anchor.diff:             ;; the key in the cache and what to pass to the dbm. We
              ;; carefully omit labels.
              (list :populate-key #'first
  -                 :populate-convert-to-dbm-sample-fn (lambda (sample)
  -                                                      (list (first sample)
  -                                                            :sample-visible-p nil
  -                                                            :omit-label-p t))
  +                 :populate-convert-to-dbm-sample-fn
  +                 (lambda (sample)
  +                   (list (first sample)
  +                         :sample-visible-p nil
  +                         :omit-label-p t))
                    :populate-map-cache-lazily-from-dbm *dbm/2*
                    :populate-periodic-fn
                    (make-instance 'periodic-fn :period 1000
  
positive.code:                         :n-gibbs 5
                          :segmenter
                          (lambda (cloud)
                            (when t #+nil (or (equal 'label (name (chunk1 cloud)))
                                              (equal 'label (name (chunk2 cloud))))
                                  (make-instance 'mnist-dbm-segment-trainer
                                                 :learning-rate (flt 0.001)
                                                 :weight-decay
                                                 (if (conditioning-cloud-p cloud)
                                                     (flt 0)
                                                     (flt 0.0002))
                                                 :batch-size 100)))
                          :sparser
                          (lambda (cloud chunk)
                            (when (and (member (name chunk) '(f1 f2))
  
negative.code:   (let ((nodes (storage (nodes striped))))
      (loop for image in images
            for stripe upfrom 0
            do (destructuring-bind (image &key omit-label-p sample-visible-p)
                   image
                 (declare (ignore omit-label-p sample-visible-p))
                 (with-stripes ((stripe striped start))
                   (clamp-array image nodes start))))))
  