anchor.diff:        (setf (slot-value chunk 'nodes)
               (matlisp:make-real-matrix size max-n-stripes))
         (setf (slot-value chunk 'old-nodes)
  -            (if (conditioning-chunk-p chunk)
  -                (nodes chunk)
  -                (matlisp:make-real-matrix size max-n-stripes)))
  +            (make-old-nodes chunk))
         (fill-chunk chunk (default-value chunk) :allp t)
         (setf (slot-value chunk 'inputs)
               (if (typep chunk 'conditioning-chunk)
  
positive.code:     (setf (slot-value cloud 'weights)
            (matlisp:make-real-matrix (chunk-size (chunk2 cloud))
                                      (chunk-size (chunk1 cloud))))
      (map-into (storage (weights cloud))
                (lambda () (flt (* 0.01 (gaussian-random-1)))))))
  
  (defmacro do-cloud-runs (((start end) cloud) &body body)
    "Iterate over consecutive runs of weights present in CLOUD."
  
negative.code: (defun conditioning-chunk-p (chunk)
    (typep chunk 'conditioning-chunk))
  
  (defgeneric make-old-nodes (chunk)
    (:method ((chunk chunk))
      (matlisp:copy (nodes chunk)))
    (:method ((chunk conditioning-chunk))
      (nodes chunk)))
  
  (defgeneric resize-chunk (chunk size max-n-stripes)
    (:method ((chunk chunk) size max-n-stripes)
      (unless (and (slot-boundp chunk 'nodes)
  