anchor.diff:                    ;; Normal and :MAP lumpies.
                     (when (and (member lower-chunk chunks)
                                (member higher-chunk chunks))
  -                    (maybe-add-connection
  -                     cloud
  -                     :from (ensure-lumpy lower-depth lower-chunk)
  -                     :to (ensure-lumpy higher-depth higher-chunk))
  -                    (when (member lower-chunk map)
  +                    (unless (typep higher-chunk 'conditioning-chunk)
  +                      (add-connection
  +                       cloud
  +                       :from (ensure-lumpy lower-depth lower-chunk)
  +                       :to (ensure-lumpy higher-depth higher-chunk)))
  +                    (when (and (member lower-chunk map)
  +                               (not (typep lower-chunk 'conditioning-chunk)))
                         ;; Add the marginals of the approximate
                         ;; posterior as an input.
                         (let ((lower-lumpy (ensure-lumpy lower-depth lower-chunk)))
  
positive.code:                  (push-all chunk-inits inits))))))
      (values (reverse defs) inits)))
  
  (defun maybe-add-connection (cloud &key from to)
    (assert (> (lumpy-depth from) (lumpy-depth to)))
    (assert (not (member from (lumpy-incomings to)
                         :key #'incoming-from-lumpy)))
    (unless (typep (lumpy-chunk to) 'conditioning-chunk)
      (push (make-incoming :from-lumpy from
                           :cloud cloud
                           :transposep (eq (lumpy-chunk from)
                                           (chunk2 cloud)))
            (lumpy-incomings to))))
  
  (defun ensure-lumpy (lumpies &key depth chunk kind)
    (or (find-lumpy lumpies :depth depth :chunk chunk :kind kind)
  
negative.code:                   ;; :RECONSTRUCTION lumpies (higher -> lower).
                    (when (and (or (member higher-chunk reconstruction)
                                   (zerop higher-depth))
                               (member lower-chunk reconstruction)
                               (not (typep lower-chunk 'conditioning-chunk)))
                      (add-connection
                       cloud
                       :from (ensure-lumpy (- higher-depth) higher-chunk
                                           (if (zerop higher-depth)
  