   
   (defmethod print-object ((processor processor) stream)
  -  (format stream "~@<#<~;~S ~_~@{~S ~:_~S~^ ~_~}~;#>~:>"
  +  (format stream "~@<#<~;~S ~_~@{~S ~:_~S~^ ~_~}~;>~:>"
             (class-name (class-of processor))
             :name (processor-name processor)
             :memory (processor-memory processor)))
   
   (defmethod print-object ((machine machine) stream)
  -  (format stream "~@<#<~;~S ~_~@{~S ~:_~S~^ ~_~}~;#>~:>"
  +  (format stream "~@<#<~;~S ~_~@{~S ~:_~S~^ ~_~}~;>~:>"
             (class-name (class-of machine))
             :name (machine-name machine)
  +          :main-memory (machine-main-memory machine)
             :processors (machine-processors machine)))
   
   ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  
positive.code:    (%processors
      :initarg :processors
      :reader machine-processors
      :type list)))
  
  ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  ;;;
  
negative.code: 
  ;;; Returns the list memories that have this one as their parent.
  (defgeneric memory-children (memory))
  
  ;;; Returns the list of processors with access to this piece of memory.
  (defgeneric memory-processors (memory))
  
  ;;; Returns the memory size in bytes.
  (defgeneric memory-size (memory))
  